Body Mass Index

Some Informative table:

description

FHIR Body Mass Index (BMI) Profile

Observation
DefinitionThis profile defines how to represent Body Mass Index (BMI) observations in FHIR using a standard LOINC code and UCUM units of measure.
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()
  • vs-2:If there is no component or hasMember element then either a value[x] or a data absent reason must be present.
    (component.empty() and hasMember.empty()) implies (dataAbsentReason.exists() or value.exists())
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)
Must SupportTrue
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.
Cardinality1...*
TypeCodeableConcept
Binding

Codes for high level observation categories.

ObservationCategoryCodes (preferred)
Must SupportTrue
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.

SlicingUnordered, Open, by coding.code(Value), coding.system(Value)
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.category:VSCat
DefinitionA code that classifies the general type of observation being made.
Cardinality1...1
TypeCodeableConcept
Binding

Codes for high level observation categories.

ObservationCategoryCodes (preferred)
Must SupportTrue
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.category:VSCat.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.category:VSCat.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.category:VSCat.coding
DefinitionA reference to a code defined by a terminology system.
Cardinality1...*
TypeCoding
Must SupportTrue
SummaryTrue
Requirements

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

Comments

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

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 subset one of the sets of component 1-3 or 4-6
  • rim:CV
  • orim:fhir:Coding rdfs:subClassOf dt:CDCoding
  • v2:C*E.1-8, C*E.10-22
  • rim:union(., ./translation)
  • orim:fhir:CodeableConcept.coding rdfs:subPropertyOf dt:CD.coding
Observation.category:VSCat.coding.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.category:VSCat.coding.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.category:VSCat.coding.system
DefinitionThe identification of the code system that defines the meaning of the symbol in the code.
Cardinality1...1
Typeuri
Must SupportTrue
SummaryTrue
Requirements

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

Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Fixed Value

http://terminology.hl7.org/CodeSystem/observation-category

Mappings
  • rim:n/a
  • v2:C*E.3
  • rim:./codeSystem
  • orim:fhir:Coding.system rdfs:subPropertyOf dt:CDCoding.codeSystem
Observation.category:VSCat.coding.version
DefinitionThe 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.
Cardinality0...1
Typestring
SummaryTrue
Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:C*E.7
  • rim:./codeSystemVersion
  • orim:fhir:Coding.version rdfs:subPropertyOf dt:CDCoding.codeSystemVersion
Observation.category:VSCat.coding.code
DefinitionA 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).
Cardinality1...1
Typecode
Must SupportTrue
SummaryTrue
Requirements

Need to refer to a particular code in the system.

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())
Fixed Value

vital-signs

Mappings
  • rim:n/a
  • v2:C*E.1
  • rim:./code
  • orim:fhir:Coding.code rdfs:subPropertyOf dt:CDCoding.code
Observation.category:VSCat.coding.display
DefinitionA representation of the meaning of the code in the system, following the rules of the system.
Cardinality0...1
Typestring
SummaryTrue
Requirements

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

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:C*E.2 - but note this is not well followed
  • rim:CV.displayName
  • orim:fhir:Coding.display rdfs:subPropertyOf dt:CDCoding.displayName
Observation.category:VSCat.coding.userSelected
DefinitionIndicates that this coding was chosen by a user directly - e.g. off a pick list of available items (codes or displays).
Cardinality0...1
Typeboolean
SummaryTrue
Requirements

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

Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:Sometimes implied by being first
  • rim:CD.codingRationale
  • orim:fhir:Coding.userSelected fhir:mapsTo dt:CDCoding.codingRationale. fhir:Coding.userSelected fhir:hasMap fhir:Coding.userSelected.map. fhir:Coding.userSelected.map a fhir:Map; fhir:target dt:CDCoding.codingRationale. fhir:Coding.userSelected\#true a [ fhir:source "true"; fhir:target dt:CDCoding.codingRationale\#O ]
Observation.category:VSCat.text
DefinitionA 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.
Cardinality0...1
Typestring
SummaryTrue
Requirements

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

Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:C*E.9. But note many systems use C*E.2 for this
  • rim:./originalText[mediaType/code="text/plain"]/data
  • orim:fhir:CodeableConcept.text rdfs:subPropertyOf dt:CD.originalText
Observation.code
DefinitionBody Mass Index (BMI).
Cardinality1...1
TypeCodeableConcept
Binding

This identifies the vital sign result type.

VitalSigns (extensible)
Must SupportTrue
SummaryTrue
AliasName, Test
Requirements
  1. SHALL contain exactly one [1..1] code, where the @code SHOULD be selected from ValueSet HITSP Vital Sign Result Type 2.16.840.1.113883.3.88.12.80.62 DYNAMIC (CONF:7301).
Comments

additional codes that translate or map to this code are allowed. For example a more granular LOINC code or code that is used locally in a system.

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.code.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.code.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.code.coding
DefinitionA reference to a code defined by a terminology system.
Cardinality0...*
TypeCoding
SummaryTrue
Requirements

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

Comments

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

SlicingUnordered, Open, by code(Value), system(Value)
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 subset one of the sets of component 1-3 or 4-6
  • rim:CV
  • orim:fhir:Coding rdfs:subClassOf dt:CDCoding
  • v2:C*E.1-8, C*E.10-22
  • rim:union(., ./translation)
  • orim:fhir:CodeableConcept.coding rdfs:subPropertyOf dt:CD.coding
Observation.code.coding:BMICode
DefinitionA reference to a code defined by a terminology system.
Cardinality1...1
TypeCoding
SummaryTrue
Requirements

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

Comments

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

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 subset one of the sets of component 1-3 or 4-6
  • rim:CV
  • orim:fhir:Coding rdfs:subClassOf dt:CDCoding
  • v2:C*E.1-8, C*E.10-22
  • rim:union(., ./translation)
  • orim:fhir:CodeableConcept.coding rdfs:subPropertyOf dt:CD.coding
Observation.code.coding:BMICode.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.code.coding:BMICode.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.code.coding:BMICode.system
DefinitionThe identification of the code system that defines the meaning of the symbol in the code.
Cardinality1...1
Typeuri
SummaryTrue
Requirements

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

Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Fixed Value

http://loinc.org

Mappings
  • rim:n/a
  • v2:C*E.3
  • rim:./codeSystem
  • orim:fhir:Coding.system rdfs:subPropertyOf dt:CDCoding.codeSystem
Observation.code.coding:BMICode.version
DefinitionThe 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.
Cardinality0...1
Typestring
SummaryTrue
Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:C*E.7
  • rim:./codeSystemVersion
  • orim:fhir:Coding.version rdfs:subPropertyOf dt:CDCoding.codeSystemVersion
Observation.code.coding:BMICode.code
DefinitionA 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).
Cardinality1...1
Typecode
SummaryTrue
Requirements

Need to refer to a particular code in the system.

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())
Fixed Value

39156-5

Mappings
  • rim:n/a
  • v2:C*E.1
  • rim:./code
  • orim:fhir:Coding.code rdfs:subPropertyOf dt:CDCoding.code
Observation.code.coding:BMICode.display
DefinitionA representation of the meaning of the code in the system, following the rules of the system.
Cardinality0...1
Typestring
SummaryTrue
Requirements

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

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:C*E.2 - but note this is not well followed
  • rim:CV.displayName
  • orim:fhir:Coding.display rdfs:subPropertyOf dt:CDCoding.displayName
Observation.code.coding:BMICode.userSelected
DefinitionIndicates that this coding was chosen by a user directly - e.g. off a pick list of available items (codes or displays).
Cardinality0...1
Typeboolean
SummaryTrue
Requirements

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

Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:Sometimes implied by being first
  • rim:CD.codingRationale
  • orim:fhir:Coding.userSelected fhir:mapsTo dt:CDCoding.codingRationale. fhir:Coding.userSelected fhir:hasMap fhir:Coding.userSelected.map. fhir:Coding.userSelected.map a fhir:Map; fhir:target dt:CDCoding.codingRationale. fhir:Coding.userSelected\#true a [ fhir:source "true"; fhir:target dt:CDCoding.codingRationale\#O ]
Observation.code.text
DefinitionA 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.
Cardinality0...1
Typestring
SummaryTrue
Requirements

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

Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:C*E.9. But note many systems use C*E.2 for this
  • rim:./originalText[mediaType/code="text/plain"]/data
  • orim:fhir:CodeableConcept.text rdfs:subPropertyOf dt:CD.originalText
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)
Must SupportTrue
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.
Cardinality0...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]
DefinitionOften just a dateTime for Vital Signs.
Cardinality1...1
TypedateTime
Must SupportTrue
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())
  • vs-1:if Observation.effective[x] is dateTime and has a value then that value shall be precise to the day
    ($this as dateTime).toString().length() >= 8
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]
DefinitionVital Signs value are recorded using the Quantity data type. For supporting observations such as Cuff size could use other datatypes such as CodeableConcept.
Cardinality0...1
TypeQuantity
Must SupportTrue
SummaryTrue
Requirements
  1. SHALL contain exactly one [1..1] value with @xsi:type="PQ" (CONF:7305).
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.

SlicingUnordered, ??, by $this(Type)
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.value[x]:valueQuantity
DefinitionVital Signs value are recorded using the Quantity data type. For supporting observations such as Cuff size could use other datatypes such as CodeableConcept.
Cardinality1...1
TypeQuantity
Must SupportTrue
SummaryTrue
Requirements
  1. SHALL contain exactly one [1..1] value with @xsi:type="PQ" (CONF:7305).
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.value[x]:valueQuantity.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.value[x]:valueQuantity.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.value[x]:valueQuantity.value
DefinitionThe value of the measured amount. The value includes an implicit precision in the presentation of the value.
Cardinality1...1
Typedecimal
Must SupportTrue
SummaryTrue
Requirements

Precision is handled implicitly in almost all cases of measurement.

Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Mappings
  • rim:n/a
  • v2:SN.2 / CQ - N/A
  • rim:PQ.value, CO.value, MO.value, IVL.high or IVL.low depending on the value
Observation.value[x]:valueQuantity.comparator
DefinitionHow the value should be understood and represented - whether the actual value is greater or less than the stated value due to measurement issues; e.g. if the comparator is "<" , then the real value is < stated value.
Cardinality0...1
Typecode
Binding

How the Quantity should be understood and represented.

QuantityComparator (required)
ModifierTrue
SummaryTrue
Requirements

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

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:SN.1 / CQ.1
  • rim:IVL properties
Observation.value[x]:valueQuantity.unit
DefinitionA human-readable form of the unit.
Cardinality1...1
Typestring
Must SupportTrue
SummaryTrue
Requirements

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

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:(see OBX.6 etc.) / CQ.2
  • rim:PQ.unit
Observation.value[x]:valueQuantity.system
DefinitionThe identification of the system that provides the coded form of the unit.
Cardinality1...1
Typeuri
Must SupportTrue
SummaryTrue
Requirements

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

Comments

see http://en.wikipedia.org/wiki/Uniform_resource_identifier

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Fixed Value

http://unitsofmeasure.org

Mappings
  • rim:n/a
  • v2:(see OBX.6 etc.) / CQ.2
  • rim:CO.codeSystem, PQ.translation.codeSystem
Observation.value[x]:valueQuantity.code
DefinitionCoded responses from the common UCUM units for vital signs value set.
Cardinality1...1
Typecode
Must SupportTrue
SummaryTrue
Requirements

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

Comments

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

Invariants
  • ele-1:All FHIR elements must have a @value or children
    hasValue() or (children().count() > id.count())
Fixed Value

kg/m2

Mappings
  • rim:n/a
  • v2:(see OBX.6 etc.) / CQ.2
  • rim:PQ.code, MO.currency, PQ.translation.code
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)
Must SupportTrue
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
DefinitionUsed when reporting vital signs panel components.
Cardinality0...*
TypeReference(QuestionnaireResponse | MolecularSequence | Vital Signs Profile)
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 | MolecularSequence | Vital Signs Profile)
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
DefinitionUsed when reporting systolic and diastolic blood pressure.
Cardinality0...*
TypeBackboneElement
Must SupportTrue
SummaryTrue
Requirements

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

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())
  • vs-3:If there is no a value a data absent reason must be present
    value.exists() or dataAbsentReason.exists()
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

This identifies the vital sign result type.

VitalSigns (extensible)
Must SupportTrue
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]
DefinitionVital Sign Value recorded with UCUM.
Cardinality0...1
TypeQuantity
Binding

Common UCUM units for recording Vital Signs.

VitalSignsUnits (required)
Must SupportTrue
SummaryTrue
Requirements
  1. SHALL contain exactly one [1..1] value with @xsi:type="PQ" (CONF:7305).
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)
Must SupportTrue
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.
Cardinality0...*
Typesee (referenceRange)
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.

Mappings
  • v2:OBX.7
  • rim:outboundRelationship[typeCode=REFV]/target[classCode=OBS, moodCode=EVN]