Structured Data Capture
4.0.0 - STU 4 International flag

This page is part of the Structured Data Capture FHIR IG (v4.0.0: STU 4) based on FHIR (HL7® FHIR® Standard) R4. This is the current published version. For a full list of available versions, see the Directory of published versions

Extension: Calculated Expression

Official URL: http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-calculatedExpression Version: 4.0.0
Standards status: Trial-use Active as of 2026-03-24 Maturity Level: 4 Computable Name: CalculatedExpressionExtension
Other Identifiers: OID:2.16.840.1.113883.4.642.40.17.42.17

Calculated value for a question answer as determined by an evaluated expression.

Context of Use

    This extension may be used on the following element(s)

    In addition, the extension can only be used when this FHIRPath expression is true:

    initial.exists().not()

Additional details on the use of this extension can be found on the Form Behavior page. For guidance on how calculatedExpression supports dynamic calculations based on other answers, refer to the Expressions page - calculatedExpression section.

Usage info

Usages:

You can also check for usages in the FHIR IG Statistics

Formal Views of Extension Content

Description Differentials, Snapshots, and other representations.

NameFlagsCard.TypeDescription & Constraints    Filter: Filtersdoco
.. Extension 0..1 Extension Expression-determined initial value
... extension 0..0 Extension
... url 1..1 uri "http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-calculatedExpression"
... value[x] 1..1 Expression Value of extension

doco Documentation for this format
NameFlagsCard.TypeDescription & Constraints    Filter: Filtersdoco
.. Extension 0..1 Extension Expression-determined initial value
... id 0..1 string Unique id for inter-element referencing
... extension 0..0 Extension
Slice: Unordered, Open by value:url
... url 1..1 uri "http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-calculatedExpression"

doco Documentation for this format

Constraints

Id Grade Path(s) Description Expression
ele-1 error **ALL** elements All FHIR elements must have a @value or children hasValue() or (children().count() > id.count())
ext-1 error **ALL** extensions Must have either extensions or value[x], not both extension.exists() != value.exists()

Summary

Simple Extension with the type Expression: Calculated value for a question answer as determined by an evaluated expression.

Maturity: 4

Differential ViewDifferential View

NameFlagsCard.TypeDescription & Constraints    Filter: Filtersdoco
.. Extension 0..1 Extension Expression-determined initial value
... extension 0..0 Extension
... url 1..1 uri "http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-calculatedExpression"
... value[x] 1..1 Expression Value of extension

doco Documentation for this format

Snapshot View

NameFlagsCard.TypeDescription & Constraints    Filter: Filtersdoco
.. Extension 0..1 Extension Expression-determined initial value
... id 0..1 string Unique id for inter-element referencing
... extension 0..0 Extension
Slice: Unordered, Open by value:url
... url 1..1 uri "http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-calculatedExpression"

doco Documentation for this format

Constraints

Id Grade Path(s) Description Expression
ele-1 error **ALL** elements All FHIR elements must have a @value or children hasValue() or (children().count() > id.count())
ext-1 error **ALL** extensions Must have either extensions or value[x], not both extension.exists() != value.exists()

Summary

Simple Extension with the type Expression: Calculated value for a question answer as determined by an evaluated expression.

Maturity: 4

 

Other representations of profile: CSV, Excel, Schematron