Each new release of the SNOMED CT International Edition introduces some changes to the content in SNOMED CT. Many of these changes are additions to the breadth and depth of clinical coverage. Other changes may include new descriptions, corrections to concept definitions, and enhancements to the expressivity of the concept model. These changes are an essential characteristic of an evolving clinical terminology which seeks to support current requirements. However, each change made to the International Edition may have an impact on the content in an extension. It is therefore important to evaluate and manage these changes when reconciling an extension with a new version of the SNOMED CT International Edition (or another extension on which it depends).
The change management process can be divided into three distinct phases:
After change management has been performed, it is important that thorough review and validation of the resulting extension is performed.
In the following sections we discuss the three phases of change management.