Does Masking Author Identity Improve Peer Review Quality?

CONTEXT: All authors may not be equal in the eyes of reviewers. Specifically, well-known authors may receive less objective (poorer quality) reviews. One study at a single journal found a small improvement in review quality when reviewers were masked to author identity. OBJECTIVES: To determine whether masking reviewers to author identity is generally associated with higher quality of review at biomedical journals, and to determine the success of routine masking techniques. DESIGN AND SETTING: A randomized controlled trial performed on external reviews of manuscripts submitted to Annals of Emergency Medicine, Annals of Internal Medicine, JAMA, Obstetrics 95% confidence interval CI, -0.2 to 0.4) and unmasked (mean difference, -0.1; 95% CI, -0.5 to 0.4) reviews. We also found no difference in the degree to which the review influenced the editorial decision (mean difference, -0.1; 95% CI,-0.3 to 0.3). Masking was often unsuccessful (overall, 68% successfully masked; 95% CI, 58%-77%), although 1 journal had significantly better masking success than others (90% successfully masked; 95% CI, 73%-98%). Manuscripts by generally known authors were less likely to be successfully masked (odds ratio, 0.3; 95% CI, 0.1-0.8). When analysis was restricted to manuscripts that were successfully masked, review quality as assessed by editors and authors still did not differ. CONCLUSIONS: Masking reviewers to author identity as commonly practiced does not improve quality of reviews. Since manuscripts of well-known authors are more difficult to mask, and those manuscripts may be more likely to benefit from masking, the inability to mask reviewers to the identity of well-known authors may have contributed to the lack of effect.