This section provides an overview of:

• SNOMED CT International Release Content Development
• Request Submission

Why is this important?

Understanding the quality and rigor of the approach to SNOMED CT content development ensures user confidence in the quality of the content when implementing or using SNOMED CT.

What is this?

SNOMED CT International Release Content Development

SNOMED CT's content development is based on four basic principles that have and continue to guide development of its clinical content and technical design including:

• Development efforts must encompass broad, inclusive involvement of diverse clinical groups and medical informatics experts.
• The clinical content must be quality focused and adhere to strict editorial rules.
• The quality improvement process must be open to public scrutiny and vendor input, to ensure that the terminology is truly useful within health care applications.
• There must be minimal barriers to adoption and use.

The content of SNOMED CT evolves with each release. The types of changes made include new concepts, new descriptions, new relationships between concepts, and new reference sets, as well as updates and retirement of any of these components. Drivers of these changes include changes in understanding of health and disease processes; introduction of new drugs, investigations, therapies and procedures; and new threats to health, as well as proposals and work provided by SNOMED CT users.
The three basic operational criteria that help determine whether new content is following the principle of creating and sustaining semantic interoperability are that SNOMED CT must be:

• Understandable: The meaning must be able to be communicated, to be understood by an average health care provider without reference to inaccessible, hidden or private meanings.
• Reproducible: It is not enough for one individual to say they think they understand the meaning. It must be shown that multiple people understand the meaning in the same way.
• Useful: The meaning must have some demonstrable use or applicability to health or health care.

Recognizing the goal that SNOMED CT should become the accepted international terminological resource for health care, it must therefore be capable of supporting multilingual terminological renderings of common concepts. For the terminology to be acceptable to the widest possible range of users it must include translations as well as alternative spellings and other variations that arise from a national and regional dialect. Furthermore it must be capable of representing differences between the underlying concepts that arise from cultural, ethnic or linguistic variations.
Clinical terminology development is challenging for a variety of reasons. Even in a single country or language people often use the same words to mean different things, as well as using different words for the same thing. The names assigned to some clinical conditions are sometimes based on an earlier incomplete or erroneous understanding and often these misleading names remain in use long after knowledge has moved on. Progress of medical knowledge and evolution of pathogenic organisms creates a continual, growing requirement to add new content and revise definitions. Efforts by specialty bodies to establish diagnostic criteria and staging scales also lead to changes, and sometimes to divergence between different or overlapping sources of authority. In the face of these challenges, content development is directed to address current and emerging priorities identified by IHTSDO Members and other stakeholders.
Continuous quality improvement is the aim of IHTSDO. Quality processes are included as part of the work completed by the team of modeler's involved in SNOMED CT development. A documented scientific process is followed and content is defined and reviewed by multiple clinician editors. Conflicts between editors are resolved through an iterative process, based on achieving agreement and consensus, before being entered into the terminology. As necessary, the authoring team consult with additional experts to review the scientific integrity of the content.

Requesting Content Additions and Changes

IHTSDO provides a request submission service to gather and process requests for additions and changes to the content of the SNOMED CT International Edition. This service is directly accessible by National Release Centers (NRC) in Member countries and recognized Terminology Authorities within organizations with whom IHTSDO is actively collaborating. Organizations within Member countries can submit their requests for additions and changes to the National Release Centre. In some cases, requests with particular local relevance may be added to a National Extension. The NRC forwards requests that it considers have international relevance to the IHTSDO for a decision. If a request is deemed to have high priority it should result in action in the next release cycle. However, requests that require significant changes that would impact on other content may take longer.