The Standardized Vocabularies are organized into Domains and Vocabularies. Domains refer to the nature or type of a clinical entity. It also defines the CDM data table where a data record is to be stored. Vocabularies are sets of Concepts imported from an external national or international existing standard, or created by the Standardized Vocabularies Team if no suitable standard is available.
Note: There is no one-to-one relationship between Domains and Vocabularies. Some Vocabularies are very broad, such as SNOMED or Read, and contain Concepts of all medical Domains. Other vocabularies are specific for a certain Domain, such as RxNorm for Drugs or ICD9Proc 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, CPT4 and HCPCS are expected by their name to contain Procedure codes only, but in reality contain Observation, Condition, Device and Drug Concepts.