Identified Issues

The analysis made shows a set of issues which needs to be discussed to determine the best way to mitigate the issues and ensure a greater level of consistency and transparency going forward.

Overlapping Use of Inactivation Reasons

• •Ambiguous Component – pure ambiguity -> removal of classification categories - > Non-conformance to Editorial Policy
• •Erroneous Component – spelling, grammar, word order -> clinically incorrect (strain v sprain, incorrect semantic tag)
• •Non-conformance to Editorial Policy – tendency to a broad interpretation of use!
• •Editorial Guidance on inactivation of FSN – overlap with Erroneous and non-Conformance to Editorial Policy

Semantic Tag Changes

• • Is there any situations in which a concept can change semantic tag without inactivating the concept and creating a proper replacement?

Classification concepts

• How can we state that a concept is an ambiguous classification concept? 
  • Should we re-introduce the 'Limited' inactivation value?
• In which situations is it okay not to provide a target replacement?
  • E.g. classification concepts may not always have a corresponding concept in SNOMED CT.
• In what situations do we use the inactivation value Erroneous?
  • Potential answer: When an FSN includes an error that impacts the meaning of the concept.
    
    

FSN vs. Logical Definition

For some time we have held that the Fully Specified Name as the “The Arbiter of Truth” when it comes to portraying the meaning of a concept. It is what is used to inform the modeling.
When displayed without the semantic tag, as the Preferred Term, it is what the clinician sees and may be recorded in the notes. On this basis, we make decisions about inactivation based upon the FSN

BUT, the use of SNOMED CT increasingly apply the defining properties to dictate what concepts are available in the Clinical user interfaces. For example, we now promote the use of ECL as the means by which we search and extract content from SNOMED CT, e.g.

• Refsets and decision support may rely on ECL queries to function correctly
• ECL queries rely on correct and complete modeling in order to function correctly

The logical definition therefore, to a higher degree than before, impact how concepts are being used for clinical data capture. 

With this evolution, it is important to carefully consider and agree on what takes precedence, the FSN, the logical definition - or both?

This needs to be clarified for us to be able to specify the recommended process for the inactivation of ambiguous concepts where there is a misalignment between the FSN and the logical definition. Should the historical associations reflect the meaning represented by the FSN and/or the meaning represented by the logical definition?

Component Moved Elsewhere & Pending Move

These two reasons for potential inactivations are considered to be primarily related to movement of concepts between the International Release and Local Editions
Few if any authoring principles are required
•It would be helpful to have the option to have a REPLACED_BY or POSSIBLY_EQUIVALENT_TO option, where appropriate, to support those who may have used the concept and are not the receiving entity e.g. O/E & C/O content
•However, there is a need to address the management, advice and tooling of the movement of content between editions of SNOMED particularly as we contemplate the concept of movement between:
•SNOMED CT Core Edition
•International Edition
•Community Edition
•Perhaps a discussion to be had with the MAG/Release Management Team etc.

Approaches to Enhance Inactivation Mechanism

General Recommendation

We suggest:

1. Significantly tighten the definition and expected use for any given inactivation reason
2. Provide drop down lists to allow authors to be more specific about the reason. For example:
   1. Adoption of the “Due To” editorial policy
   2. Change in meaning due to spelling/grammar error
   3. Mismatch between meaning of FSN and logical definition
3. Reactivate LIMITED COMPONENT for the inactivation of classification concepts with an option to use an appropriate association – this ensures a consistent approach to dealing with classification concepts historically and going forward

Ambiguous concepts

Duplicate concepts