The PhdNumericObservation reports PHD measurements that contain one of either a Basic-Nu-Observed-Value, Simple-Nu_observed-Value, or Nu_observed-Value attribute.

Used for non-compound numeric observations from Personal Health Devices.

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. For DomainResources, if more than one implicitRules policy applies, additional policies may be conveyed using the additionalImplicitRules extension.

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 its narrative along with other profiles, value sets, etc.

These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning.

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. Contained resources may be a resource type defined in the FHIR specification, or an additional resource.

An Extension

Linked device acting as a communication/data collector, translator or controller.

An Extension

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Reference to a coincident timestamp observation that relates the gateway timeline to the PHD timeline

The accuracy of a measurable quantity.

The Confidence 95 range of a measurable quantity.

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 managable, 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).

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.

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.

A unique identifier assigned to this observation.

Allows observations to be distinguished and referenced.

An identifier created from a combination of the measurement parameters like sensor timestamp, type code, unit code, patient and device identifier.

This value is used in the conditional create to prevent data duplication. PHDs will often re-send already sent data for a variety of reasons. This element is recommended unless the observation contains no timestamp or is a measurement containing a timestamp that is real time. By real time the timestamp reported by the PHD must be later than the current time reported by the PHD before any measurements are received. There might be other means to ascertain whether the data is real time. Temporarily stored data from IEEE 11073-10206 compliant devices, which are required to be deleted the data after sending, can be considered real time. An example of this are temporarily stored observations from a device implementing the Bluetooth SIG GHS profile or implementing another Bluetooth SIG medical sensor device profile.

Allows observations to be distinguished in a selective enough manner to prevent resource duplication.

The purpose of this identifier.

Applications can assume that an identifier is permanent unless it explicitly says that it is temporary.

Identifies the purpose for this identifier, if known .

Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers.

A coded type for the identifier that can be used to determine which identifier to use for a specific purpose.

This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type.

A coded type for an identifier that can be used to determine which identifier to use for a specific purpose.

Allows users to make use of identifiers when the identifier system is not known.

Establishes the namespace for the value - that is, an absolute URL that describes a set values that are unique.

Identifier.system is always case sensitive. The FHIR specification, terminology.hl7.org and HL7 affiliates (for identifiers specific to their jurisdiction) define identifier systems that SHALL be used for certain types of identifiers. Specific rules can be found here.

There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers.

The portion of the identifier typically relevant to the user and which is unique within the context of the system.

If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value). Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processor to be confident that non-case-sensitive processing is safe.

The status of the result value. Either 'final' or 'preliminary'

The value shall be set to 'final' unless a Measurement-Status attribute indicates that the measurement is preliminary. In that case this field shall be set to 'preliminary'

Codes providing the status of an observation.

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

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

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.

Codes for high level observation categories.

Used for filtering what observations are retrieved and displayed.

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

The category enables identifying observations generated by PHDs.

Codes for high level observation categories.

Used for filtering what observations are retrieved and displayed.

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

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. All codings in Observation.code are expected to be sufficiently precise to allow a user with the code and value to be able to understand the value - though not all codes will necessarily convey the same level of detail. Codings in Observation.category SHOULD be concepts that are too broad to be able to understand the meaning of the Observation.value without also having an Observation.code.

See Interoperability Issues using code value pairs in FHIR for additional information.

IEEE 11073-10101 Nomenclature codes for PHD measurements

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

The patient, or group of patients, location, device, organization, procedure or practitioner this observation is about and into whose or what 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.

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. The subject of an Observation may in some cases be a procedure. This supports the regulatory inspection use case where observations are captured during inspections of a procedure that is being performed (independent of any particular patient or whether patient related at all).

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

The actual focus of an observation when it is not the subject 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. As another use case,

a caregiver (RelatedPerson) has back strain and is unable to provide ADL support to a patient (Subject).

Examples demonstrating the use of subject and focus in an Observation:

• A parent is trained to change their child's tracheostomy tube. The child is the subject, and the parent is the focus.

• A fetal heart rate recorded in a mother's record. The mother is the subject, and the fetus is the focus.

• Features of a body structure, such as a tumor. The patient is the subject, and the specific body structure is the focus.

• Metrics captured from a medical device. The patient-attached device is the subject, the specific device metric is the focus, and the observing device itself is referenced in .device.

The time or time-period the observed value is asserted as being true. This can be a dateTime or a period. The value is based on the timestamp sent by the PHD or the time of reception by the PHG if the PHD sent no timestamp.

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.

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

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.

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.

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

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.

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.

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

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

• An observation may have:
  1. a single value here
  2. both a value and a set of related or component values
  3. only a set of related or component values.
• If a value is present, the datatype for this element should be determined by the code.
• 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 code defines a coded value.
• Attachment is used if the observation result value is a binary file such as an image. If the observation result value is derived from the binary file (for example 'X' detected and here is the proof in this image), the binary file may be directly represented using DocumentReference and referenced by derivedFrom.
• For additional guidance, see the Notes section below.
• See Interoperability Issues using code value pairs in FHIR for additional information.

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

The decoded FLOAT or SFLOAT value from a PHD Observation.

The implicit precision in the value shall be honored. The MDER encoding used in the above attributes provides this precision. The translating software shall honor that precision when generating this value. This element shall be present unless there is an error reported in the Measurement-Status attribute or the MDER encoding represents one of the special FLOAT values. In that case there is a dataAbsentReason element and the valueQuantity element is not present. Note that not all measurement status values are errors resulting in no measurement being reported here; for example the preliminary or verified status.

Precision is handled implicitly in almost all cases of measurement.

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

How the Quantity should be understood and represented.

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

A human-readable form of the unit.

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

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

The unit code needs to be translated from the 11073-10101 code from the device. This can be represented as either a UCUM code or an MDC code system. UCUM is preferred but MDC codes are also supported.

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

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

The unit code needs to be translated from the 11073-10101 code from the device. This translation means that the reporting of units is not future proof.

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.

Provides a reason why the expected value in the element Observation.valueQuantity is missing. In this case this could also be 'not-a-number', 'positive-infinity', 'negative-infinity' or 'error'.

The values in the http://terminology.hl7.org/CodeSystem/data-absent-reason system do not provide a code that matches the 'not at this resolution' and 'reserved'. In those cases one uses the generic 'error' code. If both a special FLOAT value and a Measurement-Status indicating invalid, not available, or measurement ongoing are received, the Measurement-Status mapping takes precedence.

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

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

A reference to the device that generates the measurements or the device settings for the device.

This field will reference the PHD Device.

Reference to the device-related resources that describe the sensor device taking the measurement. This element will point to a Device resource following the Phd Device Profile.

This reference points to the Device resource containing information about the sensor device that took the measurement.

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.

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

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, reference range, dataAbsentReason, and interpretation can differ between the components and are not inherited; these should be provided if appropriate.

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 managable, 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).

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.

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.

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

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

Codes identifying names of simple observations.

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

For each code contained in the Supplemental-Types attribute, a separate component is generated. The component is not generated if the attribute is absent or empty. The component shall be generated otherwise.

A PHD may send a Supplemental-Types attribute as part of the measurement. This attribute consists of a set of MDC nomenclature codes. Each code describes an aspect of the measurement, such as MDC_MODALITY_SPOT in the pulse oximeter which indicates that the provided measurement is a stable average.

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, reference range, dataAbsentReason, and interpretation can differ between the components and are not inherited; these should be provided if appropriate.

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 managable, 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).

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.

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.

68193 is the 32-bit nomenclature code indicating a 'Supplemental-Types' value

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

Codes identifying names of simple observations.

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

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

"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.

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

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

The PhdNumericObservation reports PHD measurements that contain one of either a Basic-Nu-Observed-Value, Simple-Nu_observed-Value, or Nu_observed-Value attribute.

Used for non-compound numeric observations from Personal Health Devices.

The decoded FLOAT or SFLOAT value from a PHD Observation.

The implicit precision in the value shall be honored. The MDER encoding used in the above attributes provides this precision. The translating software shall honor that precision when generating this value. This element shall be present unless there is an error reported in the Measurement-Status attribute or the MDER encoding represents one of the special FLOAT values. In that case there is a dataAbsentReason element and the valueQuantity element is not present. Note that not all measurement status values are errors resulting in no measurement being reported here; for example the preliminary or verified status.

The unit code needs to be translated from the 11073-10101 code from the device. This can be represented as either a UCUM code or an MDC code system. UCUM is preferred but MDC codes are also supported.

The unit code needs to be translated from the 11073-10101 code from the device. This translation means that the reporting of units is not future proof.

Provides a reason why the expected value in the element Observation.valueQuantity is missing. In this case this could also be 'not-a-number', 'positive-infinity', 'negative-infinity' or 'error'.

The values in the http://terminology.hl7.org/CodeSystem/data-absent-reason system do not provide a code that matches the 'not at this resolution' and 'reserved'. In those cases one uses the generic 'error' code. If both a special FLOAT value and a Measurement-Status indicating invalid, not available, or measurement ongoing are received, the Measurement-Status mapping takes precedence.

The PhdNumericObservation reports PHD measurements that contain one of either a Basic-Nu-Observed-Value, Simple-Nu_observed-Value, or Nu_observed-Value attribute.

Used for non-compound numeric observations from Personal Health Devices.

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

Within the context of the FHIR RESTful interactions, the resource has an id except for cases like the create and conditional update. Otherwise, the use of the resource id depends on the given use case.

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.

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

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 managable, 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.

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.

The version specific identifier, as it appears in the version portion of the URL. This value changes when the resource is created, updated, or deleted.

The server assigns this value, and ignores what the client specifies, except in the case that the server is imposing version integrity on updates/deletes.

When the resource last changed - e.g. when the version changed.

This element is generally omitted in instances submitted in a PUT or POST. Instead, it might be populated by the server when data is received or assigned when crafting the instance when constructing a response. The server / resource manager sets this value; what a client provides can be irrelevant. This is equivalent to the HTTP Last-Modified and SHOULD have the same value on a read interaction.

Note that there are scenarios where changes in a resource do not trigger a change in the lastUpdated value and there are scenarios where changes in lastUpdated are made even though there are no visible changes in the resource. Unless specified otherwise, this element MAY be out of sync with changes in either direction. For example:

• If a system uses mapping tables to generate resources (e.g., a facade server), updates to those tables might not be reflected in lastUpdated but do result in a difference of retrieved resource content.

• If a system generates resources from internal data (e.g., a facade server), the system's internal lastUpdated value might be changed due to changes that are not visible on FHIR resources (e.g., extended data has been changed).

• If a system updates an element that a particular client does not have access to (e.g., prevented by privacy rules), the lastUpdated value might be changed even though there are no visible changes in resource content.

Note to server implementers: updating lastUpdated too frequently is generally preferred over missing updates. It is better for client to retrieve records too frequently rather than missing updates.

A uri that identifies the data source of the resource. This provides a minimal amount of Provenance information that can be used to track or differentiate the source of information in the resource. The source may identify another server, document, message, database, etc. It can also refer to portions of a structure, such as a section, segment, row, etc.

The exact use of the source (and the possible implied Provenance.entity.role and agent.role) is left to implementer discretion. Only one nominated source is allowed; for additional provenance details, a full Provenance resource should be used. The source may correspond to Provenance.entity.what[x] or Provenance.agent.who[x], though it may be a more general or abstract reference.

This element can be used to indicate where the current master source of a resource that has a canonical URL if the resource is no longer hosted at the canonical URL.

A list of profiles (references to StructureDefinition resources) that this resource claims to conform to. The URL is a reference to StructureDefinition.url.

It is up to the server and/or other infrastructure of policy to determine whether/how these claims are verified and/or updated over time. The list of profile URLs is a set.

Security labels applied to this resource. These tags connect specific resources to the overall security policy and infrastructure.

The security labels can be updated without changing the stated version of the resource. The list of security labels is a set. Uniqueness is based the system/code, and version and display are ignored.

Security Labels from the Healthcare Privacy and Security Classification System.

Security labels applied to this resource. These tags connect specific resources to the overall security policy and infrastructure.

The security labels can be updated without changing the stated version of the resource. The list of security labels is a set. Uniqueness is based the system/code, and version and display are ignored.

Security Labels from the Healthcare Privacy and Security Classification System.

Tags applied to this resource. Tags are intended to be used to identify and relate resources to process and workflow, and applications are not required to consider the tags when interpreting the meaning of a resource.

The tags can be updated without changing the stated version of the resource. The list of tags is a set. Uniqueness is based the system/code, and version and display are ignored.

Codes that represent various types of tags, commonly workflow-related; e.g. "Needs review by Dr. Jones".

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. For DomainResources, if more than one implicitRules policy applies, additional policies may be conveyed using the additionalImplicitRules extension.

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 its narrative along with other profiles, value sets, etc.

The base language in which the resource is written.

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).

IETF language tag for a human language

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.

Contained resources do not have a 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.

These resources do not have an independent existence apart from the resource that contains them - they cannot be identified independently, nor can they have their own independent transaction scope. This is allowed to be a Parameters resource if and only if it is referenced by a resource that provides context/meaning.

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. Contained resources may be a resource type defined in the FHIR specification, or an additional resource.

An Extension

Linked device acting as a communication/data collector, translator or controller.

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

An Extension

Source of the definition for the extension code - a logical name or a URL.

The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension.

Reference to the PHG Device that received the measurement from the PHD.

Reference to a coincident timestamp observation that relates the gateway timeline to the PHD timeline

The accuracy of a measurable quantity.

The Confidence 95 range of a measurable quantity.

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 managable, 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).

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.

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.

A unique identifier assigned to this observation.

Allows observations to be distinguished and referenced.

An identifier created from a combination of the measurement parameters like sensor timestamp, type code, unit code, patient and device identifier.

This value is used in the conditional create to prevent data duplication. PHDs will often re-send already sent data for a variety of reasons. This element is recommended unless the observation contains no timestamp or is a measurement containing a timestamp that is real time. By real time the timestamp reported by the PHD must be later than the current time reported by the PHD before any measurements are received. There might be other means to ascertain whether the data is real time. Temporarily stored data from IEEE 11073-10206 compliant devices, which are required to be deleted the data after sending, can be considered real time. An example of this are temporarily stored observations from a device implementing the Bluetooth SIG GHS profile or implementing another Bluetooth SIG medical sensor device profile.

Allows observations to be distinguished in a selective enough manner to prevent resource duplication.

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

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 managable, 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.

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.

The purpose of this identifier.

Applications can assume that an identifier is permanent unless it explicitly says that it is temporary.

Identifies the purpose for this identifier, if known .

Allows the appropriate identifier for a particular context of use to be selected from among a set of identifiers.

A coded type for the identifier that can be used to determine which identifier to use for a specific purpose.

This element deals only with general categories of identifiers. It SHOULD not be used for codes that correspond 1..1 with the Identifier.system. Some identifiers may fall into multiple categories due to common usage. Where the system is known, a type is unnecessary because the type is always part of the system definition. However systems often need to handle identifiers where the system is not known. There is not a 1:1 relationship between type and system, since many different systems have the same type.

A coded type for an identifier that can be used to determine which identifier to use for a specific purpose.

Allows users to make use of identifiers when the identifier system is not known.

Establishes the namespace for the value - that is, an absolute URL that describes a set values that are unique.

Identifier.system is always case sensitive. The FHIR specification, terminology.hl7.org and HL7 affiliates (for identifiers specific to their jurisdiction) define identifier systems that SHALL be used for certain types of identifiers. Specific rules can be found here.

There are many sets of identifiers. To perform matching of two identifiers, we need to know what set we're dealing with. The system identifies a particular set of unique identifiers.

The portion of the identifier typically relevant to the user and which is unique within the context of the system.

If the value is a full URI, then the system SHALL be urn:ietf:rfc:3986. The value's primary purpose is computational mapping. As a result, it may be normalized for comparison purposes (e.g. removing non-significant whitespace, dashes, etc.) A value formatted for human display can be conveyed using the Rendered Value). Identifier.value is to be treated as case sensitive unless knowledge of the Identifier.system allows the processor to be confident that non-case-sensitive processing is safe.

Time period during which identifier is/was valid for use.

Organization that issued/manages the identifier.

The Identifier.assigner may omit the .reference element and only contain a .display element reflecting the name or other textual information about the assigning organization.

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.

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

Identifies the observation(s) that triggered the performance of this observation.

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

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 managable, 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.

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.

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 managable, 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).

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.

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.

Reference to the triggering observation.

The type of trigger. Reflex | Repeat | Re-run.

The type of TriggeredBy Observation.

Provides the reason why this observation was performed as a result of the observation(s) referenced.

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

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

The status of the result value. Either 'final' or 'preliminary'

The value shall be set to 'final' unless a Measurement-Status attribute indicates that the measurement is preliminary. In that case this field shall be set to 'preliminary'

Codes providing the status of an observation.

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

Captures the reason for the current state of the Observation.

This is generally only used for "exception" statuses such as "not-done", "suspended" or "cancelled".

Codes identifying the reason for the current state of an observation.

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

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.

Codes for high level observation categories.

Used for filtering what observations are retrieved and displayed.

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

The category enables identifying observations generated by PHDs.

Codes for high level observation categories.

Used for filtering what observations are retrieved and displayed.

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

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. All codings in Observation.code are expected to be sufficiently precise to allow a user with the code and value to be able to understand the value - though not all codes will necessarily convey the same level of detail. Codings in Observation.category SHOULD be concepts that are too broad to be able to understand the meaning of the Observation.value without also having an Observation.code.

See Interoperability Issues using code value pairs in FHIR for additional information.

IEEE 11073-10101 Nomenclature codes for PHD measurements

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

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

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 managable, 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.

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.

A reference to a code defined by a terminology system.

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.

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

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

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 managable, 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.

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.

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

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 be an absolute reference to some definition that establishes the system clearly and unambiguously.

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

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.

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.

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).

Need to refer to a particular code in the system.

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

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

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

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.

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.

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.

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

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.

The patient, or group of patients, location, device, organization, procedure or practitioner this observation is about and into whose or what 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.

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. The subject of an Observation may in some cases be a procedure. This supports the regulatory inspection use case where observations are captured during inspections of a procedure that is being performed (independent of any particular patient or whether patient related at all).

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

The actual focus of an observation when it is not the subject 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. As another use case,

a caregiver (RelatedPerson) has back strain and is unable to provide ADL support to a patient (Subject).

Examples demonstrating the use of subject and focus in an Observation:

• A parent is trained to change their child's tracheostomy tube. The child is the subject, and the parent is the focus.

• A fetal heart rate recorded in a mother's record. The mother is the subject, and the fetus is the focus.

• Features of a body structure, such as a tumor. The patient is the subject, and the specific body structure is the focus.

• Metrics captured from a medical device. The patient-attached device is the subject, the specific device metric is the focus, and the observing device itself is referenced in .device.

This observation serves as an organizer or grouper for a set of (one or more) sub-observations.

An observation that is an organizer/grouper does not have a value (or dataAbsentReason) of its own - all values are included in the sub-observations. The sub-observations are linked using hasMember element references (in some instances there may be no hasMember references, as it is possible that the organizer/grouper observation may be created first, and the sub-observations are not created until a later time). An organizer/grouper observation also does not contain any components.

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

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).

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

The time or time-period the observed value is asserted as being true. This can be a dateTime or a period. The value is based on the timestamp sent by the PHD or the time of reception by the PHG if the PHD sent no timestamp.

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.

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

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.

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.

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

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.

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.

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

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

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 managable, 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.

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.

The start of the period. The boundary is inclusive.

If the low element is missing, the meaning is that the low boundary is not known.

The end of the period. If the end of the period is missing, it means no end was known or planned at the time the instance was created. The start may be in the past, and the end date in the future, which means that period is expected/planned to end at that time.

The end value includes any matching date/time. i.e. 2012-02-03T10:00:00 is in a period that has an end value of 2012-02-03.

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

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.

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

Group is only allowed in the circumstance where the group represents a family or a household, and should not represent groups of Practitioners where other more specific resources can be used instead.

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

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

• An observation may have:
  1. a single value here
  2. both a value and a set of related or component values
  3. only a set of related or component values.
• If a value is present, the datatype for this element should be determined by the code.
• 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 code defines a coded value.
• Attachment is used if the observation result value is a binary file such as an image. If the observation result value is derived from the binary file (for example 'X' detected and here is the proof in this image), the binary file may be directly represented using DocumentReference and referenced by derivedFrom.
• For additional guidance, see the Notes section below.
• See Interoperability Issues using code value pairs in FHIR for additional information.

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

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

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 managable, 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.

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.

The decoded FLOAT or SFLOAT value from a PHD Observation.

The implicit precision in the value shall be honored. The MDER encoding used in the above attributes provides this precision. The translating software shall honor that precision when generating this value. This element shall be present unless there is an error reported in the Measurement-Status attribute or the MDER encoding represents one of the special FLOAT values. In that case there is a dataAbsentReason element and the valueQuantity element is not present. Note that not all measurement status values are errors resulting in no measurement being reported here; for example the preliminary or verified status.

Precision is handled implicitly in almost all cases of measurement.

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

How the Quantity should be understood and represented.

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

A human-readable form of the unit.

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

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

The unit code needs to be translated from the 11073-10101 code from the device. This can be represented as either a UCUM code or an MDC code system. UCUM is preferred but MDC codes are also supported.

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

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

The unit code needs to be translated from the 11073-10101 code from the device. This translation means that the reporting of units is not future proof.

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.

Provides a reason why the expected value in the element Observation.valueQuantity is missing. In this case this could also be 'not-a-number', 'positive-infinity', 'negative-infinity' or 'error'.

The values in the http://terminology.hl7.org/CodeSystem/data-absent-reason system do not provide a code that matches the 'not at this resolution' and 'reserved'. In those cases one uses the generic 'error' code. If both a special FLOAT value and a Measurement-Status indicating invalid, not available, or measurement ongoing are received, the Measurement-Status mapping takes precedence.

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

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

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

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 managable, 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.

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.

A reference to a code defined by a terminology system.

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.

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

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.

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

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.

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

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.

Codes identifying interpretations of observations.

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

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

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 managable, 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.

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.