Purpose

The main reasons for modifying a description in an extension are:

• The description term contains an error that needs fixing
• The case significance of the term needs to be changed
• The acceptability of the description has changed - e.g. from acceptable to preferred, or from preferred to acceptable.
  

Principles

Overview

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. 

Changing Mutable Description Attributes

Table 5.4.3.2-1 lists the various description attributes and their mutability. The following modifications to the mutable attributes are permitted

• Changing the active attribute to 0 (i.e. inactive).  For more information, please refer to Inactivating a Description in an Extension.
• Changing the term of the description. Please note that only limited changes may be made to the term field, as defined by editorial rules.
  • The International SNOMED CT Editorial Guide states when making a minor change to an FSN, a new description must be created and the old description must be inactivated. 
  • Permitted changes include modifications that do not alter the meaning, for example a spelling correction. For a list of permitted changes, please refer to the appropriate section of the Editorial Guide:
    • FSNs - refer to Fully Specified Name
  • When in doubt, an extension producer should inactivate the description and add a new description with the required term.

Table 5.4.3.2-1: Mutability of description attributes

Changing the Acceptability of Descriptions

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 5.4.6.2 Modify Members of a Reference Set.

Process

The table below provides a summary of the process to follow when modifying descriptions in an extension.