<status value="active" /> <date value="2026-02-27" /> <publisher value="ITCC Consortium" /> <description value="Extension to record patient age in months at the time the specimen was extracted." /> <fhirVersion value="4.0.1" /> <kind value="complex-type" /> <abstract value="false" /> <type value="Extension" /> <baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension" /> <derivation value="constraint" /> <differential> <element id="Extension"> <path value="Extension" /> <short value="Age at specimen extraction (months)" /> <min value="0" /> <max value="1" /> </element> <element id="Extension.url"> <path value="Extension.url" /> <min value="1" /> <max value="1" /> <fixedUri value="https://www.itcc-consortium.org/fhir/StructureDefinition/itcc-core-specimen-age-ext" /> </element> <element id="Extension.value[x]"> <path value="Extension.value[x]" /> <min value="1" /> <max value="1" /> <type> <code value="Quantity" /> </type> </element> <element id="Extension.valueQuantity.value"> <path value="Extension.valueQuantity.value" /> <min value="1" /> <max value="1" /> </element> <element id="Extension.valueQuantity.system"> <path value="Extension.valueQuantity.system" /> <min value="1" /> <max value="1" /> <fixedUri value="http://unitsofmeasure.org" /> </element> <element id="Extension.valueQuantity.code"> <path value="Extension.valueQuantity.code" /> <min value="1" /> <max value="1" /> <fixedCode value="mo" /> </element> <element id="Extension.valueQuantity.unit"> <path value="Extension.valueQuantity.unit" /> <min value="0" /> <max value="1" /> </element> </differential> </StructureDefinition>