title: Inconsistent reporting of surrogate outcomes in randomised clinical trials: cohort study.
abstract: OBJECTIVE
  To assess if authors of randomised clinical trials convey the fact that they have used surrogate outcomes and discussed their validity.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Six major general medical journals.
  
  
  METHODS
  Randomised clinical trials published in 2005 and 2006 that used a surrogate as a primary outcome.
  
  
  RESULTS
  Of 626 published randomised clinical trials, 109 (17%) used a surrogate as a primary outcome. Of these trials, 62 (57%, 95% confidence interval 47% to 67%) clearly reported that the primary outcome was a surrogate. Only 38 (35%, 26% to 45%) also discussed the validity of the surrogate.
  
  
  CONCLUSIONS
  Only about one third of authors of randomised clinical trials that used a surrogate as a primary outcome reported adequately on the surrogate. Better reporting is needed.
authors: Copenhagen Trial Unit, Rigshospitalet, Copenhagen University Hospital, DK-2100 Copenhagen, Denmark. Jeppelerche@hotmail.com
authors: Jeppe Lerche
authors: JL
authors: la Cour
authors: Jesper
authors: J
authors: Brok
authors: Peter C
authors: PC
authors: Gøtzsche
mesh_terms: D015331:Cohort Studies; D016032:Randomized Controlled Trials as Topic / Q000592:standards*; D015203:Reproducibility of Results; D012107:Research Design / Q000592:standards*; D016896:Treatment Outcome