title: Comparison of PubMed and Google Scholar literature searches.
abstract: BACKGROUND
  Literature searches are essential to evidence-based respiratory care. To conduct literature searches, respiratory therapists rely on search engines to retrieve information, but there is a dearth of literature on the comparative efficiencies of search engines for researching clinical questions in respiratory care.
  
  
  OBJECTIVE
  To compare PubMed and Google Scholar search results for clinical topics in respiratory care to that of a benchmark.
  
  
  METHODS
  We performed literature searches with PubMed and Google Scholar, on 3 clinical topics. In PubMed we used the Clinical Queries search filter. In Google Scholar we used the search filters in the Advanced Scholar Search option. We used the reference list of a related Cochrane Collaboration evidence-based systematic review as the benchmark for each of the search results. We calculated recall (sensitivity) and precision (positive predictive value) with 2 x 2 contingency tables. We compared the results with the chi-square test of independence and Fisher's exact test.
  
  
  RESULTS
  PubMed and Google Scholar had similar recall for both overall search results (71% vs 69%) and full-text results (43% vs 51%). PubMed had better precision than Google Scholar for both overall search results (13% vs 0.07%, P < .001) and full-text results (8% vs 0.05%, P < .001).
  
  
  CONCLUSIONS
  Our results suggest that PubMed searches with the Clinical Queries filter are more precise than with the Advanced Scholar Search in Google Scholar for respiratory care topics. PubMed appears to be more practical to conduct efficient, valid searches for informing evidence-based patient-care protocols, for guiding the care of individual patients, and for educational purposes.
authors.affiliation: Department of Respiratory and Surgical Technologies, College of Health Related Professions, University of Arkansas for Medical Sciences, #737, 4301 West Markham Street, Little Rock, AR 72205, USA. ma@uams.edu
authors.forename: Michael E
authors.initials: ME
authors.lastname: Anders
authors.forename: Dennis P
authors.initials: DP
authors.lastname: Evans
mesh_terms: D035843:Biomedical Research; D003430:Cross-Sectional Studies; D006801:Humans; D020407:Internet; D010506:Periodicals as Topic; D039781:PubMed / Q000592:standards*; D015203:Reproducibility of Results; D057386:Search Engine / Q000379:methods* / Q000592:standards