Sharing Valuesets, Codes, and Maps (SVCM), published by IHE IT Infrastructure Technical Committee. This guide is not an authorized publication; it is the continuous build for version 1.5.2-current built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/IHE/ITI.SVCM/ and changes regularly. See the Directory of published versions

2:3.97 Expand Value Set [ITI-97]

This section corresponds to transaction [ITI-97] of the IHE IT Infrastructure Technical Framework. Transaction [ITI-97] is used by the Terminology Consumer and Terminology Repository Actors.

2:3.97.1 Scope

This transaction is used by the Terminology Consumer to expand a given ValueSet to return the full list of concepts available in that ValueSet. The request is received by the Terminology Repository. The Terminology Repository processes the request and returns a response of the expanded ValueSet.

2:3.97.2 Actor Roles

Table 2:3.97.2-1: Actor Roles

2:3.97.3 Referenced Standards

• HL7 FHIR standard R4 http://hl7.org/fhir/R4/index.html

2:3.97.4 Messages

Figure 2:3.97.4-1: Interaction Diagram

2:3.97.4.1 Expand Value Set Request Message

The Expand Value Set Request message is a FHIR $expand operation on the ValueSet Resource.

2:3.97.4.1.1 Trigger Events

A Terminology Consumer triggers an Expand Value Set Request to a Terminology Repository according to the business rules for the expansion. These business rules are outside the scope of this transaction.

2:3.97.4.1.2 Message Semantics

A Terminology Consumer initiates an $expand request using HTTP GET as defined at http://hl7.org/fhir/R4/valueset-operation-expand.html on the ValueSet Resource. The required input parameters are identified in Table 3.97.4.1.2-1.

The URL for this operation is:

[base]/ValueSet/$expand?[parameter=value]

Where [base] is the URL of Terminology Repository.

See ITI TF-2: Appendix W for informative implementation material for this transaction.

Table 2:3.97.4.1.2-1: Expand Value Set Message HTTP Input Parameters

2:3.97.4.1.2.1 Example Request Message

An example request message from http://hl7.org/fhir/valueset-operation-expand.html is:

GET [base]/ValueSet/$expand?url=http://acme.com/fhir/ValueSet/23

2:3.97.4.1.3 Expected Actions

The Terminology Repository shall process the input parameters to discover the ValueSet that matches the parameters given and return a response as per Section 2:3.97.4.2 or an OperationOutcome with an error message.

2:3.97.4.2 Expand Value Set Response Message

2:3.97.4.2.1 Trigger Events

The Terminology Repository found expanded value set matching the input parameters specified by the Terminology Consumer as a result of a Expand Value Set Request.

2:3.97.4.2.2 Message Semantics

See ITI TF-2: Appendix Z.6 for more details on response format handling. See ITI TF-2: Appendix Z.7 for handling guidance for Access Denied.

The response message is a FHIR ValueSet Resource with the expansion element populated with the expanded ValueSet concepts.

2:3.97.4.2.2.1 Example Response Message

An example response message from http://hl7.org/fhir/valueset-operation-expand.html is:

HTTP/1.1 200 OK
[other headers]

<ValueSet xmlns="http://hl7.org/fhir">
  <!-- the server SHOULD populate the id with a newly created UUID
    so clients can easily track a particular expansion -->
  <id value="43770626-f685-4ba8-8d66-fb63e674c467"/>
  <!-- no need for meta, though it is allowed for security labels, profiles -->

  <!-- other value set details -->
  <expansion>
    <!-- when expanded -->
    <timestamp value="20141203T08:50:00+11:00"/>
    <contains>
      <!-- expansion contents -->
    </contains>
  </expansion>
</ValueSet>

2:3.97.4.2.3 Expected Actions

The Terminology Consumer has received the response and continues with its workflow.

2:3.97.5 Security Considerations

See the general Security Consideration in ITI TF-1: 51.5.

2:3.97.5.1 Security Audit Considerations

Note that the same audit message is recorded by both Terminology Consumer and Repository. The difference being the Audit Source element. Both sides record to show consistency between the message sent by the Consumer and the action taken at the Registry.

The actors involved shall record audit events according to the Audit Event for Expand Value Set by the Terminology Consumer and Repository.