14 Terminology

HDR FHIR supports a terminology feature to use and manage code.

The general pattern for representing coded values in resources uses the following four elements:

• system - A URI that identifies the system
• version - A string value representing a version of the original code system
• code - A string value that identifies a concept as defined by the code system
• display - A description of the concept as defined by the code system

Example:

{ 
  "system" : "http://loinc.org",
  "version" : "2.62",
  "code" : "55423-8",
  "display" : "Number of steps in unspecified time Pedometer"
}

• Uploading CodeSystems
  In most cases, it is useful to upload your own CodeSystems for use in HDR FHIR Repository. This might mean uploading external Terminologies such as LOINC/SNOMED or loading custom terminologies such as local CodeSystems defined for organizational specific use.
• Applying Deltas to CodeSystems
  A pair of FHIR operations can be used to add or remove codes from the CodeSystems. These operations directly add or remove the codes from the specified CodeSystem.
• ValueSet
  The FHIR Specification defines two resource types that are used as a part of defining and using codes.