description: 'R4B: `EvidenceVariable.characteristic.definition[x]` (new:canonical(Resource), CodeableConcept, Expression, Reference(Group,EvidenceVariable))' package_name: hl7.fhir.uv.xver-r4b.r5 derivation: constraint name: ExtensionEvidenceVariable_Characteristic_Definition type: Extension elements: url: base: {max: '1', min: 1, path: Extension.url} pattern: {type: Uri, value: 'http://hl7.org/fhir/4.3/StructureDefinition/extension-EvidenceVariable.characteristic.definition'} index: 0 value: base: {max: '1', min: 0, path: 'Extension.value[x]'} short: What code or expression defines members? choices: [valueReference, valueCanonical, valueCodeableConcept, valueExpression] index: 2 valueReference: short: What code or expression defines members? refers: ['http://hl7.org/fhir/4.3/StructureDefinition/profile-EvidenceVariable|0.1.0', 'http://hl7.org/fhir/4.3/StructureDefinition/profile-Group|0.1.0', 'http://hl7.org/fhir/StructureDefinition/EvidenceVariable|5.0.0', 'http://hl7.org/fhir/StructureDefinition/Group|5.0.0'] type: Reference base: {max: '1', min: 0, path: 'Extension.value[x]'} choiceOf: value index: 3 valueCanonical: short: What code or expression defines members? type: canonical base: {max: '1', min: 0, path: 'Extension.value[x]'} choiceOf: value index: 4 valueCodeableConcept: short: What code or expression defines members? type: CodeableConcept base: {max: '1', min: 0, path: 'Extension.value[x]'} choiceOf: value index: 5 valueExpression: short: What code or expression defines members? type: Expression 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/4.3/StructureDefinition/extension-EvidenceVariable.characteristic.definition base: http://hl7.org/fhir/StructureDefinition/Extension|5.0.0 version: 0.1.0 required: [url, valueReference, valueCanonical, valueExpression, value, valueCodeableConcept]