searching the internet
Post on 31-Dec-2015
15 Views
Preview:
DESCRIPTION
TRANSCRIPT
Douglas J. Federman, MDDivision 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 question2. Search the literature3. Assess the validity4. Apply the results5. Assess your own skills
ExampleWill 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 ThemesSkills in
searchingAccess to
information (likely improved since publication)
Clinical question tracking
Time
Clinical question priority
Personal initiativeTeam dynamicsInstitutional
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- TipsLearn the advanced interface, if availableShortcuts:
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]
Google help pages or GoogleGuide.com
Internet Search EnginesAdvantages Disadvantages
QuickNo special termsHigh # of hitsUsually effective
Non-specific resultsSifting good/bad
resultsHigh # of hitsNot 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
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 SearchAdd [ti] to your search termLooks in title or abstract for that exact
termWill not look for matching MeSH terms or
synonymsCombine terms using OR (AND is assumed)
e.g. (cardiac[ti] OR heart[ti] OR coronary[ti])
Note the parentheses are important here
Medline - Author SearchSearch 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/FiltersCore Clinical Journals or Abridged Index
MedicusLook for more specific terms in the
MeSH of relevant articles
Pubmed FeaturesFull text links for many articlesSave searches to repeat in the futureExport citations to email or a text file which
can be imported into a citation manager directly
Many other databases for researchersGenomes (sequences, domains, maps…)ProteinsChemicals
SummaryPractice practicing EBM
Ask questions that will focus your literature search using the for components 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.
top related