3. Sources of evidence
• A single study vs body of evidence
• Bias in sources
• Traditional sources:
Textbooks
Personal journal collections
Conference proceedings
Clinical guidelines
Colleagues, mentors, experts
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4. Sources of Evidence
• Primary
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– Original papers published in peer reviewed
journals
• Secondary
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– Synthesized publications of primary research
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literature that meet prespecified criteria of both
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clinical relevance and methodologic quality
– Systematic reviews, meta analysis & EB clinical
practice guidelines
5. Sources of Evidence
• Primary
– Pubmed (MEDLINE)
– EviDents (evidents.org)
• Secondary
– ADS Center for Evidence-based Dentistry (Ebd.ada.org)
– EBD journal (Nature.com/ebd)
– Oral health evidence-based practice program, Univ. of Texas
Health Sciences Center (cats.uthscsa.edu)
– The Cochrane Library (thecochranelibrary.org)
– TRIP database (tripdatabase.com)
– The Dental Elf (thedentalelf.net)
– Guidelines
6. Sources of Evidence
• Primary
– Pubmed (MEDLINE)
Text word searching
Medical Subject Heading (MeSH) i.e., Thesaurus
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Clinical queries
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Bolean Operators: AND, OR, NOT
20. Boolean operator AND combines only
sets that contain both terms
Tooth
paste
Tooth
bleaching
Tooth paste AND Tooth bleaching
21. Boolean operator OR combines sets that
contain at least one of the terms
Tooth
paste
Tooth
bleaching
Tooth paste OR tooth bleaching
22. Boolean operator NOT excludes sets that contain
the stated term even when it includes both terms
Tooth
paste
Tooth
bleaching
Tooth paste NOT Tooth bleaching
23. Structured approach to database searching
• Formulate a clear question
• Identify the type of question
3*CF
• Identify alternate terms related to PICO question (synonyms
for P, I, C, O)
• Identify MeSH terms for the PICO (use the MeSH browser)
• List the inclusion criteria limits
Language
Human subject
Age
Gender
Publication type, beginning with the highest level of
evidence (e.g. systematic review)
24. Structured approach to database searching
• Run search:
Search each concept separately
Combine retrieval with Boolean operators
• Evaluate retrieval and modify search strategy, if
necessary
• Review the citations and abstracts ( the
methodology often is included in the abstract)
• Select citations that appear to address the
question
• Access the related full-text articles or order
them
ﺍاﻟﻌﻮﺍاﻣﻞ ﺍاﻟﻤﻨﻄﻘﻴﯿﺔ
ﺍاﻻﺳﺘﺸﻬﮭﮫﺎﺩدﺍاﺕت
25.
26. Search for Evidence
• Sources of evidence
– MEDLINE
– When performing a search we should a combination of
• Text word searching
• Medical Subject Heading (MeSH) i.e., Thesaurus
Do •children with deciduous teeth who consume
Clinical queries
xylitol chewing gum, compared to children who
• Bolean Operators: AND, OR, NOT
don’t, have lower incidence of dental caries?
SBARD Intro to EBD 09 by Dr. Asim Al-Ansari