Enterprise Vocabulary Services (EVS)
EVS Tools Information
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 closely with NCI and other 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.
EVS has collected, created, and cross-mapped biomedical terminologies needed by NCI and its community. Key EVS terminology resources are summarized as follows:
- NCI Thesaurus (NCIt) is NCI's reference terminology and core biomedical ontology, covering some 100,000 key biomedical concepts with a rich set of terms, codes, definitions, and over 200,000 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) provides a broad, concept-based mapping of terms from over 70 biomedical terminologies, whose 3,600,000 terms are mapped to 1,400,000 concepts representing their shared meanings. NCIm gives access to a great diversity of biomedical terminologies, with mappings between them. NCIm also provides a rich reference resource for a broad range of users seeking definitions, synonyms, codes, and other information.
- 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.
- 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 Value Sets 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, and most are now available as CTS 2 value sets following the draft Common Terminology Services Release 2 (CTS 2) specification. In caDSR, they provide a pre-curated standard set of meanings for use by metadata curators. More than 200 value sets are currently defined in EVS, most as subsets of NCIt covering a range of standards from many 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 10,000 FDA terms and codes are stored in NCIt.
Federal Medication Terminology: EVS is also a partner in the Federal Medication (FedMed) collaboration, which is developing shared FedMed Terminology (FMT) and standards to improve the exchange and public availability of medication information.
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.
NICHD Terminology: The National Institute of Child Health and Human Development (NICHD) is working with EVS on the Pediatric Terminology Harmonization Initiative, providing standardized coding for pediatric clinical trial 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.
EVS ToolsEVS deals with a wide variety of terminology content, which is produced, exchanged and processed through many different formats, data structures, and interfaces. This requires a variety of specialized terminology tools and systems, able to handle complex data and apply sophisticated logical inference, business rules, and other processing. Many of these requirements are shared with other producers and users of terminology, and where possible EVS works collaboratively with other partners to develop shared, open source terminology tools and technology. Key EVS terminology tools are summarized as follows:
- LexEVS is the EVS terminology server, a collection of software and services to load, publish, and access vocabulary and ontology resources. NCI has provided major support over many years for Mayo Clinic development of LexEVS as an open source tool that is freely sharable. LexEVS is an essential part of EVS operations, and many NCI and external applications, including caDSR, depend on use of the LexEVS server APIs.
- EVS Terminology Browsers – NCI Term Browser and NCI Metathesaurus Browser – are cross-linked, user-friendly terminology browsers designed to meet NCI's internal and public information needs across the full range of EVS content, including support for collaborative content and standards development. The browsers are freely available as open source software, use the LexEVS servers, and have been adopted by others who use LexEVS.
- NCI Protégé is the primary EVS editing software, based on Stanford's open source Protégé tool, the development of which was mostly funded through EVS. Protégé is widely used for editing biomedical terminology and ontologies. NCI further developed Protégé plug-ins to meet EVS requirements and business rules, contributing their code back to the community to foster further Protégé development and adoption. The most demanding use is as the editing software for NCIt, but Protégé is also used locally for CTCAE and other editing work.
- Other Tools are primarily used for internal EVS terminology development work, but include important community and open software aspects:
- Term Suggestion: EVS Term Suggestion software is used extensively – both standalone and integrated into the EVS terminology browsers – to get community feedback and contributions to both NCI and EVS partner terminology products. Source code is available for community contributions and reuse.
- EVS Report Writer: EVS Report Writer is standalone software that connects to the LexEVS servers. It is used extensively to support NCI work as well as external partners. Source code is available for community contributions and reuse.
- EVS Value Set Editor is used to create and maintain CTS 2 value set and pick list definitions for loading into the LexEVS server, which resolves the definitions against referenced terminologies. The Editor was initially developed to support internal EVS operational requirements, and is used to generate the value sets currently published by EVS (see NCI Term Browser). Source code is available for community contributions and reuse.
- EVS Mapping Tool supports mapping between term lists, value sets, terminology subsets, or whole terminologies. An initial release supports internal EVS operations, and there is already some external adoption and code sharing. It provides a mix of automated and manual features for creating, editing and publishing mappings, connecting to LexEVS for terminologies available there and producing XML mapping representations.