MOVED_TO & MOVED_FROM - Editorial Guide

Current usage:

The MOVED_TO and MOVED_FROM association types combine to form a mechanism by which SNOMED CT records when jurisdictional control of a concept passes between extensions, or between the international core and an extension, in either direction (ie from CORE to Extension or vice versa, or between extensions maintained within the same release centre). It is also used to move a concept from the International Edition to the veterinary extension.

Therefore, all transfers of control have conceptually a "donor" and a "recipient" SNOMED extension/release. Although this is conceptually the case, authors/editors currently only encounter MOVED_TO as part of an inactivation reason of "Component moved elsewhere" even though SNOMED CT international release does accept transfer of concepts from other jurisdictions.

Current practice assumes that when a concept has only jurisdictional applicability, it is not semantically interoperable across international boundaries. It is also assumed that the concept has not been used outside of the applicable jurisdiction. Thus, the current use of MOVED_TO only provides a target value concept representing the namespace ID to which the concept has been moved.

Proposed changes:

The current use of MOVED_TO assumes that a concept which is deemed to be only of jurisdictional relevance will not have been used by any other member of the community of practice outside of that jurisdiction. While this may often be the case, it should not be assumed and therefore a mechanism needs to be available that supports those who have used the concept destined to be moved.

While the use of the association type "MOVED_TO" will remain unchanged, it is proposed that in addition to providing a target namespace ID, the inactivation reason COMPONENT_MOVED_ELSEWHERE will be enhanced to encourage greater use of the already permitted but optional ALTERNATIVE association, to identify potential alternative target concept(s0 within the donor product. Or, if there are no clinically appropriate replacements, then allocation of WAS_A associations to the relevant concept parents and a text note added which states "no appropriate target exists".

As greater movement of concepts occurs between modules (e.g. between the SNOMED International Core and Community Edition etc.), it may be helpful to have a new companion association type to MOVED_TO of MOVED_FROM (perhaps "DONATED_TO"). This might also be helpful to local NRC's who have to manage concepts moved to their namespace either from SNOMED International Release or from shared content between NRC's.

Combinatorial Logic:

MOVED_TO

Note: the combinations of association types listed below are unlikely to be encountered; to date, no namespace identifiers concept has ever been inactivated, however, if national licences are revoked or national boundaries change it may become necessary to support such changes. For completeness both MOVED_TO and MOVED_FROM are provided below:

Please note that in this instance these inactivations are taking place within the namespace release, not SNOMED International

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

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

(A) MOVED_TO (B) and  (B) REPLACED_BY (D) implies A MOVED_TO (D)

(A) MOVED_TO (B) and  (D) MOVED_FROM (B) implies A MOVED_TO (D)

(A) MOVED_TO (B) and  (B) POSSIBLY_EQUIVALENT_TO (D OR E) implies (A) MOVED_TO null

(A) MOVED_TO (B) and  (B) WAS_A (D AND E) implies (A) MOVED_TO null

MOVED_FROM

The MOVED_FROM association is essentially isosemantic to the SAME_AS association. Therefore, the compositional logic is identical:

(B) MOVED_FROM (A) and (B) SAME_AS (D) implies (D) SAME_AS (A)

(B) MOVED_FROM (A) and (B) MOVED_TO (D) implies (B) MOVED_FROM (A)

(B) MOVED_FROM (A) and (B) REPLACED_BY (D) implies D MOVED_FROM A

(B) MOVED_FROM (A) and (B) MOVED_FROM (D) implies (D) MOVED_FROM (A)

(B) MOVED_FROM (A) and (B) POSSIBLY_EQUIVALENT_TO (D OR E) implies (A) POSSIBLY_EQUIVALENT_TO (D OR E)

(B) MOVED_FROM (A) and (B) WAS_A (D AND E) implies A WAS_A (D AND E)