Structured vocabulary (1) DeCS – Health Sciences Descriptors – was created by BIREME (2) to serve as a unique language in indexing articles from scientific journals, books, congress proceedings, technical reports, and other types of materials, as well as for searching and retrieving subjects from scientific literature from information sources available on the Virtual Health Library (VHL) such as LILACS, MEDLINE, and others.
It was developed from the MeSH – Medical Subject Headings (3) of the U.S. National Library of Medicine (NLM) with the purpose of permitting the use of common terminology for searching in multiple languages, providing a consistent and unique environment for the retrieval of information.
DeCS is part of the LILACS Methodology and is an integrating component of the Virtual Health Library.
DeCS participates in the unified terminology development project, UMLS – Unified Medical Language System of the NLM, with the responsibility of contributing with the MeSH terms in Portuguese and Spanish.
BIREME also developed terminology in specific areas such as Public Health, Homeopathy, Science and Health, and Health Surveillance in addition to the original MeSH terms.
The concepts that characterize the DeCS vocabulary are organized in a tree structure(4) allowing a search on broader or narrower terms or on all terms from the same tree within the hierarchical structure.
DeCS is a dynamic vocabulary totaling 34,294 descriptors and 77 qualifiers, of which 29,993 come from MeSH, and 4,378 are exclusively DeCS. These DeCS exclusive descriptors have 7,859 hierarchic codes, of which 2,592 are added to 1,844 MeSH descriptors. The following are the DeCS categories and their total number of descriptors: Health Surveillance (823); Homeopathy (1,912), Public Health (3,612); and Science and Health (245). The sum is greater than the total number of descriptors, since a descriptor may occur more than once in the hierarchy. By being dynamic, it records a permanent process of change including the development of new areas of terminology.
With the creation of the national, institutional and thematic VHLs, search strategies were made available in the various topics in order to facilitate the retrieval of the existing literature.
The updating annually performed in MeSH and the modifications also carried out in the other DeCS categories demand the revision and update of the search strategies on the thematic areas of each BVS, especially the ones including hierarchical codes. Therefore, it is advised that the team responsible for their creation also make sure that these strategies can be revised annually before implementing them. Read text on how to revise strategies used in searching thematic areas of a VHL.
In addition to the NLM, which governs annual updates, BIREME/PAHO/WHO has the support of the following partners in the development and updating of DeCS/MeSH:
Facultad de Medicina de la Universidad de Chile for the translation of concepts into American Spanish;
Instituto de Salud Carlos III for the translation of concepts into European Spanish;
Institut National de la Santé et de Recherche Médicale, INSERM, that provides the translation of MeSH concepts to French; and
L‘Université de Rouen, Normandie, for the translation into French of concepts in exclusive DeCS categories.
For more information see the DeCS wiki page.
Date of last update: June, 2021
- Structured vocabularies are collections of terms, organized according to a methodology in which it is possible to specify the relation between concepts with the purpose of facilitating the access to information. The vocabularies are used as a kind of filter between the language used by the author and the terminology of the area and may also be considered as research assistants by helping the user to refine, expand or enrich his searches providing him with more objective results.
- The Latin American and Caribbean Center on Health Sciences Information, also known by its original name Biblioteca Regional de Medicina (BIREME – Regional Library of Medicine), is a specialized center of the Pan American Health Organization/World Health Organization (PAHO/WHO), oriented to technical cooperation in health scientific information. The Center was located on the central campus of the Universidade Federal de São Paulo since its inception in 1967, according to an agreement between PAHO and the Government of Brazil. Since March 2016, it is located at Rua Vergueiro 1759, 12th floor, 04101-000, São Paulo, SP, Brazil.
- The Medical Subject Headings (MeSH) thesaurus is a controlled and hierarchically-organized vocabulary produced by the National Library of Medicine. It is used for indexing, cataloging, and searching of biomedical and health-related information. MeSH includes the subject headings appearing in MEDLINE/PubMed, the NLM Catalog, and other NLM databases.
- DeCS follows the tradition of the classification systems and their respective subject heading lists which have been transformed into specialized vocabularies without, however, changing the structures of the classification systems from which they originated. Its tree structure is well-grounded in the division of knowledge in decimal classes and subclasses respecting their conceptual and semantic relationships, and its terms are presented in a hybrid structure of pre- and post-coordination. DeCS/MeSH Tree View
CHEMICALS AND DRUGS [D]
ANALYTICAL, DIAGNOSTIC AND THERAPEUTIC TECHNIQUES, AND EQUIPMENT [E]
PSYCHIATRY AND PSYCHOLOGY [F]
PHENOMENA AND PROCESSES [G]
DISCIPLINES AND OCCUPATIONS [H]
ANTHROPOLOGY, EDUCATION, SOCIOLOGY, AND SOCIAL PHENOMENA [I]
TECHNOLOGY, INDUSTRY, AND AGRICULTURE [J]
INFORMATION SCIENCE [L]
NAMED GROUPS [M]
HEALTH CARE [N]
SCIENCE AND HEALTH [SH]
PUBLIC HEALTH [SP]
PUBLICATION CHARACTERISTICS [V]
HEALTH SURVEILLANCE [VS]