title: Reporting of Positive Results in Randomized Controlled Trials of Mindfulness-Based Mental Health Interventions.
abstract: BACKGROUND
  A large proportion of mindfulness-based therapy trials report statistically significant results, even in the context of very low statistical power. The objective of the present study was to characterize the reporting of "positive" results in randomized controlled trials of mindfulness-based therapy. We also assessed mindfulness-based therapy trial registrations for indications of possible reporting bias and reviewed recent systematic reviews and meta-analyses to determine whether reporting biases were identified.
  
  
  METHODS
  CINAHL, Cochrane CENTRAL, EMBASE, ISI, MEDLINE, PsycInfo, and SCOPUS databases were searched for randomized controlled trials of mindfulness-based therapy. The number of positive trials was described and compared to the number that might be expected if mindfulness-based therapy were similarly effective compared to individual therapy for depression. Trial registries were searched for mindfulness-based therapy registrations. CINAHL, Cochrane CENTRAL, EMBASE, ISI, MEDLINE, PsycInfo, and SCOPUS were also searched for mindfulness-based therapy systematic reviews and meta-analyses.
  
  
  RESULTS
  108 (87%) of 124 published trials reported ≥1 positive outcome in the abstract, and 109 (88%) concluded that mindfulness-based therapy was effective, 1.6 times greater than the expected number of positive trials based on effect size d = 0.55 (expected number positive trials = 65.7). Of 21 trial registrations, 13 (62%) remained unpublished 30 months post-trial completion. No trial registrations adequately specified a single primary outcome measure with time of assessment. None of 36 systematic reviews and meta-analyses concluded that effect estimates were overestimated due to reporting biases.
  
  
  CONCLUSIONS
  The proportion of mindfulness-based therapy trials with statistically significant results may overstate what would occur in practice.
authors.affiliation: Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada.|Department of Psychiatry, McGill University, Montréal, Québec, Canada.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Coronado-Montoya
authors.affiliation: Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada.
authors.forename: Alexander W
authors.initials: AW
authors.lastname: Levis
authors.affiliation: Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada.|Department of Psychiatry, McGill University, Montréal, Québec, Canada.
authors.forename: Linda
authors.initials: L
authors.lastname: Kwakkenbos
authors.affiliation: Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada.|Department of Mathematics and Statistics, McGill University, Montréal, Québec, Canada.
authors.forename: Russell J
authors.initials: RJ
authors.lastname: Steele
authors.affiliation: Department of Psychiatry, Oregon Health & Science University, Portland, Oregon, United States of America.|Department of Psychiatry, Portland Veterans Affairs Medical Center, Portland, Oregon, United States of America.
authors.forename: Erick H
authors.initials: EH
authors.lastname: Turner
authors.affiliation: Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada.|Department of Psychiatry, McGill University, Montréal, Québec, Canada.|Department of Mathematics and Statistics, McGill University, Montréal, Québec, Canada.|Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montréal, Québec, Canada.|Department of Medicine, McGill University, Montréal, Québec, Canada.|Department of Educational and Counselling Psychology, McGill University, Montréal, Québec, Canada.|Department of Psychology, McGill University, Montréal, Québec, Canada.|School of Nursing, McGill University, Montréal, Québec, Canada.
authors.forename: Brett D
authors.initials: BD
authors.lastname: Thombs
mesh_terms: D015982:Bias; D015928:Cognitive Behavioral Therapy / Q000379:methods; D016208:Databases, Factual / Q000706:statistics & numerical data; D006801:Humans; D015201:Meta-Analysis as Topic; D064866:Mindfulness / Q000379:methods*; D017594:Publication Bias; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data*; D012196:Review Literature as Topic; D013315:Stress, Psychological / Q000628:therapy