Peter G. Williams

Rob Hausam

Recording, notes & attendance.

Check questions in Zulip and SNOMED International #snomed-hl7-fhir

Peter G. Williams

Rob Hausam

Peter G. Williams

Rob Hausam

HL7 Group TSMG (meeting Wed PM ET every other week) - Terminology Service Management Group (HTA Thursday AM is now a subgroup of the TSMG).   2022-05-17 RH Joint session with Vocab at last business meeting.  2022-06-14 Group has approved minimum capabilities for terminology servers.  Now looking at bigger/better HL7 Terminology Server 

Peter G. Williams 

See discussion pages for links to archived discussion:  Discussions

Marie-Alexandra Lambot 

Belgium Update + TX IG Support Update - authorities looking for independence from HL7 servers, partially due to performance considerations.   RH Suggested self hosted TxFHIR.org server code (needs built locally unless Windows install, see https://github.com/HealthIntersections/fhirserver ) available (or Ontoserver of course - as of v6.15).

ML suggested:  See http://tx.fhir.org/tx-reg/ and https://github.com/FHIR/ig-registry/blob/master/tx-registry-doco.md for alternative terminology server support

MAL: Is every FHIR message validated, and if so, against a separate server?  RH Having the same discussion with US implementation - unsure of consensus.   Group discussion on: if a message fails validation, what are you going to do with it?  Quarantine (can then get stuck)?    Bounce back (not implemented?).   ML Usually systems are not synchronously coupled, so a message rejection is not possible. Watch out for CodeSystem updates eg change to display text for a code suddenly causing large volumes of rejections.  Also watch out for text in ValueSet definitions as it can also go out of date. PWI SNOMED-CT has the option to be more forgiving for inactive descriptions.   

Belgium (via Translation User Group) would like to inactivate descriptions of inactive concepts to help avoid apparent duplications.  ML Ontoserver will detect this and use "best case" instead eg most recently inactivated descriptions.

See also https://build.fhir.org/episodeofcare.html (unchanged since R4) collects together a set of temporally linked encounters.

Peter G. Williams 

Requirement to resolve URIs representing post-coordinated expressions.

See https://chat.fhir.org/#narrow/stream/179166-implementers/topic/The.20URL.20is.20not.20valid.20-.20Snomed-ct.20compositional.20grammar.20.7B.20.7D

ML Suggests resolving to a page that displayed information about that expression - formatted nicely, diagram? - and perhaps further capabilities, but not go as far as attempting to classify in the first instance.

ECL would return implicit valuesets

"Post Coordination is modeling and shouldn't be taken lightly" - DK

Peter Jordan 

Potential for marking the expansion of certain  valuesets as incomplete because theoretically, all possible Post Coordinated Expressions exist but are not included in the expansion.  See https://build.fhir.org/ig/HL7/fhir-extensions/StructureDefinition-valueset-unclosed.html

https://jira.hl7.org/browse/FHIR-40718

DK - flag excludePostCoordinated to include or not include post coordinated values would affect this.

Peter Jordan 

Question on the future direction for Snowstorm

PWI : Potentially looking at horizontal scaling by separating out country instances on number of services.   Considering test suites eg Touchstone.   Also support for use with IG Tooling.  PJ suggests could look at Inferno (wrapper for FHIR Validator).

ALO : Snowstorm-lite would allow for quicker scaling with much reduced memory footprint, with a small number of limitations such as reduced ECL capability and restriction to single Snapshots.  See https://github.com/IHTSDO/snowstorm-lite

Regarding Using SNOMED CT with HL7 Standards

• "Simple Map Reference Sets" link is now dead - replace with one of the directional maps?
• Since we can do this with any maps (eg Complex/Extended), could the language in this section be made more general. 
• "Where [sctid] is a value from the table above" need not be limited to the table above, could be any map reference set SCTID.
• In Snowstorm, check how the correlation id is being translated into the 'equivalence' ICD-10 coming back as 'unmatched' due to the values in the ICD-10 map.   In the case of the historical associations, we could populate the equivalence based on the association type
• How is the CTV3 map working?  In that map the target is a SNOMED CT code.  However, might be better use of our time to remove the CTV3 map rather than get it working.  Note that NHS UK were generating CTV3 codes until 2016 (mapping until 2020) so if SI codes are out of step with UK codes, then that's dangerously misaligned.
• Do we want to include the attribute value reference sets here, as the reason  for inactivation gives an indication of which historical association is going to be used.
• Check the implicit maps returned eg https://browser.ihtsdotools.org/fhir/ConceptMap?_format=json

DK: How do we express equivalence now?  Should that be done with two complementing simple directional maps, or would we use a complex map with a correlation type of equivalence?

• Peter G. Williams Create HL7 Style tickets / SI Internal tickets for the required changes.

Kai Kewley 

Using the Alternate Identifier File in implicit maps.

No refset is available.  Can we use the scheme id?

On non receipt of a scheme id, we discussed that all 'mapped' values could be returned?

http://localhost:8080/fhir/ConceptMap/$translate?code=254153009&system=http://snomed.info/sct&targetsystem=http://loinc.org&url=http://snomed.info/sct?fhir_cm=705114005

So here for example, is the scheme &url=http://snomed.info/sct?fhir_cm=<scheme sctid> needed? It would cause issues by being looked up as a refset first, and code would have to be ready to fall back to also check scheme ids.

ML suggest we need the URL parameter to indicate that the alternate identifier file should be used.  Is there a URI for the Alternate Identifier File itself?  No.

The scheme id is more specific.  It is redundant because we already have the targetSystem URI.   Could it be used for anything else or confused with anything else if we tried to use it?  

URI suggestion:   http://snomed.info/sct?fhir_alt

http://localhost:8080/fhir/ConceptMap/$translate?code=254153009&system=http://snomed.info/sct&targetsystem=http://loinc.org&url=http://snomed.info/sct?fhir_alt

This will return all scheme known in the alternate identifier map.   

So here fhir_alt follows the HL7 defined pattern as per fhir_cm

The targetSystem would need to mapped to the URI (annotation/additional relationship) which gives the URI for that scheme.  705114005 |LOINC Code System|.   The additional relationship file will need to be parsed for this metadata which is needed for the FHIR server to perform these mappings between URIs and Scheme SCTIDs.

Another Question:  the source and target imply a direction and the alt identifier file can be considered to be an equivalence (Equal in R4)

R4 (also  has Product that could be used to specify the Scheme as a return value, see https://hl7.org/fhir/R4/conceptmap.html

Marie-Alexandra Lambot Daniel Karlsson 

See https://build.fhir.org/ig/hl7-eu/laboratory/branches/master/index.html

https://github.com/hl7-eu/laboratory

https://confluence.hl7.org/display/HEU/Laboratory+Report+Implementation+Guide%2C+Edition+1

Requirements for making a Terminology Server compatible with IG Tooling

See Zulip discussion here:  https://chat.fhir.org/#narrow/stream/179202-terminology/topic/Terminology.20server.20requirements.20for.20IG.20builds.2E.2E.2E

2023-07-25

• Michael Lawley is implementing the requirements in Ontoserver
• Graeme is preparing the Terminology Server registry, probably a JSON document, that would make available different terminology servers, listing the capabilities, including which code systems on each server

2023-08-22

• Michael Lawley the scope has expanded, advancing on the implementation. The registry will document which terminology server meet requirements, it is a centralized resource, maintained by HL7. There is document that describes this. An implementation guide developer would use this information to choose a compatible terminology server as the backend of the IG valuesets. There is a test suite that servers can apply to demonstrate compatibility, Graeme will be the curator of the list, the submission process for a new server is under development.

2023-10-03 ML Ontoserver still a work in progress in this area.

Question on the Observables Model - was discussed in both the MAG and the EAG.   Yongsheng Gao currently looking at proposals and next discussion will be at all staff meeting in June.

There was an inconsistent role grouping pattern in the observables, and the question was trying to find the reason for this. This is being evaluated.

Peter G. Williams There is a decision to move to the grouped pattern

Andrew Perry looking for opportunities to contribute to the observables and LOINC modeling decisions

2023-09-19 Update:  Direction of travel here suggests moving to have all attributes in a single role group, but preparatory hierarchy movements will be required first - Evaluation Procedures moving to Observables.  Discussion expected at October MAG meeting, followed by a briefing note if no major objections raised.   AP UK have concerns about problems caused with existing counterparts between the two subhierarchies.  UK did respond to RFC last week.

2023-10-03 SI responding to briefing note feedback (including encouragement from UK to engage as a matter of priority).  Discussion expected in both MAG and EAG at October Business Meetings. Two Schools of Thought:  LOINC style single observable hierarchy (order / result) vs. procedure + observable pairs for expressing ordering and results.

Michael Lawley 

Concept maps and SNOMED Maps  - how to materialize as both R4 and R5.

Metadata needed:  target CodeSystem URI,  source and target ValueSets.

Do we assume that a simple map is an equivalence.

For complex maps, how are the additional fields represented?   Eg in property, dependsOn and product (these are typed).   See 5.2.3.3 Complex and Extended Map from SNOMED CT Reference Sets  

CC Kai Kewley 

Update 2023-06-13 Now working in confluence Concept Map in R5

2023-07-11 Work being done (ML) around clarity and specification for the parameters used in implicit Concept Maps.

2023-07-25 Michael Lawley and Dion had a discussion on metadata and put together a proposal of a JSON based metadata, presumably to be presented to the MAG (clarified 2023-10-03)

• Peter G. Williams Add to FHIR Agenda for October meeting and floating topic for MAG also.

Marie-Alexandra Lambot 

Michael Lawley 

Kai Kewley 

BCP-47 requires a dash every 8 digits so SCTIDs need to be broken up to be compliant.

Also the "x-sctlang" is required. 

Also discussed GG's request to Kai Kewley in the behaviour around language headers and how they interact with the displayLanguage in the HTTP GET request.

Rob Hausam 

Daniel Karlsson 

See Tuesday meeting item #6

Changes for R5  and check on use of dialect in x form in ECL Specification Appendix C:  Appendix C - Dialect Aliases

Note that where a language reference set pulls from more than one language, the BCP-47  tag could potentially missing out the <lang> element and start directly with "x-".  Options for referring to multiple languages: could be done either with a * (see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Accept-Language#syntax ) or with a comma separated list to indicate a priority order (although this isn't supported by the FHIR parameter (unless the server went out of it's way to allow for this), or use the accept-language header).  Use case is in the displayLanguage input parameter to a ValueSet $expand operation

• Peter G. Williams This extra detail should be filled into FHIR-languages to avoid overloading/over complicating the HL7 page.

2022-08-31 ML CSIRO attempting to get R5 compliant Ontoserver ready in time for HL7 Connectathon.

2022-10-04 With this page moving to terminology.hl7.org it is no longer subject to the ballot process.  Instead a "TSMG" ticket should be created.  Daniel Karlsson and Rob Hausam will progress this. 

• Rob Hausam 

Also tracking R5 changes to concept map - see http://build.fhir.org/valueset-concept-map-relationship.html.   Peter G. Williams to check SI intention for R5 compliance.

2022-10-18 DK EHealth Working Group on Semantics - discussion on cross border infrastructure based on CDA.  Suggestion that it could move to FHIR for new specifications/developments eg Lab Reports.

2022-11-02 RH Rob will check the status and how we can help it move

2023-02-07 RH R5 Ballot is complete.   Deadline to complete resolutions is Feb 24th.   Expectation to publish late April / early May.

2023-03-07: RH R5 going through QA currently. Some last-minute changes in ConceptMap: RH change in relationship types, new ValueSet to remove ambiguity. Directions of maps (very) explicit. No-map situation simplification. Element name changes. Choice datatypes in more places. ML property, dependsOn and product clarification. E.g. property is used in implicit ConceptMaps based on SNOMED complex maps. http://hl7.org/fhir/5.0.0-draft-final/conceptmap.html 

2023-07-11 ML Added UP ticket - https://jira.hl7.org/browse/UP-436 (Unified Terminology Governance Project)

Mechanisms for working with Languages

Designation extension

24 August DK Added pull request to Snowstorm  here

Implementation by ML using existing fields and specifying LangRefset in displayLanguage parameter with "preferredForLanguage" code and wildcard  Eg https://r4.ontoserver.csiro.au/fhir/ValueSet/$expand?displayLanguage=*-x-sctlang-20581000-087109&_format=json&url=http://snomed.info/sct/20611000087101?fhir_vs=ecl/160303001&includeDesignations=true

Oct 5 Release of Ontoserver 6.5.0 which includes support for language reference sets as above.

• Peter G. Williamsdocument examples using live Snowstorm instance

Next Steps: How to promote - could we present at a Vocab call?   (1530 ET Thursdays - may clash with SI Languages call)

8 Feb 2022 DK added Designation Extension into the SNOMED on FHIR IG see http://build.fhir.org/ig/IHTSDO/snomed-ig/StructureDefinition-designation-use-context.html

Kai Kewley 

MRCM is needed for writing good ECL and also for writing 'good' Post coordinated expressions.

Going forward:  suggestion that PJ and RH expose both the MRCM and the capabilities of ECL 2.0 with the wider HL7 and FHIR Communities.  See slides on ECL 2.0 here.  ML more generally this is a refinement axis which is represented as two things - the attribute and the range of values that that attribute can take.

• Peter G. Williams make a note of this in the IG

2022-11-1 ECL 2.0 can retrieve MRCM refsets content, the question is how to return them as FHIR resources (structure map?)

Using implicit concept maps may be an option to add operations such as get acceptable attributes or get range

(note SNOMED is the only CodeSystem that uses implicit concept maps, wording around that is changing, see https://jira.hl7.org/browse/FHIR-39266 )

• Alejandro Lopez Osornio and Kai Kewley will draft a demo.

Peter G. Williams

Implementation Guide for using SNOMED CT with FHIR.

IG Documentation: http://build.fhir.org/ig/FHIR/ig-guidance/index.html

Also look at the sample IG https://github.com/fhir/sample-ig see build http://build.fhir.org/ig/FHIR/sample-ig/

• Rob Hausam to speak to Lloyd about extending the base template as per http://build.fhir.org/ig/FHIR/ig-guidance/template.html Update 24 March: Documentation on this is "TODO"
• Peter G. Williams FHIR core content to be copied over to Snowstorm instance.

TODOS 

• Check build issues http://build.fhir.org/ig/IHTSDO/snomed-ig/qa.html    Update 2022-06-20 Tooling currently giving a null pointer, see https://build.fhir.org/ig/IHTSDO/snomed-ig/failure/build.log  asked question in Zulip  See https://chat.fhir.org/#narrow/stream/179252-IG-creation/topic/Null.20pointer.20in.20ValueSetRenderer   
• Note page to manually execute build through HL7 Tooling: https://fhir.github.io/auto-ig-builder/builds.html
• Rerun locally with latest tooling (also sushi)
• Run with local snowstorm provided as Tx
• See Mark Kramer presentation   https://www.youtube.com/watch?v=OmcSuAMf20s  Also https://fshschool.org/ 
• CONTENT! 
• Merge in DUC branch (Designation Use Context) with a view to implementing in a branch of Snowstorm and making available via connectathon.ihtsdotools.org
• Clean up other branches
• Check templates are up to date - should now be self updating, see https://github.com/FHIR/sample-ig (fsh may ask to update this structure).   Sushi sending out information about new format (PJ says leading whitespace is now significant).
• ReadMe should provide links for Publisher tooling
• Add discussion on Refset / IN (see above)
• Provide link to it in http://build.fhir.org/snomedct.html and discuss further socializing.
• TerminologyCapabilities caching is overly aggressive.
• Added 2022-08-23 Discuss ownership, hosting and copyright (joint copyright with HL7).  Source will be hosted in GitHub, pull requests will be welcome with this group acting as gatekeepers (reviewers) for that?   Suzy Roy would the wording of our original collaboration be helpful here?

2022-11-1: No news, check in the next call.

2022-11-15  Suggestion to set page per meeting list to work through.  Setting up one or two HTML style pages that could then be copied and modified and then use meetings to tackle more difficult content and review.  Finding best publishing location, cross referenced between https://terminology.hl7.org/SNOMEDCT.html

Pairings - Kai, Peter, Marie, Daniel, Rob

Top Topics

• What are the various Resources in terms of how they relate to SNOMED CT (Link to Follow the yellow brick code presentation).  
• ECL in FHIR (intensional ValueSets being less brittle)
• Languages
• Terminology Binding (General Approaches)
• IPS (GPS)
• FAQs eg how to recover historical assertions using Map
• Post Coordination & Transformation
• Relevant changes in R5 eg Concept Map (correlation changes)

2022-11-29

Example markdown page that could be copied and modified:  https://github.com/IHTSDO/snomed-ig/blob/master/input/pagecontent/sct_specific_behaviours.md

Work to be presented for 13 December (payment will be made in Glory^tm)

Peter & Kai - ECL in FHIR  (Update:   Used https://hackmd.io/  for collaborative markdown editing. )

Daniel & Marie - Allergy & Intolerance : (Update: Menu item added for extensions, confirmed examples are useful and appropriate for the Allergy Guide. )

Rob - IPS

• Peter G. Williams contact Ole Vage & Feijke re Translation Group and contributing to IG relating to use of languages in FHIR (complete 2023-10-16)

2022-12-13 ECL Page reviewed - MarkDown not displaying the same as it did the IDE, revisit.

Looking for some more structure that could be applied to the apparently unordered list of ValueSets (which is machine generated).  Any documentation on how to do that would be appreciated.   Other IG's we could compare to are : https://build.fhir.org/ig/HL7/US-Core/terminology.html & http://build.fhir.org/ig/HL7/fhir-ips/  ( also http://build.fhir.org/ig/HL7/fhir-ips/terminology.html )

2023-02-07 MAL work for Allergy Implementation Guide (which the SNOMED IG will link to) see SNOMED CT Implementation Guide for Allergy, Hypersensitivity and Intolerance

2023-02-21 DK Work done for languages - https://build.fhir.org/ig/danka74/snomed-ig/branches/languages/  Discussion about overloading of parameter for both display language and search language.   Checking behaviour around fall-back on displayed terms (eg context specific → national language → English).   For example, display parameter being a comma separated list (which has a defined order, unlike repeating the same parameter multiple times (also not allowed in the spec)).

2023-10-16 PWI Update:  We had a note to follow up on https://www.hl7.org/fhir/R4/valueset-animal-breeds.html as these have mostly been inactivated and moved to the Veterinary Extension.   In following up, it was determind that this valueset is no longer present in the FHIR core as of R5.

Discussion on * version wildcard. (relates to a Zulip discussion on expanding a ValueSet against multiple editions to give a superset?)  DK How could we specify the latest version of multiple modules.   Answer http://snomed.info/sct/*   (ie not specifying the version) or http://snomed.info/sct/*/version/*  to include concepts from previous versions.

For use in the module / version URI.   Existing workaround is to use multiple include elements for each version.

7 Sept ML Sticking point - what do we do with incompatible properties eg active/inactive between two different versions - the most recent?

Use case: primarily being able to validate codes that might exist in different editions.   Secondarily, being able to validate code received in a historical record ie where codes were valid at time of data entry.

25 Jan 2022: Snowstorm will already look across all Editions loaded when a codesystem version is not specified, eg:  https://browser.ihtsdotools.org/fhir/CodeSystem/$validate-code?coding=http://snomed.info/sct|443971000124108 only exists in the US Edition.  (See also the History proposals for ECL)

• Peter G. Williamsdocument Snowstorm multi-edition validation in IG

2022-05-17 ML Ontoserver supports ValueSets that draw from more than one version, so you could use that to compute the difference between one version and another.

2022-11-1: DK: Snowstorm does not yet support multiple include elements in different versions for the SNOMED code system. ML: The semantic is not yet clear, how to decide in which versions you check properties, parents, etc. Run separately for all inclusions and join the results. May need to understand better the use cases.

Michael Chu - let's discuss.

2023-10-03 ML working on registration of congenital abnormalities - is there a way to group disorders (eg as part of a syndrome), specifically in the Condition Resource to (See Condition Related Extension in R4 http://hl7.org/fhir/R4B/extension-condition-related.html / http://hl7.org/fhir/extensions/StructureDefinition-condition-related.html )   See https://hl7.org/fhir/extensions/extension-registry.html  also condition-dueto.  JC Syndrome is just a grouper name, it doesn't "cause" the manifestations as such.

Peter Jordan

Michael Lawley

Impact of proposed changes (eg text searching in ECL) on FHIR. Questions around which language reference sets to use when there are multiple, especially partial/overriding context (referred to MAG for discussion)

8 Sept The FHIR specification does not specify a particular version of ECL, so we assume the latest.  Any enhancements added to ECL will be immediately relevant and available in FHIR.   Note that these latest additions while targeting descriptions are a concept filter, so display options (language etc) will affect the output of those concepts.   How about the filter parameter though, especially since ECL wo (ld allow multiple filters in multiple/different languages.

• Michael Lawley Suggested ticket: Parent and Child properties to (optionally?) support the Coding type.

Daniel Karlsson

Peter G. Williams

API for FHIR Resource to SNOMED Expression

• Daniel Karlsson Thought there might be some documentation from CIMI on this. Also notes from DMarkwell about constructor bindings.
• Peter G. Williams Pull these notes into confluence - can we mention it in the IG?

Peter G. Williams

Problems when dependencies do not align. Multiple code system resources represent multiple editions / versions.

ML: See code parameter to code system search. Should return code systems (ie versions) where that code is defined. International concepts would appear in every edition known to the server.

eg /CodeSystem?system=htp://snomed.info/sct&code=12345678&_elements=version

• Peter G. Williams Ticket implementing this lookup. Note that this could be implemented more generally for lookups of http://snomed.info/id/<SCTID> where the SCTID exists in an extension. Done - see STORM-262.

Peter G. Williams

CodeSystem "class vs instance" in url parameter between CodeSystem and ValueSet operations.

CodeSystem is understood.

In Valueset, url is the ValueSet url for example url = http://snomed.info/sct?fhir_vs= allows for the version URI to be used as stated in https://build.fhir.org/snomedct.html The base URL is either http://snomed.info/sct , or the URI for the edition version, in the format specified by SNOMED International in the SNOMED CT URI Specification.

The ValueSet version valueSetVersion is just some string identifier eg a timestamp or 0.1.0

Rob Hausam

What properties are returned?

Discussion: Both Ontoserver and Snowstorm are returning EffectiveTime which is not listed here (unlike other SNOMED specifics): https://build.fhir.org/snomedct.html

• Peter Jordan to raise a Jira ticket to ask for this to be returned - completed https://jira.hl7.org/browse/FHIR-26555

Point of interest: Grahame's server returns a copyright property.

Update 7 April - Question about whether this is required / desirable?

Michael Lawley

Terminology Capabilities: Default SNOMED Edition for a Server. Suggestion to invite Graham for a wider discussion. Resource is still at maturity 0.

11 August The resource is based on instances of code systems. Difficult to make statements about code systems generally, or specific SNOMED editions, etc. Will start a Zulip discussion on this. Michael Lawley Then potentially invite Grahame for a future discussion?

25 August It has been agreed that this resource will now have maturity level 1

See https://chat.fhir.org/#narrow/stream/179202-terminology/topic/tx.2Efhir.2Eorg.20New.20parameters.20for.20.24expand.20.26.20.24validate-code

8 Sept 20 Is there a Jira ticket ?   Rob says Grahame implemented this.

12 Jan:  RH update made to GG Server.   Documentation (assuming required) still outstanding.

Michael Lawley

Use case for fall back lookup when server does not know the answer to any particular question eg a façade server which has knowledge of all services it could potentially delegate to.

Aug 25: New capabilities in HAPI to allow delegation to an external terminology server.