International release criteria include affirmative answers to the following:
The guiding principle underlying the creation of a clinical reference terminology is the facilitation of semantic interoperability. To this end, content in SNOMED CT must represent unambiguous, clinically relevant information which can be exchanged and understood internationally. A reproducible and consistent approach to incorporating terminology into electronic health applications is, therefore, mandatory.
The International Release includes content necessary for international conformance and interoperability (the International Release was formerly and is colloquially known as the core). The range of concepts, attributes, qualifiers, and other components of SNOMED CT is comprehensive compared to classification systems. This supports the terminological needs of those using SNOMED CT within electronic health applications.
Addition of new content to SNOMED CT requires careful consideration. Changes and additions to the International Release of SNOMED CT follow a formal process executed by SNOMED CT authors. For content to be included in the International Release, the following criteria must be met.
Content must be submitted with:
For details on SNOMED International Content Request Service (CRS) Customer Guidance, see our website or the Confluence site. |
It must be applicable within and across healthcare disciplines internationally.
Changes and additions must follow SNOMED CT Content Request Service (CRS) Guidelines. It is very important to incorporate a clear justification for any change or addition request for the International Edition of SNOMED CT.
Content submitted for inclusion in the International Release shall be required to pass a test for "usefulness." The usefulness test can be passed in more than one way. At least one of the following must be satisfied:
Additional means of passing the usefulness test may be added in the future. Submissions that pass the usefulness criterion must also pass understandability and reproducibility tests, and conform to style rules.
SNOMED CT concepts should name classes of things. Concepts that refer to a particular instance are unacceptable.
For example, Doctor Jones pre-operative order set should not be included because it is an individual instance, not a class.
Negation in SNOMED CT is generally out of scope for the terminology. However, SNOMED CT currently has content which incorporates negation in several hierarchies. This is due to the amalgamation of legacy content from Read Codes and SNOMED RT in 2002 when the two terminologies formed SNOMED CT. The description logic approach to negation comes with a high machine processing cost, and so the decision was to deal with all negation via the Situation with explicit context hierarchy. The consequence of this approach is that the representation of negation within SNOMED CT that arises from restrictions imposed by the existing description logics results in the hierarchy being inverted, e.g., Coronary heart disease not present is not properly a subtype of Heart disease not present.
For these reasons, software vendors are encouraged to store negation in the electronic health record rather than looking for a concept which encapsulates its meaning. Storing negated findings in a separate field in the EHR, for example, would simplify querying data.
(See also Appendix: Principles for Accepting Content in the International Release)