FHIR to CDISC Joint Mapping Implementation Guide
1.0.0 - STU 1

This page is part of the CDISC Mapping FHIR IG (v1.0.0: STU 1) based on FHIR R4. This is the current published version in its permanent home (it will always be available at this URL). For a full list of available versions, see the Directory of published versions

Vital Signs

Like laboratory results, vital signs are also typically captured in Observations. FHIR actually defines specific profiles for common vital sign measures, significantly increasing the consistency of basic vital signs data. These profiles mandate the declaration of the vital-signs category. This allows vital signs to be easily separated from other observations.

One consideration to be aware of is that Blood Pressure is typically captured as a single Observation with two components, however it is sometimes captured as two distinct resource instances. When converting, both approaches will need to be accounted for.

VS Mappings

Guidance on interpreting the tables can be found here.

CDISC FHIR map (or gap) Comment
Label CDASH SDTM Element FHIRPath
Study Identifier STUDYID
Core: HR
Type: Char		 STUDYID
Core: Req
Type: Char		 ResearchStudy.identifier
0..* Identifier

ResearchSubject.where(subject=Observation.subject).study.resolve().partOf.resolve().identifier

Observation.extension(workflow-researchstudy).valueReference.resolve().partOf.resolve().identifier

 Mapping is based on presumption that research subject will be tied to site-specific ResearchStudy, which will then be part of overall ResearchStudy.

The path using the extension will only exist if the system maintaining the Observation is aware of its relevance to the Study. ResearchStudy links to Patient. Observation links to Patient. If the patients are the same, that establishes the linkage. There's also an extension that allows direct linkage to a 'study' from any resource - if the source system has actually established such a linkage.
Study Site Identifier SITEID
Core: HR
Type: Char		 DM.SITEID
Core: Req
Type: Char		 ResearchStudy.site
0..* Reference

ResearchSubject.where(subject=Observation.subject).study.resolve().identifier

Observation.extension(workflow-researchstudy).valueReference.resolve().identifier

 Mapping is based on presumption that research subject will be tied to site-specific ResearchStudy, which will then be part of overall ResearchStudy.

The path using the extension will only exist if the system maintaining the Observation is aware of its relevance to the Study.
Subject Identifier for the Study SUBJID
Core: HR
Type: Char		 DM.SUBJID
Core: Req
Type: Char		 ResearchSubject.identifier
0..* Identifier

ResearchSubject.where(individual=Observation.subject).identifier

 Study subject is found by finding the StudySubject that corresponds to the same Patient and ResearchStudy as the Observation.

No standard way to decide which subject identifier to use
Visit Name VISIT
Core: R/C
Type: Char		 VISIT
Core: Perm
Type: Char		 Encounter should have a standard instantiatesCanonical extension that would allow pointing to the ActivityDefinition. This would be the ActivityDefinition.name. Submit a change request to add the extension
Visit Date VISDAT
Core: R/C
Type: Char		 Encounter.period
0..1 Period

Observation.encounter.resolve().period.start

 Linked via Observation.encounter
Vital Signs Performed VSPERF
Core: O
Type: Char		 VSSTAT
Core: Perm
Type: Char		 Observation.status
1..1 code
Binding: ObservationStatus required

Observation.status=('final' or 'cancelled')
Vital Signs Date VSDAT
Core: R/C
Type: Char		 VSDTC
Core: Exp
Type: Char
values: ISO 8601		 Observation.effectiveDateTime
0..1 dateTime

Observation.effectiveDateTime
Vital Signs Time VSTIM
Core: R/C
Type: Char		 VSDTC
Core: Exp
Type: Char
values: ISO 8601		 Observation.effectiveDateTime
0..1 dateTime

Observation.effectiveDateTime
Category for Vital Signs VSCAT
Core: O
Type: Char		 VSCAT
Core: Perm
Type: Char		 Observation.category
0..* CodeableConcept
Binding: ObservationCategory preferred

Observation.category

 FHIR allows multiple categorizations at various levels of granularity.

Observation.category.coding.system="http://terminology.hl7.org/CodeSystem/observation-category" + Observation.category.coding.code="vital-signs". This combination can be used to extract vital sign data points from EHR system and correctly assign them to the VS domain.
Subcategory for Vital Signs VSSCAT
Core: O
Type: Char		 VSSCAT
Core: Perm
Type: Char		 Observation.category
0..* CodeableConcept
Binding: ObservationCategory preferred

Observation.category

 FHIR allows multiple categorizations at various levels of granularity.

Observation.category.coding.system="http://terminology.hl7.org/CodeSystem/observation-category" + Observation.category.coding.code="vital-signs". This combination can be used to extract vital sign data points from EHR system and correctly assign them to the VS domain.
Vital Signs Group ID VSGRPID VSGRPID
Core: Perm
Type: Char		 This would typically be done by having the related Observations being 'membersOf' a common parent Observation.
Vital Signs Planned Time Point Name VSTPT
Core: R/C
Type: Char		 VSTPT
Core: Perm
Type: Char		 Observation.extension
0..* Extension

Observation.extension('R5-Observation.instantiatesCanonical').resolve().title

 TimePoints will be represented in FHIR as PlanDefinition.activities. Referencing a PlanDefinition is supported in R5. Can use a standard extension to pre-adopt.
Vital Signs Completion Status VSSTAT
Core: O
Type: Char		 VSSTAT
Core: Perm
Type: Char		 Observation.status
1..1 code
Binding: ObservationStatus required

Observation.status

ServiceRequest.status IN {'cancelled'|'on-hold'|'revoked'| 'entered-in-error'}

 In some instances, VSSTAT="NOT DONE" records will come from FHIR Observation resources where Observation.status="cancelled". This is not an exact match and there could be observations which have been scheduled and did not happen so an observation may not exist.
ServiceRequest.status
1..1 code
Binding: ServiceRequestStatus required

Observation.status

ServiceRequest.status IN {'cancelled'|'on-hold'|'revoked'| 'entered-in-error'}
VS Result or Finding in Original Units VSORRES
Core: HR
Type: Char		 VSORRES
Core: Exp
Type: Char		 Observation.valueQuantity
0..1 Quantity obs-7

Observation.valueQuantity.value

 Ensure the value provided from the EHR is considered an actual value (result), an interpretation or range.
VS Original Units VSORRESU
Core: R/C
Type: Char		 VSORRESU
Core: Exp
Type: Char		 Observation.valueQuantity
0..1 Quantity obs-7

Observation.valueQuantity.unit
Vital Signs Clinical Significance VSCLSIG
Core: O
Type: Char		 SUPPVS.QVAL Observation.interpretation
0..* CodeableConcept
Binding: ObservationInterpretation extensible

Observation.interpretation

 If clinical significance is a boolean, then the mapping is different from the existing http://hl7.org/fhir/ValueSet/observation-interpretation ValueSet. Meaning, the values of "normal", "high", :low", etc. can reside in the --NRIND variable. There are also cases where clinical significant outcome details can exist with corresponding details that don't fit into either of those mentioned buckets.
Vital Signs Position of Subject VSPOS
Core: R/C
Type: Char		 VSPOS
Core: Perm
Type: Char		 Observation.code
1..1 CodeableConcept
Binding: ObservationCode example

Observation.code

 This is often pre-coordinated into the Observation.code, but can also be expressed in the method
Observation.method
0..1 CodeableConcept
Binding: ObservationMethod example

Observation.method
Location of Vital Signs Measurement VSLOC
Core: O
Type: Char		 VSLOC
Core: Perm
Type: Char		 Observation.bodySite
0..1 CodeableConcept
Binding: BodySite example

Observation.bodySite

 Requires knowledge or review of data to ensure location, laterality and directionality are included in the code and can be parsed.
Vital Signs Laterality VSLAT
Core: O
Type: Char		 VSLAT
Core: Perm
Type: Char		 Observation.bodySite
0..1 CodeableConcept
Binding: BodySite example

Observation.bodySite

 Requires knowledge or review of data to ensure location, laterality and directionality are included in the code and can be parsed.
Vital Signs Directionality VSDIR
Core: O
Type: Char		 VSDIR* Observation.bodySite
0..1 CodeableConcept
Binding: BodySite example

Observation.bodySite

 Requires knowledge or review of data to ensure location, laterality and directionality are included in the code and can be parsed.
Vital Signs Test code VSTESTCD VSTESTCD
Core: Req
Type: Char		 Observation.code
1..1 CodeableConcept
Binding: ObservationCode example

Observation.code.coding.code

 May use one of the following:coding.display and coding.code (plus coding.system)
Vital Signs Test Name VSTEST
Core: HR
Type: Char		 VSTEST
Core: Req
Type: Char		 Observation.code
1..1 CodeableConcept
Binding: ObservationCode example

Observation.code.coding.display

 May use one of the following:coding.display and coding.code (plus coding.system)
Vital Signs Sponsor-Defined Identifier VSSPID
Core: O
Type: Char		 VSSPID
Core: Perm
Type: Char		 Observation.identifier
0..* Identifier

Observation.identifier.where(assigner=[sponsor organization id])

 The assigner of the identifier can be explicit or inferred by the Identifier.system. Example: "assigner=sponsor", the value of assigner can either be a simple name using "display" (e.g. "assigner.display=MyPharma" or a reference to an "Organization"
Vital Signs Repetition Number VSREPNUM
Core: O
Type: Char		 SUPPVS.QVAL This could be captured as a specific ActivityDefinition where you'd have a distinct ActivityDefinition for each occurrence. However, it is more likely to be a single ActivityDefinition for the test and an extension would be added on Observation.instantiates to indicate which occurrence is the Observation.
FHIR map (or gap) CDISC Comment
Label Element FHIRPath CDASH SDTM
Study Identifier ResearchStudy.identifier
0..* Identifier

ResearchSubject.where(subject=Observation.subject).study.resolve().partOf.resolve().identifier

Observation.extension(workflow-researchstudy).valueReference.resolve().partOf.resolve().identifier

 STUDYID
Core: HR
Type: Char		 STUDYID
Core: Req
Type: Char		 Mapping is based on presumption that research subject will be tied to site-specific ResearchStudy, which will then be part of overall ResearchStudy.

The path using the extension will only exist if the system maintaining the Observation is aware of its relevance to the Study. ResearchStudy links to Patient. Observation links to Patient. If the patients are the same, that establishes the linkage. There's also an extension that allows direct linkage to a 'study' from any resource - if the source system has actually established such a linkage.
Study Site Identifier ResearchStudy.site
0..* Reference

ResearchSubject.where(subject=Observation.subject).study.resolve().identifier

Observation.extension(workflow-researchstudy).valueReference.resolve().identifier

 SITEID
Core: HR
Type: Char		 DM.SITEID
Core: Req
Type: Char		 Mapping is based on presumption that research subject will be tied to site-specific ResearchStudy, which will then be part of overall ResearchStudy.

The path using the extension will only exist if the system maintaining the Observation is aware of its relevance to the Study.
Subject Identifier for the Study ResearchSubject.identifier
0..* Identifier

ResearchSubject.where(individual=Observation.subject).identifier

 SUBJID
Core: HR
Type: Char		 DM.SUBJID
Core: Req
Type: Char		 Study subject is found by finding the StudySubject that corresponds to the same Patient and ResearchStudy as the Observation.

No standard way to decide which subject identifier to use
Visit Name Encounter should have a standard instantiatesCanonical extension that would allow pointing to the ActivityDefinition. This would be the ActivityDefinition.name. Submit a change request to add the extension VISIT
Core: R/C
Type: Char		 VISIT
Core: Perm
Type: Char
Visit Date Encounter.period
0..1 Period

Observation.encounter.resolve().period.start

 VISDAT
Core: R/C
Type: Char		 Linked via Observation.encounter
Vital Signs Performed Observation.status
1..1 code
Binding: ObservationStatus required

Observation.status=('final' or 'cancelled')

 VSPERF
Core: O
Type: Char		 VSSTAT
Core: Perm
Type: Char
Vital Signs Date Observation.effectiveDateTime
0..1 dateTime

Observation.effectiveDateTime

 VSDAT
Core: R/C
Type: Char		 VSDTC
Core: Exp
Type: Char
values: ISO 8601
Vital Signs Time Observation.effectiveDateTime
0..1 dateTime

Observation.effectiveDateTime

 VSTIM
Core: R/C
Type: Char		 VSDTC
Core: Exp
Type: Char
values: ISO 8601
Category for Vital Signs Observation.category
0..* CodeableConcept
Binding: ObservationCategory preferred

Observation.category

 VSCAT
Core: O
Type: Char		 VSCAT
Core: Perm
Type: Char		 FHIR allows multiple categorizations at various levels of granularity.

Observation.category.coding.system="http://terminology.hl7.org/CodeSystem/observation-category" + Observation.category.coding.code="vital-signs". This combination can be used to extract vital sign data points from EHR system and correctly assign them to the VS domain.
Subcategory for Vital Signs Observation.category
0..* CodeableConcept
Binding: ObservationCategory preferred

Observation.category

 VSSCAT
Core: O
Type: Char		 VSSCAT
Core: Perm
Type: Char		 FHIR allows multiple categorizations at various levels of granularity.

Observation.category.coding.system="http://terminology.hl7.org/CodeSystem/observation-category" + Observation.category.coding.code="vital-signs". This combination can be used to extract vital sign data points from EHR system and correctly assign them to the VS domain.
Vital Signs Group ID This would typically be done by having the related Observations being 'membersOf' a common parent Observation. VSGRPID VSGRPID
Core: Perm
Type: Char
Vital Signs Planned Time Point Name Observation.extension
0..* Extension

Observation.extension('R5-Observation.instantiatesCanonical').resolve().title

 VSTPT
Core: R/C
Type: Char		 VSTPT
Core: Perm
Type: Char		 TimePoints will be represented in FHIR as PlanDefinition.activities. Referencing a PlanDefinition is supported in R5. Can use a standard extension to pre-adopt.
Vital Signs Completion Status Observation.status
1..1 code
Binding: ObservationStatus required

Observation.status

ServiceRequest.status IN {'cancelled'|'on-hold'|'revoked'| 'entered-in-error'}

 VSSTAT
Core: O
Type: Char		 VSSTAT
Core: Perm
Type: Char		 In some instances, VSSTAT="NOT DONE" records will come from FHIR Observation resources where Observation.status="cancelled". This is not an exact match and there could be observations which have been scheduled and did not happen so an observation may not exist.
ServiceRequest.status
1..1 code
Binding: ServiceRequestStatus required

Observation.status

ServiceRequest.status IN {'cancelled'|'on-hold'|'revoked'| 'entered-in-error'}
VS Result or Finding in Original Units Observation.valueQuantity
0..1 Quantity obs-7

Observation.valueQuantity.value

 VSORRES
Core: HR
Type: Char		 VSORRES
Core: Exp
Type: Char		 Ensure the value provided from the EHR is considered an actual value (result), an interpretation or range.
VS Original Units Observation.valueQuantity
0..1 Quantity obs-7

Observation.valueQuantity.unit

 VSORRESU
Core: R/C
Type: Char		 VSORRESU
Core: Exp
Type: Char
Vital Signs Clinical Significance Observation.interpretation
0..* CodeableConcept
Binding: ObservationInterpretation extensible

Observation.interpretation

 VSCLSIG
Core: O
Type: Char		 SUPPVS.QVAL If clinical significance is a boolean, then the mapping is different from the existing http://hl7.org/fhir/ValueSet/observation-interpretation ValueSet. Meaning, the values of "normal", "high", :low", etc. can reside in the --NRIND variable. There are also cases where clinical significant outcome details can exist with corresponding details that don't fit into either of those mentioned buckets.
Vital Signs Position of Subject Observation.code
1..1 CodeableConcept
Binding: ObservationCode example

Observation.code

 VSPOS
Core: R/C
Type: Char		 VSPOS
Core: Perm
Type: Char		 This is often pre-coordinated into the Observation.code, but can also be expressed in the method
Observation.method
0..1 CodeableConcept
Binding: ObservationMethod example

Observation.method
Location of Vital Signs Measurement Observation.bodySite
0..1 CodeableConcept
Binding: BodySite example

Observation.bodySite

 VSLOC
Core: O
Type: Char		 VSLOC
Core: Perm
Type: Char		 Requires knowledge or review of data to ensure location, laterality and directionality are included in the code and can be parsed.
Vital Signs Laterality Observation.bodySite
0..1 CodeableConcept
Binding: BodySite example

Observation.bodySite

 VSLAT
Core: O
Type: Char		 VSLAT
Core: Perm
Type: Char		 Requires knowledge or review of data to ensure location, laterality and directionality are included in the code and can be parsed.
Vital Signs Directionality Observation.bodySite
0..1 CodeableConcept
Binding: BodySite example

Observation.bodySite

 VSDIR
Core: O
Type: Char		 VSDIR* Requires knowledge or review of data to ensure location, laterality and directionality are included in the code and can be parsed.
Vital Signs Test code Observation.code
1..1 CodeableConcept
Binding: ObservationCode example

Observation.code.coding.code

 VSTESTCD VSTESTCD
Core: Req
Type: Char		 May use one of the following:coding.display and coding.code (plus coding.system)
Vital Signs Test Name Observation.code
1..1 CodeableConcept
Binding: ObservationCode example

Observation.code.coding.display

 VSTEST
Core: HR
Type: Char		 VSTEST
Core: Req
Type: Char		 May use one of the following:coding.display and coding.code (plus coding.system)
Vital Signs Sponsor-Defined Identifier Observation.identifier
0..* Identifier

Observation.identifier.where(assigner=[sponsor organization id])

 VSSPID
Core: O
Type: Char		 VSSPID
Core: Perm
Type: Char		 The assigner of the identifier can be explicit or inferred by the Identifier.system. Example: "assigner=sponsor", the value of assigner can either be a simple name using "display" (e.g. "assigner.display=MyPharma" or a reference to an "Organization"
Vital Signs Repetition Number This could be captured as a specific ActivityDefinition where you'd have a distinct ActivityDefinition for each occurrence. However, it is more likely to be a single ActivityDefinition for the test and an extension would be added on Observation.instantiates to indicate which occurrence is the Observation. VSREPNUM
Core: O
Type: Char		 SUPPVS.QVAL