The most important tasks for peer reviewers evaluating a randomized controlled trial are not congruent with the tasks most often requested by journal editors

BACKGROUND: The peer review process is a cornerstone of biomedical research publications. However, it may fail to allow the publication of high-quality articles. We aimed to identify and sort, according to their importance, all tasks that are expected from peer reviewers when evaluating a manuscript reporting the results of a randomized controlled trial (RCT) and to determine which of these tasks are clearly requested by editors in their recommendations to peer reviewers. METHODS: We identified the tasks expected of peer reviewers from 1) a systematic review of the published literature and 2) recommendations to peer reviewers for 171 journals (i.e., 10 journals with the highest impact factor for 14 different medical areas and all journals indexed in PubMed that published more than 15 RCTs over 3 months regardless of the medical area). Participants who had peer-reviewed at least one report of an RCT had to classify the importance of each task relative to other tasks using a Q-sort technique. Finally, we evaluated editors’ recommendations to authors to determine which tasks were clearly requested by editors in their recommendations to peer reviewers. RESULTS: The Q-sort survey was completed by 203 participants, 93 (46 %) with clinical expertise, 72 (36 %) with methodological/statistical expertise, 17 (8 %) with expertise in both areas, and 21 (10 %) with other expertise. The task rated most important by participants (evaluating the risk of bias) was clearly requested by only 5 % of editors. In contrast, the task most frequently requested by editors (provide recommendations for publication), was rated in the first tertile only by 21 % of all participants. CONCLUSIONS: The most important tasks for peer reviewers were not congruent with the tasks most often requested by journal editors in their guidelines to reviewers. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12916-015-0395-3) contains supplementary material, which is available to authorized users.