9.11.1Remote Terminology Service

 

The Remote Terminology Service Enabled setting enables the use of a remote terminology service for validation. This can be useful in situations where a central terminology service exists that should be used by all FHIR services for an organization, or where a specialized terminology server should be used for advanced validation.

Remote Terminology Services

9.11.2Scope

 

As shown in the diagram above, a Remote Terminology Service may be used with either Endpoint Validation or Repository Validation.

The remote terminology service must be configured on the FHIR Storage module that is being used for validation support. When enabled, profile StructureDefinition resources will still be fetched directly from the validation support repository, but any validatation request operations (e.g. $lookup, $validate-code, $expand, $translate) will be forwarded to the remote terminology server.

9.11.3Remote Terminology Server Requirements

 

This setting expects to be configured by providing the base URL for a server that implements the FHIR Terminology Service profile. When using a remote terminology server, the following operations may be invoked against the remote server on an as-needed basis:

  • GET [base]/CodeSystem?url=[url] – Tests whether a given CodeSystem is supported on the server
  • GET [base]/ValueSet?url=[url] – Tests whether a given ValueSet is supported on the server
  • POST [base]/CodeSystem/$validate-code – Validate codes in fields where no specific ValueSet is bound
  • POST [base]/ValueSet/$validate-code – Validate codes in fields where a specific ValueSet is bound
  • POST [base]/CodeSystem/$lookup – Concept lookup and decomposition
  • POST [base]/ConceptMap/$translate – Concept translation

Please note that POST [base]/CodeSystem/$lookup is not implemented for R5 at the moment.

FHIR Terminology Servers known to work in this configuration include:

  • A separate Smile CDR FHIR Repository and FHIR Endpoint can be used as a central terminology server. This might be loaded with custom terminology, and/or preloaded with relevant Packages.
  • CSIRO Ontoserver provides an excellent and full-featured terminology service which includes complete support for many common standard vocabularies.