Purpose
The | Code to expression type reference set| is designed to enable associations between code in another code system (other-codes) and SNOMED CT concepts, where the following constraints apply:
- Some of the other-codes cannot be mapped to an individual SNOMED CT concept.
- Licensing conditions (or other considerations) prevent addition of new SNOMED CT concepts to represent the same meaning as the other-codes.
- The other-codes can be logically defined using the SNOMED concept model to represent the same meaning (sufficiently defined) or a similar though less specific meaning (primitive).
- Other requirements similar for those applicable to mapping may also apply including:
- An indication of the degree of correlation between the other-code and the SNOMED CT expression.
- An indication of whether the other-code was created before any single concept representation of that meaning in SNOMED CT or whether the single concept representation in SNOMED CT predated the creation of the association.
Data Structure
The general approach to the above requirements is to associate each of the other-codes with a representation of the same logic based definition as would have been applied to a SNOMED CT concept with that meaning. However, since the other-code are not identified by an SCTID, the logical definition cannot be represented using defining relationships. There are two potential approaches to this, one would be to use a general purpose description logic language (e.g. OWL) and the other is to use a SNOMED CT expression to represent each definition. The
|
Code to expression type reference set|
is designed to support the expression-based approach.
Field | Data type | Purpose |
|---|---|---|
id | A 128 bit unsigned integer, uniquely identifying the reference set member. | |
Specifies the inclusive date at which this change becomes effective. | ||
Specifies whether the member's state was active or inactive from the nominal release date specified by the effectiveTime field. | ||
Identifies the member version's module. Set to a child of | Module| in the metadata hierarchy. | ||
Identifies the reference set and must be a subtype of | Code to expression type reference set| which is located in the metadata hierarchy as shown below:
900000000000454005 |Foundation metadata concept|
| ||
A reference to a SNOMED CT metadata concept referring to the code system containing the other-codes. This is a subtype of | Terminology system| . | ||
The other-code associated with the SNOMED CT expression. | ||
A SNOMED CT expression that represents the SNOMED CT definition of the other-code. This expression may be a stated or inferred view of the definition provided that documentation of each identified reference set specifies the view provided. The expression must conform to the syntax defined in the SNOMED CT Compositional Grammar - Specification and Guide (http://snomed.org/scg). | ||
Indicates whether or not the expression contains a sufficient definition of the other-code in the mapTarget field.
900000000000074008 |Necessary but not sufficient concept definition status|
| ||
The correlation between the SNOMED CT expression and the other-code. Possible values are the following subtypes of 447247004 | SNOMED CT source code to target map code correlation value| :
447559001 |Broad to narrow map from SNOMED CT source code to target code|
When these values are applied to this reference set type, the phrase "SNOMED source code" is interpreted as meaning "SNOMED expression" and "target code" refers to the other-code.. | ||
Indication of whether concept was initially in one of the terminologies (SNOMED CT or other-codes) and added to the other as part of mapping or was in both terminologies at the outset. Values are subtype children of 705116007 | Original code system source for linked content value| |
Feedback
Overview
Content Tools
Apps