What are Valuesets?

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 value sets can be tested to determine whether or not it is a member of the set.

Infoway's Canadian Standards Release Centre maintains ValueSets in partnership with with Provincial, Territorial, and Federal e-Health agencies from across Canada working towards the successful implementation of National digital health solutions. These ValueSets are hosted on the Terminology server for jurisdictions and organizations to utilize. ValueSets are hosted on Infoway's FHIR Terminology Server.

ValueSets vs Subsets

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).

The terms “ValueSet” and “Subset” are used interchangeably. Specific to SNOMED CT (Systematized Nomenclature of Medicine Clinical Terms), a reference set (or refset) is a standardized format used to maintain and distribute a curated list of references to SNOMED CT components.

Types of ValueSets 

ValueSets can be grouped into categories. The categories listed below are different ways of looking at ValueSets and are not mutually exclusive:

  1. Data capture vs Data retrieval ValueSets: 

ValueSets may be used for data capture (eg, used by a physician at the point of care in an EMR to record a procedure or service provided) or for data retrieval (eg, used by a physician for retrieving information about patients who have received a specific set of procedures or services). In some cases, the content in these types of ValueSets may differ.

       2. Physician specialty vs Electronic health system-specific field ValueSet

ValueSets may be developed for physician specialties or sub-specialties (eg, cardiology or interventional cardiology) or for a more general use case (eg, immunizations, Evaluation and Management). For example, the cardiology physician specialty subset should include all procedures and services a cardiologist may conduct or perform, while an immunizations subset should contain a list of all immunization procedures and will not be limited to one physician specialty; it may be used by a general practitioner or a pediatrician to record immunizations done.

      3. Intensional vs Extensional ValueSets SNOMED CT Example

ValueSets can be developed intensionally or extensionally. The term “extensional ValueSets” refers to explicitly enumerating each and every code and/or Clinician Descriptor. On the other hand, the term “intensional ValueSets” refers to specifying the sections/hierarchies and/or subheadings that contain content that is to be included in a ValueSet. 

     4. Concept/Code Subsets vs Clinician Descriptions ValueSets

ValueSets can be developed at the code/term level or at the Clinician Descriptors level. 

Clinician Descriptor's (CDs) purpose is to clearly and specifically describe precisely the procedure or service performed by a physician/doctor or qualified healthcare professional at the point of care. Clinician Descriptors will also reflect the granularity necessary to describe clinically relevant information. As a result, many existing codes will be mapped to more than one CD. These CDs will be easily understandable to the physicians/doctors or other qualified healthcare professionals who have little or no knowledge of coding and are primarily concerned with the clinical representation of the data rather than other aspects of the data e.g. the administrative or claim reimbursement.

Clinician Descriptors are more specific services or procedures that are included in the catalogues such as the Ontario Schedule of Benefits.

These ValueSets types can be created by many methods, but here are a few commonly used: 

  1. Manual inclusion, using search and browse methods
  2. An existing ValueSet, used as a starting point for further manual inclusion and update
  3. Lexical queries, to identify candidate members, followed by manual verification and update
  4. Hierarchical queries, to identify descendants of a given concept (e.g. descendants of <73211009 |diabetes mellitus|)
  5. Attribute queries, to identify concepts with a specific attribute value (e.g. disorders with a finding site of 80891009 |heart structure|
  6. SNOMED CT queries, using the SNOMED CT Expression Constraint or Query languages, which offer additional query functionality.

pan Canadian ValueSets Maintenance 

The ongoing maintenance of Pan-Canadian value sets is a critical component of ensuring their quality, relevance, and effectiveness in supporting national interoperability. Managed by the CSRC, this process involves regular updates against standards release cycles. The process is responsive to change requests from implementers to ensure terminologies continue to evolve and remain fit for purpose.

Pan-Canadian guidelines specify how value sets should be created, curated, and maintained to ensure their accuracy and relevance across jurisdictions. They must include concepts that are applicable to at least two or more provinces or territories and align with nationally or federally mandated initiatives, such as the Pan-Canadian Health Data Content Framework or the Shared Pan-Canadian Interoperability Roadmap.

The pan-Canadian ValueSets may contain content from international terminologies and content specific to Canada, which is dependent on the international version. The pan-Canadian ValueSets are reviewed on an annual basis, SNOMED CT Canadian edition ValueSets updated are aligned to the release of SNOMED CT Canadian edition releases.

Two ValueSets HealthCareProviderRoleType and QualifiedRoleType use the SC code systems (SCPQUAL, SCPTYPE) (the "SC Code Systems") which was a code system developed by Canada Health Infoway Inc. (Infoway) to address local requirements in Canada.  SC was an abbreviation for "Standards Collaborative"

Where to find the ValueSet Template

Download the ValueSet Template from Informs or from here

How to create New ValueSets

  1. Download the ValueSet Template from InfoRMS Subset RFC project
  2. Complete the Subset Definition template. Refer to the "How to Complete" tab for guidance or contact [email protected] for assistance
  3. All Field in Red are mandatory and must be completed
  4. Refer to the Naming Convention for pan-Canadian Subsets Sets and Valuesets to create a name for the subset definition
  5. Request the ValueSet ID which is an OID, but if you are the owner of the Subset, you may provide your own unique identifier
  6. Ensure that the ValueSet name and ID is not used in used by checking the OID's for subsets
  7. Select the Codesystem(s) (SNOMED CT Canadian edition, LOINC, UCUM, HL7) You may have more than one to cover a clinical domain in some cases and if you need further guidance, contact [email protected] 
  8. Submit in InfoRMS for Review

How to Change a Valuesets

  1. Download the ValuSet from the Terminology Server in Excel format
  2. Update the fields in the downloaded file with the new information on the Subset Definition Tab
  3. An update can be done to achieve the following: Add a new code, modify a term or a code and inactivate a term or a code
  4. If Changes are made to the display names, there is an option to view the comparison from last version of the valueset which should reflect all changes applied.
  5. It may be required to validate the status of all other codes and terms in the subset before re-publishing if the terminology has been updated since the last release
    1. If the changes were only on the Concept Tab, change the «Subset version» to reflect the date of publication
    2. If the terminology versions have changed, update the «Terminology version» field
    3. If the change is to the Subset name or Subset ID (OIDS), which is always unique to each subset, contact the HL7 OIDS resource at [email protected] , to confirm the OID s unique. If the OID is unique then it can be assigned by the Subset RFC SME
  6. In InfoRMS, select the "Update Subset" as the issue type and complete the mandatory fields identified with an asterisk "*"
  7. Attach the completed Subset RFC template
  8. Once the ValueSet is updated and finalized, it will be copied into the be loaded to the UAT environment of the Terminology Server for QA

How to Retire a ValueSet

  1. Download the subset from the Terminology Server in Excel format
  2. Create a new Subset RFC by selecting the «Create» button
  3. Fill in the UI information and attach the Batch template 
  4. Complete the mandatory fields for the Requestor in InfoRMS
  5. Add a comment on the Subset RFC, the subset will be deprecated in one (1) year from now.
  6. When the one year is reached, add a comment on the RFC this subset is now Deprecated
  7. Use the InfoScribe page to identify the Inactivated subsets that will be deprecated the following year
  8. After one year ask IMT will remove the subset from the database

Quality Assurance (QA)

QA check covers the subset's metadata information and the terminology values, which include the correctness of concepts selected and the appropriate representation of the components as per the subset's template. It also covers basics data 

  1. For pan Canadian Subset which is found in the Terminology Gateway under the Subsets section. The QA is done by the Subset SME only and the standards team. It does not involve any external stakeholder.
  2. Additional Terminology Content Subsets in the Terminology Gateway require the Subset owner to validate the contents, in the UAT environment of the Terminology Gateway.
    1. Subset owners will need to be provided access to UAT for QA purposes.
    2. The Subset owner will check the subset loaded in the Terminology Gateway UAT environment (see Staging ribbon in yellow in bottom right) correctly and represents the request. Any errors must be logged in the InfoRMS Ticket and commented. A corrected template must be attached to the InfoRMS ticker and loaded in QA UAT.
    3. Once QA is complete in the UAT. sign off in InfoRMS is required before it will be promoted to the Production environment.
    4. The subset owner will check the subset has been correctly loaded in TG Prod and sign off in the InfoRMS (Release form)

Naming Convention for pan-Canadian Subsets and ValueSets 

Please refer to the Naming Convention for pan-Canadian Subsets and Valuesets.pdf document for detailed rules for consistent naming of pan-Canadian Subsets and ValueSets


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