title: Peer reviewers identified spin in manuscripts of nonrandomized studies assessing therapeutic interventions, but their impact on spin in abstract conclusions was limited.
abstract: To describe the impact of peer reviewers on spin in reports of nonrandomized studies assessing a therapeutic intervention.
  
  
  
  This 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.
  
  
  
  For 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.
  
  
  
  Peer reviewers identified many examples of spin in submitted manuscripts. However, their influence on changing spin in the abstract conclusions was low.
authors.affiliation: INSERM, UMR 1153, Epidemiology and Biostatistics Sorbonne Paris Cité Center (CRESS), METHODS Team 1 place du Parvis Notre Dame 75004, Paris, France; Paris Descartes University, Sorbonne Paris Cité, Faculté de Médecine, 1 place du Parvis Notre Dame 75004, Paris, France; Centre d'Epidémiologie Clinique, AP-HP (Assistance Publique-Hôpitaux de Paris), 1 place du Parvis Notre Dame 75004, ​Paris, France.
authors.forename: Clément
authors.initials: C
authors.lastname: Lazarus
authors.affiliation: INSERM, UMR 1153, Epidemiology and Biostatistics Sorbonne Paris Cité Center (CRESS), METHODS Team 1 place du Parvis Notre Dame 75004, Paris, France; Paris Descartes University, Sorbonne Paris Cité, Faculté de Médecine, 1 place du Parvis Notre Dame 75004, Paris, France.
authors.forename: Romana
authors.initials: R
authors.lastname: Haneef
authors.affiliation: INSERM, UMR 1153, Epidemiology and Biostatistics Sorbonne Paris Cité Center (CRESS), METHODS Team 1 place du Parvis Notre Dame 75004, Paris, France; Paris Descartes University, Sorbonne Paris Cité, Faculté de Médecine, 1 place du Parvis Notre Dame 75004, Paris, France; Centre d'Epidémiologie Clinique, AP-HP (Assistance Publique-Hôpitaux de Paris), 1 place du Parvis Notre Dame 75004, ​Paris, France; Department of Epidemiology, Columbia University Mailman School of Public Health, 22 W 168th Street, New York, NY 10032, USA.
authors.forename: Philippe
authors.initials: P
authors.lastname: Ravaud
authors.affiliation: Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Botnar Research Centre, Windmill Road, Oxford OX3 7LD, UK.
authors.forename: Sally
authors.initials: S
authors.lastname: Hopewell
authors.affiliation: Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Botnar Research Centre, Windmill Road, Oxford OX3 7LD, UK.
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Altman
authors.affiliation: INSERM, UMR 1153, Epidemiology and Biostatistics Sorbonne Paris Cité Center (CRESS), METHODS Team 1 place du Parvis Notre Dame 75004, Paris, France; Paris Descartes University, Sorbonne Paris Cité, Faculté de Médecine, 1 place du Parvis Notre Dame 75004, Paris, France; Centre d'Epidémiologie Clinique, AP-HP (Assistance Publique-Hôpitaux de Paris), 1 place du Parvis Notre Dame 75004, ​Paris, France. Electronic address: isabelle.boutron@htd.aphp.fr.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Boutron
mesh_terms: D015982:Bias; D006801:Humans; D017063:Outcome Assessment, Health Care; D017712:Peer Review, Research; D010506:Periodicals as Topic; D011643:Publishing; D058028:Research Report; D012189:Retrospective Studies
keywords: Abstract; Nonrandomized studies; Peer review; Quality reporting; Spin