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Searching the Internet

Searching the Internet

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Searching the Internet

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  1. Searching the Internet Douglas J. Federman, MD Division of General Internal Medicine University of Toledo, College of Medicine

  2. Goals • Identify sources of medical information • List resources that are appropriate for the task • List strategies to improve the sensitivity and specificity of searches

  3. 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

  4. Evidence-based Medicine (EBM) • Ask an answerable question • Search the literature • Assess the validity • Apply the results • Assess your own skills

  5. Answerable Questions: PICO • Person • Intervention • Comparison • Outcome

  6. 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?

  7. 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)

  8. 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)]

  9. 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

  10. 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

  11. Google • Google search • Probabilistic – sites can pay for high ranking, clients can cheat • Google scholar • Alternatives – Bing, Ask, AltaVista, Yahoo, Dogpile…

  12. 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] Google help pages or GoogleGuide.com

  13. Internet Search Engines Advantages Disadvantages • Quick • No special terms • High # of hits • Usually effective • Non-specific results • Sifting good/bad results • High # of hits • Not limited to journals (scholar is better for this)

  14. Medline: The journal subset of PubMed/NLM • 1950-Present • ~5280 journals • >19,000,000 articles • Organized by MeSH

  15. Medline Use their tutorial!

  16. 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

  17. Medline - Limits/Filters

  18. 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

  19. 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

  20. Medline - Author Search • Search as they are listed in citations: • Lastname F[au] • Lastname FM[au] • Use the Single Citation Matcher

  21. 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

  22. 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

  23. Medline - Clinical Queries Quick links to quickly practice EBM

  24. 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

  25. Pubmed Full Text Links

  26. Summary • Practice 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.

  27. 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