title: Publication bias in laboratory animal research: a survey on magnitude, drivers, consequences and potential solutions.
abstract: BACKGROUND
  Publication bias jeopardizes evidence-based medicine, mainly through biased literature syntheses. Publication bias may also affect laboratory animal research, but evidence is scarce.
  
  
  OBJECTIVE
  To assess the opinion of laboratory animal researchers on the magnitude, drivers, consequences and potential solutions for publication bias. And to explore the impact of size of the animals used, seniority of the respondent, working in a for-profit organization and type of research (fundamental, pre-clinical, or both) on those opinions.
  
  
  METHODS
  Internet-based survey.
  
  
  METHODS
  All animal laboratories in The Netherlands.
  
  
  METHODS
  Laboratory animal researchers.
  
  
  METHODS
  Median (interquartile ranges) strengths of beliefs on 5 and 10-point scales (1: totally unimportant to 5 or 10: extremely important).
  
  
  RESULTS
  Overall, 454 researchers participated. They considered publication bias a problem in animal research (7 (5 to 8)) and thought that about 50% (32-70) of animal experiments are published. Employees (n = 21) of for-profit organizations estimated that 10% (5 to 50) are published. Lack of statistical significance (4 (4 to 5)), technical problems (4 (3 to 4)), supervisors (4 (3 to 5)) and peer reviewers (4 (3 to 5)) were considered important reasons for non-publication (all on 5-point scales). Respondents thought that mandatory publication of study protocols and results, or the reasons why no results were obtained, may increase scientific progress but expected increased bureaucracy. These opinions did not depend on size of the animal used, seniority of the respondent or type of research.
  
  
  CONCLUSIONS
  Non-publication of "negative" results appears to be prevalent in laboratory animal research. If statistical significance is indeed a main driver of publication, the collective literature on animal experimentation will be biased. This will impede the performance of valid literature syntheses. Effective, yet efficient systems should be explored to counteract selective reporting of laboratory animal research.
authors.affiliation: Department of General Practice, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. g.terriet@amc.nl
authors.forename: Gerben
authors.initials: G
authors.lastname: ter Riet
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Korevaar
authors.forename: Marlies
authors.initials: M
authors.lastname: Leenaars
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Sterk
authors.forename: Cornelis J F
authors.initials: CJ
authors.lastname: Van Noorden
authors.forename: Lex M
authors.initials: LM
authors.lastname: Bouter
authors.forename: René
authors.initials: R
authors.lastname: Lutter
authors.forename: Ronald P Oude
authors.initials: RP
authors.lastname: Elferink
authors.forename: Lotty
authors.initials: L
authors.lastname: Hooft
mesh_terms: D032761:Animal Experimentation / Q000941:ethics*; D000818:Animals; D000830:Animals, Laboratory; D003625:Data Collection; D019317:Evidence-Based Medicine; D009426:Netherlands; D010380:Peer Review; D017594:Publication Bias; D011642:Publications / Q000941:ethics / Q000639:trends*; D015203:Reproducibility of Results; D012107:Research Design