The main reasons for modifying a description in an extension are:
Making changes to existing descriptions requires careful consideration, because the descriptions may have been used in clinical records to represent the meaning of the associated concept. Changes are, however, permitted, as long as only mutable attributes are modified. Immutable attribute values should not be modified.
The conceptId field, the languageCode field and the typeId field cannot change between different versions of the same description. If a change is required to one of these immutable attributes, then the existing description should be inactivated, and a new description with the required attribute values should will be added.
Extension producers should not modify descriptions, which are part of the International Edition. When issues with international descriptions arise, SNOMED International should be notified so the issue may be addressed in a subsequent release.
Table 184.108.40.206-1 lists the various description attributes and their mutability. The following modifications to the mutable attributes are permitted
Table 220.127.116.11-1: Mutability of description attributes
|Part of Primary Key|
Uniquely identifies the description.
Specifies the inclusive date at which the component version's state became the then current valid state of the component
Note: In distribution files the effectiveTime should follow the short ISO date format (YYYYMMDD) and should not include the hours, minutes, seconds or timezone indicator.
Specifies whether the state of the description was active or inactive from the nominal release date specified by the effectiveTime .
Identifies the description version's module. Set to a child of 900000000000443000 | Module| within the metadata hierarchy.
Identifies the concept to which this description applies. Set to the identifier of a concept in the 138875005 | SNOMED CT Concept| hierarchy within the Concept. Note that a specific version of a description is not directly bound to a specific version of the concept to which it applies. Which version of a description applies to a concept depends on its effectiveTime and the point in time at which it is accessed.
Specifies the language of the description text using the two character ISO-639-1 code. Note that this specifies a language level only, not a dialect or country code.
Identifies whether the description is fully specified name a synonym or other description type. This field is set to a child of 900000000000446008 | Description type| in the Metadata hierarchy.
The description version's text value, represented in UTF-8 encoding.
Identifies the concept enumeration value that represents the case significance of this description version. For example, the term may be completely case sensitive, case insensitive or initial letter case insensitive. This field will be set to a child of 900000000000447004 | Case significance| within the metadata hierarchy.
An extension producer may also need to change the acceptability of a description. For example, a synonym may change from being acceptable to preferred, or from being preferred to acceptable. This type of change does not require any modifications to the Description file. Instead, the associated member of the relevant language reference set must be modified. For more information, please refer to 18.104.22.168 Modify Members of a Reference Set.
The table below provides a summary of the process to follow when modifying descriptions in an extension.
A new row which represents a new version of the description is created.
The attributes of the new version of the description are set as follows:
|Language Reference Set|
If no changes to the acceptability of the description are required, then no changes to the associated language reference set members are necessary.
If changes to the acceptability of the description are required, a new version of the relevant language reference set member is added with the required acceptabilityId.