RT Journal
A1 Briel, Matthias
A1 Bassler, Dirk
A1 Wang, Amy T.
A1 Guyatt, Gordon H.
A1 Montori, Victor M.
T1 The Dangers of Stopping a Trial Too Early
JF The Journal of Bone & Joint Surgery
JO The Journal of Bone & Joint Surgery
YR 2012
FD July 18
VO 94
IS Suppl 1(E)
SP 56
OP 60
DO 10.2106/JBJS.K.01412
UL http://dx.doi.org/10.2106/JBJS.K.01412
AB Abstract: 
  To ensure that participants in randomized controlled trials are protected from harm, interim analyses and review of results by an independent data monitoring committee have become standard practice. If an analysis of accumulating data partway through a trial reveals an unanticipated degree of benefit or toxicity, or differences in outcomes between the intervention and control groups are so unimpressive that any prospect of a positive result with the planned sample size is extremely unlikely, investigators may stop the trial earlier than originally scheduled. The practice of stopping randomized controlled trials early is, however, problematic, especially if the trial is stopped for apparent benefit. Concerns in trials stopped early for apparent benefit include appropriate interpretation of results and ethical problems concerning trial participants, clinicians, and society as a whole. In this article, we review the epidemiology of trials stopped early and illustrate some of the problems and controversies associated with stopping randomized controlled trials early for apparent benefit. Finally, we offer guidance for clinicians, those running clinical trials, and authors of systematic reviews.