Observational Health Data Sciences and Informatics

The Standardized Vocabularies are organized into Domains and Vocabularies. Domains refer to the nature of type of a clinical entity, which also defines the CDM data table where a data record is stored, while Vocabularies are sets of Concepts imported from external national or international existing standards, or created by the Standardized Vocabularies Team if no suitable standard is available.

There is no one-to-one relationship between Domains and Vocabularies. Some Vocabularies are very broad, such as SNOMED-CT or Read, and contain Concepts of all medical Domains. Other vocabularies are specific for a certain Domain, such as RxNorm for Drugs or ICD-9-Proc for Procedures. In many cases Vocabularies are generally assumed in the community to be of a single Domain, when in fact they are not: For example, CPT-4 and HCPCS, are expected by their name to contain Procedure codes, only, but contain Observation, Condition, Device and Drug Concepts: