The effects of blinding on acceptance of research papers by peer review.
OBJECTIVE
To study whether reviewers aware of author identity are biased in favor of authors with more previous publications.


METHODS
Randomized controlled trial.


METHODS
Editorial office of the Journal of Developmental and Behavioral Pediatrics.


METHODS
Two "blinded" and two "nonblinded" reviewers assigned to 57 consecutive manuscripts submitted between September 1991 and March 1992.


METHODS
Spearman rank correlation coefficients were used to compare the sum of rating scores of 1 to 5 (1, accept; 5, reject) given by the two blinded reviewers, the two nonblinded reviewers, and the editors to the number of articles published previously by the first and senior authors (as determined from requested curricula vitae). Blinded reviewers were sent a questionnaire asking whether they could determine the identity of the authors, how they knew, and whether they thought binding changed the quality or difficulty of their review.


RESULTS
The Wilcoxon Sign Rank Test disclosed no differences between blinded and nonblinded scores. The number of previous articles by the senior author was significantly correlated (P < .01) with blinded scores (r = -.45) and editors' decisions (r = -.45), but not with nonblinded scores; the number of articles by the first author was correlated (P < .05) with editors' decisions (r = -.35) but not with blinded or nonblinded scores. Fifty (46%) of 108 blinded reviewers correctly guessed the identity of the authors, mostly from self-references and knowledge of the work; 86% believed blinding did not change the quality of their review, and 73% believed it did not change the difficulty of performing a review.


CONCLUSIONS
Blinded reviewers and editors in this study, but not nonblinded reviewers, gave better scores to authors with more previous articles. These results suggest that blinded reviewers may provide more unbiased reviews and that nonblinded reviewers may be affected by various types of bias.
Fisher
M
M
Department of Pediatrics, North Shore University Hospital, Cornell University Medical College, Manhasset, NY 11030.
Friedman
S B
SB
Strauss
B
B
D001319:Authorship; D006801:Humans; D008373:Manuscripts as Topic; D017712:Peer Review, Research; D010506:Periodicals as Topic; D017594:Publication Bias