Transcript Douglas J. Federman, MD Division of General Internal Medicine University of Toledo, College of Medicine.

Douglas J. Federman, MD
Division of General Internal Medicine
University of Toledo, College of Medicine
Goals
• Identify sources of medical
information
• List resources that are appropriate
for the task
• List strategies to improve the
sensitivity and specificity of searches
Personal
• entertainment
• purchasing
– compare prices
– find unusual items
• search for information about yourself
– as a physician
– as a professor
– as a residency program
NEJM January 7, 2010
Evidence-based Medicine (EBM)
1. Ask an answerable question
2. Search the literature
3. Assess the validity
4. Apply the results
5. Assess your own skills
Answerable Questions: PICO
1. Person
2. Intervention
3. Comparison
4. Outcome
Example
Will a PSA measurement benefit
my patients?
In asymptomatic, white men does
the measurement of a PSA increase
life expectancy when compared to
watchful waiting?
EBM Failures – 8 Themes
 Skills in searching
 Access to information
(likely improved since
publication)
 Clinical question
tracking
 Time
 Clinical question
priority
 Personal initiative
 Team dynamics
 Institutional culture
Academic Medicine 2005; 80(2)
Choose the Right Tool for the Job:
In the Office
• 56% of searches were performed on
Google, 9% Pubmed, 4% Google
Scholar, 3.5% Yahoo [NEJM 354(1)]
• NEJM Case studies, students found
results 58% with Google [BMJ
333(7579)]
Choose the Right Tool for the Job:
In the Office
• Brief, time constrained
• Quick, single answer searches
• Online textbooks, AFP, Stat!Ref, MD-Consult,
UptoDate, DynaMed, eMedicine, POEMS,
Cochrane database
• Many require a subscription, but your hospital
or university often has a subscription
• Internet search engines are quick, and the
answer is frequently in the top 10 items
Research
• Goal – comprehensive search
• Combine sources such as PubMed, Embase,
Cochrane database, citation search
• Use multiple modalities
• computer, bibliography, communication with
authors and experts, clinicaltrials.gov
• Use a librarian!
• Example – meta-analyses
Google
• Google search
• Probabilistic – sites can pay for
high ranking, clients can cheat
• Google scholar
• Alternatives – Bing, Ask, AltaVista,
Yahoo, Dogpile…
Google- Tips
 Learn the advanced interface, if available
 Shortcuts:
 Order matters, use the most important one first
‘+’ to force a term in
‘-’ to exclude a term
“quoted phrases”
[2004 2005] is not equal to [2004 OR 2005] or
[2004..2005]
 Wildcard [Obama voted * on the * bill]
 [site:www.utoledo.edu] or [site:.gov]
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Google help pages or GoogleGuide.com
Internet Search Engines
Advantages
Disadvantages
 Quick
 Non-specific results
 No special terms
 Sifting good/bad results
 High # of hits
 High # of hits
 Usually effective
 Not limited to journals
(scholar is better for this)
Medline:
The journal subset of PubMed/NLM
• 1950-Present
• ~5280 journals
• >19,000,000 articles
• Organized by MeSH
Use their tutorial!
Medline - Reference Structure
• MeSH
• Mapping of text to MeSH
• Free text as effective as MeSH
search for most users.
• Other databases that lease the
data may give better yields
Medline
• Search from the hospital or campus
to maximize full-text retrieval
• For non-critical searches (an article,
not all articles) consider MDConsult,
Google Scholar, or follow a reference
from UpToDate which will lead to a
full text article on the first try
Medline - Title Search
 Add [ti] to your search term
 Looks in title or abstract for that exact term
 Will not look for matching MeSH terms or
synonyms
 Combine terms using OR (AND is assumed)
 e.g. (cardiac[ti] OR heart[ti] OR
coronary[ti])
 Note the parentheses are important here
Medline - Author Search
 Search as they are listed in citations:
 Lastname F[au]
 Lastname FM[au]
 Use the Single Citation Matcher
What to do when your search fails?
• Too few articles – broadening
• Use “OR” with synonyms and word
variations
• Look for “Related Articles”
• Look at the MeSH terms from the
relevant articles
• Ugh! – search the MeSH database from
the Advanced Search page
What to do when your search fails?
 Too many articles – narrowing
 Add more terms (always start simple)
 Use Limits/Filters
 Core Clinical Journals or Abridged Index
Medicus
 Look for more specific terms in the MeSH of
relevant articles
Quick links to quickly practice EBM
Pubmed Features
 Full text links for many articles
 Save searches to repeat in the future
 Export citations to email or a text file which can be
imported into a citation manager directly
 Many other databases for researchers
 Genomes (sequences, domains, maps…)
 Proteins
 Chemicals
Summary
 Practice practicing EBM
 Ask questions that will focus your literature search using
the for components
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Person
Intervention
Comparison
Outcome
 Search the literature using the tool you are most
comfortable with. There is little evidence for a specific
tool unless you are performing a comprehensive search
for research.
Summary
 Selecting tools with full text resources will improve
speed of your tasks
 Take home: 2 sites for help
 www.googleguide.com
 www.ncbi.nlm.nih.gov/pubmed