370 likes | 452 Views
Searching the Internet. 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
E N D
Searching the Internet 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) • Ask an answerable question • Search the literature • Assess the validity • Apply the results • Assess your own skills
Answerable Questions: PICO • Person • Intervention • Comparison • 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] Google help pages or GoogleGuide.com
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)
Medline: The journal subset of PubMed/NLM • 1950-Present • ~5280 journals • >19,000,000 articles • Organized by MeSH
Medline 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
Medline - Clinical Queries 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 • 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