Observation

Defines the ID Core constraints and extensions on the Observation resource for the minimal set of data to query and retrieve observation value associated with laboratory results for a patient.

Usage

The purpose of this profile is to provide detailed information about measurements and simple assertions made about a patient, device or other subject.

Observations are a central element in healthcare, used to support diagnosis, monitor progress, determine baselines and patterns and even capture demographic characteristics. Most observations are simple name/value pair assertions with some metadata, but some observations group other observations together logically, or even are multi-component observations. Note that the DiagnosticReport resource provides a clinical or workflow context for a set of observations and the Observation resource is referenced by DiagnosticReport to represent laboratory, imaging, and other clinical and diagnostic data to form a complete report.

URL

Type URL
Canonical https://fhir.kemkes.go.id/r4/StructureDefinition/Observation

Structure

Snapshot

identifierΣ0..*Identifier
basedOnΣ I0..*Reference(CarePlan | DeviceRequest | ImmunizationRecommendation | MedicationRequest | NutritionOrder | ServiceRequest)
partOfΣ I0..*Reference(MedicationAdministration | MedicationDispense | MedicationStatement | Procedure | Immunization | ImagingStudy)
statusΣ ?!1..1codeBinding
category0..*CodeableConceptBinding
codeΣ1..1CodeableConcept
subjectΣ I1..1Reference(Patient | Group | Device | Location)
focusΣ I0..*Reference(Resource)
encounterΣ I1..1Reference(Encounter)
effectiveDateTimedateTime
effectivePeriodPeriod
effectiveTimingTiming
effectiveInstantinstant
issuedΣ0..1instant
performerΣ I0..*Reference(Practitioner | PractitionerRole | Organization | CareTeam | Patient | RelatedPerson)
valueQuantityQuantity
valueCodeableConceptCodeableConcept
valueStringstring
valueBooleanboolean
valueIntegerinteger
valueRangeRange
valueRatioRatio
valueSampledDataSampledData
valueTimetime
valueDateTimedateTime
valuePeriodPeriod
dataAbsentReasonI0..1CodeableConceptBinding
interpretation0..*CodeableConceptBinding
note0..*Annotation
bodySite0..1CodeableConcept
method0..1CodeableConcept
specimenI0..1Reference(Specimen)
deviceI0..1Reference(Device | DeviceMetric)
lowI0..1SimpleQuantity
highI0..1SimpleQuantity
type0..1CodeableConceptBinding
appliesTo0..*CodeableConcept
ageI0..1Range
text0..1string
hasMemberΣ I0..*Reference(Observation | QuestionnaireResponse | MolecularSequence)
derivedFromΣ I0..*Reference(DocumentReference | ImagingStudy | Media | QuestionnaireResponse | Observation | MolecularSequence)
codeΣ1..1CodeableConcept
valueQuantityQuantity
valueCodeableConceptCodeableConcept
valueStringstring
valueBooleanboolean
valueIntegerinteger
valueRangeRange
valueRatioRatio
valueSampledDataSampledData
valueTimetime
valueDateTimedateTime
valuePeriodPeriod
dataAbsentReasonI0..1CodeableConceptBinding
interpretation0..*CodeableConceptBinding
lowI0..1SimpleQuantity
highI0..1SimpleQuantity
type0..1CodeableConceptBinding
appliesTo0..*CodeableConcept
ageI0..1Range
text0..1string

Examples

Dictionary

Observation
DefinitionMeasurements and simple assertions made about a patient, device or other subject.
Cardinality0...*
AliasVital Signs, Measurement, Results, Tests
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.

Invariants
  • dom-2:If the resource is contained in another resource, it SHALL NOT contain nested Resources
    contained.contained.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-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-6:A resource should have narrative for robust management
    text.`div`.exists()
  • dom-5:If a resource is contained in another resource, it SHALL NOT have a security label
    contained.meta.security.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()
  • obs-6:dataAbsentReason SHALL only be present if Observation.value[x] is not present
    dataAbsentReason.empty() or value.empty()
Mappings
  • rim:Entity. Role, or Act
  • workflow:Event
  • sct-concept:< 363787002 |Observable entity|
  • v2:OBX
  • rim:Observation[classCode=OBS, moodCode=EVN]
Observation.id
DefinitionThe logical id of the resource, as used in the URL for the resource. Once assigned, this value never changes.
Cardinality0...1
TypeSystem.String
SummaryTrue
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.

Observation.meta
DefinitionThe 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.
Cardinality0...1
TypeMeta
SummaryTrue
Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • rim:N/A
Observation.implicitRules
DefinitionA 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.
Cardinality0...1
Typeuri
ModifierTrue
SummaryTrue
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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
Observation.language
DefinitionThe base language in which the resource is written.
Cardinality0...1
Typecode
Binding

A human language.

CommonLanguages (preferred)
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).

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
Observation.text
DefinitionA 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.
Cardinality0...1
TypeNarrative
Aliasnarrative, html, xhtml, display
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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • rim:N/A
  • rim:Act.text?
Observation.contained
DefinitionThese 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.
Cardinality0...*
TypeResource
Aliasinline resources, anonymous resources, contained 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.

Mappings
  • rim:Entity. Role, or Act
  • rim:N/A
Observation.extension
DefinitionMay 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.
Cardinality0...*
TypeExtension
Aliasextensions, user content
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.

SlicingUnordered, Open, by url(Value)
Invariants
  • ele-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()
Mappings
  • rim:n/a
  • rim:N/A
Observation.modifierExtension
DefinitionMay 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).
Cardinality0...*
TypeExtension
ModifierTrue
Aliasextensions, user content
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.

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.

SlicingUnordered, Open, by url(Value)
Invariants
  • ele-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()
Mappings
  • rim:n/a
  • rim:N/A
Observation.identifier
DefinitionA unique identifier assigned to this observation.
Cardinality0...*
TypeIdentifier
SummaryTrue
Requirements

Allows observations to be distinguished and referenced.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:CX / EI (occasionally, more often EI maps to a resource id or a URL)
  • rim:II - The Identifier class is a little looser than the v3 type II because it allows URIs as well as registered OIDs or GUIDs. Also maps to Role[classCode=IDENT]
  • servd:Identifier
  • workflow:Event.identifier
  • w5:FiveWs.identifier
  • v2:OBX.21 For OBX segments from systems without OBX-21 support a combination of ORC/OBR and OBX must be negotiated between trading partners to uniquely identify the OBX segment. Depending on how V2 has been implemented each of these may be an option: 1) OBR-3 + OBX-3 + OBX-4 or 2) OBR-3 + OBR-4 + OBX-3 + OBX-4 or 2) some other way to uniquely ID the OBR/ORC + OBX-3 + OBX-4.
  • rim:id
Observation.basedOn
DefinitionA 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.
Cardinality0...*
TypeReference(CarePlan | DeviceRequest | ImmunizationRecommendation | MedicationRequest | NutritionOrder | ServiceRequest)
SummaryTrue
AliasFulfills
Requirements

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

Comments

References SHALL be a reference to an actual FHIR resource, and SHALL be resolveable (allowing for access control, temporary unavailability, etc.). Resolution can be either by retrieval from the URL, or, where applicable by resource type, by treating an absolute reference as a canonical URL and looking it up in a local registry/repository.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
  • ref-1:SHALL have a contained resource if a local reference is provided
    reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))
Mappings
  • rim:n/a
  • rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity)
  • workflow:Event.basedOn
  • v2:ORC
  • rim:.inboundRelationship[typeCode=COMP].source[moodCode=EVN]
Observation.partOf
DefinitionA larger event of which this particular Observation is a component or step. For example, an observation as part of a procedure.
Cardinality0...*
TypeReference(MedicationAdministration | MedicationDispense | MedicationStatement | Procedure | Immunization | ImagingStudy)
SummaryTrue
AliasContainer
Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
  • ref-1:SHALL have a contained resource if a local reference is provided
    reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))
Mappings
  • rim:n/a
  • rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity)
  • workflow:Event.partOf
  • v2:Varies by domain
  • rim:.outboundRelationship[typeCode=FLFS].target
Observation.status
DefinitionThe status of the result value.
Cardinality1...1
Typecode
Binding

Codes providing the status of an observation.

ObservationStatus (required)
ModifierTrue
SummaryTrue
Requirements

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

Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • workflow:Event.status
  • w5:FiveWs.status
  • sct-concept:< 445584004 |Report by finality status|
  • v2:OBX-11
  • rim:status Amended & Final are differentiated by whether it is the subject of a ControlAct event with a type of "revise"
Observation.category
DefinitionA code that classifies the general type of observation being made.
Cardinality0...*
TypeCodeableConcept
Binding

Codes for high level observation categories.

ObservationCategoryCodes (preferred)
Requirements

Used for filtering what observations are retrieved and displayed.

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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:CE/CNE/CWE
  • rim:CD
  • orim:fhir:CodeableConcept rdfs:subClassOf dt:CD
  • w5:FiveWs.class
  • rim:.outboundRelationship[typeCode="COMP].target[classCode="LIST", moodCode="EVN"].code
Observation.code
DefinitionDescribes what was observed. Sometimes this is called the observation "name".
Cardinality1...1
TypeCodeableConcept
Binding

Codes identifying names of simple observations.

LOINCCodes (example)
SummaryTrue
AliasName
Requirements

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

Comments

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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:CE/CNE/CWE
  • rim:CD
  • orim:fhir:CodeableConcept rdfs:subClassOf dt:CD
  • workflow:Event.code
  • w5:FiveWs.what[x]
  • sct-concept:< 363787002 |Observable entity| OR < 386053000 |Evaluation procedure|
  • v2:OBX-3
  • rim:code
  • sct-attr:116680003 |Is a|
Observation.subject
DefinitionThe 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.
Cardinality1...1
TypeReference(Patient | Group | Device | Location)
SummaryTrue
Requirements

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
  • ref-1:SHALL have a contained resource if a local reference is provided
    reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))
Mappings
  • rim:n/a
  • rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity)
  • workflow:Event.subject
  • w5:FiveWs.subject[x]
  • v2:PID-3
  • rim:participation[typeCode=RTGT]
  • w5:FiveWs.subject
Observation.focus
DefinitionThe 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.
Cardinality0...*
TypeReference(Resource)
SummaryTrue
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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
  • ref-1:SHALL have a contained resource if a local reference is provided
    reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))
Mappings
  • rim:n/a
  • rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity)
  • w5:FiveWs.subject[x]
  • v2:OBX-3
  • rim:participation[typeCode=SBJ]
  • w5:FiveWs.subject
Observation.encounter
DefinitionThe healthcare event (e.g. a patient and healthcare provider interaction) during which this observation is made.
Cardinality1...1
TypeReference(Encounter)
SummaryTrue
AliasContext
Requirements

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

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).

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
  • ref-1:SHALL have a contained resource if a local reference is provided
    reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))
Mappings
  • rim:n/a
  • rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity)
  • workflow:Event.context
  • w5:FiveWs.context
  • v2:PV1
  • rim:inboundRelationship[typeCode=COMP].source[classCode=ENC, moodCode=EVN]
Observation.effective[x]
DefinitionThe 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.
Cardinality0...1
TypedateTime
SummaryTrue
AliasOccurrence
Requirements

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

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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • workflow:Event.occurrence[x]
  • w5:FiveWs.done[x]
  • v2:OBX-14, and/or OBX-19 after v2.4 (depends on who observation made)
  • rim:effectiveTime
Observation.issued
DefinitionThe date and time this version of the observation was made available to providers, typically after the results have been reviewed and verified.
Cardinality0...1
Typeinstant
SummaryTrue
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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • w5:FiveWs.recorded
  • v2:OBR.22 (or MSH.7), or perhaps OBX-19 (depends on who observation made)
  • rim:participation[typeCode=AUT].time
Observation.performer
DefinitionWho was responsible for asserting the observed value as "true".
Cardinality0...*
TypeReference(Practitioner | PractitionerRole | Organization | CareTeam | Patient | RelatedPerson)
SummaryTrue
Requirements

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

Comments

References SHALL be a reference to an actual FHIR resource, and SHALL be resolveable (allowing for access control, temporary unavailability, etc.). Resolution can be either by retrieval from the URL, or, where applicable by resource type, by treating an absolute reference as a canonical URL and looking it up in a local registry/repository.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
  • ref-1:SHALL have a contained resource if a local reference is provided
    reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))
Mappings
  • rim:n/a
  • rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity)
  • workflow:Event.performer.actor
  • w5:FiveWs.actor
  • v2:OBX.15 / (Practitioner) OBX-16, PRT-5:PRT-4='RO' / (Device) OBX-18 , PRT-10:PRT-4='EQUIP' / (Organization) OBX-23, PRT-8:PRT-4='PO'
  • rim:participation[typeCode=PRF]
Observation.value[x]
DefinitionThe information determined as a result of making the observation, if the information has a simple value.
Cardinality0...1
TypeQuantity
SummaryTrue
Requirements

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

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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • sct-concept:< 441742003 |Evaluation finding|
  • v2:OBX.2, OBX.5, OBX.6
  • rim:value
  • sct-attr:363714003 |Interprets|
Observation.dataAbsentReason
DefinitionProvides a reason why the expected value in the element Observation.value[x] is missing.
Cardinality0...1
TypeCodeableConcept
Binding

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

DataAbsentReason (extensible)
Requirements

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

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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:CE/CNE/CWE
  • rim:CD
  • orim:fhir:CodeableConcept rdfs:subClassOf dt:CD
  • v2:N/A
  • rim:value.nullFlavor
Observation.interpretation
DefinitionA categorical assessment of an observation value. For example, high, low, normal.
Cardinality0...*
TypeCodeableConcept
Binding

Codes identifying interpretations of observations.

ObservationInterpretationCodes (extensible)
AliasAbnormal Flag
Requirements

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

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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:CE/CNE/CWE
  • rim:CD
  • orim:fhir:CodeableConcept rdfs:subClassOf dt:CD
  • sct-concept:< 260245000 |Findings values|
  • v2:OBX-8
  • rim:interpretationCode
  • sct-attr:363713009 |Has interpretation|
Observation.note
DefinitionComments about the observation or the results.
Cardinality0...*
TypeAnnotation
Requirements

Need to be able to provide free text additional information.

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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:N/A
  • rim:Act
  • v2:NTE.3 (partner NTE to OBX, or sometimes another (child?) OBX)
  • rim:subjectOf.observationEvent[code="annotation"].value
Observation.bodySite
DefinitionIndicates the site on the subject's body where the observation was made (i.e. the target site).
Cardinality0...1
TypeCodeableConcept
Binding

Codes describing anatomical locations. May include laterality.

SNOMEDCTBodyStructures (example)
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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:CE/CNE/CWE
  • rim:CD
  • orim:fhir:CodeableConcept rdfs:subClassOf dt:CD
  • sct-concept:< 123037004 |Body structure|
  • v2:OBX-20
  • rim:targetSiteCode
  • sct-attr:718497002 |Inherent location|
Observation.method
DefinitionIndicates the mechanism used to perform the observation.
Cardinality0...1
TypeCodeableConcept
Binding

Methods for simple observations.

ObservationMethods (example)
Requirements

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

Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:CE/CNE/CWE
  • rim:CD
  • orim:fhir:CodeableConcept rdfs:subClassOf dt:CD
  • v2:OBX-17
  • rim:methodCode
Observation.specimen
DefinitionThe specimen that was used when this observation was made.
Cardinality0...1
TypeReference(Specimen)
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).

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
  • ref-1:SHALL have a contained resource if a local reference is provided
    reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))
Mappings
  • rim:n/a
  • rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity)
  • sct-concept:< 123038009 |Specimen|
  • v2:SPM segment
  • rim:participation[typeCode=SPC].specimen
  • sct-attr:704319004 |Inherent in|
Observation.device
DefinitionThe device used to generate the observation data.
Cardinality0...1
TypeReference(Device | DeviceMetric)
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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
  • ref-1:SHALL have a contained resource if a local reference is provided
    reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))
Mappings
  • rim:n/a
  • rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity)
  • sct-concept:< 49062001 |Device|
  • v2:OBX-17 / PRT -10
  • rim:participation[typeCode=DEV]
  • sct-attr:424226004 |Using device|
Observation.referenceRange
DefinitionGuidance 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.
Cardinality0...*
TypeBackboneElement
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.

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.

Invariants
  • ele-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()
Mappings
  • rim:n/a
  • v2:OBX.7
  • rim:outboundRelationship[typeCode=REFV]/target[classCode=OBS, moodCode=EVN]
Observation.referenceRange.id
DefinitionUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Cardinality0...1
TypeSystem.String
Mappings
  • rim:n/a
Observation.referenceRange.extension
DefinitionMay 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.
Cardinality0...*
TypeExtension
Aliasextensions, user content
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.

SlicingUnordered, Open, by url(Value)
Invariants
  • ele-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()
Mappings
  • rim:n/a
  • rim:N/A
Observation.referenceRange.modifierExtension
DefinitionMay 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).
Cardinality0...*
TypeExtension
ModifierTrue
SummaryTrue
Aliasextensions, user content, modifiers
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.

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.

Invariants
  • ele-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()
Mappings
  • rim:n/a
  • rim:N/A
Observation.referenceRange.low
DefinitionThe 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).
Cardinality0...1
TypeSimpleQuantity
Comments

The context of use may frequently define what kind of quantity this is and therefore what kind of units can be used. The context of use may also restrict the values for the comparator.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
  • qty-3:If a code for the unit is present, the system SHALL also be present
    code.empty() or system.exists()
  • sqty-1:The comparator is not used on a SimpleQuantity
    comparator.empty()
Mappings
  • rim:n/a
  • v2:SN (see also Range) or CQ
  • rim:PQ, IVL<PQ>, MO, CO, depending on the values
  • v2:OBX-7
  • rim:value:IVL_PQ.low
Observation.referenceRange.high
DefinitionThe 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).
Cardinality0...1
TypeSimpleQuantity
Comments

The context of use may frequently define what kind of quantity this is and therefore what kind of units can be used. The context of use may also restrict the values for the comparator.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
  • qty-3:If a code for the unit is present, the system SHALL also be present
    code.empty() or system.exists()
  • sqty-1:The comparator is not used on a SimpleQuantity
    comparator.empty()
Mappings
  • rim:n/a
  • v2:SN (see also Range) or CQ
  • rim:PQ, IVL<PQ>, MO, CO, depending on the values
  • v2:OBX-7
  • rim:value:IVL_PQ.high
Observation.referenceRange.type
DefinitionCodes to indicate the what part of the targeted reference population it applies to. For example, the normal or therapeutic range.
Cardinality0...1
TypeCodeableConcept
Binding

Code for the meaning of a reference range.

ObservationReferenceRangeMeaningCodes (preferred)
Requirements

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

Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:CE/CNE/CWE
  • rim:CD
  • orim:fhir:CodeableConcept rdfs:subClassOf dt:CD
  • sct-concept:< 260245000 |Findings values| OR < 365860008 |General clinical state finding| OR < 250171008 |Clinical history or observation findings| OR < 415229000 |Racial group| OR < 365400002 |Finding of puberty stage| OR < 443938003 |Procedure carried out on subject|
  • v2:OBX-10
  • rim:interpretationCode
Observation.referenceRange.appliesTo
DefinitionCodes 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.
Cardinality0...*
TypeCodeableConcept
Binding

Codes identifying the population the reference range applies to.

ObservationReferenceRangeAppliesToCodes (example)
Requirements

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

Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:CE/CNE/CWE
  • rim:CD
  • orim:fhir:CodeableConcept rdfs:subClassOf dt:CD
  • sct-concept:< 260245000 |Findings values| OR < 365860008 |General clinical state finding| OR < 250171008 |Clinical history or observation findings| OR < 415229000 |Racial group| OR < 365400002 |Finding of puberty stage| OR < 443938003 |Procedure carried out on subject|
  • v2:OBX-10
  • rim:interpretationCode
Observation.referenceRange.age
DefinitionThe 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.
Cardinality0...1
TypeRange
Requirements

Some analytes vary greatly over age.

Comments

The stated low and high value are assumed to have arbitrarily high precision when it comes to determining which values are in the range. I.e. 1.99 is not in the range 2 -> 3.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
  • rng-2:If present, low SHALL have a lower value than high
    low.empty() or high.empty() or (low <= high)
Mappings
  • rim:n/a
  • v2:NR and also possibly SN (but see also quantity)
  • rim:IVL<QTY[not(type="TS")]> [lowClosed="true" and highClosed="true"]or URG<QTY[not(type="TS")]>
  • rim:outboundRelationship[typeCode=PRCN].targetObservationCriterion[code="age"].value
Observation.referenceRange.text
DefinitionText 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".
Cardinality0...1
Typestring
Comments

Note that FHIR strings SHALL NOT exceed 1MB in size

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:OBX-7
  • rim:value:ST
Observation.hasMember
DefinitionThis observation is a group observation (e.g. a battery, a panel of tests, a set of vital sign measurements) that includes the target as a member of the group.
Cardinality0...*
TypeReference(Observation | QuestionnaireResponse | MolecularSequence)
SummaryTrue
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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
  • ref-1:SHALL have a contained resource if a local reference is provided
    reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))
Mappings
  • rim:n/a
  • rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity)
  • v2:Relationships established by OBX-4 usage
  • rim:outBoundRelationship
Observation.derivedFrom
DefinitionThe 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.
Cardinality0...*
TypeReference(DocumentReference | ImagingStudy | Media | QuestionnaireResponse | Observation | MolecularSequence)
SummaryTrue
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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
  • ref-1:SHALL have a contained resource if a local reference is provided
    reference.startsWith('#').not() or (reference.substring(1).trace('url') in %rootResource.contained.id.trace('ids'))
Mappings
  • rim:n/a
  • rim:The target of a resource reference is a RIM entry point (Act, Role, or Entity)
  • v2:Relationships established by OBX-4 usage
  • rim:.targetObservation
Observation.component
DefinitionSome 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.
Cardinality0...*
TypeBackboneElement
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.

Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:containment by OBX-4?
  • rim:outBoundRelationship[typeCode=COMP]
Observation.component.id
DefinitionUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Cardinality0...1
TypeSystem.String
Mappings
  • rim:n/a
Observation.component.extension
DefinitionMay 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.
Cardinality0...*
TypeExtension
Aliasextensions, user content
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.

SlicingUnordered, Open, by url(Value)
Invariants
  • ele-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()
Mappings
  • rim:n/a
  • rim:N/A
Observation.component.modifierExtension
DefinitionMay 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).
Cardinality0...*
TypeExtension
ModifierTrue
SummaryTrue
Aliasextensions, user content, modifiers
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.

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.

Invariants
  • ele-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()
Mappings
  • rim:n/a
  • rim:N/A
Observation.component.code
DefinitionDescribes what was observed. Sometimes this is called the observation "code".
Cardinality1...1
TypeCodeableConcept
Binding

Codes identifying names of simple observations.

LOINCCodes (example)
SummaryTrue
Requirements

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

Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:CE/CNE/CWE
  • rim:CD
  • orim:fhir:CodeableConcept rdfs:subClassOf dt:CD
  • w5:FiveWs.what[x]
  • sct-concept:< 363787002 |Observable entity| OR < 386053000 |Evaluation procedure|
  • v2:OBX-3
  • rim:code
Observation.component.value[x]
DefinitionThe information determined as a result of making the observation, if the information has a simple value.
Cardinality0...1
TypeQuantity
SummaryTrue
Requirements

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

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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • sct-concept:363714003 |Interprets| < 441742003 |Evaluation finding|
  • v2:OBX.2, OBX.5, OBX.6
  • rim:value
  • sct-attr:363714003 |Interprets|
Observation.component.dataAbsentReason
DefinitionProvides a reason why the expected value in the element Observation.component.value[x] is missing.
Cardinality0...1
TypeCodeableConcept
Binding

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

DataAbsentReason (extensible)
Requirements

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

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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:CE/CNE/CWE
  • rim:CD
  • orim:fhir:CodeableConcept rdfs:subClassOf dt:CD
  • v2:N/A
  • rim:value.nullFlavor
Observation.component.interpretation
DefinitionA categorical assessment of an observation value. For example, high, low, normal.
Cardinality0...*
TypeCodeableConcept
Binding

Codes identifying interpretations of observations.

ObservationInterpretationCodes (extensible)
AliasAbnormal Flag
Requirements

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

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.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:CE/CNE/CWE
  • rim:CD
  • orim:fhir:CodeableConcept rdfs:subClassOf dt:CD
  • sct-concept:< 260245000 |Findings values|
  • v2:OBX-8
  • rim:interpretationCode
  • sct-attr:363713009 |Has interpretation|
Observation.component.referenceRange
DefinitionGuidance 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.
Cardinality0...*
TypeBackboneElement
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.

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.

Invariants
  • ele-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()
Mappings
  • rim:n/a
  • v2:OBX.7
  • rim:outboundRelationship[typeCode=REFV]/target[classCode=OBS, moodCode=EVN]
Observation.component.referenceRange.id
DefinitionUnique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.
Cardinality0...1
TypeSystem.String
Mappings
  • rim:n/a
Observation.component.referenceRange.extension
DefinitionMay 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.
Cardinality0...*
TypeExtension
Aliasextensions, user content
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.

SlicingUnordered, Open, by url(Value)
Invariants
  • ele-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()
Mappings
  • rim:n/a
  • rim:N/A
Observation.component.referenceRange.modifierExtension
DefinitionMay 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).
Cardinality0...*
TypeExtension
ModifierTrue
SummaryTrue
Aliasextensions, user content, modifiers
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.

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.

Invariants
  • ele-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()
Mappings
  • rim:n/a
  • rim:N/A
Observation.component.referenceRange.low
DefinitionThe 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).
Cardinality0...1
TypeSimpleQuantity
Comments

The context of use may frequently define what kind of quantity this is and therefore what kind of units can be used. The context of use may also restrict the values for the comparator.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
  • qty-3:If a code for the unit is present, the system SHALL also be present
    code.empty() or system.exists()
  • sqty-1:The comparator is not used on a SimpleQuantity
    comparator.empty()
Mappings
  • rim:n/a
  • v2:SN (see also Range) or CQ
  • rim:PQ, IVL<PQ>, MO, CO, depending on the values
  • v2:OBX-7
  • rim:value:IVL_PQ.low
Observation.component.referenceRange.high
DefinitionThe 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).
Cardinality0...1
TypeSimpleQuantity
Comments

The context of use may frequently define what kind of quantity this is and therefore what kind of units can be used. The context of use may also restrict the values for the comparator.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
  • qty-3:If a code for the unit is present, the system SHALL also be present
    code.empty() or system.exists()
  • sqty-1:The comparator is not used on a SimpleQuantity
    comparator.empty()
Mappings
  • rim:n/a
  • v2:SN (see also Range) or CQ
  • rim:PQ, IVL<PQ>, MO, CO, depending on the values
  • v2:OBX-7
  • rim:value:IVL_PQ.high
Observation.component.referenceRange.type
DefinitionCodes to indicate the what part of the targeted reference population it applies to. For example, the normal or therapeutic range.
Cardinality0...1
TypeCodeableConcept
Binding

Code for the meaning of a reference range.

ObservationReferenceRangeMeaningCodes (preferred)
Requirements

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

Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:CE/CNE/CWE
  • rim:CD
  • orim:fhir:CodeableConcept rdfs:subClassOf dt:CD
  • sct-concept:< 260245000 |Findings values| OR < 365860008 |General clinical state finding| OR < 250171008 |Clinical history or observation findings| OR < 415229000 |Racial group| OR < 365400002 |Finding of puberty stage| OR < 443938003 |Procedure carried out on subject|
  • v2:OBX-10
  • rim:interpretationCode
Observation.component.referenceRange.appliesTo
DefinitionCodes 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.
Cardinality0...*
TypeCodeableConcept
Binding

Codes identifying the population the reference range applies to.

ObservationReferenceRangeAppliesToCodes (example)
Requirements

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

Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:CE/CNE/CWE
  • rim:CD
  • orim:fhir:CodeableConcept rdfs:subClassOf dt:CD
  • sct-concept:< 260245000 |Findings values| OR < 365860008 |General clinical state finding| OR < 250171008 |Clinical history or observation findings| OR < 415229000 |Racial group| OR < 365400002 |Finding of puberty stage| OR < 443938003 |Procedure carried out on subject|
  • v2:OBX-10
  • rim:interpretationCode
Observation.component.referenceRange.age
DefinitionThe 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.
Cardinality0...1
TypeRange
Requirements

Some analytes vary greatly over age.

Comments

The stated low and high value are assumed to have arbitrarily high precision when it comes to determining which values are in the range. I.e. 1.99 is not in the range 2 -> 3.

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
  • rng-2:If present, low SHALL have a lower value than high
    low.empty() or high.empty() or (low <= high)
Mappings
  • rim:n/a
  • v2:NR and also possibly SN (but see also quantity)
  • rim:IVL<QTY[not(type="TS")]> [lowClosed="true" and highClosed="true"]or URG<QTY[not(type="TS")]>
  • rim:outboundRelationship[typeCode=PRCN].targetObservationCriterion[code="age"].value
Observation.component.referenceRange.text
DefinitionText 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".
Cardinality0...1
Typestring
Comments

Note that FHIR strings SHALL NOT exceed 1MB in size

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:OBX-7
  • rim:value:ST