Peer reviewers identified spin in manuscripts of nonrandomized studies assessing therapeutic interventions, but their impact on spin in abstract conclusions was limited

ObjectivesTo describe the impact of peer reviewers on spin in reports of nonrandomized studies assessing a therapeutic intervention.Study Design and SettingThis is a systematic review and retrospective before-after study. The sample consists of primary reports (n = 128) published in BioMed Central Medical Series journals between January 1, 2011, and December 31, 2013. The main outcome measures are the following: number and type of spin examples identified, deleted, or added by peer reviewers in the whole manuscript; number of reports with spin in abstract conclusions not detected by peer reviewers; the level of spin (i.e., no, low, moderate, and high level of spin) in the abstract conclusions before and after the peer review.ResultsFor 70 (55%) submitted manuscripts, peer reviewers identified at least one example of spin. Of 123 unique examples of spin identified by peer reviewers, 82 (67%) were completely deleted by the authors. For 19 articles (15%), peer reviewers requested adding some spin, and for 11 (9%), the spin was added by the authors. Peer reviewers failed to identify spin in abstract conclusions of 97 (76%) reports.ConclusionPeer reviewers identified many examples of spin in submitted manuscripts. However, their influence on changing spin in the abstract conclusions was low.