make sense and may not have acceptable psychometric properties for patients receiving CAM modalities that do not take a quantitative approach to sensations like pain.

In both CAM and conventional medicine, there are treatments that have some defined boundaries or ranges of acceptable options, as embodied in a training manual, but the healer or provider may have immense room to use variations and his or her own judgment in individual interactions with specific patients. Many psychotherapies, for example, have a general framework and some well-defined features or boundaries, but the specific words used or issues raised at any point in time in a therapy session may differ. These decisions are up to the therapist and are based on a combination of formal training, experience, instinct, and immediate feedback from the patient. It is extremely difficult to study the effectiveness of a specific utterance or even sequence of microlevel interactions between the therapist and the patient, but it may be possible to study the effectiveness of an individual therapist or the approach to therapy taken as a whole. Similarly, in some CAM modalities, it will not be possible to study the effectiveness of a specific maneuver performed in the context of a 30-minute hands-on interaction with a patient (e.g., massage), but it may be possible to evaluate the effectiveness of the approach taken as a whole in comparison with that of some alternative approach to the same problem.

Addressing the special challenges mentioned above for research in CAM will require a broadening of thinking about the types of study designs that can produce valid evidence of treatment effectiveness. RCTs and systematic reviews of multiple RCTs will still stand as the “gold standard” of evidence when the key questions have to do with treatment efficacy and when the treatment is amenable to the narrow definition, standardization, and the use of strict controls typical of RCTs. (See Chapter 5 for a discussion of such trials.) When RCTs cannot be done, however, or when the results of RCTs may not be generalizable to the real world of CAM practice, it will be necessary to use other study designs. Some of these options are described in the following sections.