The official version of the OHIE workflows can be found in the OpenHIE Architecture Specification.


Description: This transaction allows a PoS, or any OHIE component, to access terminological information in the terminology service and retrieve the set of all Concepts in the Value Set. Rather than testing each code contained in an incoming patient data message for Value Set membership, this operation enables a component to "cache" the Value Set members and test individual membership locally, avoiding extensive network overhead. Due to the likely updating of Value Set definitions, on the other hand, components should periodically refresh their local copy of the expansion.

Both external systems and systems inside the HIE may perform this transaction directly with the TS.  The sequence diagram below shows the steps that occur for a system using this transaction.   

  1. Expansion: Retrieve the set of Concept Codes that are members of the HIV Value Set.

Sponsor:  Jack Bowie

Status:  This operation has been extensively tested in FHIR Connectathons. 

Referenced Standards and APIs

Assumptions and Prerequisites


Technical details

Below enter each interaction that makes up the described workflow above.

RefInteractionEndpointDataTransaction Specification
1ValueSet expansion requestTS

The expand request is triggered by a PoS or other HIE component.

Input: The target ValueSet.

FHIR ValueSet Resource, $expand operation
2ValueSet expansion responsePoS

The response is sent back to the requesting system.

Output: a ValueSet Resource containing the list of Concept members..

 FHIR ValueSet Resource, $expand operation