Conversion of Data to the OMOP CDM
The OMOP-CDM structures and harmonizes patient-level data, including details of visits with health care services, diagnoses, medical procedures, drugs, and laboratory test results, and de-identifies clinical content. A diagnosis record consists of a patient identifier, the date of diagnosis, a code for the diagnosis, and the mapping and coding system (International Classification of Diseases, Tenth Revision [ICD-10]) to the OMOP-CDM Standardized Vocabularies.20 In this mapping process, the Systematic Nomenclature of Medicine (SNOMED) is used as the target vocabulary for diagnostic codes, RxNorm for drugs, and Logical Observation Identifiers Names and Codes for other observations, such as laboratory results and measurements of vital signs.19