Standard methods for testing safety data are needed to ensure the safe conduct of clinical trials. In particular, objective rules for reliably identifying unsafe treatments need to be put into place to help protect patients from unnecessary harm. DMCs are uniquely qualified to evaluate accumulating unblinded data and make recommendations about the continuing safe conduct of a trial. However, it is the trial leadership who must make the tough ethical decision about stopping a trial, and they could benefit from objective statistical rules that help them judge the strength of evidence contained in the blinded data. To be discussed: 1. Are DMCs sufficient to ensure the continuing safe conduct of a trial? 2. How can we best help trial leadership to make the tough ethical decisions about stopping a trial? 3. What characteristics should be considered when designing safety screens (objective rules for reliably identifying unsafe treatments)?