description: The amount of time that the Adverse Reaction persisted. package_name: hl7.fhir.r3.examples derivation: constraint name: duration type: Extension elements: extension: {index: 0} url: type: uri pattern: {type: Uri, value: 'http://hl7.org/fhir/StructureDefinition/allergyintolerance-duration'} index: 1 valueDuration: {type: Duration, index: 2} package_version: 3.0.2 extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/StructureDefinition/allergyintolerance-duration base: http://hl7.org/fhir/StructureDefinition/Extension version: null