Terminology Server

Yes, you can use the following API calls to determine the latest version for code systems, such as SNOMED CT and pCLOCD within the Postman Collection. For detailed instructions on how to access the Postman Collection, please refer to the following link: Postman Instructions

• For SNOMED CT, please use the following:
  • HTTP GET
    https://terminologystandardsservice.ca/fhir/CodeSystem?url=http://snomed.info/sct&_elements=version&_sort=-version&_count=1://snomed.info/sct&_elements=version&_sort=-version&_count=1

• For pCLOCD, please use the following:
  • HTTP GET
    https://terminologystandardsservice.ca/fhir/ValueSet/$expand?url=https://fhir.infoway-inforoute.ca/CodeSystem/pCLOCD?fhir_vs&count=0

Please note that you will need to authenticate before making these requests.

Example CURL Command is provided below:

Yes, there are two ways to access this content. One method involves using an API, such as Postman, which can handle larger datasets without the limitations that may be encountered with other tools. A demonstration of this process is available in our training video, "Terminology Server Drop-in Session FHIR API" (timestamp 35:20). If you need access to the entire content, the Syndication server allows you to retrieve the full artifact.

Depending on your needs, it’s important to choose the correct format for downloading the content. We always make the FHIR representation available, with the exception of SNOMED CT CA and LOINC. For these two Code Systems, there are binary and native versions, as they cannot be represented in a flat Code System. For simpler, standard artifacts, the Syndication system provides all the necessary data.

Ontoserver is designed to be flexible and can function both as an integrated component and as a standalone solution. With the FHIR APIs, Ontoserver can support vendor-specific functions, allowing systems to find specific representations of terminology as needed.

Shrimp has been enhanced with a language toggle in the top right-hand corner, which applies to both the terminology content and the application interface, including menus and links. To browse in your preferred language, you can use the language toggle to select “en” or “fr”. Please note that as the Shrimp browser is available globally, there may be additional languages added in the menu options. For example, “id” which represents the Indonesian language. This would not apply to Canadian terminology content which is available only in EN and FR. Please see our Shrimp User Guide for more details regarding this new feature. We appreciate your continued patience as we work to further improve this functionality.

Yes, “latest” refers to the most recent version of the Code System available in the current versioning stream. We aim to ensure that the most up-to-date content is accessible in the Terminology Server. For guidance on browsing Code Systems in Shrimp, the Shrimp User Guide and Shrimp training video are available in the training resources section for your reference.

From the FHIR perspective, the national SNOMED CT CA Edition code.system is the default global code system "http://snomed.info/sct". Use of “version’ would be included to denote that a code is from the Canadian Edition. This version is based on the most dependent module (French module): http://snomed.info/sct/20611000087101.

If an implementation is not leveraging a Canadian terminology service such as Infoway’s Terminology Server that defaults to the Canadian Edition, solutions would need to include the SNOMED CT CA Edition (in the coding.version)

Examples by Use Case

1. Example of recommended format without reference to version for use in Canada in ecosystems where tooling and vendor software implicitly use the SNOMED CT CA edition in their ValueSets, terminology services (e.g. National Vaccine Catalogue):
   "vaccineCode": {
     "coding": {  {
       "system":  "http://snomed.info/sct",
         "code":  "34921000087108"
     }  }
   }
2. Example of recommended format including version for use in ecosystems where data exchange may occur with tooling and vendor software that operate in US or other jurisdictions where SNOMED CT CA edition isn’t the default. This might apply to vendors that use SNOMED International or SNOMED CT US Edition by default, for example, such as a US based vendor operating in Canada (e.g. for smartphone apps).
   "vaccineCode": {
     "coding": {  {
       "system":  "http://snomed.info/sct",
       "version": "http://snomed.info/sct/20611000087101",
         "code":  "34921000087108"
     }  }
   }

   Guidance on the application of code system versioning

   For implementers, look to the respective FHIR Implementation Guide for guidance on whether to include the code system version.

   For FHIR implementation guide authors, use the guidance above based on the expected data exchange ecosystem.
   
   
   
   
   
   
   
   
   

The Terminology Gateway is partially decommissioned as of April 30, 2025, as part of our service enhancement initiative. Since that date, the Terminology Gateway no longer publishes ongoing standard releases—with the exception of PrescribeIT® content, which remains supported on the legacy system. This means that all future standard releases will be available exclusively through our enhanced FHIR Terminology Server.

For downloading resources, please note that the final official release for SNOMED CT CA, pCLOCD, CCDD, and ValueSets on the Terminology Gateway is the March 2025 release. After this release, the Terminology Server will be the sole source for updates and downloads. We kindly encourage you to transition to the FHIR Terminology Server at your earliest convenience to take advantage of its up-to-date content and robust features. Please navigate to the training resources section to help you navigate the enhanced server and fully realize its benefits.

We appreciate your understanding and cooperation during this transition and are here to support you every step of the way.

Yes, our Ontoserver allows you to seamlessly browse, search, and download terminology content in multiple formats to fit your needs. Through FHIR APIs, you can integrate terminology content programmatically and access files in FHIR-compliant XML and JSON formats, as well as simplified CSV representations for operations like ValueSet $expand. You can automate the downloads for terminology resources using the Syndication API feed , which provides detailed listings for each CodeSystem. Additionally, the Shrimp Browser provides an intuitive way to search and explore terminology content, while our enhanced OntoCommand interface enables direct downloads of CodeSystems and ValueSet artifacts in your preferred formats.

While Ontoserver has the capability for runtime use and access by end systems, Infoway’s Terminology Server currently does not cover runtime use by end systems within its Service Level Agreement (SLA). Alternatively, the content available in the Terminology Server can be syndicated for runtime use, allowing consumer systems to have autonomous control over the terminology data.

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Your feedback is invaluable in helping us refine and improve our Terminology Server and we look forward to your continued support and collaboration to ensure that together we are driving health care interoperability forward in Canada. Please use the below contact us icon to submit your feedback.

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A ValueSet in healthcare informatics, particularly in standards like FHIR (Fast Healthcare Interoperability Resources), refers to a uniquely identifiable set of valid concept representations. This means it is a collection of codes or terms from one or more code systems, which can be used to specify the allowable values for an element in a healthcare resource. Each concept in the ValueSet can be tested to confirm whether it is included in the set or not.

In Terminology Gateway, the term “Subset” is used to identify a set where all elements are also contained in another set. In other words, if you have a set A, a subset of A (denoted B) includes only elements that are also in A. These subsets include constrained lists of allowable values or terminology from the source code systems (i.e. SNOMED CT Canadian Edition, pCLOCD, UCUM, SCP or HL7).

Therefore, the terms “ValueSet” and “Subset” are used interchangeably. Subsets previously hosted on the Terminology Gateway are the same as ValueSets now hosted on the FHIR Terminology Server. 

As part of the transition to a FHIR-based Terminology Server, there will be no changes to how ValueSets are accessed for review purposes. The Canonical ValueSet FHIR URIs in IGs should already be using the ValueSet FHIR URI and these will be mapped to the new FHIR-based Terminology Server.

Yes, the Terminology Server is designed to support all FHIR terminology operations including the ValueSets compose element (both intensional and extensional) to perform the $validate-code operation. The current approach is to load all ValueSets onto the Terminology Server as composed rather than pre-expanded. This enables enhanced functionality, including $validate-code, and allows for $expand operations. The $expand operation supports full expansion requests and a wide variety of parameterized and focused expansions. For more information, please refer to the HL7 FHIR documentation.

ValueSets will automatically be updated in the Terminology Server via releases from HL7 Terminology (THO). Updates and changes will exclusively occur within the Terminology Server. To assist you in navigating the Terminology Server and effectively accessing ValueSets, comprehensive training materials and resources are available in the training materials section. Request for additions or changes to the Value sets will need a Request for Change (RFC). 

All pan-Canadian ValueSets defined by Infoway will transition to semantic versioning as part of the migration to the new Terminology Server.

• Semantic versioning is considered a best practice, especially as we move to a fully FHIR-enabled Terminology Server. It reduces conflicts and maintenance efforts for FHIR Implementation Guide (IG) developers and implementers by providing a more consistent versioning structure. The shift addresses known limitations of dynamic versioning in the Terminology Gateway, a concern discussed and supported by the expert community. More information on these discussions can be found here: FHIR Chat Discussion on Versioning.

Changes for Implementers:

• Baseline Versioning: All ValueSets on the new Terminology Server will begin with a baseline version of 1.0.0, following semantic versioning principles for improved stability and predictability in updates.
• FHIR Implementation Guides with “Stub” ValueSets: FHIR implementation guides that employ “stub” ValueSets using date-based versioning will encounter collisions when using FHIR tooling. FHIR tooling will try to compare the date-versioned stub ValueSet against TS’s semantically-versioned ValueSet, and will fail to determine which ValueSet takes priority. FHIR guides using stub ValueSets should be republished using semantic versioning, and a reasonable backdate (e.g. 1900-01-01).
• Continuity with Terminology Gateway: The current Terminology Gateway (TG) is partially decommissioned and will only host PrescribeIT content moving forward. Versioning on the TG remains unchanged for the foreseeable future, ensuring continuity for users who still rely on it during the transition.
• Consistency and Clarity: Semantic versioning clearly communicates the significance of changes. Major updates (e.g., 2.0.0) indicate breaking changes, while minor or patch updates (e.g., 1.1.0 or 1.0.1) signify additions or fixes without disruption, aiding implementers in assessing impacts.
• Simplified Upgrades and Compatibility: Implementers gain better visibility into backward-compatible changes, streamlining the update process by clarifying when major upgrades are necessary versus when minor updates can be safely applied.
• Improved Governance and Change Management: The new versioning scheme allows implementers to align their processes for managing updates, establishing protocols to adopt changes while minimizing disruption risks.
• Impact on Implementation Timelines: Unlike date-based versioning, updates under semantic versioning will depend on the nature of changes rather than a fixed schedule, potentially altering when updates need to be applied by implementers.

This transition aims to streamline the management of ValueSets, enhance stability, and simplify the implementation process for developers and users alike.