9.1. Managing Content Changes in SNOMED CT

This section of the guide addresses potential issues that may affect implementations when new releases of SNOMED CT contain changes to content.

The likely impact of four general types of change are considered.

Content additions.
Content inactivation (e.g. inactivation of a Concept).
Changes to relationships between concepts
Changes to the Concept Model leading to systematic changes to a range of components.

The impact of these changes is assessed in terms of the main record service functions

Data entry (e.g. potential requirements to change to data entry protocols).
Data storage (e.g. whether pre-existing data needs to be migrated or processed in a particular way to ensure consistency).
Data retrieval (e.g. whether existing queries are likely to need revising to take account of the changes).
Communications (e.g. whether communication specification are likely to be affected and in particular potential issues from cross-version communications).

Following discussion of these general considerations, the remainder of this section holds specific advice related to any content changes in a release which are expected to require attention from implementers.