description: This extension provides a reference to the DiagnosticReport instance that is associated with this Composition. package_name: hl7.fhir.uv.lab-report.r4b derivation: constraint name: DiagnosticReportReference type: Extension elements: extension: {index: 0} url: pattern: {type: Uri, value: 'http://hl7.org/fhir/uv/lab-report/StructureDefinition/composition-diagnosticReportReference'} index: 1 value: choices: [valueReference] index: 3 valueReference: type: Reference choiceOf: value refers: ['http://hl7.org/fhir/StructureDefinition/DiagnosticReport'] index: 4 package_version: 1.0.0-ballot extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/uv/lab-report/StructureDefinition/composition-diagnosticReportReference base: http://hl7.org/fhir/StructureDefinition/Extension version: 1.0.0-ballot