The SNOMED RT Procedure Model

BACKGROUND SNOMED RT represents a fundamental change from prior versions of SNOMED. The logic-based structure of SNOMED RT enables concepts to be defined more explicitly, providing an opportunity to address inconsistencies and ambiguities present in prior SNOMED concept definitions. OBJECTIVES Create a unifying organizational strategy for all SNOMED RT procedures, and remove ambiguities in procedure concept definitions. METHODS A comprehensive model of procedures was developed, based on a set of guiding principles and a review of known existing models. RESULTS All SNOMED RT procedures are categorized by a common set of "root procedures" (high level atomic actions), and are more explicitly defined by a shared set of defining relationships. CONCLUSIONS While the objectives have largely been met, open issues continue to be addressed. The similarity between procedure models of SNOMED RT and the U.K. s Clinical Terms Version 3 is proving to greatly facilitate the full integration of the two terminologies into a merged vocabulary to be known as SNOMED Clinical Terms (SNOMED CT), slated to be released in the near future.