DeCS/MeSH Description, uses, services, updating Visit of Isabelle Wachsmuth (WHO) and América Valdes (PAHO) BIREME, São Paulo, August 2007

Description DeCS – the Portuguese acronym for Descritores em Ciências da Saúde, ie, Health Sciences Descriptors Controlled multilingual vocabulary created by BIREME in 1982, fully compatible with MeSH –Update frequency idem MeSH –Currently available in Portuguese, Spanish and English –Provides for Public Health, Homeopathy, and Science and Health terminology An integrating component of the VHL and GHL, allowing –Meta searching, ie, multiple IS can be searched at the same time –Multilingual searching to literature

Uses Serves as a controlled (unique, standard) vocabulary for indexing scientific and technical health-related literature - at the concept level, it groups synonymous terms into concept units; Permits searching by subject (concepts), independently of the language - natural language used in document titles, abstracts and full texts is ambiguous and therefore leads to long/complex search expressions, lack of specificity and unreliable results Hierarchical codes allow for exploding (searching) all terms of a conceptual hierarchy (branch)

DeCS Structure MeSH and DeCS Categories Types of DeCS/MeSH terms Vocabulary Characteristics

MeSH and DeCS Categories descriptorssynonyms Anatomy [A] Organisms [B] Diseases [C] Chemicals and Drugs [D] Analytical, Diagnostic and Therapeutic Techniques and Equipment [E] Psychiatry and Psychology [F] Biological Sciences [G] Natural Sciences [H] Anthropology, Education, Sociology and Social Phenomena [I] Technology, Industry, Agriculture [J] Humanities [K] Information Science [L] Named Groups [M] Health Care [N] Publication Characteristics [V]13655 Geographicals [Z] Subtotal MeSH Homeopathy [HP] Science and Health [SH] Public Health [SP] Health Surveillance [VS] Subtotal DeCS-only Total

Types of DeCS/MeSH terms Descriptors Synonyms Qualifiers Check-tags Publication Types

Descriptors Also known as Main Headings or Preferred Terms –used for indexing and effective retrieval of document citations. Types of DeCS/MeSH Concepts

Synonyms Synonyms, also known as Used For (UF) terms, cross-references or entry terms, have the same meaning or nearly the same meaning as the descriptor and are used as alternate terms in search expressions, obtaining the same search result. Types of DeCS/MeSH Concepts

Health-related terms that are used for indexing in conjunction with descriptors. This combination permits retrieving only those citations which are concerned with a particular aspect of a subject. For example, Steroids/adverse effects, finds documents about the side effects of using steroids Qualifiers Types of DeCS/MeSH Concepts Qualifiers are searched preceeding them by a slash in the Alphabetical index or Keywords in Context index.

Check tags (or Limits) Check tags are generic terms used to limit the scope of research subjects, such as: Male; Female; Humans; Animals; Rats; Cats; Cattle; etc; and age groups The age groups are : Infant, Newborn (birth to 1 month) Infant (1 to 23 months) Child, Pre-school (2 to 5 years) Child (6 to 12 years) Adolescent (13 to 18 years)* Adult (19 to 44 years)* Middle Age (45 to 64 years) Aged (65 and older) * according to MeSH/NLM Types of DeCS/MeSH Concepts

Publication Types Terms used for describing the document format which allows another means for restricting the search result. Examples: Editorial [Publication Type], Letter [Publication Type], Review [Publication Type], Clinical Trial [Publication Type], Clinical Trial, Phase I [Publication Type], etc. The list of existing Publication Types is accessible through: the DeCS “Tree” index (V – category); the DeCS “Keyword in Context” index, by writing “publication”; the “Publication type” index from the information sources. Types of DeCS/MeSH Concepts

Vocabulary Characteristics MULTILINGUAL to date, 11 of the MeSH translations have been incorporated to the UMLS (Unified Medical Language System) Metathesaurus POLYHIERARCHICAL POSTCOORDINATION PRECOORDINATION

Multilingual DeCS is trilingual (English, Spanish and Portuguese) Arab, Franch, Chinese, Russian and other MeSH translations are candidate languages for the DeCS/MeSH vocabulary in the GHL initiative From DeCS the Spanish and Portuguese MeSH terms are exported for the UMLS metathesaurus (Unified Medical Language System) To date, there are 11 MeSH translations incorporated into the UMLS Metathesaurus Vocabulary Characteristics 2 of 5

Polyhierarchical A descriptor may belong to more than one category or to several branches of the same category. Polyhierarchy exists due to the multidisciplinary nature of many concepts. Vocabulary Characteristics 3 of 5

Postcoordination Descriptor+Descriptor Descriptor+Qualifier Descriptor+Check tag Descriptor+Publication Type The act of coordinating two or more concepts at the moment of searching for literature with the objective of narrowing the scope of a subject. The DeCS/MeSH vocabulary permits four types of terminological postcoordination. Vocabulary Characteristics 4 of 5

Precoordination There are two types of precoordination: 1) Descriptor1/qualifier use Descriptor2 Examples: HEART/abnormalities use “HEART DEFECTS, CONGENITAL” PREGNANCY/complications use “PREGNANCY COMPLICATIONS” 2) Descriptor1 AND Descriptor2 use Descriptor3 Examples: “WOUNDS AND INJURIES” and HEART use “HEART INJURIES” TRANSPLANTATION and KIDNEY use “KIDNEY TRANSPLANTATION” Vocabulary Characteristics 5 of 5

DeCS Services DeCS Server –for users Search by Words –Word –Exact Descriptor Search by Index –Alphabetic –Keywords in Context (KWIC) –Tree (hierarchical navigation) DeCS XML Server –for computer applications

VHL>HEALTH TERMINOLOGY The DeCS Search system known as DeCS Server other language interfaces

DeCS Server

A Sample DeCS Record

Adding new languages The Arabic, French, Chinese, Russian and other translations of MeSH are candidate languages for DeCS/MeSH vocabulary in the GHL initiative –BIREME prepares the installation packages The full adoption of DeCS for a given instance of the GHL initiative requires the corresponding translation of the DeCS categories –BIREME provides guidelines and advice for this activity –The resulting translation data is formatted according to the current MeSH translation file format (plain text or XML format)

Creation of new categories A new category will be added to DeCS under the criteria published in “DeCS Update Guide” –Lack of a controlled terminology for indexing documents in a health science domain not covered or not fully expressed by DeCS/MeSH; –Validation of the proposed terminology by the DeCS Technical Committee; –New concepts may be added to DeCS also under the criteria published in “DeCS Update Guide”.

DeCS homepage. Available at DeCS description and uses. Available at Guidelines for DeCS Updating. Available at This presentation: Bibliography