SNOMED CT: utility for a general medical evaluation template.

BACKGROUND: The U.S. government has licensed SNOMED CT to permit broad-based evaluation and use of the terminology. We evaluated the ability of SNOMED CT to represent terms used for interface objects (e.g., labels and captions) and concepts used for data and branching logic in a general medical evaluation template in use within the Department of Veterans Affairs. METHODS: The general medical evaluation form definition, report definition, and script files were parsed and 1573 expressions were mapped into SNOMED CT. Compositional expressions required to represent 1171 concepts. Double independent reviews were conducted. Exact concept level matches were used to evaluate reference coverage. Exact term level matches were required for interface terms. Semantics were analyzed for a randomly selected subset of 20 terms. RESULTS: Sensitivity of SNOMED CT as a reference terminology was 63.8% , ranging from 29.3% for history items to 92.4% for exam items. SNOMED CT's sensitivity as an "interface terminology" was 55.0%. 80% of the necessary linking semantics for the subset were present. Subgroup statistics are presented. DISCUSSION: SNOMED CT is promising as a terminology for knowledge representation underlying a large general medical evaluation. Its performed less well as an interface terminology.