Peter G. Williams

Rob Hausam

Recording, notes & attendance.

Peter G. Williams

Peter G. Williams

Recent events:

Upcoming events:

Peter G. Williams

The SNOMED Allergy CRG have developed guidelines for representing allergies in EHRs and messages. It contains a section on the use of FHIR AllergyIntolerance resource which refers to the two SNOMED on FHIR AllergyIntolerence profiles.

The current (R4, and future R5) FHIR resource does not have sufficient detail to allow mapping to the SNOMED allergy model. Could be raised by the HL7 Patient Care WG.

Plan:

Marie-Alexandra Lambot Rob Hausam will update the FHIR section in the Allrgey CRG Guide and provide to the group for discussion.

Rob Hausam

• Rob Hausamplease provide links

Discussion about proposed federation.  ML Doesn't work so well with SNOMED CT because there's not a single authoritative source due to country extensions (and multiple versions being released).  Use case for this is mainly in creation of IGs.  Agreement that what a conformant server should be able to state in Capability Statement is helpful.   ML Touchstone test script artefacts need investment.  See https://touchstone.aegis.net/touchstone/

See also https://inferno.healthit.gov/

16 Nov Update RH: Updates in for next ballot (not January now).

30 Nov RH: Next ballot confirmed May.

Peter Jordan

Ontoserver examples: https://r4.ontoserver.csiro.au/fhir/ValueSet?_format=json

Implicit: https://r4.ontoserver.csiro.au/fhir/ValueSet/$expand?url=http://snomed.info/sct?fhir_vs=isa/410607006&count=5&_format=json

Gives url = "http://snomed.info/sct/32506021000036107/version/20211130?fhir_vs=isa%2F410607006"

Snowstorm examples: https://snowstorm.ihtsdotools.org/fhir/ValueSet

Implicit example: https://snowstorm.ihtsdotools.org/fhir/ValueSet/$expand?url=http://snomed.info/sct?fhir_vs=isa/410607006&system-version=http://snomed.info/xsct&count=5   here we just return the url parameter that was specified in the GET request.

SNOMED International follows published URI spec in this matter, see 2.7 URIs for SNOMED Resources  for pre-defined ValueSets. Hmm, we agreed that valueSet was a thing that existed independently of it's implementation (Kuala Lumpur discussion) but that hasn't made it to the spec.

• Peter G. Williamsfollow up with Linda Bird

Query is about what version gets used in the parameter field.   The spec says "The server decides which parameters to include here, but at a minimum, the list SHOULD include all of the parameters that affect the $expand operation. If the expansion will be persisted all of these parameters SHALL be included. If the codeSystem on the server has a specified version then this version SHALL be provided as a parameter in the expansion (note that not all code systems have a version)."

Marie-Alexandra Lambot

ClinicalStatusValuesDiscussion_v1.1.docx

Rob Hausam

Suzy Roy

Heiko Waldmuller

Peter G. Williams

"Using postcoordinated codes over an information model that the syntax fits the MRCM."   Question on how to post-coordinate medication plan type concepts into PCE

PWI - Well FHIR is pretty clear on this question in that - as far as the specification is concerned:  a post coordinated SNOMED code IS a SNOMED code, so they can be used interchangeably.  The syntax is well documented - SNOMED Compositional Grammar http://snomed.org/scg   What the MRCM does is tell you what attribute types can be used in a given domain (ie subhierarchy) and what attribute values can be used with each attribute type.   The constraints of the MRCM are really outside of the concerns of FHIR, but we can certainly talk around that topic this evening.   We do not have a way to express the MRCM in FHIR....that's perhaps something we could look at.

ML - recommended using existing resources or extending http://build.fhir.org/basic.html

PJ - suggested looking at http://build.fhir.org/allergyintolerance.html

DK - See also work done by this group of profiling allergy intolerance - AllergyIntolerance Binding

Please report back Heiko!

Peter Jordan

Normally when a filter is applied eg "Size 12" + "green" we expect both qualities to be true at the same time and this is held true by the FHIR Spec that says "If multiple filters are specified, they SHALL all be true."  (see http://build.fhir.org/valueset-definitions.html#ValueSet.compose.include.filter)  However  http://hl7.org/fhir/R4/valueset-substance-code.json.html  has two filters that pick up substances PLUS products   and obviously they can't both be true at the same time.    So it seems like sometimes we use conjunction and sometimes disjunction?  

Snowstorm GitHub issue #285 changes behaviour from AND to OR when multiple filters are applied.

Answer is: the separate includes are disjunctive and objects within the same filter array are conjunctive.

Text here is clearer: http://build.fhir.org/valueset.html#compositions

SideNote:   Wildcard for versions in $expand, see https://jira.hl7.org/browse/FHIR-15998   Note that "version" here would mean multiple editions.

• Peter G. Williamsraise tracker to improve clarity of text

Peter Jordan

Michael Lawley

$validate-code, obviously.   ML  Transformations of Close to User Form happen under the hood of the TS.   You might want to see normalized form, although it will be dependent on the particular edition in use.    Current Snowstorm development is WIP / experimental rather than a ratified spec.   Order of transformation is important + existing issues with negation in hierarchy subsuming in unwanted ways.   PJ Essential to have first pass attempt to bottom out issues, highly beneficial. 

$subsumes

What about ValueSet $expand - return Normalized form or original input?   Classification will be needed before membership of ValueSets can be determined.

$find-matches could be used to find / check PCEs / Normalized equivalencies.   Alternatively, deprecate this operation altogether!

$translate could return normalized forms of CTUF.  ML Syntactic differentiator needed?

Update 13 JulySander Mertenshas completed a multilingual tool for creating concepts based on template:   https://postco.test-nictiz.nl/#/     (source:  https://github.com/mertenssander/postco) 

TODO Peter G. WilliamsCopy text out and archive.

Request that SI make the GPS ValueSet available as an extensional definition.

SI are (I think - PWI) in agreement to do this.

• Peter G. Williamsticket and progress.   MAINT-1740 Target October 15 into production (need SearchAfter functionality for Refset Members).   Also check date for next GPS publication.

16 Nov Update:   "Search After" functionality will be available in Prod 1 Dec.

Daniel Karlsson

Jeremy Rogers

Collecting topics for TB stream here, with a view to having a call when there's sufficient material

FamilyMemberHistory - how is "no family history of X" best represented?

FreshDesk ticket question on Allergy substance cross field validation.  DK: Mappings to other information models, is that helpful?

15 Dec 2020 DK Asking if the member forum are still keen to see engagement in this area - offer to help country implementations.   Difficult to make decisions on binding without a concrete use case.  ML We could look at / review IGs (DK As we did for COVID).

• Suzy Royplease work with Daniel and Nick E. to take forward something appropriate for next MF (will be in the New Year).

12 Jan 2021 Update: Contact planned with the MF - next call (Jan 22) is topic based, so after that one - 2 Feb (with Daniel)

9 Feb 2021 Update: Briefing note (DK) ready to be presented to MF.   Now (23 Feb) submitted for discussion, waiting for date in March or April.

9 March 2021 Update: Daniel to present to MF on 11 March (Thursday!)

23 March Update:  Presentation given, awaiting feedback.   Reminder Suzy Roy?

06 April Update: SR There's a follow up in April business meeting (member forum meeting) for feedback. DK reading through/presenting resources may not have been the best approach; maybe presenting use cases would be better. PJ agrees as its more relatable. 

20 April:   Topic for discussion - new Resources introduced in R4B.    Also (Linn Brandt) Use case: Registries need nullFlavor-concepts in their value sets. Which code system to use?  Consider "Long COVID no longer present" as a topical example.  4 May DK: This is more of a negation issue than null flavour, also probability.   JL Distinction between unknown and uncertain.

4 May Jay Lyle - FHIR Binding, proposal review in Observations and presence of findings eg for more of an examination based context. 

1 June Peter G. Williams to check in with JL.  Done, said nothing further for this group at this time.

Oct 5 Request for input from nutrition CRG.

Michael Lawley

Licensing issues for IGs referring to SNOMED codes. Is this written down anywhere with some sort of rigour?

Consider the licence statement that is presented when accessing the browser. Should something similar be mandated for inclusion in any document published? What if a patient's medical record were to be published?

• Peter G. Williams find clarity here - email discussion started with Suzy Royand Jane Millar

Update 12 Jan - "One Page Policy" to be discussed internally.   HL7 agreement indicates other parties would require affiliate licence unless they restricted their usage to the Global Patient Set.

26 Jan Question from PJ about inclusion of COVID Vaccine concepts in the GPS (advised that it is only released yearly)  FYI Rory Davidson See also MF discussion here.  SuzyR will follow up.  See also early preview page.

Michael Lawley

Mechanisms for working with Languages

Designation extension

Update 19 May: Suggestion that we work an example for SNOMED to discuss with Regenstrief (LOINC)

Update 2 June: Started worked example Designation Extension Example

Update 17 Nov:  Proposal to add more values into designation use https://jira.hl7.org/browse/UP-107

Update 1 Dec: Latest build: http://build.fhir.org/ig/IHTSDO/snomed-ig/branches/duc/StructureDefinition-designation-use-context.html   Ticket: https://jira.hl7.org/browse/UP-155 being replaced by https://jira.hl7.org/browse/FHIR-29821   ML suggested we need an additional value for 'Not Acceptable' that would need an additional value to be explicit, rather than relying on the absence of a 'row'.   Designation Use codeset, or the infrastructure codesystem?  See also http://build.fhir.org/languages.html##term

Update 15 Dec:  Discussing cardinality - when a designation can be applied to multiple roles, do we have repeated elements in a single extension block, or multiple extension blocks?  PJ Checking use case.    Use Case:  To allow tell the client what all use contexts (roles) are available so that it can a) select one making an informed choice and b) gradual degradation where the best available terms are used where they exist, falling back to a less preferable term where they do not.  Worked example from ML: https://gist.github.com/pgwilliams/8c742d68878b1fda0638a798668e42f2    also http://build.fhir.org/ig/IHTSDO/snomed-ig/branches/lawley-patch-1/CodeSystem-CodeSystemDesignationUseExample1.html 
On question if this should be part of core spec or remain in SNOMED IG we can consider if this is of use to any other Terminology eg LOINC or RxNorm.

12 Jan Update: Rob Hausam looking for clarity to take forward with Vocab group.   How to align this with other in-flight trackers (eg https://jira.hl7.org/browse/UP-107) that propose expanding designation use which - we think - seeks to overload designation use in a way that wouldn't ( ?) allow more than one value at the same time and these features of designations can vary independently.

12 Jan Proposal:   All 3 elements (including designation type) should be included in our proposed extension.   SNOMED implementations would then pick the most appropriate designation.use value from whatever set is offered in the spec   eg FSN where it is an FSN (because - although also considered 'preferred' - these are seldom used for user interfaces), PreferredForLanguage where we have the preferred term for a given language/dialect and Synonym for anything else.

26 Jan: RH update - is ongoing discussion.  Attempting "best of both worlds" approach.  Not on the Vocab group's agenda, won't be in R4B.    Question from ML about display vs preferredForLanguage here.  Proposed extension to list of designation use will necessitate repetition of designations where they have multiple uses.   See DK example here:  http://build.fhir.org/ig/IHTSDO/snomed-ig/branches/duc/ValueSet-DrugValueSetExample1.json.html

RH: Suggestion that Ontoserver and/or Snowstorm could try an implementation of our extension.   Clients are expected to ignore extensions that they don't understand.

9 Feb 2021 ML Experience with NL and LOINC.  Could we explore using Language tag with a private X language (eg nl-x-sctlang-87587989-78574801 BCP 47: privateuse = "x" 1*("-" (1*8alphanum)) ) and the language reference set id - ie allows for things like Patient Friendly Terms.   The preferred term would be mapped to the display element.   Language tags allows for weighted preferences (ie fall back options).  Pros:  avoids an extension and re-uses an existing part of the specification.  DK "No reason not to implement this, the two approaches are not in conflict".   Question: is "Preferred for Language" definitely happening?   RH: Yes

23 Feb 2021 RH brought up discussion with Vocab group.  Check in on tracker UP-107. DK Still a requirement to present results (eg expansion) with the language refsets visible (to know which designation was in which langrefset) - better to use extension or overload core spec?   Querying is fine, issue is making clear what is being returned. Suggested possible to use the BCP47 refset form in the language element.   Difficulty when returning fall back options as display term is that we can't say what we fell back to.

9 March 2021 DK An implementation is now needed.   DK tried out with Snowstorm:  BCP-47 works but not for extension language referencesets (also for designation)  ( note dialect alias configured in application.properties is a separate solution which could also be improved: https://github.com/IHTSDO/snowstorm/blob/master/src/main/resources/application.properties#L217 ).  SM NL BCP-47solution getting great feedback.

23 March 2021 DK Testing Snowstorm which looks at designation and language headers.   Just needs attention especially for extension content.  

20 April 2021 RH Looking to target next ballot round.   Could we host this extension ourselves in the meantime and target May connectathon? Peter G. Williams

27 July RH & ML:- Still a work in progress. DK will return Aug 1; we should follow up with him next time.

ML:- Potentially fall into R5 on Ontoserver.

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. 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
• Rerun with latest tooling (also sushi)
• Run with local snowstorm provided as Tx
• See Mark Kramer presentation 
• CONTENT!  (PWI speak to PTB)
• 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.

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.

Rob Hausam (primarily Vocab WG)

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 would 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.