description: References a resource or provides a code or text that specifies a substance that is added to a laboratory specimen (part of the container device or added to the specimen indenpendently).
package_name: hl7.fhir.uv.extensions.r4b
derivation: constraint
name: SpecimenAdditive
type: Extension
elements:
  extension: {index: 0}
  url:
    pattern: {type: uri, value: 'http://hl7.org/fhir/StructureDefinition/specimen-additive'}
    type: uri
    index: 1
  value:
    choices: [valueCodeableReference]
    index: 3
  valueCodeableReference: {type: CodeableReference, choiceOf: value, index: 4}
package_version: 5.3.0-ballot-tc
extensions: {}
class: extension
kind: complex-type
url: http://hl7.org/fhir/StructureDefinition/specimen-additive
base: http://hl7.org/fhir/StructureDefinition/Extension
version: 5.3.0-ballot-tc
required: [value, valueCodeableReference]