title: Published methodological quality of randomized controlled trials does not reflect the actual quality assessed in protocols.
abstract: OBJECTIVE
  To assess whether the reported methodological quality of randomized controlled trials (RCTs) reflects the actual methodological quality and to evaluate the association of effect size (ES) and sample size with methodological quality.
  
  
  METHODS
  Systematic review. This is a retrospective analysis of all consecutive phase III RCTs published by eight National Cancer Institute Cooperative Groups up to 2006. Data were extracted from protocols (actual quality) and publications (reported quality) for each study.
  
  
  RESULTS
  Four hundred twenty-nine RCTs met the inclusion criteria. Overall reporting of methodological quality was poor and did not reflect the actual high methodological quality of RCTs. The results showed no association between sample size and actual methodological quality of a trial. Poor reporting of allocation concealment and blinding exaggerated the ES by 6% (ratio of hazard ratio [RHR]: 0.94; 95% confidence interval [CI]: 0.88, 0.99) and 24% (RHR: 1.24; 95% CI: 1.05, 1.43), respectively. However, actual quality assessment showed no association between ES and methodological quality.
  
  
  CONCLUSIONS
  The largest study to date shows that poor quality of reporting does not reflect the actual high methodological quality. Assessment of the impact of quality on the ES based on reported quality can produce misleading results.
authors.affiliation: Division and Center for Evidence-Based Medicine and Outcomes Research, Department of Internal Medicine, Clinical and Translational Science Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA.
authors.forename: Rahul
authors.initials: R
authors.lastname: Mhaskar
authors.forename: Benjamin
authors.initials: B
authors.lastname: Djulbegovic
authors.forename: Anja
authors.initials: A
authors.lastname: Magazin
authors.forename: Heloisa P
authors.initials: HP
authors.lastname: Soares
authors.forename: Ambuj
authors.initials: A
authors.lastname: Kumar
mesh_terms: D000465:Algorithms; D015982:Bias; D002985:Clinical Protocols / Q000592:standards*; D016001:Confidence Intervals; D006801:Humans; D016017:Odds Ratio; D010506:Periodicals as Topic; D016032:Randomized Controlled Trials as Topic / Q000592:standards*; D012107:Research Design / Q000592:standards*; D058028:Research Report / Q000592:standards*; D018401:Sample Size; D000078202:Systematic Reviews as Topic