This element is meant to denote quantities of items such as medications.

Data model

Definition of the Quantity element
Field Type Status Description
unit OntologyClass required The kind of unit.
value double required the value of the quantity in the units e.g. 2.0 mg


          "id": "NCIT:C28253",
          "label": "Milligram"
  "value": 30


Ontology terms for units can be taken from the National Cancer Institute Thesaurus (NCIT), from the subhierarchy for Unit of Measure (Code C25709).


The corresponding value of the quantity in the units. In the example, a Quantity element for 30 mg is shown.