title: Role of editorial and peer review processes in publication bias: analysis of drug trials submitted to eight medical journals.
abstract: BACKGROUND
  Publication bias is generally ascribed to authors and sponsors failing to submit studies with negative results, but may also occur after submission. We evaluated whether submitted manuscripts on randomized controlled trials (RCTs) with drugs are more likely to be accepted if they report positive results.
  
  
  METHODS
  Manuscripts submitted from January 2010 through April 2012 to one general medical journal (BMJ) and seven specialty journals (Annals of the Rheumatic Diseases, British Journal of Ophthalmology, Gut, Heart, Thorax, Diabetologia, and Journal of Hepatology) were included, if at least one study arm assessed the efficacy or safety of a drug and a statistical test was used to evaluate treatment effects. Publication status was retrospectively retrieved from submission systems or provided by journals. Sponsorship and trial results were extracted from manuscripts and classified according to predefined criteria. Main outcome measure was acceptance for publication.
  
  
  RESULTS
  Of 15,972 manuscripts submitted, 472 (3.0%) were drug RCTs, of which 98 (20.8%) were published. Among submitted drug RCTs, 287 (60.8%) had positive and 185 (39.2%) negative results. Of these, 60 (20.9%) and 38 (20.5%), respectively, were published. Manuscripts on non-industry trials (n = 213) reported positive results in 138 (64.8%) manuscripts, compared to 71 (47.7%) on industry-supported trials (n = 149), and 78 (70.9%) on industry-sponsored trials (n = 110). Twenty-seven (12.7%) non-industry trials were published, compared to 27 (18.1%) industry-supported and 44 (40.0%) industry-sponsored trials. After adjustment for other trial characteristics, manuscripts reporting positive results were not more likely to be published (OR, 1.00; 95% CI, 0.61 to 1.66). Submission to specialty journals, sample size, multicentre status, journal impact factor, and corresponding authors from Europe or US were significantly associated with publication.
  
  
  CONCLUSIONS
  For the selected journals, there was no tendency to preferably publish manuscripts on drug RCTs that reported positive results, suggesting that publication bias may occur mainly prior to submission.
authors.affiliation: Clinical Research Centre Nijmegen, Department of Pharmacology - Toxicology, Radboud University Medical Centre, Nijmegen, The Netherlands.
authors.forename: Marlies
authors.initials: M
authors.lastname: van Lent
authors.affiliation: Department of Primary and Community Care, Radboud University Medical Centre, Nijmegen, The Netherlands.
authors.forename: John
authors.initials: J
authors.lastname: Overbeke
authors.affiliation: Clinical Research Centre Nijmegen, Department of Pharmacology - Toxicology, Radboud University Medical Centre, Nijmegen, The Netherlands; Teva Pharmaceuticals, Amsterdam, The Netherlands.
authors.forename: Henk Jan
authors.initials: HJ
authors.lastname: Out
mesh_terms: D004345:Drug Industry; D035081:Editorial Policies; D006801:Humans; D017712:Peer Review, Research; D017594:Publication Bias / Q000706:statistics & numerical data; D011643:Publishing; D016032:Randomized Controlled Trials as Topic / Q000592:standards / Q000706:statistics & numerical data; D012109:Research Support as Topic; D012189:Retrospective Studies; D018401:Sample Size