Welcome to EVS

Since 1997, NCI Enterprise Vocabulary Services (EVS) has provided terminology content, tools, and services to accurately code, analyze and share cancer and biomedical research, clinical and public health information.

EVS works with many partners to develop, license and publish terminology, jointly develop software tools, and support harmonization and shared standards. EVS provides the foundational layer for NCI's informatics infrastructure, and plays an important role in federal and international standards efforts (see EVS Use and Collaborations). The EVS Wiki provides extensive details on these and other EVS resources, tools and services.  The EVS Downloads web page offers downloads of EVS terminology content and tools.

EVS Terminology

EVS creates, compiles, and cross-maps biomedical terminology needed by NCI and its community. EVS publishes NCI Thesaurus (NCIt) as its core reference terminology and biomedical ontology. EVS also makes available standalone versions of other terminologies and ontologies of special interest, and provides access with extensive cross-mappings to more than 75 terminologies in the NCI Metathesaurus.

  • NCI Thesaurus (NCIt) is NCI's reference terminology and core biomedical ontology, covering some 120,000 key biomedical concepts with a rich set of terms, codes, 115,000 textual definitions, and over 400,000 inter-concept relationships. NCIt combined and extended core NCI terminologies within a scientifically and technically rigorous framework. NCIt is now a broadly shared coding and semantic infrastructure resource – nearly half of NCIt concepts include content explicitly tagged by one or more EVS partners (see the shared terminology development wiki page).
  • NCI Metathesaurus (NCIm) Maps 7,000,000 terms from more than 100 sources into 2,500,000 biomedical concepts that represent their meaning.. NCIm contains most terminologies used by NCI for clinical care, translational and basic research, and provides a rich source of definitions, synonyms, codes, and other information.  NCIm starts from a subset of NLM's UMLS Metathesaurus, and modifies and extends it with many additional sources.
  • Other Terminologies: EVS licenses, processes and makes available individually through EVS systems, many other terminologies of special interest to NCI and the research community. EVS has helped create, harmonize with, and publish several of these terminologies.  EVS Explore publishes all terminologies hosted by NCI EVS in an integrated environment, providing search, cross-links, and a user friendly interface to ICD-10-CM, CTCAE, MedDRA, SNOMED CT, MED-RT, GO, and many other terminologies and ontologies used by NCI and its partners.
  • Terminology Mappings: Pairwise mappings between several supported terminologies have also been created and published to support data translation and cross-reference. As with standalone terminologies above, such mappings generally reflect special EVS community interests and collaborations.
  • Terminology Subsets and Data Standards: EVS works with many partners to create and support standardized terminology for biomedical coding. Hundreds of NCIt subsets and other code lists are maintained by EVS. More than 550 subsets are currently defined in EVS, most as subsets of NCIt covering a range of standards from EVS partners.  Key EVS supported terminology standards include:
    • FDA Terminology: EVS is working with the U.S. Food and Drug Administration (FDA) to develop and support controlled terminology in several areas. More than 15,000 FDA terms and codes are stored in NCIt.
    • MED-RT™: Medication Reference Terminology (MED-RT™) is the successor to the Veterans Health Administration National Drug File – Reference Terminology (VHA NDF-RT™). MED-RT™ provides formal ontological representations of medication terminology, pharmacologic classifications, such as mechanisms of action (MoA), physiologic effects (PE), established pharmacologic class (EPC) and asserted relationships between them. MED-RT incorporates data the following terminologies: RxNorm for prescribable medications, active ingredients, and relationships between them; MeSH for indexing chemical structure and therapeutics using its concept hierarchies, and SNOMED CT International to aid in mapping between FDA pharmacologic classes and its product and substance hierarchies. It also maintains the National Committee on Vital and Health Statistics (NCVHS) standards for describing medication pharmacologic classification: MoA and PE hierarchy concepts.
    • CDISC Terminology: The Clinical Data Interchange Standards Consortium (CDISC) -- an international, non-profit organization that develops and supports global data standards for medical research -- has chosen EVS as its terminology partner.
    • NCPDP Terminology: The National Council for Prescription Drug Programs (NCPDP) creates and promotes the transfer of data related to medications, supplies, and services through the development of standards and industry guidance, and now uses NCIt in two of its standards.
    • Pediatric Terminology: The National Institute of Child Health and Human Development (NICHD) and EVS are working with numerous contributors from national and international academic, clinical and research institutions to provide standardized terminology for coding pediatric clinical trials and other research activities.

Making these terminology resources more easily available, mapping between them, harmonizing coding standards, and promoting agreement on best practices, are all core EVS priorities.