Are implanted defibrillators effective therapy in the elderly?: Asked, not answered.

There is a general agreement that before a therapy can be accepted into widespread clinical use, demonstration of efficacy in randomized clinical trials (RCTs) is absolutely necessary. There are, however, a growing number of experts who believe that demonstration of RCT efficacy might not be a sufficient basis for widespread acceptance.1 RCTs may not enroll subjects representative of patients in community settings, who may differ from RCT subjects in age, gender distribution, disease severity, comorbidity burden, and intensity of ancillary therapy. Additionally, randomized trials may not enroll sufficient numbers of subjects to demonstrate safety from rare adverse events. As a result of these differences, some therapies with demonstrated efficacy may have a smaller effect or no effect at all in community patients. For example, spironolactone reduced mortality in a randomized trial,2 but in community-based studies, its effectiveness was limited by rates of adverse events significantly higher than in the trial.3,4