Background/aim: To investigate the effect of masking the author's identity to peer reviewers on reviewer bias in an ophthalmic subspecialty journal.
Design: A retrospective study of 531 manuscripts, involving 1182 masked reviews, submitted to Journal of American Association for Pediatric Ophthalmology and Strabismus from 2000 to 2005.
Methods: Data were extracted from recommendation forms completed by each referee during review. Investigated variables consisted of reviewer's knowledge of author identity, recommendation (accept, revise, or reject publishing), eventual manuscript status (published or not), review quality, gender, country, medical practice setting (academic or private) and editorial board status.
Results: This study involved the largest number of manuscripts ever used to evaluate the importance of author masking. Reviewer's knowledge of the author's identity had no effect on review quality. However, proportionally fewer manuscripts were published when there was no idea of the author's identity, compared with when it was allegedly known or suspected (p<0.0001). Manuscripts had lower recommendation scores when there was no idea of the author's identity compared with when allegedly known (p = 0.0001) or suspected (p = 0.004).
Conclusion: Reviewers were more favourable when they allegedly knew or suspected the author's identity. Double-masking may improve the quality of biomedical publishing or at least reduce reviewer bias for effectively masked manuscripts.