particular CAM therapies, their motivations for the use of such therapies, and how they understand health and illness.

The committee believes that it is desirable to use a variety of study designs in the conduct of research of CAM therapies. Given the limited amount of funding available for clinical studies of CAM therapies, decisions about what to evaluate should be made on the basis of one or more of the following criteria. Clearly, no intervention will meet all criteria and a therapy should not be excluded from consideration because it does not meet any one particular criterion, for example, biological plausibility. However, the absence of such a mechanism inevitably will raise the level of skepticism about the potential effectiveness of a treatment (whether conventional or CAM) and will increase both the basic research needed to justify funding for clinical studies and the level of evidence from clinical studies needed to consider a treatment as “established.”

• A biologically plausible mechanism exists for the intervention but it is recognized that the science base on which plausibility is judged is a work in progress.

• Research could plausibly lead to the discovery of biological mechanisms of disease or treatment effect.

• The condition is highly prevalent (e.g., diabetes mellitus).

• The condition causes a heavy burden of suffering.

• The potential benefit is great.

• Some evidence that the intervention is effective already exists.

• Some evidence that there are safety concerns exists.

• The research design is feasible and research will likely yield an unambiguous result.

• The target condition or the intervention is important enough to have been detected by existing population surveillance mechanisms.

Should CAM be held to the same standards of evidence as conventional medicine? Regardless of the specific choices made about study design, whether it be traditional or innovative, a question that the committee addressed was whether CAM therapies should be held to the same standards of evidence as medications, surgical procedures, or other therapies used in conventional medicine. By the “same standards of evidence,” the committee means that an insurance company would require “A-level evidence” (that is, evidence derived from consistent findings from multiple RCTs), for example, to include specific herbal therapies in a pharmacy benefit or formulary if they required A-level evidence for coverage of prescription drugs.

Research on treatment effectiveness is research about cause-effect relationships between the provision of particular treatments and defined pa-