Overview of NCI Thesaurus (NCIt)
NCI Thesaurus (NCIt) (download) is NCI's reference terminology. NCIt provides the concepts used in caCORE and caBIG to establish data semantics. It covers terminology for clinical care, translational and basic research, and public information and administrative activities. NCIt is also a widely recognized standard for biomedical coding and reference, used by a broad variety of public and private partners both nationally and internationally.
NCIt content comes from NCI, partners such as FDA and CDISC, caBIG and other groups, user requests, and an ongoing review of the open literature. This content is organized in a richly structured description logic environment, with more than 200,000 relationships between concepts to help define and connect them. Individual concepts include codes, terms, abbreviations, synonyms, definitions, links to outside sources, and a wide variety of other useful information.
The NCI Thesaurus is updated monthly. The differences between one month's release and the next are summarized on the NCI EVS list server. API access to the complete history of every concept in the Thesaurus is supported in caCORE EVS 3.2 and EVS/caCORE 4.x. Real-time access to the complete history of every concept provides NCI Thesaurus users with the capability to deal with change over time due to the way that information is coded or classified.
NCIt is registered in the HL7 OID Registry as 2.16.840.1.113883.3.26.1.1 .
NCIt is one component of EVS terminology resources. The NCI Metathesaurus (NCIm) provides rich synonymy and mappings among the codes and terms used in more than 70 biomedical terminologies. EVS browsers and LexBIG/LexEVS servers provide access to a wide variety of other terminologies and ontologies such as CTCAE, GO, ICD-9-CM, LOINC, MedDRA, SNOMED CT, and the VA's NDF-RT.
Semantics of NCIt
NCIt provides four features which together provide proven sufficient basis for the semantic integration of the caCORE. These four features are:
- Permanent, non-semantic concept codes
- NCI preferred terms for each concept
- English language definitions
- Synonyms
More complete description of the semantics of NCIt is available. A document briefly describing the editorial policies governing change to NCIt content is included with the semantics information.
