Decisions & Recommendations

2015-10-27

1. Restrictions on laterality be relaxed.

2. IHTSDO should add lateralized concepts as needed and not proactively pre-coordinate every laterality.

3. The AG unanimously recommended laterality Option 4, which is essentially the same idea as option 3 but implemented with a new attribute like “has laterality” that users add to the same role group instead of having it outside the same role group.

The early decision was reviewed at a number of the following EAG conference calls and it was decided to use the current capabilities in the terminology to support lateralized content.

Decision: The addition of pre-coordinated structures using the existing "LATERALITY" attribute was approved in light of the timeframe for support of nesting.

• Editors to add pre-coordinated lateralized body structures to the terminology as needed to fully define concepts in other hierarchies

2015-12-10: The suggested modeling change will be managed as part of the effort to create clarity re: use of substance vs product concept as attribute values to define concepts in other hierarchies (associated with the Drug - International Release Model and Content project). Details can be found on the following Confluence site:
https://confluence.ihtsdotools.org/display/DIRMC

New attributes to describe temporal context

Discussion related to the need for representing temporal context beyond the existing AFTER relationship. Initial proposal was to add temporal values to the OCCURRENCE range. This was not accepted.

Later discussion included the creation of new temporal attributes to distinguish between causality and temporality of combined disorders.

• Create specific temporal concepts under ASSOCIATED WITH, including:

TEMPORALLY RELATED TO

BEFORE

DURING

Add AFTER as a subtype of TEMPORALLY RELATED TO

• Update MRCM to support the new attributes and ranges

• Content will be incrementally updated based on approved combined disorder editorial guidance, as discovered.

2015-10-27

2015-11-30

No decision at the 2015-10-27 meeting. Additional input from implementers will be sought.

2015-11-30 discussion

1. Retire the concepts as ambiguous (and this was the most radical solution).
2. Add them to the findings hierarchy but keep them as siblings to the lateralized structures, which unlinks them from bilateral, left and right.
3. Leave them where they are.

• Inactivate existing unilateral concepts, replacing them with specific lateralized content

• Inactivate WAS-A relationships and point to next higher concept as an IS-A relationship

This is an "english-language" issue as it does not affect translations. While it has been the standard for SNOMED CT for over 10 years, recent changes to the FSN naming patterns has resulted in a large number of "non-user-friendly" FSNs, especially for combined disorders. The addition of descriptions with these terms was proposed as being of little value.

The determination of when a description matching the FSN provided value would be left up to the editor. The authoring tool would still create one when a new concept was created, but the retention of that description would not be mandatory

• Have the technical services group update the validation rules of the authoring tool to allow for a concept to be saved without a description matching the FSN.

More evaluation is needed because it was about more than just URLs. There were a lot of issues around text definitions that need to be discussed.

Discussion page created.

• Editorial guide to be updated reflecting the policy on the use of slashes in FSNs. See section 7.2.2.6

The Oxford comma is a comma added after the penultimate term in a list, e.g. For example "Disorder of head, neck, and shoulders". The purpose if its use is to make explicit the fact that the terms are part of a list. The editorial guide is silent about its use, but the example provided does not use the Oxford comma.

There are currently 347 FSNs in SNOMED CT that use the Oxford comma. Most of these are terms obtained from other terminology, such as ICD and nursing. There are 2500 that contain comma delimited lists but do not use the Oxford comma.

Should SNOMED CT be consistent in the use of this grammar mark or maintain fidelity to the original source of the terms that do use it?

Acknowledged that for primitive hierarchies, grouper terms are necessary to navigate and organize the hierarchy.

Decision: Primitive groupers may be added to top level hierarchies that d not have a supporting concept model.

For hierarchies with a concept model the usefulness of fully defined groupers is limited to convenience groupings based on preferred classifications (e.g. disorder by site), Primitive intermediate groupers, while discouraged, are sometimes necessary when the concept model is not robust enough to support the full definition of a subset of terms. However, they add a substantial management burden.

Decision: Fully defined intermediate groupers may be added if they provide demonstrable benefit to organizing and navigating the terminology. Intermediate primitive groupers will only be added on a case by case basis and by approval from the Head of Terminology or the Principle Terminologist.

• Tracker item created - IHTSDO - 834

Decision:

IHTSDO will not accept concepts with multiple body sites

Ranges to use the word "to" to separate numbers, e.g. 2 to 2.5 mg

Question remains as to whether to include the unit after the first number, i.e. 2 mg to 2.5 mg

Decisions:

• Groupers are allowed so long as they fulfill the minimum requirements of being fully defined, have no stated subtypes.
• Existing groupers must be remodeled to fulfill these criteria.

The naming standards being applied to FSNs in some cases leads to "non-user friendly" terms. What is the need for a duplicate description of these terms if they do not provide usefulness in clinical records.

Decisions:

• The need for duplicate description of the FSN term is no longer required if it does not provide usefulness.
• Tooling needs to be updated to not throw an error when a duplicate term is not proesent
• The decision to remove a duplicate term is made by the editor creating the concept

IHTSDO currently accepts "names" of assessment instruments and staging scales; however, there is nothing in the editorial guide that specifically addresses the responses to assessment instrument questions.

Proposed general guidance:

• Only assessment instruments that allow "unrestricted use" should have their response values added
• Response values must adhere to current FSN naming guidelines. Verbatim responses from the assessment will be added as PTs.
• Assessment responses will be added under an assessment specific "grouper" term to facilitate navigation
• IP-restricted assessment values may only be added upon permission of the pubisher. It is the responsibility of the requester to secure that permission

 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. 

Decisions:

• disjunctive concepts that have been added to the substance hierarchy be inactivated
• any observables that might have used these concepts be modeled without the component hierarchy as be added as primitive concepts to the core
• Combined substance allergies will be remodeled as primitive concepts with the CAUSATIVE AGENT relationships removed.

-gram and -graphy are used interchangeably, but there is also guidance that says only use one. So editorial guidance was needed.

Decision: Use the verb (-graphy) for the FSN and include the noun (-gram) as a synonym.

To be accurate the finding site should be "Vascular structure of X organ", for angiography, Impact of such a change needs testing

• Penni Hernandez to do a test on angiography and come back to the group with the results.
• Rename procedures for consistency to "Angiography of X"

Given that "devices" submitted as specimens are sufficiently defined by using the relationship SPECIMEN SOURCE IDENTITY = <<Device

Extending the range of SPECIMEN SOURCE IDENTITY to include <Physical object would allow for new specimen concepts that were not devices to be modeled.

Existing Inception document: Modeling "disease in remission"

Related issue: IHTSDO-407 Frequencies and Courses

Need to evaluate/test the proposed options for addressing this. Solution must be applicable to general notion of disease phases.

• Need to test options before making a final recommendation

Proposed editorial guidance:

"If two body structures are needed to fully define the finding site for a condition, then a combined anatomic structure shall be created to represent that body structure."

Batch changes to the terminology as part of the quality improvement process may lead to changes in terming, location within a hierarchy or addition/removal of ancestors or descendents.

SNOMED Int'l needs to develop a more robust policy related to what is a substantive change and what is the notfication/approval process needed to be completed before the change can be released.

2017-03-30

2017-04-25

A proposal for review and revision of the following types of disorders was discussed:

• Disorders DUE TO another disorder
• Disorders AFTER another disorder
• Disorders AFTER a procedure
• Disorders DUE TO a procedure
• Disorders DURING a procedure

The initial document was taken through a number of revisions and approved by the Head of Terminology in September, 2017

Complete

In process

2017-03-30

2017-04-25

2017-03-30

2017-04-25

General agreement that the indication for the procedure should not be pre-coordinated with the procedure itself. Systems should leverage the supporting information model to capture the relationships (e.g. CIMI, FHIR).

One exception to this is whether the indication actually changes the way a procedure is performed (such as a surgical approach). However, this would only apply when the concept model does not support modeling the change in procedure.