Appendix A: Summary of Types and Use Cases

Terminology Service Requirement Types

This section summarizes the main types of terminology service requirements. For each requirement type, typical use cases are identified, along with how terminology services are applied to those use cases.

Summary of Requirement Types

Required Terminology Services	Use Cases	Application to Use Cases
Select Edition and Version	All	Required unless the server only hosts one edition and version. These settings are applied before or as part of a service request.
Get a Concept, Description, or Relationship	- Explore and review SNOMED CT - EHR data entry - EHR data entry design - EHR reporting and analytics - Reference set editing - Terminology authoring and review	Retrieve specified concepts to explore their descriptions, definitions, and hierarchy position; record data in an EHR; constrain UI templates; add concepts to reports or subsets; select attributes and values for authoring.
Get Terms for a Concept	- Explore and review SNOMED CT - EHR data entry design - EHR data entry - Display EHR data - Reporting and analytics - Authoring and review	Display terms in search results, hierarchies, UI templates, EHR data displays, human-readable reports, and concept definitions.
Get Definition of a Concept	- Explore and review SNOMED CT - Authoring and review	Display inferred definitions from relationships and stated definitions from OWL axioms. Show both in authoring environments.
Get and Test Concept Subtypes and Supertypes	- Explore and review SNOMED CT - EHR data entry design - EHR data entry - Reporting and analytics	Display hierarchy views, apply subtype constraints in templates, constrain searches for entry, and apply subsumption tests in queries.
Get and Test Reference Set Membership	- EHR data entry design - EHR data entry - Reporting and analytics - Reference set editing	Constrain searches by reference set membership, list reference set members for entry, and apply membership tests in queries and subset editing.
Validate and Apply Expression Constraints	- EHR data entry design - EHR data entry - Reporting and analytics - Reference set editing	Apply expression constraints in templates, searches, reports, and analytics. Define subsets using intentional definitions.
Find Concepts	- Explore and review SNOMED CT - EHR data entry - EHR data entry design - Reporting and analytics - Authoring and review	Search for concepts to display, enter, include in templates, use in reports/queries, or define new concepts.
Identify Changes to the Terminology	- Terminology change management - Manage impact of changes on EHR apps - Manage impact on extensions	Identify added/changed/inactivated components, review inactive concepts in templates, records, and queries, and assess extension dependencies.
Get Data from a Reference Set	- Explore and review SNOMED CT	Retrieve acceptability of descriptions in language reference sets.
Get History Data	- Terminology change management - Manage impact on EHR apps - Manage impact on extensions	Identify inactivation reasons, retrieve replacements via historical associations, produce human-readable change reports, and support impact analysis.
Get Mapping Data	- Mapping data to/from another code system	Retrieve maps for concepts in a specified map reference set.
Get Concept Model Rules	- EHR data entry - EHR data entry design - Reporting and analytics - Authoring and review	Constrain and validate refinements during data entry, NLP, template design, reporting queries, and concept definitions.
Validate Concept Definitions and Expressions	- EHR data entry - EHR data entry design	Record and validate expressions when no single concept matches. Create templates that record expressions.
Test Expression Subsumption	- EHR data entry - Reporting and analytics	Apply subsumption tests in queries and include subsumed or equivalent expressions in reports.

Focus on Read-Only Services

This guide primarily focuses on read-only terminology services without a user interface.

Why Read-Only?

• Applicable to all healthcare applications that require access to SNOMED CT.

• Add-update services are only needed by those maintaining editions/extensions, which is a smaller audience.

• Update services are interdependent and require complex version control and validation, making them unsuitable for generalized documentation here.

• Detailed functionality of authoring tools is provided separately with those tools.

Why No User Interface?

• Services without a UI can be reused flexibly across different applications.

• Applications can present SNOMED CT data in their own design styles while reusing the same terminology services.

• UI-based terminology services are essentially composites of general services + UI components, with many possible combinations that cannot all be documented.

• Instead, this guide notes general examples of binding terminology services to UI controls.