Implementing a research agenda for complementary and alternative medicine.

Complementary and alternative medicine (CAM) consists of diverse clinical interventions that are practiced because of their popularity rather than the prior demonstration of safety and efficacy required for conventional agents. CAM therapies can be grouped into five categories: biologically based therapies, manipulative and body-based interventions, mind-body interventions, "energy" therapies, and alternative medical systems. The present evidence that individual CAM interventions are efficacious is largely anecdotal, but hundreds of small trials have yielded positive results. For a few modalities, existing data are either very encouraging or else sufficient to conclude that they are ineffective. CAM interventions are presumed to be safe, yet they may not be, particularly in the case of botanical agents with inherent toxicities, significant drug interactions, or potent adulterants. The public health questions regarding CAM can only be addressed through a research agenda that defines which interventions have favorable therapeutic indices. Implementation of this agenda involves adequate characterization and standardization of the product or practice, with rigorous investigation to demonstrate its safety, mechanism of action, and efficacy.