Validity of the Impact Factor of Journals as a Measure of Randomized Controlled Trial Quality
J Clin Psychiatry 2006;67(1):37-40
© Copyright 2017 Physicians Postgraduate Press, Inc.
Purchase This PDF for $40.00
If you are not a paid subscriber, you may purchase the PDF.
(You'll need the free Adobe Acrobat Reader.)
Receive immediate full-text access to JCP. You can subscribe to JCP online-only ($86) or print + online ($156 individual).
With your subscription, receive a free PDF collection of the NCDEU Festschrift articles. Hurry! This offer ends December 31, 2011.
If you are a paid subscriber to JCP and do not yet have a username and password, activate your subscription now.
As a paid subscriber who has activated your subscription, you have access to the HTML and PDF versions of this item.
Click here to login.
Did you forget your password?
Still can't log in? Contact the Circulation Department at 1-800-489-1001 x4 or send email
Objective: To assess whether the impact factor, a measure of the frequency with which journal articles are cited in the scientific literature, is a proxy measure of the quality of articles reporting the results of randomized controlled trials.
Method: The quality of trials included in an ongoing Cochrane review concerned with the antidepressant fluoxetine was assessed using the Cochrane Collaboration Depression, Anxiety, and Neurosis quality assessment instrument, the Jadad scale, and the quality criterion of the Cochrane Collaboration Handbook. Journal impact factors were extracted from the Journal Citation Report.
Results: A total of 131 articles reported results from 132 clinical trials comparing fluoxetine with other antidepressants. The relationship between trial quality and the impact factor of journals where these studies were published, stratified by period of publication, revealed that journals with impact factors above 4 points published only trials with above-average overall quality ratings, while journals with impact factors below 4 points published both high- and low-quality trials. The Jadad scale revealed similar quality in trials published in journals with high, medium, and low impact factors (Pearson chi2 = 0.298, p = .861), and the quality criterion of the Cochrane Collaboration Handbook showed unclear randomization in the majority of trials and in all 15 trials published in high-impact factor journals (Pearson chi2 = 4.678, p = .096).
Conclusion: The impact factor of journals is not a valid measure of randomized controlled trial quality.