Three common procedure code systems are supported in the Standard Vocabulary:
All three are used for the OMOP Standard Vocabulary as low-level concept codes for procedures. These low-level codes are linked to SNOMED-CT “Procedure” concepts (figure 6) for classification purposes.
As described above, all of SNOMED-CT is loaded into the Concept table, providing the Standard Vocabulary for Conditions and Procedures. The other concepts are available for the convenience of the researcher, but only concepts of the concept_class “Procedure” (similar to "Clinical Finding") are designated Standard Vocabulary concepts with a concept_level greater than 0.
ICD-9-Procedure, CPT-4 and HCPCS concepts are loaded from their respective sources, together with their relationships to SNOMED-CT.