Systematized Nomenclature of Medicine

For the collection of information officially organized with the SNOMED system, see SNOMED CT.

The Systematized Nomenclature of Medicine (SNOMED) is a multiaxial, hierarchical classification system . As in any such system, a disease may be located in a body organ which results in a code in a topography axis and may lead to morphological alterations represented by a morphology code.

Purpose

SNOMED was designed as a comprehensive nomenclature of clinical medicine for the purpose of accurately storing and/or retrieving records of clinical care in human and veterinary medicine. The metaphor used by Roger A. Côté, the first editorial chair, was that SNOMED would become the periodical table of element 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 (see Reference Ontology and Multi-Axial Design, below).

History

SNOMED was originally conceived by Dr. Roger A. Côté as an extension of the design of the Systematized Nomenclature of Pathology (SNOP) applicable for all medicine. SNOP was originally designed by Dr. Arnold Pratt to describe pathological specimen 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 the College of American Pathologists by Drs. Côté and Dr. Arnold Pratt and the former was appointed as Editorial Chair of the Committee on Nomenclature and Classification of Diseases of the College of American Pathologists and developed the Systematized Nomenclature of Medicine (SNOMED) from 1973 to 1997. In 1998, Dr. Kent Spackman was appointed Chair of this Committee and spearheaded the transformation of the multi-axis systems into a highly computable form (See SNOMED CT): a directed acyclic graph anchored in formal representation logic.

Brief timeline:

• 1965 SNOP
• 1974 SNOMED
• 1979 SNOMED II
• 1993 SNOMED International 3.0
• 1995 SNOMED Microglossary of Signs and Symptoms
• 1993-98 SNOMED International versions 3.1-3.5

Reference ontology

SNOMED was designed from its inception with complex concepts defined in term of simpler ones. For example, a disease can be defined in terms of its abnormal anatomy, abnormal functions and morphology. In some cases, the etiology of the disease is known and can be attributed to an infectious agent, a physical trauma or a chemical or pharmaceutical agent.

Multi-axial design

The current concept uses eleven (11) axes that comprise terms organised in hierarchical trees. The axes and some examples are provided below:

T (Topography) – Anatomic terms

• (T-28000) Lung
• (T-32000) Heart
• (T-51000) Mouth
• (T-D2500) Hip
• (T-D9600) Heel

M (Morphology) – Changes found in cells, tissues and organs

• (M-40000) Inflammation
• (M-44000) Granuloma
• (M-54700) Infarcted
• (M-54701) Microscopic infarct

For the Morphology axis, SNOMED has agreed to collaborate and use the same harmonized codes shared with International Classification of Diseases for Oncology. Additional examples on topology are provided on that page.

L (Living organisms) – Bacteria and viruses

• (L-21801) Mycobacterium tuberculosis
• (L-25116) Streptococcus pneumoniae

C (Chemical) – Drugs

• (C-C137A) Bufferin Analgesic Tablets
• (C-C137B) Bufferin Analgesic Caplets

F (Function) – Signs and symptoms

• (F-03003) Fever

J (Occupation) – Terms that describe the occupation

• Businessman
• School teacher
• Computer programmer
• Doctor
• Nurse
• Beautician

D (Diagnosis) – Diagnostic terms

• (D-13510) Pneumococcal pneumonia
• (D-14800) Tuberculosis
• (D3-15000) Myocardial infarction

S (Social context) – Social conditions and important relationships in medicine

• (S-10120) Mother

See also

• Diagnosis codes
• Medical classification
• SNOMED CT
• Medical Dictionary for Regulatory Activities (MedDRA)
• DOCLE

External links

• Official page at snomed.org (now redirects to www.ihtsdo.org)
• Studies of the formal structure of SNOMED CT at buffalo.edu
• Browser at vetmed.vt.edu
• Dataline SNOMED Browser: Looks up clinical terms online for free.
• SNOCat: the SNOMED Categorizer/Browser to automatically encode medical narratives - provided by the BiTeM group (http://bitem.hesge.ch) !