Effect of open peer review on quality of reviews and on reviewers' recommendations: a randomised trial

Objectives To examine the effect on peer review of asking reviewers to have their identity revealed to the authors of the paper. Design Randomised trial. Consecutive eligible papers were sent to two revie wers who were randomised to have their identity revealed to the authors or to remain anonymous. Editors and authors were blind to the intervention. Main outcome measures The quality of the reviews was independently rated by two editors and the corresponding author using a validated instrument Addi tional outcomes were the time taken to complete the review and the recommen dation regarding publication. A questionnaire survey was undertaken of the authors of a cohort of manuscripts submitted for publication to find out th eir views on open peer review. Results Two editors' assessments were obtained for 113 out of 125 manuscrip ts, and the corresponding author's assessment was obtained for 105. Reviewe rs randomised to be asked to be identified were 12% (95% confidence interva l 0.2% to 24%) more likely to decline to review than reviewers randomised t o remain anonymous (35% v 23%). There was no significant difference in qual ity (scored on a scale of 1 to 5) between anonymous reviewers (3.06 (SD 0.7 2)) and identified reviewers (3.09 (0.68)) (P = 0.68, 95% confidence interv al for difference -0.19 to 0.12), and no significant difference in the reco mmendation regarding publication or time taken to review the paper. The edi tors' quality score for reviews (3.05 (SD 0.70)) was significantly higher t han that of authors (2.90 (0.87)) (P < 0.005, 95% confidence interval for d ifference -0.26 to -0.03). Most authors were in favour of open peer review. Conclusions Asking reviewers to consent to being identified to the author h ad no important effect on the quality of the review, the recommendation reg arding publication, or the time taken to review, but it significantly incre ased the likelihood of reviewers declining to review.