Achieving Logical Equivalence between SNOMED CT and ICD-10-PCS Surgical Procedures

Surgical procedures are coded in SNOMED CT in the electronic health record and in ICD-10-PCS in administrative systems. We compared the logical definitions of SNOMED CT concepts to the ICD-10-PCS axial components to identify overlap and gaps. The biggest discrepancy was in the surgical approach which was specified in all ICD-10-PCS codes but only in 8.7% of SNOMED CT surgical procedures. Among the top 100 commonly used ICD-10-PCS codes, 25% could be matched fully in meaning and logical definition to pre-coordinated SNOMED CT concepts. Using post-coordination, it was possible to represent the full meaning of 86% of ICD-10-PCS codes. Logical mapping between SNOMED CT and ICD-10-PCS is feasible but will be more productive if more SNOMED CT concepts can become fully-defined. Short of full logical matching, partial logical matches can also be useful in suggesting candidate maps for expert review and to support interactive post-coordination.