Premature trial suspension will inevitably alter equipoise.

Premature Trial Suspension Will Inevitably Alter Equipoise To the Editor: The research report by the EVA-3S Investigators1 has implications which could far exceed their understandable desire to optimize safety within the trial. Following an early interim analysis, the investigators observed that the death/stroke rate after unprotected carotid angioplasty was 10.3% (6/58), as compared with 26.7% (4/15) following unprotected angioplasty. This led to a recommendation that all future angioplasties in the trial should be performed with protection. This is despite the fact that the trial was neither powered to make this judgment, nor was the difference statistically significant. I can readily sympathize with the dilemma faced by the Investigators but, in publishing this alert, they have probably rendered continuation of EVA-3S all but impossible. They have now revealed the outcome data for the entire angioplasty limb of the trial (12.5% death/stroke) and it is likely that this is considerably higher than anticipated when the trial was conceived. Consequently, this alert will inevitably alter the equanimity of physicians (and especially surgeons) considering continued randomization within the study. With the increasing trend toward “individual ethics” (ie, the needs of the individual outweigh the needs of the many), what risk will the EVA-3S Investigators now be advised to quote, bearing in mind that the actual data are public knowledge and also accessible to their prospective patients?