Snowstorm FHIR API does not interpret ECL v2.0 query correctly (returning refset member fields) about snowstorm

[kaicode]

Hi @ulsa123,
I responded on the Jira ticket but will post again here for community visibility:

Unfortunately it is not possible for a FHIR interface to return specific fields from reference set members using ECL. It just doesn't fit in with the permitted response format.

Please remove the specific field section from the ECL to make it work:

^ 447562003 |ICD-10 complex map reference set|  {{ M mapTarget = wild:"J45*" }}

https://dailybuild-qa.northeurope.cloudapp.azure.com/snowstorm/snomed-ct/fhir/ValueSet/$expand?url=http://snomed.info/sct?fhir_vs=ecl/%5E%20447562003%20%7CICD-10%20complex%20map%20reference%20set%7C%20%20%7B%7B%20M%20mapTarget%20%3D%20wild%3A%22J45*%22%20%7D%7D&system-version=http://snomed.info/xsct/51000202101

This is consistent with other FHIR servers including Ontoserver. I do think that the ECL specification could mention this to help communicate this fact and the Snowstorm error message could be improved.

Thanks for raising this.

[kaicode]

@ulsa123 you can fetch refset member fields using the native Snowstorm API:
https://snowstorm.ihtsdotools.org/snowstorm/snomed-ct/MAIN/SNOMEDCT-NO/concepts?ecl=%5E%20%20%5BmapAdvice%5D%20447562003%20%7CICD-10%20complex%20map%20reference%20set%7C%20%20%7B%7B%20M%20mapTarget%20%3D%20wild%3A%22J45*%22%20%7D%7D
.. it's just not supported in FHIR APIs.

[ulsa123]

Yes, and that is usefull.
We considered The FHIR api to dynamically populate and expand a FHIR valueset with expressions.

[kaicode]

It's a good idea to use the FHIR interface wherever you can. It's a shame the refset member fields sit outside of this.

Expanding ValueSets with expressions should work in FHIR once that is implemented. A workflow for this is in discussion with the SNOMED on FHIR working group.

[kaicode]

I'm not sure if this helps but the latest implementation of the FHIR API in the Snowstorm X project returns the ICD-10 map advice when translating SNOMED CT codes to ICD-10.
e.g. https://dev-is-browser.ihtsdotools.org/fhir/ConceptMap/$translate?code=254153009&system=http://snomed.info/sct&targetsystem=http://hl7.org/fhir/sid/icd-10

This version of Snowstorm is available here: https://github.com/IHTSDO/snowstorm-x/releases

[kaicode]

@ulsa123 I think your issue has already been resolved but just to let you know..

Snowstorm version 8.1.0 has just been published https://github.com/IHTSDO/snowstorm/releases
The new version of the FHIR API includes the ICD-10 complex map advice in the response message field when using $translate.
Unfortunately there is still no standard way to do this in FHIR R4. I heard that it might get introduced in the FHIR R5 specification.