Searching bibliographic databases

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Searching bibliographic databases

• Scottish Prospective Trainers Course, NHS
  Scotland
• October 2003
• J Bruce, University of Aberdeen

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Overview

• Bibliographic databases relevant to health
  medicine
• Principles for formulating a search strategy
• Practical session
• Aim of session
• To understand the basic principles of literature
  searching
• To demonstrate appropriate use of controlled
  vocabulary free-text searching

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Bibliographic databases

• Primary source - article, publication
• Secondary information source - reference to
  primary source (citation)
• Different producers -
• NLM, USA
• Elsevier, Netherlands
• Different interfaces e.g. Ovid, PubMed,
  Silverplatter etc

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Features of databases

• Subject area economics, medicine, occupational
  health, education,sociology etc.
• Limited coverage /- overlap
• Time span e.g. Medline from 1966-present
• Each database indexes differently - use thesaurus
  within each
• - Medical Subject Headings (MeSH)
• Search strategy will differ between each
  database

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Biomedical databases

• Medline
• Embase
• CINAHL
• The Cochrane Library
• HealthSTAR
• Others
• Science Citation Index / SSCI
• EDINA, ERIC,
• PsychLIT / PsychINFO.

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Medline functions

• Clinical medicine, health care delivery
• 1966 - present, updated monthly
• Complex hierarchical tree arrangement
• Advanced searching functions
• Mapping function / use of synonyms
• Explode / focus MeSH
• Partial words, truncation ()
• Wildcards () etc.

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Limitations of Medline

• Non-English language articles under-represented
• Predominantly USA journals / publishers e.g.
  journals not indexed on MEDLINE
• Journal of Health Services Research Policy
• British Journal of Health Psychology
• Spelling e.g.gynecology / hemorrhage
  terminology day surgery/ambulatory care etc.
  Use map function
• Delay from publication to indexing
• Check journal websites for recent volumes

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Embase

• Medical, health database - clinical medicine,
  health care delivery, social aspects,
  pharmaceutical, toxicology
• Good source European literature, often overlooked
  
• 1980 present
• Index thesaurus differs from Medline

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CINAHL

• Cumulative Index of Nursing Allied Health
  Literature
• Nursing, health promotion, health education,
  allied professions
• 1982 - present
• Different thesaurus to Medline

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The Cochrane Library

• CC - international network of professionals who
  conduct reviews maintain trial registers
• The Cochrane Library database
• 4 databases within library
• Systematic Review database, trial register,
  methodology register etc.
• Terms based on Medline
• Website / access via NELH

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Formulating a search strategy

• Clarify what you want define as a question
• Break question into component concepts
• Select source database/s
• Identify controlled vocabulary terms using
  thesaurus
• Identify synonyms depends on database
• cancer / carcinoma / neoplasms
• myocardial infarction /ischaemia

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What are the costs of rehabilitation following
myocardial infarction?

• Myocardial infarction
• other related terms (within heart diseases)
• explode all terms, include sub-headings
• myocardial infarction OR myocardial ischaemia
• Rehabilitation
• what does it incorporate?
• Explode all terms, include sub-headings
• Cost
• cost and cost analysis, explode all terms etc.

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Boolean operators
MI cost
NOT
OR
AND
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Using boolean operators

• exp myocardial infarction/
• exp myocardial ischaemia/
• myocardial infarction.tw..
• exp rehabilitation
• exp occupational therapyetc.
• exp costs and cost analysis
• exp health care costs etc
• Combine 4 AND 7 AND 10 n11

Combine 1 OR 2 OR 3 211,000
Combine 5 OR 6 133,000
Combine 8 OR 9 31,000
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Medline functions

• / at end of word denotes MeSH term
• exp means exploded term
• exp myocardial infarction/
• .sh is subheading
• exp myocardial infarction / rh
• .tw is textword, free-text vocabulary
• myocardial infarction.tw

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Summary of search process

• Define your question
• Identify your key terms / phrases
• Select databases
• Formulate search strategy
• Appraise articles

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Access to databases

• http//www.elib.scot.nhs.uk/
• Register for Athens password

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Access
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