Expectations for comparative effectiveness and efficacy research: with welcomed questions may come unwelcome answers.

I N DERMATOLOGY, MOST randomized clinical trials or randomized controlled trials (RCTs) are for the purpose of obtaining US Food and Drug Administration marketing approval and are placebo controlled. While such studies serve to prove that the agents can work, they do not inform the clinical choice of which agent is best in a specific clinical circumstance. Although the cost to obtain marketing approval is often great and is complained about by developers of therapeutic agents, the growing interest in and funding of comparative efficacy research (CER) may ultimately show that the current regulatory requirements, although costly, provide circumstances favorable to developers and marketers of therapeutic agents. Applying medical knowledge gained by the scientific method (evidence) to clinical decision making has been called evidence-based medicine. The gold standard or level 1 evidence is generated by RCTs 1 However, it is well recognized that RCTs rarely provide information most desired by decision makers, be they clini-cians, patients, insurers, or health policy makers. This shortcoming has even led to the proposal that for new agents that have proven efficacy over older agents reimbursement be at higher levels than that for new agents that do not provide evidence of superiority over older or standard agents. 2 As noted, the reason RCTs do not often offer sufficient guidance for decision makers is that RCTs are designed to optimize chances of showing a difference (disproving the null hypothesis). Inclusion and exclusion criteria are used to select a highly defined population of patients to either receive the test agent or the control, often a placebo. Altogether, the narrowly selected study population, frequent return visits, intense monitoring, and special inducements (sometimes financial) to ensure compliance create a situation in which both the safety and the efficacy of an agent is likely to be greater in an RCT than that found in a conventional practice setting. In the United States, treatment must be shown to be effective but not necessarily better or equal to the available treatments. Therefore, registration studies often compare agents being developed with a placebo rather than with the standard treatment. The realm in which comparisons to or among standard or available treatments are made is known as CER. " Effectiveness " is used to indicate that it is the outcome in the practice setting that is of interest, leaving " efficacy " to indicate the outcome in the optimized , less generalizable RCT. Comparative …