Date Published: February 22, 2011
Publisher: Public Library of Science
Partial Text: It is now just over six years  since many medical journals began requiring that trials be registered before considering the trial report for publication. Such a policy was set up explicitly to reduce what was considered to be widespread bias in favor of publication of “positive” trials and to ensure that all clinical trials be made public prior to participant enrollment. Given the importance of clinical trials for estimating the efficacy and safety of interventions, and their role in approval of new drugs and devices, such a policy seemed uncontroversial. Although it is known that some trials still go unregistered, there are strong incentives (such as journal publication) and, in some countries legally enforceable mandates, for authors to register these studies before enrolling patients. The existence and widespread uptake of trial registration helps researchers, patients, and funders understand how many trials are being undertaken and which interventions are being evaluated. It also allows studies to be traced from inception through to completion and publication .