Comparisons of Citations in Web of Science, Scopus, and Google Scholar for Articles Published in General Medical Journals | Medical Journals and Publishing | JAMA | JAMA Network
[Skip to Navigation]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address 18.204.227.34. Please contact the publisher to request reinstatement.
1.
Thomson Reuters.  ISI Web of Knowledge Web site. http://www.isiwebofknowledge.com. Accessed June 7, 2009
2.
Callaham M, Wears RL, Weber E. Journal prestige, publication bias, and other characteristics associated with citation of published studies in peer-reviewed journals.  JAMA. 2002;287(21):2847-285012038930PubMedGoogle ScholarCrossref
3.
Gami AS, Montori VM, Wilczynski NL, Haynes RB. Author self-citation in the diabetes literature.  CMAJ. 2004;170(13):1925-192715210641PubMedGoogle ScholarCrossref
4.
Kulkarni AV, Busse JW, Shams I. Characteristics associated with citation rate of the medical literature.  PLoS One. 2007;2(5):e40317476325PubMedGoogle ScholarCrossref
5.
Patsopoulos NA, Analatos AA, Ioannidis JP. Relative citation impact of various study designs in the health sciences.  JAMA. 2005;293(19):2362-236615900006PubMedGoogle ScholarCrossref
6.
Patsopoulos NA, Ioannidis JP, Analatos AA. Origin and funding of the most frequently cited papers in medicine: database analysis.  BMJ. 2006;332(7549):1061-106416547014PubMedGoogle ScholarCrossref
7.
Elsevier.  Scopus Web site. http://www.scopus.com. Accessed June 7, 2009
8.
Google.  Google Scholar beta Web site. http://scholar.google.com. Accessed June 7, 2009
9.
Bakkalbasi N, Bauer K, Glover J, Wang L. Three options for citation tracking: Google Scholar, Scopus and Web of Science.  Biomed Digit Libr. 2006;3(7):716805916PubMedGoogle ScholarCrossref
10.
Falagas ME, Pitsouni EI, Malietzis GA, Pappas G. Comparison of PubMed, Scopus, Web of Science, and Google Scholar: strengths and weaknesses.  FASEB J. 2008;22(2):338-34217884971PubMedGoogle ScholarCrossref
11.
Hull D, Pettifer SR, Kell DB. Defrosting the digital library: bibliographic tools for the next generation web.  PLoS Comput Biol. 2008;4(10):e100020418974831PubMedGoogle ScholarCrossref
12.
Jacso P. As we may search: comparison of major features of the Web of Science, Scopus, and Google Scholar citation-based and citation-enhanced databases.  Curr Sci. 2005;89(9):1537-1547Google Scholar
13.
Harzing AWK, van der Wal R. Google Scholar as a new source for citation analysis.  Ethics Sci Environ Polit. 2008;8(1):62-73Google Scholar
14.
Kousha K, Thelwall M. Sources of Google Scholar citations outside the science citation index: a comparison between four science disciplines.  Scientometrics. 2008;74(2):273-294Google ScholarCrossref
15.
Kleinbaum DG, Kupper LL, Muller KE. Collinearity Concepts: Applied Regression Analysis and Other Multivariable Methods. Belmont, CA: Wadsworth Publishing Co; 1988:209-214
16.
Meho LI, Yang K. Impact of data sources on citation counts and rankings of LIS faculty: Web of Science versus Scopus and Google Scholar.  J Am Soc Inf Sci Technol. 2007;58(13):2105-2125Google ScholarCrossref
17.
Thomson Reuters.  The Thomson Reuters journal selection process. http://thomsonreuters.com/products_services/science/free/essays/journal_selection_process. Accessed June 7, 2009
18.
Meho LI. The rise and rise of citation analysis.  Physics World. 2007;20(1):32-36Google Scholar
19.
Burnham JF. Scopus database: a review.  Biomed Digit Libr. 2006;3(1):116522216PubMedGoogle ScholarCrossref
20.
Elsevier.  Scopus in detail: what does it cover? http://www.info.scopus.com/detail/what. Accessed June 7, 2009
21.
Noruzi A. Google Scholar: the new generation of citation indexes.  LIBRI. 2005;55(4):170-180Google ScholarCrossref
22.
Giustini D. How Google is changing medicine.  BMJ. 2005;331(7531):1487-148816373722PubMedGoogle ScholarCrossref
23.
Elsevier.  Content coverage. http://info.scopus.com/docs/content_coverage.pdf. Accessed June 7, 2009
25.
Google.  Librarian central. http://www.google.com/librariancenter/articles/0612_01.html. Accessed June 7, 2009
26.
Google.  Support for scholarly publishers. http://scholar.google.com/intl/en/scholar/publishers.html. Accessed June 7, 2009
27.
Elsevier.  Scopus in detail: facts and figures. http://www.info.scopus.com/detail/facts. Accessed June 7, 2009
Brief Report
September 9, 2009

Comparisons of Citations in Web of Science, Scopus, and Google Scholar for Articles Published in General Medical Journals

Author Affiliations

Author Affiliations: Hospital for Sick Children, Toronto, Ontario, Canada (Dr Kulkarni and Mss Aziz and Shams); Institute for Work and Health, Toronto, Ontario, Canada (Dr Busse); and the Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada (Dr Busse).

JAMA. 2009;302(10):1092-1096. doi:10.1001/jama.2009.1307
Abstract

Context Until recently, Web of Science was the only database available to track citation counts for published articles. Other databases are now available, but their relative performance has not been established.

Objective To compare the citation count profiles of articles published in general medical journals among the citation databases of Web of Science, Scopus, and Google Scholar.

Design Cohort study of 328 articles published in JAMA, Lancet, or the New England Journal of Medicine between October 1, 1999, and March 31, 2000. Total citation counts for each article up to June 2008 were retrieved from Web of Science, Scopus, and Google Scholar. Article characteristics were analyzed in linear regression models to determine interaction with the databases.

Main Outcome Measures Number of citations received by an article since publication and article characteristics associated with citation in databases.

Results Google Scholar and Scopus retrieved more citations per article with a median of 160 (interquartile range [IQR], 83 to 324) and 149 (IQR, 78 to 289), respectively, than Web of Science (median, 122; IQR, 66 to 241) (P < .001 for both comparisons). Compared with Web of Science, Scopus retrieved more citations from non–English-language sources (median, 10.2% vs 4.1%) and reviews (30.8% vs 18.2%), and fewer citations from articles (57.2% vs 70.5%), editorials (2.1% vs 5.9%), and letters (0.8% vs 2.6%) (all P < .001). On a log10-transformed scale, fewer citations were found in Google Scholar to articles with declared industry funding (nonstandardized regression coefficient, −0.09; 95% confidence interval [CI], −0.15 to −0.03), reporting a study of a drug or medical device (−0.05; 95% CI, −0.11 to 0.01), or with group authorship (−0.29; 95% CI, −0.35 to −0.23). In multivariable analysis, group authorship was the only characteristic that differed among the databases; Google Scholar had significantly fewer citations to group-authored articles (−0.30; 95% CI, −0.36 to −0.23) compared with Web of Science.

Conclusion Web of Science, Scopus, and Google Scholar produced quantitatively and qualitatively different citation counts for articles published in 3 general medical journals.

×