Are safety committees really safe?

In an increasing number of recent major clinical trials, independent safety committees or safety monitors have been involved. Their role and function is not yet defined and continues to evolve. The aim of this paper is to discuss the role and tasks of safety committees as a result of our collective experience as members of three safety committees of studies evaluating antithrombotic prophylaxis against postoperative deep vein thrombosis. We believe that the type of pharmacological intervention used is of less important that the general experiences gained, which can be extrapolated to other studies and should stimulate a more general debate.