A number of FHIR Terminology Service Operations have unique considerations when working with SNOMED CT
| Operation Name | Resource | Considerations | Priority for implementation |
|---|
| $validate-code | ValueSet | Further discussion by the SNOMED on FHIR working group can be read here: Implementing Terminology Services with SNOMED CT | 2b |
| $validate-code | CodeSystem |
| 2b |
| $expand | ValueSet | Implicit valuesets (Valuesets defined using ECL), filters, POST (upload) valuesets | 1 |
| $lookup | CodeSystem |
| 2 |
| $translate | ConceptMap |
| 5 |
| $subsumes | CodeSystem |
| 3 |
| $closure | ConceptMap |
| 4 |
| $find-matches | CodeSystem | See Find Matches, however using the $expand operation with ECL will allow for more expressive querying. | 6 |
Best Practice Discussions
Paging - note that the $expand operation defines its own offset and count (count be 0 if you're interested in the total number of matches)
Limits on value set sizes - 1M configurable limit, default page size of 1K
Default language considerations - http headers, server settings (Link to Reuben's work and discussion of X-headers for LangRefsets)
Algorithms for text searching (reference implementation course eg "PNE PNE" finding Pneumococcal pneumonia)