Transcript Slide 1

DeCS/MeSH description,
uses, services, updating
Adalberto Tardelli
BIREME/PAHO/WHO
GHL Workshop
March 27, 2007
• Objectives
• Applicability
• Agenda
DeCS/MeSH description,
uses, services, updating
– DeCS/MeSH description and uses
– DeCS/MeSH services
– Adding new languages
– Creation of new categories
– Exercises
– Bibliography
• Objectives
– The objective of this session addresses health
sciences terminology and introduces the thesaurus
Medical Subject Headings (MeSH) and its version
Health Sciences Descriptors (DeCS) that operates
the English, Spanish and Portuguese translations with
extensions of additional categories. The session will
deal also with the methodology BIREME uses to
translate and to add new categories.
• Applicability
– Health terminology from MeSH and its different
translations are used for indexing literature and
effective retrieval. The session will also help on how
to manage translation and additional categories.
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
(*)
The Medical Subject Headings (MeSH®) thesaurus is a controlled vocabulary
produced by the National Library of Medicine and used for indexing,
cataloging, and searching for biomedical and health-related information and
documents
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)
MeSH and DeCS Categories
descriptors
synonyms
Anatomy [A]
1489
2133
Organisms [B]
3485
7934
Diseases [C]
4228
7728
Chemicals and Drugs [D]
8391
10993
Analytical, Diagnostic and Therapeutic Techniques and Equipment [E]
2234
3575
853
1139
2077
2768
Natural Sciences [H]
522
582
Anthropology, Education, Sociology and Social Phenomena [I]
459
691
Technology, Industry, Agriculture [J]
304
669
Humanities [K]
176
137
Information Science [L]
362
449
Named Groups [M]
188
291
1121
1695
Publication Characteristics [V]
136
55
Geographicals [Z]
371
290
24355
37956
1950
1469
218
133
3486
3507
830
1230
4726
3467
29081
41423
Psychiatry and Psychology [F]
Biological Sciences [G]
Health Care [N]
Subtotal MeSH
Homeopathy [HP]
Science and Health [SH]
Public Health [SP]
Health Surveillance [VS]
Subtotal DeCS-only
Total
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
http://decs2007.bvsalud.org
VHL>HEALTH TERMINOLOGY
other language interfaces
The DeCS Search system
known as DeCS Server
DeCS Server
A Sample DeCS Record
Types of DeCS/MeSH terms
•
•
•
•
•
Descriptors
Synonyms
Qualifiers
Check-tags
Publication Types
Types of DeCS/MeSH Concepts
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
Qualifiers
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 are searched preceeding them by
a slash in the Alphabetical index or
Keywords in Context index.
Types of DeCS/MeSH Concepts
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)
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 (KWIC), by writing “publication”;
• the “Publication type” index of the bibliographical databases.
Vocabulary Characteristics
• MULTILINGUAL
• to date, 11 of the MeSH translations have been
incorporated to the UMLS (Unified Medical Language
System) Metathesaurus
• POLYHIERARCHICAL
• POSTCOORDINATION
• PRECOORDINATION
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.
Postcoordination
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.
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•
•
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Descriptor+Descriptor
Descriptor+Qualifier
Descriptor+Check tag
Descriptor+Publication Type
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”
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”.
Exercise
Using http://decs2007.bvsalud.org,
search the term: MYOCARDIOPATHIES
a) what
b) what
is its corresponding descriptor?
are the other synonyms?
c) what is its hierarchical code?
d) is it a MeSH concept or a DeCS-only concept?
e) is it possible to search MEDLINE or LILACS for
diagnosis on myocardiopathies?
Bibliography
DeCS homepage. Available at
http://decs2007.bvsalud.org/I/homepagei.htm
DeCS description and uses. Available at
http://decs2007.bvsalud.org/I/decswebi2007.htm
Guidelines for DeCS Updating. Available at
http://decs2007.bvsalud.org/I/guidelines1a.pdf
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