Do clinical trials adequately serve clinical practitioners?

Clinical trials are indispensable to evidence-based medicine, yet their results may not translate directly to individual patients. This review provides guidance for clinicians attempting to apply trial results to points of care. Using cardiovascular trials as examples, we examine how study design, eligibility criteria, background therapy, dose, endpoint selection, monitoring intensity, adherence, crossover, analysis strategy, and control-group event rates influence interpretation and transportability. We emphasize careful interpretation of composite and net clinical benefit endpoints and outline limitations of propensity-score methods. Cross-trial comparisons of antiarrhythmic therapies demonstrate how differences in populations, endpoint definitions, time origins, and surveillance can produce divergent absolute event rates despite similar therapies or protocols. Finally, we propose questions for clinicians attempting to apply trial outcomes to their patient care practices integrated with the individual patient's characteristics, competing risks, goals, and preferences.