When clinical research fails: a study of controlled trials that were discontinued
Research Project
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01.02.2011
- 31.01.2013
Clinical trials may be discontinued for different reasons, for example when it becomes apparent that a clinically relevant treatment effect will not be seen; when unanticipated adverse effects occur; or when outcomes are clearly superior in one study group. In addition, many trials are discontinued due to insufficient recruitment (slow accrual) of participants. This has ethical implications because participants consent on the premise of contributing to the advancement of medical knowledge, research ethics committees and funding agencies spend considerable resources on reviewing protocols of planned studies, and finite resources for research are wasted. Little is known about the epidemiology of discontinued trials in Switzerland. We propose to assemble a cohort of clinical trials based on protocols approved by research ethics committees in Lausanne, Basel, Lucerne, and Zurich between 2000 and 2004. We will explore other sources of trials, for example trials funded by the Swiss National Science Foundation. We will analyze this cohort to determine the risk of discontinuation of trials for different reasons. Using a case-control design, we will focus on trials that were discontinued due to insufficient recruitment. We will compare these trials with trials that were completed and thus identify characteristics of study protocols associated with discontinuation due to poor recruitment. Finally, we will examine the publication history of trials that were discontinued, and assess to what extent any lessons learned have been disseminated. We will extract relevant data from the files of the collaborating ethics committees and from published trial reports, and through a survey of trialists. The study will be based on over 1000 protocols of clinical trials, and about 150 trials that were discontinued due to poor recruitment. The proposed research is timely: recruitment of trial participants has repeatedly been identified as a serious ?bottleneck? in clinical research. The planning of effective recruitment strategies and anticipation of problems is a core task of the Clinical Trial Units (CTUs) that have been established in Switzerland with the support of SNSF. Our study will provide important insights into the problems with recruitment of participants that were encountered in randomized trials conducted in Switzerland in the recent past. It will identify modifiable barriers to successful study completion and inform future recommendations to individual trialists, research groups and units providing methodological support.
