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Ambiguous

“POSSIBLY_EQUIVALENT_TO”

This inactivation reason explicitly states that the inactivated concept is inherently ambiguous but that each of the potential meanings represented by the ambiguous concept is semantically identical to one of the “POSSIBLY_EQUIVALENT_TO” target concepts, whether currently present or could be created in SNOMED CT.

The implication of this definition is that for any given ambiguous concept there must be 2 or more POSSIBLY_EQUIVALENT_TO target concepts.

• Identify all potential meanings represented in the ambiguous concept
  Identify ALL possible meanings that arise from the ambiguity. Identify semantically equivalent SCT concepts where they exist, and create new concepts where they do not exist.
• Non or partial synonymous synonyms
  Resolve these by inactivation as "Not semantically equivalent component' and the association type of "REFERS_TO" reassigning the description to either an existing concept or if necessary creating a new concept.
• Ensure that the synonyms on the inactive concept are represented within the appropriate active concept(s).
• Classification concept
  If the concept's ambiguity results from a classification disjunction or conjunction, use the inactivation reason of "Classification concept".
• Incorrect modeling
  Where the modeling of the concept is at variance with the meaning of the FSN, correct the modeling - this advice may change once the QI project has been completed and ECL is widely used.
• Additional notes:
  1. Identifying true ambiguity rather than lack of specificity or the meaning is "not known" and resolving the full suite of POSSIBLY_EQUIVALENT_To target concepts can sometimes be difficult.
  2. Share difficult ambiguous inactivations in the internal editor's meetings
  3. It is possible that one of the interpretations of the ambiguity gives rise to a concept that is not clinically meaningful. It is still important to create a concept to represent this meaning so that there is full semantic equivalence between the sum of the POSSIBLY_EQUIVALENT_TO targets and the ambiguous concept being inactivated as this is the only way of supporting analysis of historically coded clinical data that may have used the ambiguous concept. As a secondary action, the concept that is not clinically meaningful may then itself be inactivated.