description: Specifies whether the related artifact is defining a primary citation for the measure (i.e. one that should appear in the narrative for the measure specification. package_name: hl7.fhir.us.cqfmeasures derivation: constraint name: PopulationBasis type: Extension elements: url: type: uri pattern: {type: Uri, value: 'http://hl7.org/fhir/us/cqfmeasures/StructureDefinition/cqfm-isPrimaryCitation'} index: 0 value: choices: [valueBoolean] index: 2 valueBoolean: {type: boolean, choiceOf: value, index: 3} package_version: 1.1.0 class: extension kind: complex-type url: http://hl7.org/fhir/us/cqfmeasures/StructureDefinition/cqfm-isPrimaryCitation base: http://hl7.org/fhir/StructureDefinition/Extension version: 1.1.0