Online accesses to medical research articles on publication predicted citations up to 15 years later.
OBJECTIVE
To examine whether the number of early online accesses to medical research articles predicts citations in the scientific literature over time.


METHODS
Cohort study of research articles published in the BMJ between January and June 1999. The number of online assesses within 1 week of publication was examined in relation to citation counts in 1999-2004, 2004-2009, and 2009-2014.


RESULTS
The 148 included articles were accessed on average 691 times up publication, and each was cited on average 33 times in 1999-2004, 32 times in 2004-2009, and 26 times in 2009-2014. The logarithm of accesses predicted the logarithm of citations for all three subsequent periods, but the association weakened over time (correlation with citations in 1999-2004: 0.54, 2004-2009: 0.49, 2009-2014: 0.39; all P < 0.001). In addition to online accesses, the presence of an abstract also predicted more citations for all periods.


CONCLUSIONS
Early interest in a medical research article, reflected by online accesses within a week of publication, predicts citations up to 15 years later. This strengthens the validity of online usage as a measure of the scientific merit of publications.
Division of Clinical Epidemiology, University Hospitals of Geneva, 6 Rue Gabrielle-Perret-Gentil, Geneva CH-1211, Switzerland and Department of Community Health and Medicine, Faculty of Medicine, University of Geneva. Electronic address: thomas.perneger@hcuge.ch.
Thomas V
TV
Perneger
D035843:Biomedical Research / Q000706:statistics & numerical data* / Q000639:trends*; D015331:Cohort Studies; D006801:Humans; D055811:Journal Impact Factor; D009862:Online Systems; D066295:Open Access Publishing / Q000706:statistics & numerical data* / Q000639:trends*; D010506:Periodicals as Topic / Q000706:statistics & numerical data* / Q000639:trends*; D015203:Reproducibility of Results; D013223:Statistics as Topic; D013997:Time Factors
Citations; Online usage; Research assessment