title: Publication bias in the medical literature: a review by a Canadian Research Ethics Board.
abstract: BACKGROUND
  We reviewed the publication record of all protocols submitted to the Capital District Health Authority Research Ethics Board (REB) in Halifax, Nova Scotia, for the period 1995-1996. Because of a heightened awareness of the issue, we hypothesized that there would be less publication bias (a failure to report negative results) and a higher publication rate from completed studies, than previously reported.
  
  
  METHODS
  Closed studies were identified from the REB database. Publications were identified by the investigators, requests from sponsors, and a literature review. For each publication, we identified authors, title, journal, number of subjects enrolled, and whether or not the publication was a report of a randomized clinical trial. Comparisons were done using a Student's t test, the Chi-square statistic, or Fisher's exact test as appropriate.
  
  
  RESULTS
  From the database of closed studies, 106 remained unpublished, while completed investigations resulted in 84 publications (44% publication rate). The median time to publication was 32.5 months. Publication of statistically significant results occurred in 71/84 trials. Publication of protocols submitted by departments ranged from 91% (anesthesia; 10/11) to 25% [nursing; 2/8 (P<0.05)]. Trials investigating new drugs in Phase 3 or 4 studies were more likely to be published than trials investigating agents in Phase 1 or 2 (P<0.05), and were less likely to be published if sponsored by a pharmaceutical company (P<0.05).
  
  
  CONCLUSIONS
  Publication bias continues to be a problem, particularly for early phase investigative studies. Our results suggest that a different approach is required to reduce publication bias. The role that REBs and peer-reviewed journals might play requires further exploration.
authors.affiliation: Dalhousie University and the Capital District Health Authority, Halifax, Nova Scotia, Canada. rihall@dal.ca
authors.forename: Richard
authors.initials: R
authors.lastname: Hall
authors.forename: Cecilia
authors.initials: C
authors.lastname: de Antueno
authors.forename: Adam
authors.initials: A
authors.lastname: Webber
mesh_terms: D000328:Adult; D002170:Canada; D002985:Clinical Protocols / Q000592:standards; D028744:Ethics Committees, Research; D006801:Humans; D010506:Periodicals as Topic / Q000592:standards; D017594:Publication Bias / Q000706:statistics & numerical data*; D012106:Research / Q000458:organization & administration*; D012108:Research Personnel / Q000941:ethics*; D015871:Scientific Misconduct; D013997:Time Factors