US Core Implementation Guide
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US Core Implementation Guide, published by HL7 International / Cross-Group Projects. This guide is not an authorized publication; it is the continuous build for version 8.0.0-ballot built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/US-Core/ and changes regularly. See the Directory of published versions

Resource Profile: USCorePulseOximetryProfile - Detailed Descriptions

Page standards status: Trial-use Maturity Level: 3

Definitions for the us-core-pulse-oximetry resource profile.

Guidance on how to interpret the contents of this table can be found here

0. Observation
ShortUS Core Pulse Oximetry Profile
Must Supportfalse
2. Observation.code
ShortOxygen Saturation by Pulse Oximetry
Comments

The code (59408-5 Oxygen saturation in Arterial blood by Pulse oximetry) is included as an additional observation code to FHIR Core vital Oxygen Saturation code (2708-6 Oxygen saturation in Arterial blood).

Must Supporttrue
4. Observation.code.coding
Control2..?
Must Supporttrue
SlicingThis element introduces a set of slices on Observation.code.coding. The slices areUnordered and Open, and can be differentiated using the following discriminators:
  • value @ $this
  • 6. Observation.code.coding:PulseOx
    Slice NamePulseOx
    Control1..1
    TypeCoding
    Must Supporttrue
    Pattern Value{
      "system" : "http://loinc.org",
      "code" : "59408-5"
    }
    8. Observation.code.coding:O2Sat
    Slice NameO2Sat
    Control1..1
    TypeCoding
    Must Supporttrue
    Pattern Value{
      "system" : "http://loinc.org",
      "code" : "2708-6"
    }
    10. Observation.valueQuantity
    Definition

    The oxygen saturation by pulse oximetry value is expressed as a percentage (0-100) of the total hemoglobin content of the blood.

    ShortOxygen Saturation by Pulse Oximetry Value
    Must Supporttrue
    12. Observation.valueQuantity.value
    Control1..1
    Must Supporttrue
    14. Observation.valueQuantity.unit
    Control1..1
    Must Supporttrue
    16. Observation.valueQuantity.system
    Control1..1
    Typeuri
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Must Supporttrue
    Fixed Valuehttp://unitsofmeasure.org
    18. Observation.valueQuantity.code
    Control1..1
    Typecode
    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
    Must Supporttrue
    Fixed Value%
    20. Observation.component
    Definition

    Used when reporting flow rates or oxygen concentration.

    ShortUsed when reporting flow rates or oxygen concentration.
    Must Supporttrue
    SlicingThis element introduces a set of slices on Observation.component. The slices areUnordered and Open, and can be differentiated using the following discriminators:
    • value @ code
    • 22. Observation.component:FlowRate
      Slice NameFlowRate
      ShortInhaled oxygen flow rate
      Control0..1
      Must Supporttrue
      24. Observation.component:FlowRate.code
      TypeCodeableConcept
      Must Supporttrue
      Pattern Value{
        "coding" : [{
          "system" : "http://loinc.org",
          "code" : "3151-8"
        }]
      }
      26. Observation.component:FlowRate.valueQuantity
      ShortVital Sign Component Value
      Must Supporttrue
      28. Observation.component:FlowRate.valueQuantity.value
      Control1..1
      Must Supporttrue
      30. Observation.component:FlowRate.valueQuantity.unit
      Control1..1
      Must Supporttrue
      32. Observation.component:FlowRate.valueQuantity.system
      Control1..1
      Typeuri
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Must Supporttrue
      Fixed Valuehttp://unitsofmeasure.org
      34. Observation.component:FlowRate.valueQuantity.code
      Control1..1
      Typecode
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Must Supporttrue
      Fixed ValueL/min
      36. Observation.component:Concentration
      Slice NameConcentration
      ShortInhaled oxygen concentration
      Control0..1
      Must Supporttrue
      38. Observation.component:Concentration.code
      TypeCodeableConcept
      Must Supporttrue
      Pattern Value{
        "coding" : [{
          "system" : "http://loinc.org",
          "code" : "3150-0"
        }]
      }
      40. Observation.component:Concentration.valueQuantity
      ShortVital Sign Component Value
      Must Supporttrue
      42. Observation.component:Concentration.valueQuantity.value
      Control1..1
      Must Supporttrue
      44. Observation.component:Concentration.valueQuantity.unit
      Control1..1
      Must Supporttrue
      46. Observation.component:Concentration.valueQuantity.system
      Control1..1
      Typeuri
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Must Supporttrue
      Fixed Valuehttp://unitsofmeasure.org
      48. Observation.component:Concentration.valueQuantity.code
      Control1..1
      Typecode
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Must Supporttrue
      Fixed Value%

      Guidance on how to interpret the contents of this table can be found here

      0. Observation
      Definition

      The FHIR Vitals Signs profile sets minimum expectations for the Observation Resource to record, search and fetch the vital signs associated with a patient.


      Measurements and simple assertions made about a patient, device or other subject.

      ShortUS Core Pulse Oximetry ProfileMeasurements and simple assertions
      Comments

      Used for simple observations such as device measurements, laboratory atomic results, vital signs, height, weight, smoking status, comments, etc. Other resources are used to provide context for observations such as laboratory reports, etc.

      Control0..*
      Is Modifierfalse
      Must Supportfalse
      Summaryfalse
      Alternate NamesVital Signs, Measurement, Results, Tests
      Invariantsdom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources (contained.contained.empty())
      dom-3: If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource (contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().as(canonical) | %resource.descendants().as(uri) | %resource.descendants().as(url))) or descendants().where(reference = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(canonical) = '#').exists()).not()).trace('unmatched', id).empty())
      dom-4: If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated (contained.meta.versionId.empty() and contained.meta.lastUpdated.empty())
      dom-5: If a resource is contained in another resource, it SHALL NOT have a security label (contained.meta.security.empty())
      dom-6: A resource should have narrative for robust management (text.`div`.exists())
      obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present (dataAbsentReason.empty() or value.empty())
      obs-7: If Observation.code is the same as an Observation.component.code then the value element associated with the code SHALL NOT be present (value.empty() or component.code.where(coding.intersect(%resource.code.coding).exists()).empty())
      vs-2: If there is no component or hasMember element then either a value[x] or a data absent reason must be present. ((component.empty() and hasMember.empty()) implies (dataAbsentReason.exists() or value.exists()))
      obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present (dataAbsentReason.empty() or value.empty())
      obs-7: If Observation.code is the same as an Observation.component.code then the value element associated with the code SHALL NOT be present (value.empty() or component.code.where(coding.intersect(%resource.code.coding).exists()).empty())
      2. Observation.implicitRules
      Definition

      A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

      ShortA set of rules under which this content was created
      Comments

      Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element. Often, when used, the URL is a reference to an implementation guide that defines these special rules as part of it's narrative along with other profiles, value sets, etc.

      Control0..1
      Typeuri
      Is Modifiertrue because This element is labeled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies it's meaning or interpretation
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Summarytrue
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      4. Observation.modifierExtension
      Definition

      May be used to represent additional information that is not part of the basic definition of the resource and that modifies the understanding of the element that contains it and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

      Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

      ShortExtensions that cannot be ignored
      Comments

      There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

      Control0..*
      TypeExtension
      Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them
      Summaryfalse
      Requirements

      Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.


      Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

      Alternate Namesextensions, user content
      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
      6. Observation.status
      Definition

      The status of the result value.

      Shortregistered | preliminary | final | amended +
      Comments

      This element is labeled as a modifier because the status contains codes that mark the resource as not currently valid.

      Control1..1
      BindingThe codes SHALL be taken from ObservationStatushttp://hl7.org/fhir/ValueSet/observation-status|4.0.1
      (required to http://hl7.org/fhir/ValueSet/observation-status|4.0.1)
      Typecode
      Is Modifiertrue because This element is labeled as a modifier because it is a status element that contains status entered-in-error which means that the resource should not be treated as valid
      Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
      Must Supporttrue
      Summarytrue
      Requirements

      Need to track the status of individual results. Some results are finalized before the whole report is finalized.

      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      8. Observation.category
      Definition

      A code that classifies the general type of observation being made.

      ShortClassification of type of observation
      Comments

      In addition to the required category valueset, this element allows various categorization schemes based on the owner’s definition of the category and effectively multiple categories can be used at once. The level of granularity is defined by the category concepts in the value set.

      Control10..*
      BindingThe codes SHOULD be taken from ObservationCategoryCodeshttp://hl7.org/fhir/ValueSet/observation-category
      (preferred to http://hl7.org/fhir/ValueSet/observation-category)

      Codes for high level observation categories.

      TypeCodeableConcept
      Is Modifierfalse
      Must Supporttrue
      Summaryfalse
      Requirements

      Used for filtering what observations are retrieved and displayed.

      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
      SlicingThis element introduces a set of slices on Observation.category. The slices areUnordered and Open, and can be differentiated using the following discriminators:
      • value @ coding.code
      • value @ coding.system
      • 10. Observation.category:VSCat
        Slice NameVSCat
        Definition

        A code that classifies the general type of observation being made.

        ShortClassification of type of observation
        Comments

        In addition to the required category valueset, this element allows various categorization schemes based on the owner’s definition of the category and effectively multiple categories can be used at once. The level of granularity is defined by the category concepts in the value set.

        Control10..1*
        BindingThe codes SHOULD be taken from ObservationCategoryCodeshttp://hl7.org/fhir/ValueSet/observation-category
        (preferred to http://hl7.org/fhir/ValueSet/observation-category)

        Codes for high level observation categories.

        TypeCodeableConcept
        Is Modifierfalse
        Must Supporttrue
        Summaryfalse
        Requirements

        Used for filtering what observations are retrieved and displayed.

        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        12. Observation.category:VSCat.coding
        Definition

        A reference to a code defined by a terminology system.

        ShortCode defined by a terminology system
        Comments

        Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.

        Control10..*
        TypeCoding
        Is Modifierfalse
        Must Supporttrue
        Summarytrue
        Requirements

        Allows for alternative encodings within a code system, and translations to other code systems.

        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        14. Observation.category:VSCat.coding.system
        Definition

        The identification of the code system that defines the meaning of the symbol in the code.

        ShortIdentity of the terminology system
        Comments

        The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should reference to some definition that establishes the system clearly and unambiguously.

        Control10..1
        Typeuri
        Is Modifierfalse
        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
        Must Supporttrue
        Summarytrue
        Requirements

        Need to be unambiguous about the source of the definition of the symbol.

        Fixed Valuehttp://terminology.hl7.org/CodeSystem/observation-category
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        16. Observation.category:VSCat.coding.code
        Definition

        A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

        ShortSymbol in syntax defined by the system
        Control10..1
        Typecode
        Is Modifierfalse
        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
        Must Supporttrue
        Summarytrue
        Requirements

        Need to refer to a particular code in the system.

        Fixed Valuevital-signs
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        18. Observation.code
        Definition

        Coded Responses from C-CDA Vital Sign Results.


        Describes what was observed. Sometimes this is called the observation "name".

        ShortOxygen Saturation by Pulse OximetryType of observation (code / type)
        Comments

        The code (59408-5 Oxygen saturation in Arterial blood by Pulse oximetry) is included as an additional observation code to FHIR Core vital Oxygen Saturation code (2708-6 Oxygen saturation in Arterial blood).


        All code-value and, if present, component.code-component.value pairs need to be taken into account to correctly understand the meaning of the observation.

        Control1..1
        BindingUnless not suitable, these codes SHALL be taken from For example codes, see Vital Sign Result Type .http://hl7.org/fhir/ValueSet/observation-codes
        (extensible to http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113883.3.88.12.80.62)

        Vital sign result types


        Codes identifying names of simple observations.

        TypeCodeableConcept
        Is Modifierfalse
        Must Supporttrue
        Summarytrue
        Requirements
        1. SHALL contain exactly one [1..1] code, where the @code SHOULD be selected from ValueSet HITSP Vital Sign Result Type 2.16.840.1.113883.3.88.12.80.62 DYNAMIC (CONF:7301).

        Knowing what kind of observation is being made is essential to understanding the observation.

        Alternate NamesName
        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        20. Observation.code.coding
        Definition

        A reference to a code defined by a terminology system.

        ShortCode defined by a terminology system
        Comments

        Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.

        Control20..*
        TypeCoding
        Is Modifierfalse
        Must Supporttrue
        Summarytrue
        Requirements

        Allows for alternative encodings within a code system, and translations to other code systems.

        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
        SlicingThis element introduces a set of slices on Observation.code.coding. The slices areUnordered and Open, and can be differentiated using the following discriminators:
        • value @ $this
        • 22. Observation.code.coding:PulseOx
          Slice NamePulseOx
          Definition

          A reference to a code defined by a terminology system.

          ShortCode defined by a terminology system
          Comments

          Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.

          Control10..1*
          TypeCoding
          Is Modifierfalse
          Must Supporttrue
          Summarytrue
          Requirements

          Allows for alternative encodings within a code system, and translations to other code systems.

          Pattern Value{
            "system" : "http://loinc.org",
            "code" : "59408-5"
          }
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          24. Observation.code.coding:O2Sat
          Slice NameO2Sat
          Definition

          A reference to a code defined by a terminology system.

          ShortCode defined by a terminology system
          Comments

          Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.

          Control10..1*
          TypeCoding
          Is Modifierfalse
          Must Supporttrue
          Summarytrue
          Requirements

          Allows for alternative encodings within a code system, and translations to other code systems.

          Pattern Value{
            "system" : "http://loinc.org",
            "code" : "2708-6"
          }
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          26. Observation.subject
          Definition

          The patient, or group of patients, location, or device this observation is about and into whose record the observation is placed. If the actual focus of the observation is different from the subject (or a sample of, part, or region of the subject), the focus element or the code itself specifies the actual focus of the observation.

          ShortWho and/or what the observation is about
          Comments

          One would expect this element to be a cardinality of 1..1. The only circumstance in which the subject can be missing is when the observation is made by a device that does not know the patient. In this case, the observation SHALL be matched to a patient through some context/channel matching technique, and at this point, the observation should be updated.

          Control10..1
          TypeReference(US Core Patient Profile, Patient, Group, Device, Location)
          Is Modifierfalse
          Must Supporttrue
          Summarytrue
          Requirements

          Observations have no value if you don't know who or what they're about.

          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          28. Observation.effective[x]
          Definition

          Often just a dateTime for Vital Signs.


          The time or time-period the observed value is asserted as being true. For biological subjects - e.g. human patients - this is usually called the "physiologically relevant time". This is usually either the time of the procedure or of specimen collection, but very often the source of the date/time is not known, only the date/time itself.

          ShortOften just a dateTime for Vital SignsClinically relevant time/time-period for observation
          Comments

          At least a date should be present unless this observation is a historical report. For recording imprecise or "fuzzy" times (For example, a blood glucose measurement taken "after breakfast") use the Timing datatype which allow the measurement to be tied to regular life events.


          At least a date should be present unless this observation is a historical report. For recording imprecise or "fuzzy" times (For example, a blood glucose measurement taken "after breakfast") use the Timing datatype which allow the measurement to be tied to regular life events.

          Control10..1
          This element is affected by the following invariants: vs-1
          TypeChoice of: dateTime, Period, Timing, instant
          [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Must Supporttrue
          Must Support TypesdateTime
          Summarytrue
          Requirements

          Knowing when an observation was deemed true is important to its relevance as well as determining trends.

          Alternate NamesOccurrence
          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          vs-1: if Observation.effective[x] is dateTime and has a value then that value shall be precise to the day ($this is dateTime implies $this.toString().length() >= 10)
          30. Observation.performer
          Definition

          Who was responsible for asserting the observed value as "true".

          ShortWho is responsible for the observation
          Control0..*
          TypeReference(US Core Practitioner Profile, US Core Organization Profile, US Core Patient Profile, PractitionerRole, US Core CareTeam Profile, US Core RelatedPerson Profile, Practitioner, Organization, CareTeam, Patient, RelatedPerson)
          Is Modifierfalse
          Must Supporticon Added:true
          Must Support TypesNo must-support rules about the choice of types/profiles
          Summarytrue
          Requirements

          May give a degree of confidence in the observation and also indicates where follow-up questions should be directed.

          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          32. Observation.value[x]
          Definition

          Vital Signs value are typically recorded using the Quantity data type.


          The information determined as a result of making the observation, if the information has a simple value.

          ShortVital Signs ValueActual result
          Comments

          An observation may have; 1) a single value here, 2) both a value and a set of related or component values, or 3) only a set of related or component values. If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.


          An observation may have; 1) a single value here, 2) both a value and a set of related or component values, or 3) only a set of related or component values. If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

          Control0..1
          This element is affected by the following invariants: obs-7, vs-2
          BindingUnless not suitable, these codes SHALL be taken from For codes, see VitalSignsUnits
          (extensible to http://hl7.org/fhir/ValueSet/ucum-vitals-common|4.0.1)

          Common UCUM units for recording Vital Signs.

          TypeChoice of: Quantity, CodeableConcept, string, boolean, integer, Range, Ratio, SampledData, time, dateTime, Period
          [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
          Is Modifierfalse
          Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
          Must Supporttrue
          Must Support TypesQuantity
          Summarytrue
          Requirements
          1. SHALL contain exactly one [1..1] value with @xsi:type="PQ" (CONF:7305).

          An observation exists to have a value, though it might not if it is in error, or if it represents a group of observations.

          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
          SlicingThis element introduces a set of slices on Observation.value[x]. The slices areUnordered and Open, and can be differentiated using the following discriminators:
          • type @ $this
          • 34. Observation.value[x]:valueQuantity
            Slice NamevalueQuantity
            Definition

            The oxygen saturation by pulse oximetry value is expressed as a percentage (0-100) of the total hemoglobin content of the blood.


            The information determined as a result of making the observation, if the information has a simple value.

            ShortOxygen Saturation by Pulse Oximetry ValueActual result
            Comments

            An observation may have; 1) a single value here, 2) both a value and a set of related or component values, or 3) only a set of related or component values. If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.


            An observation may have; 1) a single value here, 2) both a value and a set of related or component values, or 3) only a set of related or component values. If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

            Control0..1
            This element is affected by the following invariants: obs-7, vs-2
            BindingUnless not suitable, these codes SHALL be taken from For codes, see VitalSignsUnits
            (extensible to http://hl7.org/fhir/ValueSet/ucum-vitals-common|4.0.1)

            Common UCUM units for recording Vital Signs.

            TypeQuantity, dateTime, boolean, string, SampledData, Period, Ratio, integer, time, Range, CodeableConcept
            [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
            Is Modifierfalse
            Must Supporttrue
            Must Support TypesQuantity
            Summarytrue
            Requirements
            1. SHALL contain exactly one [1..1] value with @xsi:type="PQ" (CONF:7305).

            An observation exists to have a value, though it might not if it is in error, or if it represents a group of observations.

            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            36. Observation.value[x]:valueQuantity.value
            Definition

            The value of the measured amount. The value includes an implicit precision in the presentation of the value.

            ShortNumerical value (with implicit precision)
            Comments

            The implicit precision in the value should always be honored. Monetary values have their own rules for handling precision (refer to standard accounting text books).

            Control10..1
            Typedecimal
            Is Modifierfalse
            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
            Must Supporttrue
            Summarytrue
            Requirements

            Precision is handled implicitly in almost all cases of measurement.

            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            38. Observation.value[x]:valueQuantity.comparator
            Definition

            How the value should be understood and represented - whether the actual value is greater or less than the stated value due to measurement issues; e.g. if the comparator is "<" , then the real value is < stated value.

            Short< | <= | >= | > - how to understand the value
            Control0..1
            BindingThe codes SHALL be taken from QuantityComparatorhttp://hl7.org/fhir/ValueSet/quantity-comparator|4.0.1
            (required to http://hl7.org/fhir/ValueSet/quantity-comparator|4.0.1)

            How the Quantity should be understood and represented.

            Typecode
            Is Modifiertrue because This is labeled as "Is Modifier" because the comparator modifies the interpretation of the value significantly. If there is no comparator, then there is no modification of the value
            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
            Summarytrue
            Requirements

            Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.

            Meaning if MissingIf there is no comparator, then there is no modification of the value
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            40. Observation.value[x]:valueQuantity.unit
            Definition

            A human-readable form of the unit.

            ShortUnit representation
            Control10..1
            Typestring
            Is Modifierfalse
            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
            Must Supporttrue
            Summarytrue
            Requirements

            There are many representations for units of measure and in many contexts, particular representations are fixed and required. I.e. mcg for micrograms.

            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            42. Observation.value[x]:valueQuantity.system
            Definition

            The identification of the system that provides the coded form of the unit.

            ShortSystem that defines coded unit form
            Control10..1
            This element is affected by the following invariants: qty-3
            Typeuri
            Is Modifierfalse
            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
            Must Supporttrue
            Summarytrue
            Requirements

            Need to know the system that defines the coded form of the unit.

            Fixed Valuehttp://unitsofmeasure.org
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            44. Observation.value[x]:valueQuantity.code
            Definition

            A computer processable form of the unit in some unit representation system.

            ShortCoded form of the unit
            Comments

            The preferred system is UCUM, but SNOMED CT can also be used (for customary units) or ISO 4217 for currency. The context of use may additionally require a code from a particular system.

            Control10..1
            Typecode
            Is Modifierfalse
            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
            Must Supporttrue
            Summarytrue
            Requirements

            Need a computable form of the unit that is fixed across all forms. UCUM provides this for quantities, but SNOMED CT provides many units of interest.

            Fixed Value%
            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            46. Observation.dataAbsentReason
            Definition

            Provides a reason why the expected value in the element Observation.value[x] is missing.

            ShortWhy the result is missing
            Comments

            Null or exceptional values can be represented two ways in FHIR Observations. One way is to simply include them in the value set and represent the exceptions in the value. For example, measurement values for a serology test could be "detected", "not detected", "inconclusive", or "specimen unsatisfactory".

            The alternate way is to use the value element for actual observations and use the explicit dataAbsentReason element to record exceptional values. For example, the dataAbsentReason code "error" could be used when the measurement was not completed. Note that an observation may only be reported if there are values to report. For example differential cell counts values may be reported only when > 0. Because of these options, use-case agreements are required to interpret general observations for null or exceptional values.

            Control0..1
            This element is affected by the following invariants: obs-6, vs-2
            BindingUnless not suitable, these codes SHALL be taken from DataAbsentReasonhttp://hl7.org/fhir/ValueSet/data-absent-reason
            (extensible to http://hl7.org/fhir/ValueSet/data-absent-reason)

            Codes specifying why the result (Observation.value[x]) is missing.

            TypeCodeableConcept
            Is Modifierfalse
            Must Supporttrue
            Summaryfalse
            Requirements

            For many results it is necessary to handle exceptional values in measurements.

            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            48. Observation.component
            Definition

            Used when reporting flow rates or oxygen concentration.


            Some observations have multiple component observations. These component observations are expressed as separate code value pairs that share the same attributes. Examples include systolic and diastolic component observations for blood pressure measurement and multiple component observations for genetics observations.

            ShortUsed when reporting flow rates or oxygen concentration.Component results
            Comments

            For a discussion on the ways Observations can be assembled in groups together see Notes below.


            For a discussion on the ways Observations can be assembled in groups together see Notes below.

            Control0..*
            TypeBackboneElement
            Is Modifierfalse
            Must Supporttrue
            Summarytrue
            Requirements

            Component observations share the same attributes in the Observation resource as the primary observation and are always treated a part of a single observation (they are not separable). However, the reference range for the primary observation value is not inherited by the component values and is required when appropriate for each component observation.

            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
            vs-3: If there is no a value a data absent reason must be present (value.exists() or dataAbsentReason.exists())
            SlicingThis element introduces a set of slices on Observation.component. The slices areUnordered and Open, and can be differentiated using the following discriminators:
            • value @ code
            • 50. Observation.component.modifierExtension
              Definition

              May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

              Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

              ShortExtensions that cannot be ignored even if unrecognized
              Comments

              There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

              Control0..*
              TypeExtension
              Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
              Summarytrue
              Requirements

              Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.


              Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

              Alternate Namesextensions, user content, modifiers
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
              52. Observation.component.code
              Definition

              Describes what was observed. Sometimes this is called the observation "code".

              ShortCoded vital sign result typeType of component observation (code / type)
              Comments

              All code-value and component.code-component.value pairs need to be taken into account to correctly understand the meaning of the observation.

              Control1..1
              BindingUnless not suitable, these codes SHALL be taken from For example codes, see Vital Sign Result Type .http://hl7.org/fhir/ValueSet/observation-codes
              (extensible to http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113883.3.88.12.80.62)

              Vital sign result types


              Codes identifying names of simple observations.

              TypeCodeableConcept
              Is Modifierfalse
              Must Supporttrue
              Summarytrue
              Requirements

              Knowing what kind of observation is being made is essential to understanding the observation.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              54. Observation.component.value[x]
              Definition

              Vital Signs value are typically recorded using the Quantity data type. For supporting observations such as cuff size could use other datatypes such as CodeableConcept.


              The information determined as a result of making the observation, if the information has a simple value.

              ShortVital Sign Component ValueActual component result
              Comments

              Used when observation has a set of component observations. An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived). If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.


              Used when observation has a set of component observations. An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived). If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

              Control0..1
              This element is affected by the following invariants: vs-3
              BindingUnless not suitable, these codes SHALL be taken from For codes, see VitalSignsUnits
              (extensible to http://hl7.org/fhir/ValueSet/ucum-vitals-common|4.0.1)

              Common UCUM units for recording Vital Signs.

              TypeChoice of: Quantity, CodeableConcept, string, boolean, integer, Range, Ratio, SampledData, time, dateTime, Period
              [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
              Is Modifierfalse
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              Must Supporttrue
              Must Support TypesQuantity
              Summarytrue
              Requirements
              1. SHALL contain exactly one [1..1] value with @xsi:type="PQ" (CONF:7305).

              An observation exists to have a value, though it might not if it is in error, or if it represents a group of observations.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              56. Observation.component.dataAbsentReason
              Definition

              Provides a reason why the expected value in the element Observation.component.value[x] is missing.

              ShortWhy the component result is missing
              Comments

              "Null" or exceptional values can be represented two ways in FHIR Observations. One way is to simply include them in the value set and represent the exceptions in the value. For example, measurement values for a serology test could be "detected", "not detected", "inconclusive", or "test not done".

              The alternate way is to use the value element for actual observations and use the explicit dataAbsentReason element to record exceptional values. For example, the dataAbsentReason code "error" could be used when the measurement was not completed. Because of these options, use-case agreements are required to interpret general observations for exceptional values.

              Control0..1
              This element is affected by the following invariants: obs-6, vs-3
              BindingUnless not suitable, these codes SHALL be taken from DataAbsentReasonhttp://hl7.org/fhir/ValueSet/data-absent-reason
              (extensible to http://hl7.org/fhir/ValueSet/data-absent-reason)

              Codes specifying why the result (Observation.value[x]) is missing.

              TypeCodeableConcept
              Is Modifierfalse
              Must Supporttrue
              Summaryfalse
              Requirements

              For many results it is necessary to handle exceptional values in measurements.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              58. Observation.component:FlowRate
              Slice NameFlowRate
              Definition

              Used when reporting component observation such as systolic and diastolic blood pressure.


              Some observations have multiple component observations. These component observations are expressed as separate code value pairs that share the same attributes. Examples include systolic and diastolic component observations for blood pressure measurement and multiple component observations for genetics observations.

              ShortInhaled oxygen flow rateComponent results
              Comments

              For a discussion on the ways Observations can be assembled in groups together see Notes below.


              For a discussion on the ways Observations can be assembled in groups together see Notes below.

              Control0..1*
              TypeBackboneElement
              Is Modifierfalse
              Must Supporttrue
              Summarytrue
              Requirements

              Component observations share the same attributes in the Observation resource as the primary observation and are always treated a part of a single observation (they are not separable). However, the reference range for the primary observation value is not inherited by the component values and is required when appropriate for each component observation.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              vs-3: If there is no a value a data absent reason must be present (value.exists() or dataAbsentReason.exists())
              60. Observation.component:FlowRate.modifierExtension
              Definition

              May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

              Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

              ShortExtensions that cannot be ignored even if unrecognized
              Comments

              There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

              Control0..*
              TypeExtension
              Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
              Summarytrue
              Requirements

              Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.


              Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

              Alternate Namesextensions, user content, modifiers
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
              62. Observation.component:FlowRate.code
              Definition

              Describes what was observed. Sometimes this is called the observation "code".

              ShortCoded vital sign result typeType of component observation (code / type)
              Comments

              All code-value and component.code-component.value pairs need to be taken into account to correctly understand the meaning of the observation.

              Control1..1
              BindingUnless not suitable, these codes SHALL be taken from For example codes, see Vital Sign Result Type .http://hl7.org/fhir/ValueSet/observation-codes
              (extensible to http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113883.3.88.12.80.62)

              Vital sign result types


              Codes identifying names of simple observations.

              TypeCodeableConcept
              Is Modifierfalse
              Must Supporttrue
              Summarytrue
              Requirements

              Knowing what kind of observation is being made is essential to understanding the observation.

              Pattern Value{
                "coding" : [{
                  "system" : "http://loinc.org",
                  "code" : "3151-8"
                }]
              }
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              64. Observation.component:FlowRate.value[x]
              Definition

              Vital Signs value are typically recorded using the Quantity data type. For supporting observations such as cuff size could use other datatypes such as CodeableConcept.


              The information determined as a result of making the observation, if the information has a simple value.

              ShortVital Sign Component ValueActual component result
              Comments

              Used when observation has a set of component observations. An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived). If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.


              Used when observation has a set of component observations. An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived). If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

              Control0..1
              This element is affected by the following invariants: vs-3
              BindingUnless not suitable, these codes SHALL be taken from For codes, see VitalSignsUnits
              (extensible to http://hl7.org/fhir/ValueSet/ucum-vitals-common|4.0.1)

              Common UCUM units for recording Vital Signs.

              TypeQuantity, dateTime, boolean, string, SampledData, Period, Ratio, integer, time, Range, CodeableConcept
              [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
              Is Modifierfalse
              Must Supporttrue
              Must Support TypesQuantity
              Summarytrue
              Requirements
              1. SHALL contain exactly one [1..1] value with @xsi:type="PQ" (CONF:7305).

              An observation exists to have a value, though it might not if it is in error, or if it represents a group of observations.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              66. Observation.component:FlowRate.value[x].value
              Definition

              The value of the measured amount. The value includes an implicit precision in the presentation of the value.

              ShortNumerical value (with implicit precision)
              Comments

              The implicit precision in the value should always be honored. Monetary values have their own rules for handling precision (refer to standard accounting text books).

              Control10..1
              Typedecimal
              Is Modifierfalse
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              Must Supporttrue
              Summarytrue
              Requirements

              Precision is handled implicitly in almost all cases of measurement.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              68. Observation.component:FlowRate.value[x].comparator
              Definition

              How the value should be understood and represented - whether the actual value is greater or less than the stated value due to measurement issues; e.g. if the comparator is "<" , then the real value is < stated value.

              Short< | <= | >= | > - how to understand the value
              Control0..1
              BindingThe codes SHALL be taken from QuantityComparatorhttp://hl7.org/fhir/ValueSet/quantity-comparator|4.0.1
              (required to http://hl7.org/fhir/ValueSet/quantity-comparator|4.0.1)

              How the Quantity should be understood and represented.

              Typecode
              Is Modifiertrue because This is labeled as "Is Modifier" because the comparator modifies the interpretation of the value significantly. If there is no comparator, then there is no modification of the value
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              Summarytrue
              Requirements

              Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.

              Meaning if MissingIf there is no comparator, then there is no modification of the value
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              70. Observation.component:FlowRate.value[x].unit
              Definition

              A human-readable form of the unit.

              ShortUnit representation
              Control10..1
              Typestring
              Is Modifierfalse
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              Must Supporttrue
              Summarytrue
              Requirements

              There are many representations for units of measure and in many contexts, particular representations are fixed and required. I.e. mcg for micrograms.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              72. Observation.component:FlowRate.value[x].system
              Definition

              The identification of the system that provides the coded form of the unit.

              ShortSystem that defines coded unit form
              Control10..1
              This element is affected by the following invariants: qty-3
              Typeuri
              Is Modifierfalse
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              Must Supporttrue
              Summarytrue
              Requirements

              Need to know the system that defines the coded form of the unit.

              Fixed Valuehttp://unitsofmeasure.org
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              74. Observation.component:FlowRate.value[x].code
              Definition

              A computer processable form of the unit in some unit representation system.

              ShortCoded form of the unit
              Comments

              The preferred system is UCUM, but SNOMED CT can also be used (for customary units) or ISO 4217 for currency. The context of use may additionally require a code from a particular system.

              Control10..1
              Typecode
              Is Modifierfalse
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              Must Supporttrue
              Summarytrue
              Requirements

              Need a computable form of the unit that is fixed across all forms. UCUM provides this for quantities, but SNOMED CT provides many units of interest.

              Fixed ValueL/min
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              76. Observation.component:FlowRate.dataAbsentReason
              Definition

              Provides a reason why the expected value in the element Observation.component.value[x] is missing.

              ShortWhy the component result is missing
              Comments

              "Null" or exceptional values can be represented two ways in FHIR Observations. One way is to simply include them in the value set and represent the exceptions in the value. For example, measurement values for a serology test could be "detected", "not detected", "inconclusive", or "test not done".

              The alternate way is to use the value element for actual observations and use the explicit dataAbsentReason element to record exceptional values. For example, the dataAbsentReason code "error" could be used when the measurement was not completed. Because of these options, use-case agreements are required to interpret general observations for exceptional values.

              Control0..1
              This element is affected by the following invariants: obs-6, vs-3
              BindingUnless not suitable, these codes SHALL be taken from DataAbsentReasonhttp://hl7.org/fhir/ValueSet/data-absent-reason
              (extensible to http://hl7.org/fhir/ValueSet/data-absent-reason)

              Codes specifying why the result (Observation.value[x]) is missing.

              TypeCodeableConcept
              Is Modifierfalse
              Must Supporttrue
              Summaryfalse
              Requirements

              For many results it is necessary to handle exceptional values in measurements.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              78. Observation.component:Concentration
              Slice NameConcentration
              Definition

              Used when reporting component observation such as systolic and diastolic blood pressure.


              Some observations have multiple component observations. These component observations are expressed as separate code value pairs that share the same attributes. Examples include systolic and diastolic component observations for blood pressure measurement and multiple component observations for genetics observations.

              ShortInhaled oxygen concentrationComponent results
              Comments

              For a discussion on the ways Observations can be assembled in groups together see Notes below.


              For a discussion on the ways Observations can be assembled in groups together see Notes below.

              Control0..1*
              TypeBackboneElement
              Is Modifierfalse
              Must Supporttrue
              Summarytrue
              Requirements

              Component observations share the same attributes in the Observation resource as the primary observation and are always treated a part of a single observation (they are not separable). However, the reference range for the primary observation value is not inherited by the component values and is required when appropriate for each component observation.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              vs-3: If there is no a value a data absent reason must be present (value.exists() or dataAbsentReason.exists())
              80. Observation.component:Concentration.modifierExtension
              Definition

              May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

              Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

              ShortExtensions that cannot be ignored even if unrecognized
              Comments

              There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

              Control0..*
              TypeExtension
              Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
              Summarytrue
              Requirements

              Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.


              Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

              Alternate Namesextensions, user content, modifiers
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
              82. Observation.component:Concentration.code
              Definition

              Describes what was observed. Sometimes this is called the observation "code".

              ShortCoded vital sign result typeType of component observation (code / type)
              Comments

              All code-value and component.code-component.value pairs need to be taken into account to correctly understand the meaning of the observation.

              Control1..1
              BindingUnless not suitable, these codes SHALL be taken from For example codes, see Vital Sign Result Type .http://hl7.org/fhir/ValueSet/observation-codes
              (extensible to http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113883.3.88.12.80.62)

              Vital sign result types


              Codes identifying names of simple observations.

              TypeCodeableConcept
              Is Modifierfalse
              Must Supporttrue
              Summarytrue
              Requirements

              Knowing what kind of observation is being made is essential to understanding the observation.

              Pattern Value{
                "coding" : [{
                  "system" : "http://loinc.org",
                  "code" : "3150-0"
                }]
              }
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              84. Observation.component:Concentration.value[x]
              Definition

              Vital Signs value are typically recorded using the Quantity data type. For supporting observations such as cuff size could use other datatypes such as CodeableConcept.


              The information determined as a result of making the observation, if the information has a simple value.

              ShortVital Sign Component ValueActual component result
              Comments

              Used when observation has a set of component observations. An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived). If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.


              Used when observation has a set of component observations. An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived). If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

              Control0..1
              This element is affected by the following invariants: vs-3
              BindingUnless not suitable, these codes SHALL be taken from For codes, see VitalSignsUnits
              (extensible to http://hl7.org/fhir/ValueSet/ucum-vitals-common|4.0.1)

              Common UCUM units for recording Vital Signs.

              TypeQuantity, dateTime, boolean, string, SampledData, Period, Ratio, integer, time, Range, CodeableConcept
              [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
              Is Modifierfalse
              Must Supporttrue
              Must Support TypesQuantity
              Summarytrue
              Requirements
              1. SHALL contain exactly one [1..1] value with @xsi:type="PQ" (CONF:7305).

              An observation exists to have a value, though it might not if it is in error, or if it represents a group of observations.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              86. Observation.component:Concentration.value[x].value
              Definition

              The value of the measured amount. The value includes an implicit precision in the presentation of the value.

              ShortNumerical value (with implicit precision)
              Comments

              The implicit precision in the value should always be honored. Monetary values have their own rules for handling precision (refer to standard accounting text books).

              Control10..1
              Typedecimal
              Is Modifierfalse
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              Must Supporttrue
              Summarytrue
              Requirements

              Precision is handled implicitly in almost all cases of measurement.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              88. Observation.component:Concentration.value[x].comparator
              Definition

              How the value should be understood and represented - whether the actual value is greater or less than the stated value due to measurement issues; e.g. if the comparator is "<" , then the real value is < stated value.

              Short< | <= | >= | > - how to understand the value
              Control0..1
              BindingThe codes SHALL be taken from QuantityComparatorhttp://hl7.org/fhir/ValueSet/quantity-comparator|4.0.1
              (required to http://hl7.org/fhir/ValueSet/quantity-comparator|4.0.1)

              How the Quantity should be understood and represented.

              Typecode
              Is Modifiertrue because This is labeled as "Is Modifier" because the comparator modifies the interpretation of the value significantly. If there is no comparator, then there is no modification of the value
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              Summarytrue
              Requirements

              Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.

              Meaning if MissingIf there is no comparator, then there is no modification of the value
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              90. Observation.component:Concentration.value[x].unit
              Definition

              A human-readable form of the unit.

              ShortUnit representation
              Control10..1
              Typestring
              Is Modifierfalse
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              Must Supporttrue
              Summarytrue
              Requirements

              There are many representations for units of measure and in many contexts, particular representations are fixed and required. I.e. mcg for micrograms.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              92. Observation.component:Concentration.value[x].system
              Definition

              The identification of the system that provides the coded form of the unit.

              ShortSystem that defines coded unit form
              Control10..1
              This element is affected by the following invariants: qty-3
              Typeuri
              Is Modifierfalse
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              Must Supporttrue
              Summarytrue
              Requirements

              Need to know the system that defines the coded form of the unit.

              Fixed Valuehttp://unitsofmeasure.org
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              94. Observation.component:Concentration.value[x].code
              Definition

              A computer processable form of the unit in some unit representation system.

              ShortCoded form of the unit
              Comments

              The preferred system is UCUM, but SNOMED CT can also be used (for customary units) or ISO 4217 for currency. The context of use may additionally require a code from a particular system.

              Control10..1
              Typecode
              Is Modifierfalse
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              Must Supporttrue
              Summarytrue
              Requirements

              Need a computable form of the unit that is fixed across all forms. UCUM provides this for quantities, but SNOMED CT provides many units of interest.

              Fixed Value%
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              96. Observation.component:Concentration.dataAbsentReason
              Definition

              Provides a reason why the expected value in the element Observation.component.value[x] is missing.

              ShortWhy the component result is missing
              Comments

              "Null" or exceptional values can be represented two ways in FHIR Observations. One way is to simply include them in the value set and represent the exceptions in the value. For example, measurement values for a serology test could be "detected", "not detected", "inconclusive", or "test not done".

              The alternate way is to use the value element for actual observations and use the explicit dataAbsentReason element to record exceptional values. For example, the dataAbsentReason code "error" could be used when the measurement was not completed. Because of these options, use-case agreements are required to interpret general observations for exceptional values.

              Control0..1
              This element is affected by the following invariants: obs-6, vs-3
              BindingUnless not suitable, these codes SHALL be taken from DataAbsentReasonhttp://hl7.org/fhir/ValueSet/data-absent-reason
              (extensible to http://hl7.org/fhir/ValueSet/data-absent-reason)

              Codes specifying why the result (Observation.value[x]) is missing.

              TypeCodeableConcept
              Is Modifierfalse
              Must Supporttrue
              Summaryfalse
              Requirements

              For many results it is necessary to handle exceptional values in measurements.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))

              Guidance on how to interpret the contents of this table can be found here

              0. Observation
              Definition

              The FHIR Vitals Signs profile sets minimum expectations for the Observation Resource to record, search and fetch the vital signs associated with a patient.

              ShortUS Core Pulse Oximetry Profile
              Comments

              Used for simple observations such as device measurements, laboratory atomic results, vital signs, height, weight, smoking status, comments, etc. Other resources are used to provide context for observations such as laboratory reports, etc.

              Control0..*
              Is Modifierfalse
              Must Supportfalse
              Summaryfalse
              Alternate NamesVital Signs, Measurement, Results, Tests
              Invariantsdom-2: If the resource is contained in another resource, it SHALL NOT contain nested Resources (contained.contained.empty())
              dom-3: If the resource is contained in another resource, it SHALL be referred to from elsewhere in the resource or SHALL refer to the containing resource (contained.where((('#'+id in (%resource.descendants().reference | %resource.descendants().as(canonical) | %resource.descendants().as(uri) | %resource.descendants().as(url))) or descendants().where(reference = '#').exists() or descendants().where(as(canonical) = '#').exists() or descendants().where(as(canonical) = '#').exists()).not()).trace('unmatched', id).empty())
              dom-4: If a resource is contained in another resource, it SHALL NOT have a meta.versionId or a meta.lastUpdated (contained.meta.versionId.empty() and contained.meta.lastUpdated.empty())
              dom-5: If a resource is contained in another resource, it SHALL NOT have a security label (contained.meta.security.empty())
              dom-6: A resource should have narrative for robust management (text.`div`.exists())
              obs-6: dataAbsentReason SHALL only be present if Observation.value[x] is not present (dataAbsentReason.empty() or value.empty())
              obs-7: If Observation.code is the same as an Observation.component.code then the value element associated with the code SHALL NOT be present (value.empty() or component.code.where(coding.intersect(%resource.code.coding).exists()).empty())
              vs-2: If there is no component or hasMember element then either a value[x] or a data absent reason must be present. ((component.empty() and hasMember.empty()) implies (dataAbsentReason.exists() or value.exists()))
              2. Observation.id
              Definition

              The logical id of the resource, as used in the URL for the resource. Once assigned, this value never changes.

              ShortLogical id of this artifact
              Comments

              The only time that a resource does not have an id is when it is being submitted to the server using a create operation.

              Control0..1
              Typeid
              Is Modifierfalse
              Summarytrue
              4. Observation.meta
              Definition

              The metadata about the resource. This is content that is maintained by the infrastructure. Changes to the content might not always be associated with version changes to the resource.

              ShortMetadata about the resource
              Control0..1
              TypeMeta
              Is Modifierfalse
              Summarytrue
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              6. Observation.implicitRules
              Definition

              A reference to a set of rules that were followed when the resource was constructed, and which must be understood when processing the content. Often, this is a reference to an implementation guide that defines the special rules along with other profiles etc.

              ShortA set of rules under which this content was created
              Comments

              Asserting this rule set restricts the content to be only understood by a limited set of trading partners. This inherently limits the usefulness of the data in the long term. However, the existing health eco-system is highly fractured, and not yet ready to define, collect, and exchange data in a generally computable sense. Wherever possible, implementers and/or specification writers should avoid using this element. Often, when used, the URL is a reference to an implementation guide that defines these special rules as part of it's narrative along with other profiles, value sets, etc.

              Control0..1
              Typeuri
              Is Modifiertrue because This element is labeled as a modifier because the implicit rules may provide additional knowledge about the resource that modifies it's meaning or interpretation
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              Summarytrue
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              8. Observation.language
              Definition

              The base language in which the resource is written.

              ShortLanguage of the resource content
              Comments

              Language is provided to support indexing and accessibility (typically, services such as text to speech use the language tag). The html language tag in the narrative applies to the narrative. The language tag on the resource may be used to specify the language of other presentations generated from the data in the resource. Not all the content has to be in the base language. The Resource.language should not be assumed to apply to the narrative automatically. If a language is specified, it should it also be specified on the div element in the html (see rules in HTML5 for information about the relationship between xml:lang and the html lang attribute).

              Control0..1
              BindingThe codes SHOULD be taken from CommonLanguages
              (preferred to http://hl7.org/fhir/ValueSet/languages)

              A human language.

              Additional BindingsPurpose
              AllLanguagesMax Binding
              Typecode
              Is Modifierfalse
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              Summaryfalse
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              10. Observation.text
              Definition

              A human-readable narrative that contains a summary of the resource and can be used to represent the content of the resource to a human. The narrative need not encode all the structured data, but is required to contain sufficient detail to make it "clinically safe" for a human to just read the narrative. Resource definitions may define what content should be represented in the narrative to ensure clinical safety.

              ShortText summary of the resource, for human interpretation
              Comments

              Contained resources do not have narrative. Resources that are not contained SHOULD have a narrative. In some cases, a resource may only have text with little or no additional discrete data (as long as all minOccurs=1 elements are satisfied). This may be necessary for data from legacy systems where information is captured as a "text blob" or where text is additionally entered raw or narrated and encoded information is added later.

              Control0..1
              TypeNarrative
              Is Modifierfalse
              Summaryfalse
              Alternate Namesnarrative, html, xhtml, display
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              12. Observation.contained
              Definition

              These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, and nor can they have their own independent transaction scope.

              ShortContained, inline Resources
              Comments

              This should never be done when the content can be identified properly, as once identification is lost, it is extremely difficult (and context dependent) to restore it again. Contained resources may have profiles and tags In their meta elements, but SHALL NOT have security labels.

              Control0..*
              TypeResource
              Is Modifierfalse
              Summaryfalse
              Alternate Namesinline resources, anonymous resources, contained resources
              14. Observation.extension
              Definition

              May be used to represent additional information that is not part of the basic definition of the resource. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

              ShortAdditional content defined by implementations
              Comments

              There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

              Control0..*
              TypeExtension
              Is Modifierfalse
              Summaryfalse
              Alternate Namesextensions, user content
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
              16. Observation.modifierExtension
              Definition

              May be used to represent additional information that is not part of the basic definition of the resource and that modifies the understanding of the element that contains it and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer is allowed to define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

              Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

              ShortExtensions that cannot be ignored
              Comments

              There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

              Control0..*
              TypeExtension
              Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the resource that contains them
              Summaryfalse
              Requirements

              Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

              Alternate Namesextensions, user content
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
              18. Observation.identifier
              Definition

              A unique identifier assigned to this observation.

              ShortBusiness Identifier for observation
              NoteThis is a business identifier, not a resource identifier (see discussion)
              Control0..*
              TypeIdentifier
              Is Modifierfalse
              Summarytrue
              Requirements

              Allows observations to be distinguished and referenced.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              20. Observation.basedOn
              Definition

              A plan, proposal or order that is fulfilled in whole or in part by this event. For example, a MedicationRequest may require a patient to have laboratory test performed before it is dispensed.

              ShortFulfills plan, proposal or order
              Control0..*
              TypeReference(CarePlan, DeviceRequest, ImmunizationRecommendation, MedicationRequest, NutritionOrder, ServiceRequest)
              Is Modifierfalse
              Summarytrue
              Requirements

              Allows tracing of authorization for the event and tracking whether proposals/recommendations were acted upon.

              Alternate NamesFulfills
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              22. Observation.partOf
              Definition

              A larger event of which this particular Observation is a component or step. For example, an observation as part of a procedure.

              ShortPart of referenced event
              Comments

              To link an Observation to an Encounter use encounter. See the Notes below for guidance on referencing another Observation.

              Control0..*
              TypeReference(MedicationAdministration, MedicationDispense, MedicationStatement, Procedure, Immunization, ImagingStudy)
              Is Modifierfalse
              Summarytrue
              Alternate NamesContainer
              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              24. Observation.status
              Definition

              The status of the result value.

              Shortregistered | preliminary | final | amended +
              Comments

              This element is labeled as a modifier because the status contains codes that mark the resource as not currently valid.

              Control1..1
              BindingThe codes SHALL be taken from ObservationStatus
              (required to http://hl7.org/fhir/ValueSet/observation-status|4.0.1)
              Typecode
              Is Modifiertrue because This element is labeled as a modifier because it is a status element that contains status entered-in-error which means that the resource should not be treated as valid
              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
              Must Supporttrue
              Summarytrue
              Requirements

              Need to track the status of individual results. Some results are finalized before the whole report is finalized.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              26. Observation.category
              Definition

              A code that classifies the general type of observation being made.

              ShortClassification of type of observation
              Comments

              In addition to the required category valueset, this element allows various categorization schemes based on the owner’s definition of the category and effectively multiple categories can be used at once. The level of granularity is defined by the category concepts in the value set.

              Control1..*
              BindingThe codes SHOULD be taken from ObservationCategoryCodes
              (preferred to http://hl7.org/fhir/ValueSet/observation-category)

              Codes for high level observation categories.

              TypeCodeableConcept
              Is Modifierfalse
              Must Supporttrue
              Summaryfalse
              Requirements

              Used for filtering what observations are retrieved and displayed.

              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
              SlicingThis element introduces a set of slices on Observation.category. The slices areUnordered and Open, and can be differentiated using the following discriminators:
              • value @ coding.code
              • value @ coding.system
              • 28. Observation.category:VSCat
                Slice NameVSCat
                Definition

                A code that classifies the general type of observation being made.

                ShortClassification of type of observation
                Comments

                In addition to the required category valueset, this element allows various categorization schemes based on the owner’s definition of the category and effectively multiple categories can be used at once. The level of granularity is defined by the category concepts in the value set.

                Control1..1
                BindingThe codes SHOULD be taken from ObservationCategoryCodes
                (preferred to http://hl7.org/fhir/ValueSet/observation-category)

                Codes for high level observation categories.

                TypeCodeableConcept
                Is Modifierfalse
                Must Supporttrue
                Summaryfalse
                Requirements

                Used for filtering what observations are retrieved and displayed.

                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                30. Observation.category:VSCat.id
                Definition

                Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

                ShortUnique id for inter-element referencing
                Control0..1
                Typestring
                Is Modifierfalse
                XML FormatIn the XML format, this property is represented as an attribute.
                Summaryfalse
                32. Observation.category:VSCat.extension
                Definition

                May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

                ShortAdditional content defined by implementations
                Comments

                There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                Control0..*
                TypeExtension
                Is Modifierfalse
                Summaryfalse
                Alternate Namesextensions, user content
                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                SlicingThis element introduces a set of slices on Observation.category.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
                • value @ url
                • 34. Observation.category:VSCat.coding
                  Definition

                  A reference to a code defined by a terminology system.

                  ShortCode defined by a terminology system
                  Comments

                  Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.

                  Control1..*
                  TypeCoding
                  Is Modifierfalse
                  Must Supporttrue
                  Summarytrue
                  Requirements

                  Allows for alternative encodings within a code system, and translations to other code systems.

                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  36. Observation.category:VSCat.coding.id
                  Definition

                  Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

                  ShortUnique id for inter-element referencing
                  Control0..1
                  Typestring
                  Is Modifierfalse
                  XML FormatIn the XML format, this property is represented as an attribute.
                  Summaryfalse
                  38. Observation.category:VSCat.coding.extension
                  Definition

                  May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

                  ShortAdditional content defined by implementations
                  Comments

                  There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                  Control0..*
                  TypeExtension
                  Is Modifierfalse
                  Summaryfalse
                  Alternate Namesextensions, user content
                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                  ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                  SlicingThis element introduces a set of slices on Observation.category.coding.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
                  • value @ url
                  • 40. Observation.category:VSCat.coding.system
                    Definition

                    The identification of the code system that defines the meaning of the symbol in the code.

                    ShortIdentity of the terminology system
                    Comments

                    The URI may be an OID (urn:oid:...) or a UUID (urn:uuid:...). OIDs and UUIDs SHALL be references to the HL7 OID registry. Otherwise, the URI should come from HL7's list of FHIR defined special URIs or it should reference to some definition that establishes the system clearly and unambiguously.

                    Control1..1
                    Typeuri
                    Is Modifierfalse
                    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                    Must Supporttrue
                    Summarytrue
                    Requirements

                    Need to be unambiguous about the source of the definition of the symbol.

                    Fixed Valuehttp://terminology.hl7.org/CodeSystem/observation-category
                    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                    42. Observation.category:VSCat.coding.version
                    Definition

                    The version of the code system which was used when choosing this code. Note that a well-maintained code system does not need the version reported, because the meaning of codes is consistent across versions. However this cannot consistently be assured, and when the meaning is not guaranteed to be consistent, the version SHOULD be exchanged.

                    ShortVersion of the system - if relevant
                    Comments

                    Where the terminology does not clearly define what string should be used to identify code system versions, the recommendation is to use the date (expressed in FHIR date format) on which that version was officially published as the version date.

                    NoteThis is a business version Id, not a resource version Id (see discussion)
                    Control0..1
                    Typestring
                    Is Modifierfalse
                    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                    Summarytrue
                    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                    44. Observation.category:VSCat.coding.code
                    Definition

                    A symbol in syntax defined by the system. The symbol may be a predefined code or an expression in a syntax defined by the coding system (e.g. post-coordination).

                    ShortSymbol in syntax defined by the system
                    Control1..1
                    Typecode
                    Is Modifierfalse
                    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                    Must Supporttrue
                    Summarytrue
                    Requirements

                    Need to refer to a particular code in the system.

                    Fixed Valuevital-signs
                    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                    46. Observation.category:VSCat.coding.display
                    Definition

                    A representation of the meaning of the code in the system, following the rules of the system.

                    ShortRepresentation defined by the system
                    Control0..1
                    Typestring
                    Is Modifierfalse
                    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                    Summarytrue
                    Requirements

                    Need to be able to carry a human-readable meaning of the code for readers that do not know the system.

                    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                    48. Observation.category:VSCat.coding.userSelected
                    Definition

                    Indicates that this coding was chosen by a user directly - e.g. off a pick list of available items (codes or displays).

                    ShortIf this coding was chosen directly by the user
                    Comments

                    Amongst a set of alternatives, a directly chosen code is the most appropriate starting point for new translations. There is some ambiguity about what exactly 'directly chosen' implies, and trading partner agreement may be needed to clarify the use of this element and its consequences more completely.

                    Control0..1
                    Typeboolean
                    Is Modifierfalse
                    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                    Summarytrue
                    Requirements

                    This has been identified as a clinical safety criterium - that this exact system/code pair was chosen explicitly, rather than inferred by the system based on some rules or language processing.

                    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                    50. Observation.category:VSCat.text
                    Definition

                    A human language representation of the concept as seen/selected/uttered by the user who entered the data and/or which represents the intended meaning of the user.

                    ShortPlain text representation of the concept
                    Comments

                    Very often the text is the same as a displayName of one of the codings.

                    Control0..1
                    Typestring
                    Is Modifierfalse
                    Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                    Summarytrue
                    Requirements

                    The codes from the terminologies do not always capture the correct meaning with all the nuances of the human using them, or sometimes there is no appropriate code at all. In these cases, the text is used to capture the full meaning of the source.

                    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                    52. Observation.code
                    Definition

                    Coded Responses from C-CDA Vital Sign Results.

                    ShortOxygen Saturation by Pulse Oximetry
                    Comments

                    The code (59408-5 Oxygen saturation in Arterial blood by Pulse oximetry) is included as an additional observation code to FHIR Core vital Oxygen Saturation code (2708-6 Oxygen saturation in Arterial blood).

                    Control1..1
                    BindingUnless not suitable, these codes SHALL be taken from Vital Sign Result Type .
                    (extensible to http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113883.3.88.12.80.62)

                    Vital sign result types

                    TypeCodeableConcept
                    Is Modifierfalse
                    Must Supporttrue
                    Summarytrue
                    Requirements
                    1. SHALL contain exactly one [1..1] code, where the @code SHOULD be selected from ValueSet HITSP Vital Sign Result Type 2.16.840.1.113883.3.88.12.80.62 DYNAMIC (CONF:7301).
                    Alternate NamesName
                    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                    54. Observation.code.id
                    Definition

                    Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

                    ShortUnique id for inter-element referencing
                    Control0..1
                    Typestring
                    Is Modifierfalse
                    XML FormatIn the XML format, this property is represented as an attribute.
                    Summaryfalse
                    56. Observation.code.extension
                    Definition

                    May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

                    ShortAdditional content defined by implementations
                    Comments

                    There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                    Control0..*
                    TypeExtension
                    Is Modifierfalse
                    Summaryfalse
                    Alternate Namesextensions, user content
                    Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                    ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                    SlicingThis element introduces a set of slices on Observation.code.extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
                    • value @ url
                    • 58. Observation.code.coding
                      Definition

                      A reference to a code defined by a terminology system.

                      ShortCode defined by a terminology system
                      Comments

                      Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.

                      Control2..*
                      TypeCoding
                      Is Modifierfalse
                      Must Supporttrue
                      Summarytrue
                      Requirements

                      Allows for alternative encodings within a code system, and translations to other code systems.

                      Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                      SlicingThis element introduces a set of slices on Observation.code.coding. The slices areUnordered and Open, and can be differentiated using the following discriminators:
                      • value @ $this
                      • 60. Observation.code.coding:PulseOx
                        Slice NamePulseOx
                        Definition

                        A reference to a code defined by a terminology system.

                        ShortCode defined by a terminology system
                        Comments

                        Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.

                        Control1..1
                        TypeCoding
                        Is Modifierfalse
                        Must Supporttrue
                        Summarytrue
                        Requirements

                        Allows for alternative encodings within a code system, and translations to other code systems.

                        Pattern Value{
                          "system" : "http://loinc.org",
                          "code" : "59408-5"
                        }
                        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                        62. Observation.code.coding:O2Sat
                        Slice NameO2Sat
                        Definition

                        A reference to a code defined by a terminology system.

                        ShortCode defined by a terminology system
                        Comments

                        Codes may be defined very casually in enumerations, or code lists, up to very formal definitions such as SNOMED CT - see the HL7 v3 Core Principles for more information. Ordering of codings is undefined and SHALL NOT be used to infer meaning. Generally, at most only one of the coding values will be labeled as UserSelected = true.

                        Control1..1
                        TypeCoding
                        Is Modifierfalse
                        Must Supporttrue
                        Summarytrue
                        Requirements

                        Allows for alternative encodings within a code system, and translations to other code systems.

                        Pattern Value{
                          "system" : "http://loinc.org",
                          "code" : "2708-6"
                        }
                        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                        64. Observation.code.text
                        Definition

                        A human language representation of the concept as seen/selected/uttered by the user who entered the data and/or which represents the intended meaning of the user.

                        ShortPlain text representation of the concept
                        Comments

                        Very often the text is the same as a displayName of one of the codings.

                        Control0..1
                        Typestring
                        Is Modifierfalse
                        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                        Summarytrue
                        Requirements

                        The codes from the terminologies do not always capture the correct meaning with all the nuances of the human using them, or sometimes there is no appropriate code at all. In these cases, the text is used to capture the full meaning of the source.

                        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                        66. Observation.subject
                        Definition

                        The patient, or group of patients, location, or device this observation is about and into whose record the observation is placed. If the actual focus of the observation is different from the subject (or a sample of, part, or region of the subject), the focus element or the code itself specifies the actual focus of the observation.

                        ShortWho and/or what the observation is about
                        Comments

                        One would expect this element to be a cardinality of 1..1. The only circumstance in which the subject can be missing is when the observation is made by a device that does not know the patient. In this case, the observation SHALL be matched to a patient through some context/channel matching technique, and at this point, the observation should be updated.

                        Control1..1
                        TypeReference(US Core Patient Profile)
                        Is Modifierfalse
                        Must Supporttrue
                        Summarytrue
                        Requirements

                        Observations have no value if you don't know who or what they're about.

                        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                        68. Observation.focus
                        Definition

                        The actual focus of an observation when it is not the patient of record representing something or someone associated with the patient such as a spouse, parent, fetus, or donor. For example, fetus observations in a mother's record. The focus of an observation could also be an existing condition, an intervention, the subject's diet, another observation of the subject, or a body structure such as tumor or implanted device. An example use case would be using the Observation resource to capture whether the mother is trained to change her child's tracheostomy tube. In this example, the child is the patient of record and the mother is the focus.

                        ShortWhat the observation is about, when it is not about the subject of record
                        Comments

                        Typically, an observation is made about the subject - a patient, or group of patients, location, or device - and the distinction between the subject and what is directly measured for an observation is specified in the observation code itself ( e.g., "Blood Glucose") and does not need to be represented separately using this element. Use specimen if a reference to a specimen is required. If a code is required instead of a resource use either bodysite for bodysites or the standard extension focusCode.

                        Control0..*
                        TypeReference(Resource)
                        Is Modifierfalse
                        Summarytrue
                        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                        70. Observation.encounter
                        Definition

                        The healthcare event (e.g. a patient and healthcare provider interaction) during which this observation is made.

                        ShortHealthcare event during which this observation is made
                        Comments

                        This will typically be the encounter the event occurred within, but some events may be initiated prior to or after the official completion of an encounter but still be tied to the context of the encounter (e.g. pre-admission laboratory tests).

                        Control0..1
                        TypeReference(Encounter)
                        Is Modifierfalse
                        Summarytrue
                        Requirements

                        For some observations it may be important to know the link between an observation and a particular encounter.

                        Alternate NamesContext
                        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                        72. Observation.effective[x]
                        Definition

                        Often just a dateTime for Vital Signs.

                        ShortOften just a dateTime for Vital Signs
                        Comments

                        At least a date should be present unless this observation is a historical report. For recording imprecise or "fuzzy" times (For example, a blood glucose measurement taken "after breakfast") use the Timing datatype which allow the measurement to be tied to regular life events.

                        Control1..1
                        This element is affected by the following invariants: vs-1
                        TypeChoice of: dateTime, Period
                        [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
                        Is Modifierfalse
                        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                        Must Supporttrue
                        Must Support TypesdateTime
                        Summarytrue
                        Requirements

                        Knowing when an observation was deemed true is important to its relevance as well as determining trends.

                        Alternate NamesOccurrence
                        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                        vs-1: if Observation.effective[x] is dateTime and has a value then that value shall be precise to the day ($this is dateTime implies $this.toString().length() >= 10)
                        74. Observation.issued
                        Definition

                        The date and time this version of the observation was made available to providers, typically after the results have been reviewed and verified.

                        ShortDate/Time this version was made available
                        Comments

                        For Observations that don’t require review and verification, it may be the same as the lastUpdated time of the resource itself. For Observations that do require review and verification for certain updates, it might not be the same as the lastUpdated time of the resource itself due to a non-clinically significant update that doesn’t require the new version to be reviewed and verified again.

                        Control0..1
                        Typeinstant
                        Is Modifierfalse
                        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                        Summarytrue
                        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                        76. Observation.performer
                        Definition

                        Who was responsible for asserting the observed value as "true".

                        ShortWho is responsible for the observation
                        Control0..*
                        TypeReference(US Core Practitioner Profile, US Core Organization Profile, US Core Patient Profile, PractitionerRole, US Core CareTeam Profile, US Core RelatedPerson Profile)
                        Is Modifierfalse
                        Must Supporticon Added:true
                        Must Support TypesNo must-support rules about the choice of types/profiles
                        Summarytrue
                        Requirements

                        May give a degree of confidence in the observation and also indicates where follow-up questions should be directed.

                        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                        78. Observation.value[x]
                        Definition

                        Vital Signs value are typically recorded using the Quantity data type.

                        ShortVital Signs Value
                        Comments

                        An observation may have; 1) a single value here, 2) both a value and a set of related or component values, or 3) only a set of related or component values. If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

                        Control0..1
                        This element is affected by the following invariants: obs-7, vs-2
                        BindingUnless not suitable, these codes SHALL be taken from VitalSignsUnits
                        (extensible to http://hl7.org/fhir/ValueSet/ucum-vitals-common|4.0.1)

                        Common UCUM units for recording Vital Signs.

                        TypeChoice of: Quantity, CodeableConcept, string, boolean, integer, Range, Ratio, SampledData, time, dateTime, Period
                        [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
                        Is Modifierfalse
                        Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                        Must Supporttrue
                        Must Support TypesQuantity
                        Summarytrue
                        Requirements
                        1. SHALL contain exactly one [1..1] value with @xsi:type="PQ" (CONF:7305).
                        Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                        SlicingThis element introduces a set of slices on Observation.value[x]. The slices areUnordered and Open, and can be differentiated using the following discriminators:
                        • type @ $this
                        • 80. Observation.value[x]:valueQuantity
                          Slice NamevalueQuantity
                          Definition

                          The oxygen saturation by pulse oximetry value is expressed as a percentage (0-100) of the total hemoglobin content of the blood.

                          ShortOxygen Saturation by Pulse Oximetry Value
                          Comments

                          An observation may have; 1) a single value here, 2) both a value and a set of related or component values, or 3) only a set of related or component values. If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

                          Control0..1
                          This element is affected by the following invariants: obs-7, vs-2
                          BindingUnless not suitable, these codes SHALL be taken from VitalSignsUnits
                          (extensible to http://hl7.org/fhir/ValueSet/ucum-vitals-common|4.0.1)

                          Common UCUM units for recording Vital Signs.

                          TypeQuantity
                          [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
                          Is Modifierfalse
                          Must Supporttrue
                          Must Support TypesQuantity
                          Summarytrue
                          Requirements
                          1. SHALL contain exactly one [1..1] value with @xsi:type="PQ" (CONF:7305).
                          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                          82. Observation.value[x]:valueQuantity.id
                          Definition

                          Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

                          ShortUnique id for inter-element referencing
                          Control0..1
                          Typestring
                          Is Modifierfalse
                          XML FormatIn the XML format, this property is represented as an attribute.
                          Summaryfalse
                          84. Observation.value[x]:valueQuantity.extension
                          Definition

                          May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

                          ShortAdditional content defined by implementations
                          Comments

                          There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                          Control0..*
                          TypeExtension
                          Is Modifierfalse
                          Summaryfalse
                          Alternate Namesextensions, user content
                          Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                          ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                          SlicingThis element introduces a set of slices on Observation.value[x].extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
                          • value @ url
                          • 86. Observation.value[x]:valueQuantity.value
                            Definition

                            The value of the measured amount. The value includes an implicit precision in the presentation of the value.

                            ShortNumerical value (with implicit precision)
                            Comments

                            The implicit precision in the value should always be honored. Monetary values have their own rules for handling precision (refer to standard accounting text books).

                            Control1..1
                            Typedecimal
                            Is Modifierfalse
                            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                            Must Supporttrue
                            Summarytrue
                            Requirements

                            Precision is handled implicitly in almost all cases of measurement.

                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            88. Observation.value[x]:valueQuantity.comparator
                            Definition

                            How the value should be understood and represented - whether the actual value is greater or less than the stated value due to measurement issues; e.g. if the comparator is "<" , then the real value is < stated value.

                            Short< | <= | >= | > - how to understand the value
                            Control0..1
                            BindingThe codes SHALL be taken from QuantityComparator
                            (required to http://hl7.org/fhir/ValueSet/quantity-comparator|4.0.1)

                            How the Quantity should be understood and represented.

                            Typecode
                            Is Modifiertrue because This is labeled as "Is Modifier" because the comparator modifies the interpretation of the value significantly. If there is no comparator, then there is no modification of the value
                            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                            Summarytrue
                            Requirements

                            Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.

                            Meaning if MissingIf there is no comparator, then there is no modification of the value
                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            90. Observation.value[x]:valueQuantity.unit
                            Definition

                            A human-readable form of the unit.

                            ShortUnit representation
                            Control1..1
                            Typestring
                            Is Modifierfalse
                            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                            Must Supporttrue
                            Summarytrue
                            Requirements

                            There are many representations for units of measure and in many contexts, particular representations are fixed and required. I.e. mcg for micrograms.

                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            92. Observation.value[x]:valueQuantity.system
                            Definition

                            The identification of the system that provides the coded form of the unit.

                            ShortSystem that defines coded unit form
                            Control1..1
                            This element is affected by the following invariants: qty-3
                            Typeuri
                            Is Modifierfalse
                            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                            Must Supporttrue
                            Summarytrue
                            Requirements

                            Need to know the system that defines the coded form of the unit.

                            Fixed Valuehttp://unitsofmeasure.org
                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            94. Observation.value[x]:valueQuantity.code
                            Definition

                            A computer processable form of the unit in some unit representation system.

                            ShortCoded form of the unit
                            Comments

                            The preferred system is UCUM, but SNOMED CT can also be used (for customary units) or ISO 4217 for currency. The context of use may additionally require a code from a particular system.

                            Control1..1
                            Typecode
                            Is Modifierfalse
                            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                            Must Supporttrue
                            Summarytrue
                            Requirements

                            Need a computable form of the unit that is fixed across all forms. UCUM provides this for quantities, but SNOMED CT provides many units of interest.

                            Fixed Value%
                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            96. Observation.dataAbsentReason
                            Definition

                            Provides a reason why the expected value in the element Observation.value[x] is missing.

                            ShortWhy the result is missing
                            Comments

                            Null or exceptional values can be represented two ways in FHIR Observations. One way is to simply include them in the value set and represent the exceptions in the value. For example, measurement values for a serology test could be "detected", "not detected", "inconclusive", or "specimen unsatisfactory".

                            The alternate way is to use the value element for actual observations and use the explicit dataAbsentReason element to record exceptional values. For example, the dataAbsentReason code "error" could be used when the measurement was not completed. Note that an observation may only be reported if there are values to report. For example differential cell counts values may be reported only when > 0. Because of these options, use-case agreements are required to interpret general observations for null or exceptional values.

                            Control0..1
                            This element is affected by the following invariants: obs-6, vs-2
                            BindingUnless not suitable, these codes SHALL be taken from DataAbsentReason
                            (extensible to http://hl7.org/fhir/ValueSet/data-absent-reason)

                            Codes specifying why the result (Observation.value[x]) is missing.

                            TypeCodeableConcept
                            Is Modifierfalse
                            Must Supporttrue
                            Summaryfalse
                            Requirements

                            For many results it is necessary to handle exceptional values in measurements.

                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            98. Observation.interpretation
                            Definition

                            A categorical assessment of an observation value. For example, high, low, normal.

                            ShortHigh, low, normal, etc.
                            Comments

                            Historically used for laboratory results (known as 'abnormal flag' ), its use extends to other use cases where coded interpretations are relevant. Often reported as one or more simple compact codes this element is often placed adjacent to the result value in reports and flow sheets to signal the meaning/normalcy status of the result.

                            Control0..*
                            BindingUnless not suitable, these codes SHALL be taken from ObservationInterpretationCodes
                            (extensible to http://hl7.org/fhir/ValueSet/observation-interpretation)

                            Codes identifying interpretations of observations.

                            TypeCodeableConcept
                            Is Modifierfalse
                            Summaryfalse
                            Requirements

                            For some results, particularly numeric results, an interpretation is necessary to fully understand the significance of a result.

                            Alternate NamesAbnormal Flag
                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            100. Observation.note
                            Definition

                            Comments about the observation or the results.

                            ShortComments about the observation
                            Comments

                            May include general statements about the observation, or statements about significant, unexpected or unreliable results values, or information about its source when relevant to its interpretation.

                            Control0..*
                            TypeAnnotation
                            Is Modifierfalse
                            Summaryfalse
                            Requirements

                            Need to be able to provide free text additional information.

                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            102. Observation.bodySite
                            Definition

                            Indicates the site on the subject's body where the observation was made (i.e. the target site).

                            ShortObserved body part
                            Comments

                            Only used if not implicit in code found in Observation.code. In many systems, this may be represented as a related observation instead of an inline component.

                            If the use case requires BodySite to be handled as a separate resource (e.g. to identify and track separately) then use the standard extension bodySite.

                            Control0..1
                            BindingFor example codes, see SNOMEDCTBodyStructures
                            (example to http://hl7.org/fhir/ValueSet/body-site)

                            Codes describing anatomical locations. May include laterality.

                            TypeCodeableConcept
                            Is Modifierfalse
                            Summaryfalse
                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            104. Observation.method
                            Definition

                            Indicates the mechanism used to perform the observation.

                            ShortHow it was done
                            Comments

                            Only used if not implicit in code for Observation.code.

                            Control0..1
                            BindingFor example codes, see ObservationMethods
                            (example to http://hl7.org/fhir/ValueSet/observation-methods)

                            Methods for simple observations.

                            TypeCodeableConcept
                            Is Modifierfalse
                            Summaryfalse
                            Requirements

                            In some cases, method can impact results and is thus used for determining whether results can be compared or determining significance of results.

                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            106. Observation.specimen
                            Definition

                            The specimen that was used when this observation was made.

                            ShortSpecimen used for this observation
                            Comments

                            Should only be used if not implicit in code found in Observation.code. Observations are not made on specimens themselves; they are made on a subject, but in many cases by the means of a specimen. Note that although specimens are often involved, they are not always tracked and reported explicitly. Also note that observation resources may be used in contexts that track the specimen explicitly (e.g. Diagnostic Report).

                            Control0..1
                            TypeReference(Specimen)
                            Is Modifierfalse
                            Summaryfalse
                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            108. Observation.device
                            Definition

                            The device used to generate the observation data.

                            Short(Measurement) Device
                            Comments

                            Note that this is not meant to represent a device involved in the transmission of the result, e.g., a gateway. Such devices may be documented using the Provenance resource where relevant.

                            Control0..1
                            TypeReference(Device, DeviceMetric)
                            Is Modifierfalse
                            Summaryfalse
                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            110. Observation.referenceRange
                            Definition

                            Guidance on how to interpret the value by comparison to a normal or recommended range. Multiple reference ranges are interpreted as an "OR". In other words, to represent two distinct target populations, two referenceRange elements would be used.

                            ShortProvides guide for interpretation
                            Comments

                            Most observations only have one generic reference range. Systems MAY choose to restrict to only supplying the relevant reference range based on knowledge about the patient (e.g., specific to the patient's age, gender, weight and other factors), but this might not be possible or appropriate. Whenever more than one reference range is supplied, the differences between them SHOULD be provided in the reference range and/or age properties.

                            Control0..*
                            TypeBackboneElement
                            Is Modifierfalse
                            Summaryfalse
                            Requirements

                            Knowing what values are considered "normal" can help evaluate the significance of a particular result. Need to be able to provide multiple reference ranges for different contexts.

                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            obs-3: Must have at least a low or a high or text (low.exists() or high.exists() or text.exists())
                            112. Observation.referenceRange.id
                            Definition

                            Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

                            ShortUnique id for inter-element referencing
                            Control0..1
                            Typestring
                            Is Modifierfalse
                            XML FormatIn the XML format, this property is represented as an attribute.
                            Summaryfalse
                            114. Observation.referenceRange.extension
                            Definition

                            May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

                            ShortAdditional content defined by implementations
                            Comments

                            There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                            Control0..*
                            TypeExtension
                            Is Modifierfalse
                            Summaryfalse
                            Alternate Namesextensions, user content
                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                            116. Observation.referenceRange.modifierExtension
                            Definition

                            May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

                            Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

                            ShortExtensions that cannot be ignored even if unrecognized
                            Comments

                            There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                            Control0..*
                            TypeExtension
                            Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
                            Summarytrue
                            Requirements

                            Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

                            Alternate Namesextensions, user content, modifiers
                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                            118. Observation.referenceRange.low
                            Definition

                            The value of the low bound of the reference range. The low bound of the reference range endpoint is inclusive of the value (e.g. reference range is >=5 - <=9). If the low bound is omitted, it is assumed to be meaningless (e.g. reference range is <=2.3).

                            ShortLow Range, if relevant
                            Control0..1
                            This element is affected by the following invariants: obs-3
                            TypeQuantity(SimpleQuantity)
                            Is Modifierfalse
                            Summaryfalse
                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            120. Observation.referenceRange.high
                            Definition

                            The value of the high bound of the reference range. The high bound of the reference range endpoint is inclusive of the value (e.g. reference range is >=5 - <=9). If the high bound is omitted, it is assumed to be meaningless (e.g. reference range is >= 2.3).

                            ShortHigh Range, if relevant
                            Control0..1
                            This element is affected by the following invariants: obs-3
                            TypeQuantity(SimpleQuantity)
                            Is Modifierfalse
                            Summaryfalse
                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            122. Observation.referenceRange.type
                            Definition

                            Codes to indicate the what part of the targeted reference population it applies to. For example, the normal or therapeutic range.

                            ShortReference range qualifier
                            Comments

                            This SHOULD be populated if there is more than one range. If this element is not present then the normal range is assumed.

                            Control0..1
                            BindingThe codes SHOULD be taken from ObservationReferenceRangeMeaningCodes
                            (preferred to http://hl7.org/fhir/ValueSet/referencerange-meaning)

                            Code for the meaning of a reference range.

                            TypeCodeableConcept
                            Is Modifierfalse
                            Summaryfalse
                            Requirements

                            Need to be able to say what kind of reference range this is - normal, recommended, therapeutic, etc., - for proper interpretation.

                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            124. Observation.referenceRange.appliesTo
                            Definition

                            Codes to indicate the target population this reference range applies to. For example, a reference range may be based on the normal population or a particular sex or race. Multiple appliesTo are interpreted as an "AND" of the target populations. For example, to represent a target population of African American females, both a code of female and a code for African American would be used.

                            ShortReference range population
                            Comments

                            This SHOULD be populated if there is more than one range. If this element is not present then the normal population is assumed.

                            Control0..*
                            BindingFor example codes, see ObservationReferenceRangeAppliesToCodes
                            (example to http://hl7.org/fhir/ValueSet/referencerange-appliesto)

                            Codes identifying the population the reference range applies to.

                            TypeCodeableConcept
                            Is Modifierfalse
                            Summaryfalse
                            Requirements

                            Need to be able to identify the target population for proper interpretation.

                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            126. Observation.referenceRange.age
                            Definition

                            The age at which this reference range is applicable. This is a neonatal age (e.g. number of weeks at term) if the meaning says so.

                            ShortApplicable age range, if relevant
                            Control0..1
                            TypeRange
                            Is Modifierfalse
                            Summaryfalse
                            Requirements

                            Some analytes vary greatly over age.

                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            128. Observation.referenceRange.text
                            Definition

                            Text based reference range in an observation which may be used when a quantitative range is not appropriate for an observation. An example would be a reference value of "Negative" or a list or table of "normals".

                            ShortText based reference range in an observation
                            Control0..1
                            Typestring
                            Is Modifierfalse
                            Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                            Summaryfalse
                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            130. Observation.hasMember
                            Definition

                            Used when reporting vital signs panel components.

                            ShortUsed when reporting vital signs panel components
                            Comments

                            When using this element, an observation will typically have either a value or a set of related resources, although both may be present in some cases. For a discussion on the ways Observations can assembled in groups together, see Notes below. Note that a system may calculate results from QuestionnaireResponse into a final score and represent the score as an Observation.

                            Control0..*
                            TypeReference(QuestionnaireResponse, MolecularSequence, Vital Signs Profile)
                            Is Modifierfalse
                            Summarytrue
                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            132. Observation.derivedFrom
                            Definition

                            The target resource that represents a measurement from which this observation value is derived. For example, a calculated anion gap or a fetal measurement based on an ultrasound image.

                            ShortRelated measurements the observation is made from
                            Comments

                            All the reference choices that are listed in this element can represent clinical observations and other measurements that may be the source for a derived value. The most common reference will be another Observation. For a discussion on the ways Observations can assembled in groups together, see Notes below.

                            Control0..*
                            TypeReference(DocumentReference, ImagingStudy, Media, QuestionnaireResponse, MolecularSequence, Vital Signs Profile)
                            Is Modifierfalse
                            Summarytrue
                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            134. Observation.component
                            Definition

                            Used when reporting flow rates or oxygen concentration.

                            ShortUsed when reporting flow rates or oxygen concentration.
                            Comments

                            For a discussion on the ways Observations can be assembled in groups together see Notes below.

                            Control0..*
                            TypeBackboneElement
                            Is Modifierfalse
                            Must Supporttrue
                            Summarytrue
                            Requirements

                            Component observations share the same attributes in the Observation resource as the primary observation and are always treated a part of a single observation (they are not separable). However, the reference range for the primary observation value is not inherited by the component values and is required when appropriate for each component observation.

                            Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                            vs-3: If there is no a value a data absent reason must be present (value.exists() or dataAbsentReason.exists())
                            SlicingThis element introduces a set of slices on Observation.component. The slices areUnordered and Open, and can be differentiated using the following discriminators:
                            • value @ code
                            • 136. Observation.component.id
                              Definition

                              Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

                              ShortUnique id for inter-element referencing
                              Control0..1
                              Typestring
                              Is Modifierfalse
                              XML FormatIn the XML format, this property is represented as an attribute.
                              Summaryfalse
                              138. Observation.component.extension
                              Definition

                              May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

                              ShortAdditional content defined by implementations
                              Comments

                              There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                              Control0..*
                              TypeExtension
                              Is Modifierfalse
                              Summaryfalse
                              Alternate Namesextensions, user content
                              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                              ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                              140. Observation.component.modifierExtension
                              Definition

                              May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

                              Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

                              ShortExtensions that cannot be ignored even if unrecognized
                              Comments

                              There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                              Control0..*
                              TypeExtension
                              Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
                              Summarytrue
                              Requirements

                              Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

                              Alternate Namesextensions, user content, modifiers
                              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                              ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                              142. Observation.component.code
                              Definition

                              Describes what was observed. Sometimes this is called the observation "code".

                              ShortCoded vital sign result type
                              Comments

                              All code-value and component.code-component.value pairs need to be taken into account to correctly understand the meaning of the observation.

                              Control1..1
                              BindingUnless not suitable, these codes SHALL be taken from Vital Sign Result Type .
                              (extensible to http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113883.3.88.12.80.62)

                              Vital sign result types

                              TypeCodeableConcept
                              Is Modifierfalse
                              Must Supporttrue
                              Summarytrue
                              Requirements

                              Knowing what kind of observation is being made is essential to understanding the observation.

                              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                              144. Observation.component.value[x]
                              Definition

                              Vital Signs value are typically recorded using the Quantity data type. For supporting observations such as cuff size could use other datatypes such as CodeableConcept.

                              ShortVital Sign Component Value
                              Comments

                              Used when observation has a set of component observations. An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived). If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

                              Control0..1
                              This element is affected by the following invariants: vs-3
                              BindingUnless not suitable, these codes SHALL be taken from VitalSignsUnits
                              (extensible to http://hl7.org/fhir/ValueSet/ucum-vitals-common|4.0.1)

                              Common UCUM units for recording Vital Signs.

                              TypeChoice of: Quantity, CodeableConcept, string, boolean, integer, Range, Ratio, SampledData, time, dateTime, Period
                              [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
                              Is Modifierfalse
                              Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                              Must Supporttrue
                              Must Support TypesQuantity
                              Summarytrue
                              Requirements
                              1. SHALL contain exactly one [1..1] value with @xsi:type="PQ" (CONF:7305).
                              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                              146. Observation.component.dataAbsentReason
                              Definition

                              Provides a reason why the expected value in the element Observation.component.value[x] is missing.

                              ShortWhy the component result is missing
                              Comments

                              "Null" or exceptional values can be represented two ways in FHIR Observations. One way is to simply include them in the value set and represent the exceptions in the value. For example, measurement values for a serology test could be "detected", "not detected", "inconclusive", or "test not done".

                              The alternate way is to use the value element for actual observations and use the explicit dataAbsentReason element to record exceptional values. For example, the dataAbsentReason code "error" could be used when the measurement was not completed. Because of these options, use-case agreements are required to interpret general observations for exceptional values.

                              Control0..1
                              This element is affected by the following invariants: obs-6, vs-3
                              BindingUnless not suitable, these codes SHALL be taken from DataAbsentReason
                              (extensible to http://hl7.org/fhir/ValueSet/data-absent-reason)

                              Codes specifying why the result (Observation.value[x]) is missing.

                              TypeCodeableConcept
                              Is Modifierfalse
                              Must Supporttrue
                              Summaryfalse
                              Requirements

                              For many results it is necessary to handle exceptional values in measurements.

                              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                              148. Observation.component.interpretation
                              Definition

                              A categorical assessment of an observation value. For example, high, low, normal.

                              ShortHigh, low, normal, etc.
                              Comments

                              Historically used for laboratory results (known as 'abnormal flag' ), its use extends to other use cases where coded interpretations are relevant. Often reported as one or more simple compact codes this element is often placed adjacent to the result value in reports and flow sheets to signal the meaning/normalcy status of the result.

                              Control0..*
                              BindingUnless not suitable, these codes SHALL be taken from ObservationInterpretationCodes
                              (extensible to http://hl7.org/fhir/ValueSet/observation-interpretation)

                              Codes identifying interpretations of observations.

                              TypeCodeableConcept
                              Is Modifierfalse
                              Summaryfalse
                              Requirements

                              For some results, particularly numeric results, an interpretation is necessary to fully understand the significance of a result.

                              Alternate NamesAbnormal Flag
                              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                              150. Observation.component.referenceRange
                              Definition

                              Guidance on how to interpret the value by comparison to a normal or recommended range.

                              ShortProvides guide for interpretation of component result
                              Comments

                              Most observations only have one generic reference range. Systems MAY choose to restrict to only supplying the relevant reference range based on knowledge about the patient (e.g., specific to the patient's age, gender, weight and other factors), but this might not be possible or appropriate. Whenever more than one reference range is supplied, the differences between them SHOULD be provided in the reference range and/or age properties.

                              Control0..*
                              TypeSeettp://hl7.org/fhir/StructureDefinition/Observation#Observation.referenceRange
                              Is Modifierfalse
                              Summaryfalse
                              Requirements

                              Knowing what values are considered "normal" can help evaluate the significance of a particular result. Need to be able to provide multiple reference ranges for different contexts.

                              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                              152. Observation.component:FlowRate
                              Slice NameFlowRate
                              Definition

                              Used when reporting component observation such as systolic and diastolic blood pressure.

                              ShortInhaled oxygen flow rate
                              Comments

                              For a discussion on the ways Observations can be assembled in groups together see Notes below.

                              Control0..1
                              TypeBackboneElement
                              Is Modifierfalse
                              Must Supporttrue
                              Summarytrue
                              Requirements

                              Component observations share the same attributes in the Observation resource as the primary observation and are always treated a part of a single observation (they are not separable). However, the reference range for the primary observation value is not inherited by the component values and is required when appropriate for each component observation.

                              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                              vs-3: If there is no a value a data absent reason must be present (value.exists() or dataAbsentReason.exists())
                              154. Observation.component:FlowRate.id
                              Definition

                              Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

                              ShortUnique id for inter-element referencing
                              Control0..1
                              Typestring
                              Is Modifierfalse
                              XML FormatIn the XML format, this property is represented as an attribute.
                              Summaryfalse
                              156. Observation.component:FlowRate.extension
                              Definition

                              May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

                              ShortAdditional content defined by implementations
                              Comments

                              There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                              Control0..*
                              TypeExtension
                              Is Modifierfalse
                              Summaryfalse
                              Alternate Namesextensions, user content
                              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                              ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                              158. Observation.component:FlowRate.modifierExtension
                              Definition

                              May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

                              Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

                              ShortExtensions that cannot be ignored even if unrecognized
                              Comments

                              There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                              Control0..*
                              TypeExtension
                              Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
                              Summarytrue
                              Requirements

                              Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

                              Alternate Namesextensions, user content, modifiers
                              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                              ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                              160. Observation.component:FlowRate.code
                              Definition

                              Describes what was observed. Sometimes this is called the observation "code".

                              ShortCoded vital sign result type
                              Comments

                              All code-value and component.code-component.value pairs need to be taken into account to correctly understand the meaning of the observation.

                              Control1..1
                              BindingUnless not suitable, these codes SHALL be taken from Vital Sign Result Type .
                              (extensible to http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113883.3.88.12.80.62)

                              Vital sign result types

                              TypeCodeableConcept
                              Is Modifierfalse
                              Must Supporttrue
                              Summarytrue
                              Requirements

                              Knowing what kind of observation is being made is essential to understanding the observation.

                              Pattern Value{
                                "coding" : [{
                                  "system" : "http://loinc.org",
                                  "code" : "3151-8"
                                }]
                              }
                              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                              162. Observation.component:FlowRate.value[x]
                              Definition

                              Vital Signs value are typically recorded using the Quantity data type. For supporting observations such as cuff size could use other datatypes such as CodeableConcept.

                              ShortVital Sign Component Value
                              Comments

                              Used when observation has a set of component observations. An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived). If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

                              Control0..1
                              This element is affected by the following invariants: vs-3
                              BindingUnless not suitable, these codes SHALL be taken from VitalSignsUnits
                              (extensible to http://hl7.org/fhir/ValueSet/ucum-vitals-common|4.0.1)

                              Common UCUM units for recording Vital Signs.

                              TypeQuantity
                              [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
                              Is Modifierfalse
                              Must Supporttrue
                              Must Support TypesQuantity
                              Summarytrue
                              Requirements
                              1. SHALL contain exactly one [1..1] value with @xsi:type="PQ" (CONF:7305).
                              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                              164. Observation.component:FlowRate.value[x].id
                              Definition

                              Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

                              ShortUnique id for inter-element referencing
                              Control0..1
                              Typestring
                              Is Modifierfalse
                              XML FormatIn the XML format, this property is represented as an attribute.
                              Summaryfalse
                              166. Observation.component:FlowRate.value[x].extension
                              Definition

                              May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

                              ShortAdditional content defined by implementations
                              Comments

                              There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                              Control0..*
                              TypeExtension
                              Is Modifierfalse
                              Summaryfalse
                              Alternate Namesextensions, user content
                              Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                              ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                              SlicingThis element introduces a set of slices on Observation.component.value[x].extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
                              • value @ url
                              • 168. Observation.component:FlowRate.value[x].value
                                Definition

                                The value of the measured amount. The value includes an implicit precision in the presentation of the value.

                                ShortNumerical value (with implicit precision)
                                Comments

                                The implicit precision in the value should always be honored. Monetary values have their own rules for handling precision (refer to standard accounting text books).

                                Control1..1
                                Typedecimal
                                Is Modifierfalse
                                Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                                Must Supporttrue
                                Summarytrue
                                Requirements

                                Precision is handled implicitly in almost all cases of measurement.

                                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                170. Observation.component:FlowRate.value[x].comparator
                                Definition

                                How the value should be understood and represented - whether the actual value is greater or less than the stated value due to measurement issues; e.g. if the comparator is "<" , then the real value is < stated value.

                                Short< | <= | >= | > - how to understand the value
                                Control0..1
                                BindingThe codes SHALL be taken from QuantityComparator
                                (required to http://hl7.org/fhir/ValueSet/quantity-comparator|4.0.1)

                                How the Quantity should be understood and represented.

                                Typecode
                                Is Modifiertrue because This is labeled as "Is Modifier" because the comparator modifies the interpretation of the value significantly. If there is no comparator, then there is no modification of the value
                                Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                                Summarytrue
                                Requirements

                                Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.

                                Meaning if MissingIf there is no comparator, then there is no modification of the value
                                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                172. Observation.component:FlowRate.value[x].unit
                                Definition

                                A human-readable form of the unit.

                                ShortUnit representation
                                Control1..1
                                Typestring
                                Is Modifierfalse
                                Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                                Must Supporttrue
                                Summarytrue
                                Requirements

                                There are many representations for units of measure and in many contexts, particular representations are fixed and required. I.e. mcg for micrograms.

                                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                174. Observation.component:FlowRate.value[x].system
                                Definition

                                The identification of the system that provides the coded form of the unit.

                                ShortSystem that defines coded unit form
                                Control1..1
                                This element is affected by the following invariants: qty-3
                                Typeuri
                                Is Modifierfalse
                                Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                                Must Supporttrue
                                Summarytrue
                                Requirements

                                Need to know the system that defines the coded form of the unit.

                                Fixed Valuehttp://unitsofmeasure.org
                                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                176. Observation.component:FlowRate.value[x].code
                                Definition

                                A computer processable form of the unit in some unit representation system.

                                ShortCoded form of the unit
                                Comments

                                The preferred system is UCUM, but SNOMED CT can also be used (for customary units) or ISO 4217 for currency. The context of use may additionally require a code from a particular system.

                                Control1..1
                                Typecode
                                Is Modifierfalse
                                Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                                Must Supporttrue
                                Summarytrue
                                Requirements

                                Need a computable form of the unit that is fixed across all forms. UCUM provides this for quantities, but SNOMED CT provides many units of interest.

                                Fixed ValueL/min
                                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                178. Observation.component:FlowRate.dataAbsentReason
                                Definition

                                Provides a reason why the expected value in the element Observation.component.value[x] is missing.

                                ShortWhy the component result is missing
                                Comments

                                "Null" or exceptional values can be represented two ways in FHIR Observations. One way is to simply include them in the value set and represent the exceptions in the value. For example, measurement values for a serology test could be "detected", "not detected", "inconclusive", or "test not done".

                                The alternate way is to use the value element for actual observations and use the explicit dataAbsentReason element to record exceptional values. For example, the dataAbsentReason code "error" could be used when the measurement was not completed. Because of these options, use-case agreements are required to interpret general observations for exceptional values.

                                Control0..1
                                This element is affected by the following invariants: obs-6, vs-3
                                BindingUnless not suitable, these codes SHALL be taken from DataAbsentReason
                                (extensible to http://hl7.org/fhir/ValueSet/data-absent-reason)

                                Codes specifying why the result (Observation.value[x]) is missing.

                                TypeCodeableConcept
                                Is Modifierfalse
                                Must Supporttrue
                                Summaryfalse
                                Requirements

                                For many results it is necessary to handle exceptional values in measurements.

                                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                180. Observation.component:FlowRate.interpretation
                                Definition

                                A categorical assessment of an observation value. For example, high, low, normal.

                                ShortHigh, low, normal, etc.
                                Comments

                                Historically used for laboratory results (known as 'abnormal flag' ), its use extends to other use cases where coded interpretations are relevant. Often reported as one or more simple compact codes this element is often placed adjacent to the result value in reports and flow sheets to signal the meaning/normalcy status of the result.

                                Control0..*
                                BindingUnless not suitable, these codes SHALL be taken from ObservationInterpretationCodes
                                (extensible to http://hl7.org/fhir/ValueSet/observation-interpretation)

                                Codes identifying interpretations of observations.

                                TypeCodeableConcept
                                Is Modifierfalse
                                Summaryfalse
                                Requirements

                                For some results, particularly numeric results, an interpretation is necessary to fully understand the significance of a result.

                                Alternate NamesAbnormal Flag
                                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                182. Observation.component:FlowRate.referenceRange
                                Definition

                                Guidance on how to interpret the value by comparison to a normal or recommended range.

                                ShortProvides guide for interpretation of component result
                                Comments

                                Most observations only have one generic reference range. Systems MAY choose to restrict to only supplying the relevant reference range based on knowledge about the patient (e.g., specific to the patient's age, gender, weight and other factors), but this might not be possible or appropriate. Whenever more than one reference range is supplied, the differences between them SHOULD be provided in the reference range and/or age properties.

                                Control0..*
                                TypeSeettp://hl7.org/fhir/StructureDefinition/Observation#Observation.referenceRange
                                Is Modifierfalse
                                Summaryfalse
                                Requirements

                                Knowing what values are considered "normal" can help evaluate the significance of a particular result. Need to be able to provide multiple reference ranges for different contexts.

                                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                184. Observation.component:Concentration
                                Slice NameConcentration
                                Definition

                                Used when reporting component observation such as systolic and diastolic blood pressure.

                                ShortInhaled oxygen concentration
                                Comments

                                For a discussion on the ways Observations can be assembled in groups together see Notes below.

                                Control0..1
                                TypeBackboneElement
                                Is Modifierfalse
                                Must Supporttrue
                                Summarytrue
                                Requirements

                                Component observations share the same attributes in the Observation resource as the primary observation and are always treated a part of a single observation (they are not separable). However, the reference range for the primary observation value is not inherited by the component values and is required when appropriate for each component observation.

                                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                vs-3: If there is no a value a data absent reason must be present (value.exists() or dataAbsentReason.exists())
                                186. Observation.component:Concentration.id
                                Definition

                                Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

                                ShortUnique id for inter-element referencing
                                Control0..1
                                Typestring
                                Is Modifierfalse
                                XML FormatIn the XML format, this property is represented as an attribute.
                                Summaryfalse
                                188. Observation.component:Concentration.extension
                                Definition

                                May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

                                ShortAdditional content defined by implementations
                                Comments

                                There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                                Control0..*
                                TypeExtension
                                Is Modifierfalse
                                Summaryfalse
                                Alternate Namesextensions, user content
                                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                                190. Observation.component:Concentration.modifierExtension
                                Definition

                                May be used to represent additional information that is not part of the basic definition of the element and that modifies the understanding of the element in which it is contained and/or the understanding of the containing element's descendants. Usually modifier elements provide negation or qualification. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension. Applications processing a resource are required to check for modifier extensions.

                                Modifier extensions SHALL NOT change the meaning of any elements on Resource or DomainResource (including cannot change the meaning of modifierExtension itself).

                                ShortExtensions that cannot be ignored even if unrecognized
                                Comments

                                There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                                Control0..*
                                TypeExtension
                                Is Modifiertrue because Modifier extensions are expected to modify the meaning or interpretation of the element that contains them
                                Summarytrue
                                Requirements

                                Modifier extensions allow for extensions that cannot be safely ignored to be clearly distinguished from the vast majority of extensions which can be safely ignored. This promotes interoperability by eliminating the need for implementers to prohibit the presence of extensions. For further information, see the definition of modifier extensions.

                                Alternate Namesextensions, user content, modifiers
                                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                                192. Observation.component:Concentration.code
                                Definition

                                Describes what was observed. Sometimes this is called the observation "code".

                                ShortCoded vital sign result type
                                Comments

                                All code-value and component.code-component.value pairs need to be taken into account to correctly understand the meaning of the observation.

                                Control1..1
                                BindingUnless not suitable, these codes SHALL be taken from Vital Sign Result Type .
                                (extensible to http://cts.nlm.nih.gov/fhir/ValueSet/2.16.840.1.113883.3.88.12.80.62)

                                Vital sign result types

                                TypeCodeableConcept
                                Is Modifierfalse
                                Must Supporttrue
                                Summarytrue
                                Requirements

                                Knowing what kind of observation is being made is essential to understanding the observation.

                                Pattern Value{
                                  "coding" : [{
                                    "system" : "http://loinc.org",
                                    "code" : "3150-0"
                                  }]
                                }
                                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                194. Observation.component:Concentration.value[x]
                                Definition

                                Vital Signs value are typically recorded using the Quantity data type. For supporting observations such as cuff size could use other datatypes such as CodeableConcept.

                                ShortVital Sign Component Value
                                Comments

                                Used when observation has a set of component observations. An observation may have both a value (e.g. an Apgar score) and component observations (the observations from which the Apgar score was derived). If a value is present, the datatype for this element should be determined by Observation.code. A CodeableConcept with just a text would be used instead of a string if the field was usually coded, or if the type associated with the Observation.code defines a coded value. For additional guidance, see the Notes section below.

                                Control0..1
                                This element is affected by the following invariants: vs-3
                                BindingUnless not suitable, these codes SHALL be taken from VitalSignsUnits
                                (extensible to http://hl7.org/fhir/ValueSet/ucum-vitals-common|4.0.1)

                                Common UCUM units for recording Vital Signs.

                                TypeQuantity
                                [x] NoteSeeChoice of Data Typesfor further information about how to use [x]
                                Is Modifierfalse
                                Must Supporttrue
                                Must Support TypesQuantity
                                Summarytrue
                                Requirements
                                1. SHALL contain exactly one [1..1] value with @xsi:type="PQ" (CONF:7305).
                                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                196. Observation.component:Concentration.value[x].id
                                Definition

                                Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.

                                ShortUnique id for inter-element referencing
                                Control0..1
                                Typestring
                                Is Modifierfalse
                                XML FormatIn the XML format, this property is represented as an attribute.
                                Summaryfalse
                                198. Observation.component:Concentration.value[x].extension
                                Definition

                                May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.

                                ShortAdditional content defined by implementations
                                Comments

                                There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.

                                Control0..*
                                TypeExtension
                                Is Modifierfalse
                                Summaryfalse
                                Alternate Namesextensions, user content
                                Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                ext-1: Must have either extensions or value[x], not both (extension.exists() != value.exists())
                                SlicingThis element introduces a set of slices on Observation.component.value[x].extension. The slices areUnordered and Open, and can be differentiated using the following discriminators:
                                • value @ url
                                • 200. Observation.component:Concentration.value[x].value
                                  Definition

                                  The value of the measured amount. The value includes an implicit precision in the presentation of the value.

                                  ShortNumerical value (with implicit precision)
                                  Comments

                                  The implicit precision in the value should always be honored. Monetary values have their own rules for handling precision (refer to standard accounting text books).

                                  Control1..1
                                  Typedecimal
                                  Is Modifierfalse
                                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                                  Must Supporttrue
                                  Summarytrue
                                  Requirements

                                  Precision is handled implicitly in almost all cases of measurement.

                                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                  202. Observation.component:Concentration.value[x].comparator
                                  Definition

                                  How the value should be understood and represented - whether the actual value is greater or less than the stated value due to measurement issues; e.g. if the comparator is "<" , then the real value is < stated value.

                                  Short< | <= | >= | > - how to understand the value
                                  Control0..1
                                  BindingThe codes SHALL be taken from QuantityComparator
                                  (required to http://hl7.org/fhir/ValueSet/quantity-comparator|4.0.1)

                                  How the Quantity should be understood and represented.

                                  Typecode
                                  Is Modifiertrue because This is labeled as "Is Modifier" because the comparator modifies the interpretation of the value significantly. If there is no comparator, then there is no modification of the value
                                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                                  Summarytrue
                                  Requirements

                                  Need a framework for handling measures where the value is <5ug/L or >400mg/L due to the limitations of measuring methodology.

                                  Meaning if MissingIf there is no comparator, then there is no modification of the value
                                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                  204. Observation.component:Concentration.value[x].unit
                                  Definition

                                  A human-readable form of the unit.

                                  ShortUnit representation
                                  Control1..1
                                  Typestring
                                  Is Modifierfalse
                                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                                  Must Supporttrue
                                  Summarytrue
                                  Requirements

                                  There are many representations for units of measure and in many contexts, particular representations are fixed and required. I.e. mcg for micrograms.

                                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                  206. Observation.component:Concentration.value[x].system
                                  Definition

                                  The identification of the system that provides the coded form of the unit.

                                  ShortSystem that defines coded unit form
                                  Control1..1
                                  This element is affected by the following invariants: qty-3
                                  Typeuri
                                  Is Modifierfalse
                                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                                  Must Supporttrue
                                  Summarytrue
                                  Requirements

                                  Need to know the system that defines the coded form of the unit.

                                  Fixed Valuehttp://unitsofmeasure.org
                                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                  208. Observation.component:Concentration.value[x].code
                                  Definition

                                  A computer processable form of the unit in some unit representation system.

                                  ShortCoded form of the unit
                                  Comments

                                  The preferred system is UCUM, but SNOMED CT can also be used (for customary units) or ISO 4217 for currency. The context of use may additionally require a code from a particular system.

                                  Control1..1
                                  Typecode
                                  Is Modifierfalse
                                  Primitive ValueThis primitive element may be present, or absent, or replaced by an extension
                                  Must Supporttrue
                                  Summarytrue
                                  Requirements

                                  Need a computable form of the unit that is fixed across all forms. UCUM provides this for quantities, but SNOMED CT provides many units of interest.

                                  Fixed Value%
                                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                  210. Observation.component:Concentration.dataAbsentReason
                                  Definition

                                  Provides a reason why the expected value in the element Observation.component.value[x] is missing.

                                  ShortWhy the component result is missing
                                  Comments

                                  "Null" or exceptional values can be represented two ways in FHIR Observations. One way is to simply include them in the value set and represent the exceptions in the value. For example, measurement values for a serology test could be "detected", "not detected", "inconclusive", or "test not done".

                                  The alternate way is to use the value element for actual observations and use the explicit dataAbsentReason element to record exceptional values. For example, the dataAbsentReason code "error" could be used when the measurement was not completed. Because of these options, use-case agreements are required to interpret general observations for exceptional values.

                                  Control0..1
                                  This element is affected by the following invariants: obs-6, vs-3
                                  BindingUnless not suitable, these codes SHALL be taken from DataAbsentReason
                                  (extensible to http://hl7.org/fhir/ValueSet/data-absent-reason)

                                  Codes specifying why the result (Observation.value[x]) is missing.

                                  TypeCodeableConcept
                                  Is Modifierfalse
                                  Must Supporttrue
                                  Summaryfalse
                                  Requirements

                                  For many results it is necessary to handle exceptional values in measurements.

                                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                  212. Observation.component:Concentration.interpretation
                                  Definition

                                  A categorical assessment of an observation value. For example, high, low, normal.

                                  ShortHigh, low, normal, etc.
                                  Comments

                                  Historically used for laboratory results (known as 'abnormal flag' ), its use extends to other use cases where coded interpretations are relevant. Often reported as one or more simple compact codes this element is often placed adjacent to the result value in reports and flow sheets to signal the meaning/normalcy status of the result.

                                  Control0..*
                                  BindingUnless not suitable, these codes SHALL be taken from ObservationInterpretationCodes
                                  (extensible to http://hl7.org/fhir/ValueSet/observation-interpretation)

                                  Codes identifying interpretations of observations.

                                  TypeCodeableConcept
                                  Is Modifierfalse
                                  Summaryfalse
                                  Requirements

                                  For some results, particularly numeric results, an interpretation is necessary to fully understand the significance of a result.

                                  Alternate NamesAbnormal Flag
                                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))
                                  214. Observation.component:Concentration.referenceRange
                                  Definition

                                  Guidance on how to interpret the value by comparison to a normal or recommended range.

                                  ShortProvides guide for interpretation of component result
                                  Comments

                                  Most observations only have one generic reference range. Systems MAY choose to restrict to only supplying the relevant reference range based on knowledge about the patient (e.g., specific to the patient's age, gender, weight and other factors), but this might not be possible or appropriate. Whenever more than one reference range is supplied, the differences between them SHOULD be provided in the reference range and/or age properties.

                                  Control0..*
                                  TypeSeettp://hl7.org/fhir/StructureDefinition/Observation#Observation.referenceRange
                                  Is Modifierfalse
                                  Summaryfalse
                                  Requirements

                                  Knowing what values are considered "normal" can help evaluate the significance of a particular result. Need to be able to provide multiple reference ranges for different contexts.

                                  Invariantsele-1: All FHIR elements must have a @value or children (hasValue() or (children().count() > id.count()))