description: 'R4: `EvidenceVariable.characteristic.participantEffective[x]` (new:dateTime, Duration, Period, Timing)' package_name: hl7.fhir.uv.xver-r4.r4b derivation: constraint name: ExtensionEvidenceVariable_Characteristic_ParticipantEffective type: Extension elements: url: base: {max: '1', min: 1, path: Extension.url} pattern: {type: Uri, value: 'http://hl7.org/fhir/4.0/StructureDefinition/extension-EvidenceVariable.characteristic.participantEffective'} index: 0 value: base: {max: '1', min: 0, path: 'Extension.value[x]'} short: What time period do participants cover choices: [valueDateTime, valuePeriod, valueDuration, valueTiming] index: 2 valueDateTime: short: What time period do participants cover type: dateTime base: {max: '1', min: 0, path: 'Extension.value[x]'} choiceOf: value index: 3 valuePeriod: short: What time period do participants cover type: Period base: {max: '1', min: 0, path: 'Extension.value[x]'} choiceOf: value index: 4 valueDuration: short: What time period do participants cover type: Duration base: {max: '1', min: 0, path: 'Extension.value[x]'} choiceOf: value index: 5 valueTiming: short: What time period do participants cover type: Timing base: {max: '1', min: 0, path: 'Extension.value[x]'} choiceOf: value index: 6 package_version: 0.1.0 class: extension kind: complex-type url: http://hl7.org/fhir/4.0/StructureDefinition/extension-EvidenceVariable.characteristic.participantEffective base: http://hl7.org/fhir/StructureDefinition/Extension|4.3.0 version: 0.1.0 required: [url]