description: Statement about the degree of clinical certainty that the specific substance was the cause of the manifestation in this reaction event. package_name: hl7.fhir.uv.extensions derivation: constraint name: AICertainty type: Extension elements: extension: {index: 0} url: pattern: {type: Uri, value: 'http://hl7.org/fhir/StructureDefinition/allergyintolerance-certainty'} index: 1 value: choices: [valueCodeableConcept] index: 3 valueCodeableConcept: {type: CodeableConcept, choiceOf: value, index: 4} package_version: 5.1.0-cibuild extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/StructureDefinition/allergyintolerance-certainty base: http://hl7.org/fhir/StructureDefinition/Extension version: 5.1.0-cibuild required: [value, valueCodeableConcept]