Clinical trials in the wake of Vioxx: requiring statistically extreme evidence of benefit to ensure the safety of new drugs.

Clinical trials have become the preeminent tool for investigating new diagnostic, therapeutic, and preventive treatment strategies. During these trials, periodic interim data analyses are conducted by data monitoring committees (DMCs) to ensure participant safety. If accumulated data indicate harm to participants, clear evidence of superior efficacy, or futility of collecting additional data, studies may be terminated before their planned conclusion.