Comparative effectiveness research: who will do the studies?

A key tenet of comparative effectiveness research is that it should be conducted in real-world health care settings. This article addresses a basic question: What is the capacity of the clinical research enterprise to conduct such studies? We argue that the clinical trial system is already at capacity and will not be able to absorb large amounts of comparative effectiveness research without diverting resources from other needs. We propose a federally funded national clinical research infrastructure that would increase comparative effectiveness research capacity by encouraging community-based clinicians and their patients to participate in trials.