REFERS_TO - Discussion

The REFERS_TO association is used specifically to manage non-synonymy. 

Where a description on a particular concept is not, in fact, a true synonym of the Fully Specified Name for that same concept, then:

• only the offending description should be inactivated, and not also the entire concept (unless its Fully Specified Name is itself ambiguous).

• in the 900000000000490003 Description inactivation indicator reference set, the reason for the description being inactivated should be recorded as 723278000 Not semantically equivalent component

• a single REFERS_TO association should be added between each inactivated description and exactly one concept whose Fully Specified Name correctly corresponds to the meaning of that description. In the rare case where a non-synonymous description is also itself ambiguous, it should still carry only a single REFERS_TO but this will point to a single inactive (ambiguous) concept that accurately captures that ambiguity, and that inactive concept should then itself have appropriate POSSIBLY_EQUIVALENT_TO associations.

For example, given:

...the synonym was inactivated and a REFERS_TO 116566001 Steroid (substance) added. 

Note: the 900000000000531004 REFERS TO concept association reference set is therefore unique amongst association reference sets: all entries in its referencedComponentId column must be an identifier for a SNOMED description rather than for a SNOMED concept, as is the case for all other association reference sets. Its linkedcomponentIds, however, are all still identifiers for concepts.

Combinatorial Logic

Whenever an already stated REFERS_TO target itself also becomes inactive - whether at the same release or later - the combinatorial logic is:

(A) REFERS_TO (B) and (B) SAME_AS (C) implies (A) REFERS_TO (C)

(A) REFERS_TO (B) and (B) REPLACED_BY (C) implies (A) REFERS_TO (B)¹

(A) REFERS_TO (B) and (B) MOVED_TO (C) implies (A) REFERS_TO (B)²

(A) REFERS_TO (B) and (B) MOVED_FROM (C) implies (A) REFERS_TO (C)

(A) REFERS_TO (B) and (B) POSSIBLY_EQUIVALENT_TO (C OR D) implies (A) REFERS_TO (C OR D)

(A) REFERS_TO (B) and (B) WAS_A (C AND D) implies (A) WAS_A (C AND D)

Notes

1. inferring A REFERS_TO C is not safe because REPLACED_BY is not reliably a statement of true semantic identity

2. inferring A MOVED_TO C would be problematic: A is a description identifier and this inference would not fit within the current pattern of the MOVED_TO association reference set. Conversely,