Overview
The Sharing ValueSets, Codes and Maps (SVCM) Profile defines a lightweight interface through which healthcare systems may retrieve centrally managed uniform nomenclature and mappings between code systems based on the HL7 Fast Healthcare Interoperability Resources (FHIR) specification.
SVCM supports querying for value sets and code systems using the standard HL7 FHIR resources. It also supports looking up and validating codes as well as expanding a value set to list all the available codes.
Optionally concept maps can also be included to translate from one code system or value set to another (e.g. SNOMED CT to LOINC).
Terminologies managed in value sets are most useful when they are widely shared and standardized across geography and disciplines to add clarity and specificity.
Actors and Transactions
The following diagram provides an overview of the SVCM profile Actors, Transactions and their interactions.
The table below lists the transactions for each actor directly involved in the SVCM profile. To claim compliance with SVCM, an actor shall support all required transactions (labeled “R”) and may support the optional transactions (labeled “O”).
Actor | Transaction | Optionality |
|---|---|---|
Terminology Consumer | Query Value Set [ITI-95] Query Code System [ITI-96] Expand Value Set [ITI-97] Lookup Code [ITI-98] Validate Code [ITI-99] Query Concept Map [ITI-100] Translate Code [ITI-101] | O (*) O (*) O (*) O (*) O (*) O O |
Terminology Repository | Query Value Set [ITI-95] Query Code System [ITI-96] Expand Value Set [ITI-97] Lookup Code [ITI-98] Validate Code [ITI-99] Query Concept Map [ITI-100] Translate Code [ITI-101] | R R R R R O O |
(*) A Terminology Consumer shall support at least one of these transactions.
Transactions
- Query Value Set [ITI-95] - used by the Terminology Consumer to find value sets based on criteria it provides in the query parameters of the request message, or to retrieve a specific value set. Uses a FHIR ValueSet query.
- Query Code System [ITI-96] - used by the Terminology Consumer to solicit information about code systems whose data match data provided in the query parameters on the request message. Uses a FHIR CodeSystem query.
- Expand Value Set [ITI-97] - used by the Terminology Consumer to expand a given ValueSet to return the full list of concepts available in that ValueSet. Uses a FHIR $expand ValueSet operation.
- Lookup Code [ITI-98] - used by the Terminology Consumer to lookup a given code to return the full details. Uses a FHIR $lookup ValueSet or CodeSystem operation.
- Validate Code [ITI-99] - used by the Terminology Consumer to validate the existence of a given code in a value set or code system. Uses a FHIR $validate-code ValueSet or CodeSystem operation.
- Query Concept Map [ITI-100] - used by the Terminology Consumer that supports the Translate Option to solicit information about concept maps whose data match data provided in the query parameters on the request message. Uses a FHIR ConceptMap query.
- Translate Code [ITI-101] - used by the Terminology Consumer that supports the Translate Option to translate a given code from a ValueSet to a code from another ValueSet based on a ConceptMap Resource. Uses a FHIR $translate ConceptMap operation.
Sequence Diagram
Terminology Gateway
Value Sets that are part of pan-Canadian specifications are published in the Terminology Gateway. The Terminology Gateway provides a FHIR API interface compatible with the Terminology Repository SVCM actor, and implements the following transactions:
- Query Value Set [ITI-95]
- Expand Value Set [ITI-97]
- Validate Code [ITI-99]
- Query Concept Map [ITI-100]
- Translate Code [ITI-101]
For performance reasons, the Terminology Gateway isn't supposed to be queried at runtime. Instead, it is recommended to rely on its notification services to update a local database to be used for validation.