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8.30 Resource ObservationDefinition - Content

Orders and Observations icon Work GroupMaturity Level: 1 Trial UseSecurity Category: Business Compartments: No defined compartments

Set of definitional characteristics for a kind of observation or measurement produced or consumed by an orderable health care service.

8.30.1 Scope and Usage

An instance of ObservationDefinition represents the definitional aspects of a kind of observation. This resource is used in a catalog of products or services for healthcare. It represents a set of constraints applicable to the value produced by observations of this kind. It helps the consumer of the results of observations of that kind, to interpret properly these results. If one wants to technically constrain an Observation resource for a particular use case across implementers, a profile is the preferred option and may include profiling on ObservationDefinition and Observation.

For instance, in a catalog of laboratory in vitro diagnostic services, the ObservationDefinition resources describe the observations that should be provided by the orderer alongside with an ordered service (questions asked at order entry or at specimen collection, prior results) as well as the observations that will be reported once the service has been performed.

Observation Definition resources can be used to describe observations which may need to be evaluated in order to determine whether a specific medicine can be administered or held (e.g., weight, lab value result) and provide guidance on the dose to be administered (e.g., sliding scale insulin dose).

In the catalog of tests of an in vitro diagnostic device, ObservationDefinition resources can be used to characterize (absolute range, unit, decimal precision, critical values ...) the observations that will be produced by the IVD tests performed by the device.

ObservationDefinition may be used to characterize observations from any discipline.

8.30.2 Boundaries and Relationships

An ObservationDefinition resource provides the definitional characteristics for a certain kind of observation. Each time that kind of observation is collected and recorded it is instantiated as an Observation resource, which conforms to these definitional characteristics. Thus, there is a relationship between ObservationDefinition and Observation: The latter may instantiate the former.

When an Observation instantiates an ObservationDefinition, the elements of the Observation resource are expected to inherit their content from the corresponding definitional elements declared in the ObservationDefinition resource:

  • Category, code, datatype of the value, bodySite, method.
  • Each referenceRange element present in Observation should come from a qualifiedValue element of ObservationDefinition.
  • If ObservationDefinition has declared a ValueSet of valid coded values, and if Observation has a valueCodeableConcept, the value is expected to be part of that ValueSet.
  • The subject of the Observation should be conformant with one of the subjectCodeableConcept listed in ObservationDefinition.
  • If the Observation has a device element, the referenced Device resource should conform to a DeviceDefinition or Device referenced by ObservationDefinition.device (if present).
  • If the Observation has a specimen element, the referenced Specimen resource should conform to a SpecimenDefinition referenced by ObservationDefinition.specimen (if present).

ObservationDefinition can specify units allowed for the valueQuantity element by setting ObservationDefinition.permittedUnit.

ObservationDefinitions are only to be used when describing the contents of an observation (including observations in order catalogs or panels). When additional structure, sequence, or rules are needed, the Questionnaire resource should be used.

8.30.3 References to this Resource

8.30.4 Resource Content

Structure

NameFlagsCard.TypeDescription & Constraintsdoco
.. ObservationDefinition TU DomainResource Definition of an observation
+ Warning: Name should be usable as an identifier for the module by machine processing applications such as code generation
+ Rule: If permittedUnit exists, then permittedDataType=Quantity must exist.

Elements defined in Ancestors: id, meta, implicitRules, language, text, contained, extension, modifierExtension
Interfaces Implemented: MetadataResource
... url Σ 0..1 uri Logical canonical URL to reference this ObservationDefinition (globally unique)
... identifier Σ 0..1 Identifier Business identifier of the ObservationDefinition
... version Σ 0..1 string Business version of the ObservationDefinition
... versionAlgorithm[x] Σ 0..1 How to compare versions
Binding: Version Algorithm (Extensible)
.... versionAlgorithmString string
.... versionAlgorithmCoding Coding
... name ΣC 0..1 string Name for this ObservationDefinition (computer friendly)
... title ΣT 0..1 string Name for this ObservationDefinition (human friendly)
... status ?!Σ 1..1 code draft | active | retired | unknown
Binding: PublicationStatus (Required)
... experimental Σ 0..1 boolean If For testing only - never for real usage
... date Σ 0..1 dateTime Date last changed
... publisher ΣT 0..1 string The name of the individual or organization that published the ObservationDefinition
... contact Σ 0..* ContactDetail Contact details for the publisher

... description T 0..1 markdown Natural language description of the ObservationDefinition
... useContext Σ 0..* UsageContext Content intends to support these contexts

... jurisdiction ΣXD 0..* CodeableConcept Intended jurisdiction for this ObservationDefinition (if applicable)
Binding: Jurisdiction ValueSet (Extensible)

... purpose T 0..1 markdown Why this ObservationDefinition is defined
... copyright T 0..1 markdown Use and/or publishing restrictions
... copyrightLabel T 0..1 string Copyright holder and year(s)
... approvalDate 0..1 date When ObservationDefinition was approved by publisher
... lastReviewDate 0..1 date Date on which the asset content was last reviewed by the publisher
... effectivePeriod Σ 0..1 Period The effective date range for the ObservationDefinition
... derivedFromCanonical Σ 0..* canonical(ObservationDefinition) Based on FHIR definition of another observation

... derivedFromUri Σ 0..* uri Based on external definition

... subject Σ 0..* CodeableConcept Type of subject for the defined observation

... performerType Σ 0..1 CodeableConcept Desired kind of performer for such kind of observation
... category Σ 0..* CodeableConcept General type of observation
Binding: Observation Category Codes (Example)

... code Σ 1..1 CodeableConcept Type of observation
Binding: LOINC Codes (Example)
... permittedDataType C 0..* code Quantity | CodeableConcept | string | boolean | integer | Range | Ratio | SampledData | time | dateTime | Period
Binding: Observation Data Type (Required)

... multipleResultsAllowed 0..1 boolean Multiple results allowed for conforming observations
... bodySite 0..1 CodeableConcept Body part to be observed
Binding: SNOMED CT Body Structures (Example)
... method 0..1 CodeableConcept Method used to produce the observation
Binding: Observation Methods (Example)
... specimen 0..* Reference(SpecimenDefinition) Kind of specimen used by this type of observation

... device 0..* Reference(DeviceDefinition | Device) Measurement device or model of device

... preferredReportName 0..1 string The preferred name to be used when reporting the observation results
... permittedUnit C 0..* Coding Unit for quantitative results
Binding: UCUM Codes (Preferred)

... qualifiedValue 0..* BackboneElement Set of qualified values for observation results

.... context 0..1 CodeableConcept Context qualifier for the set of qualified values
Binding: Observation Reference Range Meaning Codes (Extensible)
.... appliesTo 0..* CodeableConcept Targetted population for the set of qualified values
Binding: Observation Reference Range Applies To Codes (Example)

.... gender 0..1 code male | female | other | unknown
Binding: AdministrativeGender (Required)
.... age 0..1 Range Applicable age range for the set of qualified values
.... gestationalAge 0..1 Range Applicable gestational age range for the set of qualified values
.... condition 0..1 string Condition associated with the set of qualified values
.... rangeCategory 0..1 code reference | critical | absolute
Binding: Observation Range Category (Required)
.... range 0..1 Range The range for continuous or ordinal observations
.... validCodedValueSet 0..1 canonical(ValueSet) Value set of valid coded values as part of this set of qualified values
.... normalCodedValueSet 0..1 canonical(ValueSet) Value set of normal coded values as part of this set of qualified values
.... abnormalCodedValueSet 0..1 canonical(ValueSet) Value set of abnormal coded values as part of this set of qualified values
.... criticalCodedValueSet 0..1 canonical(ValueSet) Value set of critical coded values as part of this set of qualified values
.... interpretation 0..* CodeableConcept Expected coded interpretation values
Binding: Observation Interpretation Codes (Extensible)

... hasMember 0..* Reference(ObservationDefinition | Questionnaire) Definitions of related resources belonging to this kind of observation group

... component C 0..* BackboneElement Component results
+ Rule: If permittedUnit exists, then permittedDataType=Quantity must exist.

.... code 1..1 CodeableConcept Type of observation
Binding: LOINC Codes (Example)
.... permittedDataType C 0..* code Quantity | CodeableConcept | string | boolean | integer | Range | Ratio | SampledData | time | dateTime | Period
Binding: Observation Data Type (Required)

.... permittedUnit C 0..* Coding Unit for quantitative results
Binding: UCUM Codes (Preferred)

.... qualifiedValue 0..* see qualifiedValue Set of qualified values for observation results


doco Documentation for this format icon

See the Extensions for this resource

 

Additional definitions: Master Definition XML + JSON, XML Schema/Schematron + JSON Schema, ShEx (for Turtle) , the spreadsheet version & the dependency analysis

8.30.4.1 Terminology Bindings

Path ValueSet Type Documentation
ObservationDefinition.versionAlgorithm[x] VersionAlgorithm Extensible

Indicates the mechanism used to compare versions to determine which is more current.
ObservationDefinition.status PublicationStatus Required

The lifecycle status of an artifact.
ObservationDefinition.jurisdiction JurisdictionValueSet Extensible

This value set defines a base set of codes for country, country subdivision and region for indicating where a resource is intended to be used.

Note: The codes for countries and country subdivisions are taken from ISO 3166 icon while the codes for "supra-national" regions are from UN Standard country or area codes for statistical use (M49) icon.
ObservationDefinition.category ObservationCategoryCodes Example

Observation Category codes.
ObservationDefinition.code LOINCCodes (a valid code from LOINC icon) Example

This value set includes all LOINC codes
ObservationDefinition.permittedDataType ObservationDataType Required

Permitted data type for observation value.
ObservationDefinition.bodySite SNOMEDCTBodyStructures Example

This value set includes all codes from SNOMED CT icon where concept is-a 442083009 (Anatomical or acquired body site (body structure)).
ObservationDefinition.method ObservationMethods Example

Observation Method codes from SNOMED CT icon where concept is-a 272394005 (Technique (qualifier value)) or is-a 129264002 (Action (qualifier value)) or is-a 386053000 (Evaluation procedure(procedure))
ObservationDefinition.permittedUnit UCUMCodes (a valid code from UCUM icon) Preferred

Unified Code for Units of Measure (UCUM). This value set includes all UCUM codes
ObservationDefinition.qualifiedValue.context ObservationReferenceRangeMeaningCodes Extensible

This value set defines a set of codes that can be used to indicate the meaning/use of a reference range for a particular target population.
ObservationDefinition.qualifiedValue.appliesTo ObservationReferenceRangeAppliesToCodes Example

This value set defines a set of codes that can be used to indicate the particular target population the reference range applies to.
ObservationDefinition.qualifiedValue.gender AdministrativeGender Required

The gender of a person used for administrative purposes.
ObservationDefinition.qualifiedValue.rangeCategory ObservationRangeCategory Required

Codes identifying the category of observation range.
ObservationDefinition.qualifiedValue.interpretation ObservationInterpretationCodes (a valid code from ObservationInterpretation icon) Extensible

A categorical assessment, providing a rough qualitative interpretation of the observation value, such as “normal”/ “abnormal”,”low” / “high”, “better” / “worse”, “susceptible” / “resistant”, “expected”/ “not expected”. The value set is intended to be for ANY use where coded representation of an interpretation is needed.

Notes:

This is being communicated in v2.x in OBX-8 (Observation Interpretation), in v3 in ObservationInterpretation (CWE) in R1 (Representative Realm) and in FHIR in Observation.interpretation. Historically these values come from the laboratory domain, and these codes are extensively used. The value set binding is extensible, so codes outside the value set that are needed for interpretation concepts (i.e. particular meanings) that are not included in the value set can be used, and these new codes may also be added to the value set and published in a future version.
ObservationDefinition.component.code LOINCCodes (a valid code from LOINC icon) Example

This value set includes all LOINC codes
ObservationDefinition.component.permittedDataType ObservationDataType Required

Permitted data type for observation value.
ObservationDefinition.component.permittedUnit UCUMCodes (a valid code from UCUM icon) Preferred

Unified Code for Units of Measure (UCUM). This value set includes all UCUM codes

8.30.4.2 Constraints

UniqueKeyLevelLocationDescriptionExpression
img cnl-0Warning (base)Name should be usable as an identifier for the module by machine processing applications such as code generationname.exists() implies name.matches('^[A-Z]([A-Za-z0-9_]){1,254}$')
img obd-0Rule (base)If permittedUnit exists, then permittedDataType=Quantity must exist.permittedUnit.exists() implies permittedDataType.exists(value = 'Quantity')
img obd-1Rule ObservationDefinition.componentIf permittedUnit exists, then permittedDataType=Quantity must exist.permittedUnit.exists() implies permittedDataType.exists(value = 'Quantity')



8.30.5 Search Parameters

Search parameters for this resource. See also the full list of search parameters for this resource, and check the Extensions registry for search parameters on extensions related to this resource. The common parameters also apply. See Searching for more information about searching in REST, messaging, and services.

Name Type Description Expression In Common
category token Category (class) of observation ObservationDefinition.category
code token Observation code ObservationDefinition.code
experimental token Not for genuine usage (true) ObservationDefinition.experimental
identifier token The unique identifier associated with the specimen definition ObservationDefinition.identifier 35 Resources
method token Method of observation ObservationDefinition.method
status token Publication status of the ObservationDefinition: draft, active, retired, unknown ObservationDefinition.status 35 Resources
title string Human-friendly name of the ObservationDefinition ObservationDefinition.title 28 Resources
url uri The uri that identifies the observation definition ObservationDefinition.url 34 Resources