Date

25 October 2016

Location

Wellington, New Zealand

Attendees and Observers

See agenda page

1 Call to Order

Jim Case (JCA) welcomed the group.

2 Conflicts of interest

None declared

3 Approval of 20160822 ad 20160928 minutes

Approved without comment

4 Disjunctive components

Review of the previous discussion and identification of remaining issues.  LOINC parts that contain the “+” sign have been identified as meaning “either or both”, which is not supported by the current DL constructs in SNOMED CT.  How to model observables that use these types of component values needs resolution.  Initial proposal based on discussions from the Observables Project recommended that these observable concept be modeled as primitives and leave the component relationship out of the model.

Discussion: GRE suggested that the issue is whether these terms are clinically useful if fully defined.  With GCIs you can fully defined some of these disjunctive concepts, but many of the concept at issue are more like “apples and/or oranges”, which makes them less clinically useful.  Full disjunction is not a likely solution to the issue currently.  GRE mentioned that at the modeling group the main issue to be addressed is GCIs.  The issue is that a conjunctively defined concept is defined by its parents, while a disjunctively defined concept is defined by its children.  Thus you will have “monocytes” as a child of “Monocytes and/or macrophages”, which is an intermediate primitive concept, which has little clinical value.  Do we want a lot of these in SNOMED CT?  It is unclear whether there is value to trying to address these so they can be fully defined.

DKA identified that these concepts are LOINC parts needed to fully define the LOINC expressions, but GRE stated again that these might do more harm than good.  An alternative is to create them in an extension and classify them separately from the core using a full DL representation in OWL.  GRE mentioned that there are differences in importing extensions in OWL vs. RF2.  The challenge was identified and alternatives initially discussed, but the resolution can be postponed until a later date.

A summary by JCA stated that the discussion implies that technical changes to the core must be supported before we can begin adding these components to the core.  In the short term, there is a need to implement the observables model in the core.  So most of these issues must be handled outside the core.  What are the short term conclusions and what are the longer term solutions?

GRE – In the short term, extensions can address this as they need.

JCA – What about the core?  FAS said that the terms with “&” in them represented panels and were out of scope for the core, but those with the “+” sign are in scope and part of the agreement is that IHTSDO would find a way to represent these in the core. There are considerable impacts around adding these to the core and their influence on inferences.  Since we haven’t yet figured a way to handle these externally, should we revise our approach to adding these to the core.  FAS stated that at this time just adding the affected concepts as primitive would meet the immediate needs.  However, about 100 of these have already been added to the core.  What do we do with these?  JCA – question as to whether the ones that have already been added are valid as they are in the substance hierarchy as a combined substance, which these are clearly not.  We should consider that these were invalid to begin with and should be retired.

MCO – asked about the existing ratio concepts (e.g. BUN/Creatinine)?  DKA these would be represented as distinct attributes in the observables model.  However there is no tested solution that fits the core right now to handle these concepts.  Also, the management of the number of GCIs would be problematic.

JCA proposed that the disjunctive concepts that have been added to the substance hierarchy be inactivated. – agreed to by EAG members

JCA proposed that any observables that might have used these concepts be modeled without the component hierarchy as be added as primitive concepts to the core – agreed to by EAG members

JCA proposed that we refer the remaining issues to the modeling advisory group as it is not a content issue, but a modeling issue.  – agreed to by EAG members.

TMO asked whether this would be implemented for the 20170301 release? JCA indicated that this is dependent on available resources, but that it needed to be done at the soonest possible time.  In the meantime the editorial staff would be advised not to use the existing terms.

BGO asked how this would affect the combination drug products that are targets for allergies?  Most are modeled incorrectly as having both parents.  KCA stated that the difference here is whether the ALL restriction is being used.  If the SOME restriction is used then it is logically correct.  BGO stated that for allergies, the implication is one or the other, not either or. So the question is the modeling the allergies, not the substances.  GRE says the solution again is GCIs.  BGO should we just remove the causative agent or leave them with both incorrect parents?  There are not many of these.  JCA recommended the same process be used here, i.e. make them primitive and remove the causative agent relationship.

FAS asked about a prior decision that was made regarding microbiology reporting in which we came to a different conclusion.  JCA recommended that this be tabled for a later discussion

5 Drug concept model meeting summary and discussion – TMO

TMO summarized the organizational issues that were addressed at the drug model meeting on the prior Sunday.

Final deliverables:

-        Concept classes with populated example

-        Terming and modeling guidelines

-        Clear position with respect to external standards (e.g. IDMP)

Major decisions about the model from the meeting

-        Will not support universal (ALL) restriction

-        Will not support nesting

-        Will support numeric values, but not as concrete domain

Testing for support of numeric values will initially focus on creation of combined value/unit constructs supplied by RxNorm and AMT.

Information about the project combined into one confluence site:

https://confluence.ihtsdotools.org/display/IAP/Drug+Model+Directory

KCA expressed his support for the outcome of these initial discussions and support for this from the VA.

JCA stressed that the boundary of what would be supported by the International release would be drug products (single or multiple) at the level of strength, using one of the options currently under test for representation of strength (one concept or two).

Discussion of issues:

What is a product?  The definition of product in SNOMED CT now was presented.  KCA mentioned that the current definition uses language that is specific to the UK.  This was verified by the AU members of the group as well.  KCA stated the underlying definition is acceptable except for the use of virtual products.  Would like to see it revised to something similar to the Australian definition. 

• Action: Get a copy of the current Australian and US definitions for drug product and revise the current SNOMED CT definition to reflect a more specific definition that does not include virtual products and Product categories.  Add to a discussion page on the EAG site (JCA).  Goal is to come up with a more terse definition.

Question: Is the prescribing use case out of scope for the drug content in the International release?

The current definition does include this.  However, the goal of the common drug model is to provide support for the use cases including prescribing, but the content at the International level may not be sufficient and must be augmented by jurisdictional extensions to meet their specific use cases.

Question: Is there a need for new semantic tags to represent abstract, generic and trade products?

It was previously agreed that trade products are out of scope so not needed for that.  Additional discussion lead to a discussion that new semantic tags are not immediately needed, but may become more important as the generic model is implemented by NRCs.

Prior policy decisions from the Drug Model Group were presented

• Action: Briefing paper for addressing the current ambiguous FSNs will be sent to the MF for discussion at the December meeting. (JCA)

GRE mentioned that it is important to recognize that combined products are not the same as products with multiple ingredients.

6 Extension of range of CAUSATIVE AGENT to include Product

Currently, there are many duplicate substances created to support modeling due to restriction on the range of CAUSATIVE AGENT.

Discussion: GRE the issue is what is the result on inferences.  Use of a product is OK, but things must be aligned so that you are still transitive to the substance in the product.  We may need to do some additional work to define the property correctly so that these inferences are maintained.

GRE (cont) I think it will require a property change, rec get in touch with the modeling team about that.

JCA: the major use cases are pretty apparent, but many instances something in the product that would cause the adverse react.

GRE: almost every adverse reaction is from a product. Supporting this is something we have to do to extend the range;

Confusion about whether adverse reaction, guidance not clear about which to use product or substance for causative agent

JCA: Can we remove duplication of substance and/or product from the hierarchy so remove the ambiguity, not sure if it;s possible or not  haven't done the testing yet;

JCA:sounds like this is a good idea, modleing considerations need to be taken under advicement,, and to define fiarly strict ed guidance on when to use product and when to use subjstancel\GRE: would be nice to have concretet examplesl so can send them for conusotatiol jca: i think we have a numer of use cases avaiolable to send t modeling agl also need to look at cross over bet prod and subst in terms of matching concelps and see if feasibe to eliminate one or the other of thosel

7 Assessment instrument responses

JCA: come up with policy on assessment tool responses to the intnerationao edition. Jca used the introductory materia; on the agenda, includign proposed generkato guidancel

(1) Only assessment instruments that are in the public domain should have their response values added.

KCA: i think domain is not a sufficiently defined term, some licence agreements woud not be agreebalell maybe just say an appropriate license that llows it to be distributed with snomedl internpretation of any specific license goes to MB, and they can decide if