TheSystematized Nomenclature of Medicine (SNOMED) is a systematic, computer-processable collection ofmedical terms, in human andveterinary medicine, to provide codes, terms, synonyms and definitions which coveranatomy,diseases, findings, procedures,microorganisms, substances, etc. It allows a consistent way to index, store, retrieve, and aggregate medical data across specialties and sites of care. Although now international, SNOMED was started in theU.S. by theCollege of American Pathologists (CAP)[1] in 1973 and revised into the 1990s. In 2002 CAP's SNOMED Reference Terminology (SNOMED RT) was merged with, and expanded by, theNational Health Service's Clinical Terms Version 3 (previously known as theRead codes) to produce SNOMED CT.[2][3]
Versions of SNOMED released prior to 2001 were based on a multiaxial,hierarchical classification system.[1][4] As in any such system, a disease may be located in a bodyorgan (anatomy), which results in a code in a topography axis and may lead tomorphological alterations represented by a morphology code.
In 2002 the first release ofSNOMED CT adopted a completely different structure. A sub-type hierarchy, supported by defining relationships based ondescription logic, replaced the axes described in this article. Versions of SNOMED prior to SNOMED CT are planned to be formally deprecated from 2017.[5] Therefore, readers interested in current information about SNOMED are directed to the article onSNOMED CT.
SNOMED was designed as a comprehensivenomenclature of clinical medicine for the purpose of accurately storing and/or retrieving records of clinical care in human andveterinary medicine.The metaphor used byRoger A. Côté, the first editorial chair, was that SNOMED would become theperiodic table of elements of medicine because of its definitional organization beyond the hierarchical design. Indeed, diseases and procedures were ordered hierarchically and are further referenced back to more elementary terms[citation needed]
SNOMED was originally conceived by Côté as an extension of the design of the Systematized Nomenclature of Pathology (SNOP) applicable for all medicine. SNOP was originally designed by Arnold Pratt to describe pathological specimens according to their morphology and anatomy (topography). The ambitious development of SNOMED required many more axes (see multi-axial design, below). SNOMED was jointly proposed for development to theCollege of American Pathologists by Côté and Pratt. The former was appointed as editorial chair of the Committee on Nomenclature and Classification of Diseases of the CAP and developed the SNOMED from 1973 to 1997. In 1998,Kent Spackman was appointed to chair this committee and spearheaded the transformation of the multi-axis systems into a highly computable form (SeeSNOMED CT): adirected acyclic graph anchored in formal representation logic. In 2007, the newly formedInternational Health Terminology Standards Development Organisation (IHTSDO) acquired all the Intellectual Property ofSNOMED CT and all antecedent SNOMED versions.[citation needed]
Brief timeline:
SNOMED was designed from its inception with complex concepts defined in terms of simpler ones. For example, a disease can be defined in terms of its abnormal anatomy, abnormal functions andmorphology. In some cases, theetiology of the disease is known and can be attributed to an infectious agent, a physical trauma or a chemical or pharmaceutical agent.[citation needed]
The current concept uses eleven (11) axes that comprise terms organised in hierarchical trees. The axes and some examples are provided below:
For the Morphology axis, SNOMED hasagreed to collaborate and use the same harmonized codes shared withInternational Classification of Diseases for Oncology. Additional examples on topology are provided on that page.