FHIR Extensions Pack
5.4.0 - May 2026 International flag

FHIR Extensions Pack, published by HL7 International / FHIR Infrastructure. This guide is not an authorized publication; it is the continuous build for version 5.4.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/fhir-extensions/ and changes regularly. See the Directory of published versions

Extension: Parameter definition

Official URL: http://hl7.org/fhir/StructureDefinition/cqf-parameterDefinition Version: 5.4.0
Standards status: Trial-use Maturity Level: 2 Responsible: HL7 International / Clinical Decision Support Computable Name: ParameterDefinition
Other Identifiers: OID:2.16.840.1.113883.4.642.5.1578

The definition of a parameter that is expected to be provided as part of the invocation of the trigger.

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:

($this is ParameterDefinition).not() or ($this.ofType(ParameterDefinition).type in ('BackboneElement' | 'Extension'))

Usage info

Usages:

  • This Extension is not used by any profiles in this Specification

You can also check for usages in the FHIR IG Statistics

Changes since version 5.3.0:

  • No changes
  • Formal Views of Extension Content

    Description of Profiles, Differentials, Snapshots, and how the XML and JSON presentations work.

    This structure is derived from Extension

    Summary

    Simple Extension with the type ParameterDefinition: The definition of a parameter that is expected to be provided as part of the invocation of the trigger.

    Maturity: 2

    This structure is derived from Extension

    NameFlagsCard.TypeDescription & Constraints    Filter: doco
    Extension 0..* Extension What parameter
    Extension.extension 0..0 Extension
    Extension.url 1..1 uri "http://hl7.org/fhir/StructureDefinition/cqf-parameterDefinition"
    Extension.value[x] 1..1 ParameterDefinition Value of extension

    doco Documentation for this format
    NameFlagsCard.TypeDescription & Constraints    Filter: doco
    Extension 0..* Extension What parameter
    Extension.id 0..1 id Unique id for inter-element referencing
    Extension.extension 0..0 Extension
    Slice: Unordered, Open by value:url

    Slicing Note: The rules on this element (including its children) apply to all the slices, but are not repeated in them
    Extension.url 1..1 uri "http://hl7.org/fhir/StructureDefinition/cqf-parameterDefinition"
    Extension.value[x] 1..1 ParameterDefinition Value of extension

    doco Documentation for this format

    This structure is derived from Extension

    Summary

    Simple Extension with the type ParameterDefinition: The definition of a parameter that is expected to be provided as part of the invocation of the trigger.

    Maturity: 2

    Differential View

    This structure is derived from Extension

    NameFlagsCard.TypeDescription & Constraints    Filter: doco
    Extension 0..* Extension What parameter
    Extension.extension 0..0 Extension
    Extension.url 1..1 uri "http://hl7.org/fhir/StructureDefinition/cqf-parameterDefinition"
    Extension.value[x] 1..1 ParameterDefinition Value of extension

    doco Documentation for this format

    Snapshot View

    NameFlagsCard.TypeDescription & Constraints    Filter: doco
    Extension 0..* Extension What parameter
    Extension.id 0..1 id Unique id for inter-element referencing
    Extension.extension 0..0 Extension
    Slice: Unordered, Open by value:url

    Slicing Note: The rules on this element (including its children) apply to all the slices, but are not repeated in them
    Extension.url 1..1 uri "http://hl7.org/fhir/StructureDefinition/cqf-parameterDefinition"
    Extension.value[x] 1..1 ParameterDefinition Value of extension

    doco Documentation for this format

     

    Other representations of profile: CSV, Excel, Schematron

    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()

    R4B

    The extension is unchanged in R4B

    R4

    The extension is unchanged in R4

    R3

    The extension is represented a little differently in R3:

    • Replace the type ParameterDefinition with a set of extensions for the content of the type along with the _datatype extension
    • Note: Extensions that have been modified for R3 are still draft while real-world experience is collected
    Name Flags Card. Type Description & Constraints      Filter: doco
    Extension 0..* Extension What parameter
    Extension. Slices for extension 0 ..* Extension Extension
    Slice: Unordered, Open by value:url
    Extension.Slices for extension. extension:_datatype 1..1 (Complex) DataType name 'ParameterDefinition' from R5
    URL: http://hl7.org/fhir/StructureDefinition/_datatype
    Extension.Slices for extension.extension:_datatype. value[x] 1.. 1 string Value of extension
    Fixed Value: ParameterDefinition
    Extension.Slices for extension. extension:name 0..1 Extension Name used to access the parameter value
    Extension.Slices for extension.extension:name. extension 0 .. 0 Extension
    Extension.Slices for extension.extension:name. url 1 .. 1 uri "name"
    Extension.Slices for extension.extension:name. value[x] 1.. 1 code Value of extension
    Extension.Slices for extension. extension:use 1..1 Extension in | out
    Extension.Slices for extension.extension:use. extension 0 .. 0 Extension
    Extension.Slices for extension.extension:use. url 1 .. 1 uri "use"
    Extension.Slices for extension.extension:use. value[x] 1.. 1 code Value of extension
    Binding: OperationParameterUse ( required ) : Whether the parameter is input or output.
    Extension.Slices for extension. extension:min 0..1 Extension Minimum cardinality
    Extension.Slices for extension.extension:min. extension 0 .. 0 Extension
    Extension.Slices for extension.extension:min. url 1 .. 1 uri "min"
    Extension.Slices for extension.extension:min. value[x] 1.. 1 integer Value of extension
    Extension.Slices for extension. extension:max 0..1 Extension Maximum cardinality (a number of *)
    Extension.Slices for extension.extension:max. extension 0 .. 0 Extension
    Extension.Slices for extension.extension:max. url 1 .. 1 uri "max"
    Extension.Slices for extension.extension:max. value[x] 1.. 1 string Value of extension
    Extension.Slices for extension. extension:documentation 0..1 Extension A brief description of the parameter
    Extension.Slices for extension.extension:documentation. extension 0 .. 0 Extension
    Extension.Slices for extension.extension:documentation. url 1 .. 1 uri "documentation"
    Extension.Slices for extension.extension:documentation. value[x] 1.. 1 string Value of extension
    Extension.Slices for extension. extension:type 1..1 Extension What type of value
    Extension.Slices for extension.extension:type. extension 0 .. 0 Extension
    Extension.Slices for extension.extension:type. url 1 .. 1 uri "type"
    Extension.Slices for extension.extension:type. value[x] 1.. 1 code Value of extension
    Binding: FHIRTypes ( required ) : List of FHIR types (resources, data types).
    Extension.Slices for extension. extension:profile 0..1 Extension What profile the value is expected to be
    Extension.Slices for extension.extension:profile. extension 0 .. 0 Extension
    Extension.Slices for extension.extension:profile. url 1 .. 1 uri "profile"
    Extension.Slices for extension.extension:profile. value[x] 1.. 1 uri Value of extension
    Extension. url 1 .. 1 uri "http://hl7.org/fhir/StructureDefinition/cqf-parameterDefinition"
    Extension. value[x] 0 .. 0 Value of extension

    doco Documentation for this format

    Search Parameters for this Extension

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