Comparison of PubMed and Google Scholar literature searches

Respir Care. 2010 May;55(5):578-83.


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.

Publication types

  • Comparative Study

MeSH terms

  • Biomedical Research
  • Cross-Sectional Studies
  • Humans
  • Internet*
  • Periodicals as Topic*
  • PubMed / standards*
  • Reproducibility of Results
  • Search Engine / methods*
  • Search Engine / standards