The main reasons for modifying a concept in an extension are:
If an extension producer needs to modify the definition of a concept, this will necessitate adding, modifying or inactivating the relationships for which the given concept is the source. For more information, please refer to 5.4.4 Authoring Relationships.
If an extension producer needs to modify the terms used to describe the concept, this will necessitate adding, modifying or inactivating the descriptions associated with the concept. For more information, please refer to 5.4.3 Authoring Descriptions.
The clinical meaning of each concept in SNOMED CT is permanent, and can not be modified over time. This clinical meaning is captured by the concept's Fully Specified Name. Changing the clinical meaning of a concept therefore requires inactivating the concept, and creating a new concept that represents the new meaning.
The following changes, however, are permitted:
The attributes of a concept may be modified, as long as the change is limited to the values of its mutable attributes. The values of immutable attributes should never be modified.
The effectiveTime attribute is used to support the versioning of each concept. Permitted concept modifications therefore include:
It should be noted that extensions should not modify the attributes of an international concept, unless this modification is necessary to meet legitimate clinical needs or to correct identified clinical issues. Any new version of an international concept that is created by an extension producer (other than SNOMED International) and which modifies the concept's mutable attributes, should be:
The table below provides a summary of the process to follow when modifying a concept in an extension.
File Type | Process |
---|---|
Concept | A new row, which represents the new version of the concept, is added to the concept file. |
The attributes of the new version of the concept are set as follows:
|