title: Capture-recapture is a potentially useful method for assessing publication bias.
abstract: OBJECTIVE
  Publication bias is a problem in systematic reviews of randomized controlled trials. The aim of this study was to assess the influence of publication bias in a systematic review of the effectiveness of Progressive Resistance Training (PRT) in older people.
  
  
  METHODS
  The relevant studies were ascertained from three sources: electronic databases, experts, and handsearching. Capture-recapture, visual inspection of funnel plots, two statistical tests, and two methods that make adjustments for publication bias, were employed to check the robustness of the conclusions of the systematic review.
  
  
  RESULTS
  The methods employed gave broadly consistent results. Capture-recapture estimated that 3 (95% CI ) relevant studies were missed, while Trim and Fill suggested 16 studies had been missed. Both Egger's test for bias and a funnel plot regression approach suggested that publication bias was present. A selection model approach suggested that the funnel plot asymmetry observed may not be entirely due to publication bias.
  
  
  CONCLUSIONS
  Capture-recapture is a potentially useful method for assessing publication bias. Further research in the form of simulation studies is required, using a variety of scenarios to investigate the extent to which each method approximates the truth.
authors.affiliation: The Clinical Trials Research Unit, 3 Ferncroft Street, Grafton, Faculty of Medicine and Health Sciences, Private Bag 92019, University of Auckland, New Zealand. d.bennett@ctru.auckland.ac.nz
authors.forename: Derrick A
authors.initials: DA
authors.lastname: Bennett
authors.forename: Nancy K
authors.initials: NK
authors.lastname: Latham
authors.forename: Caroline
authors.initials: C
authors.lastname: Stretton
authors.forename: Craig S
authors.initials: CS
authors.lastname: Anderson
mesh_terms: D000368:Aged; D003627:Data Interpretation, Statistical; D004185:Disability Evaluation; D015444:Exercise / Q000502:physiology; D006801:Humans; D015201:Meta-Analysis as Topic; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology; D017594:Publication Bias; D016032:Randomized Controlled Trials as Topic; D012196:Review Literature as Topic; D013223:Statistics as Topic