CAM is often perceived as effective by those who use it. For instance,
in the above survey,3 43% of asthma patients thought that
breathing techniques were useful to “a great” or “some” extent.
For acupuncture, this figure amounted to 44%, herbalism, 42%, and
homoeopathy, 43%.3 Perceived effectiveness, however, is
composed of specific and nonspecific effectiveness, ie,
therapeutic success can be brought about by a specific mechanism of the
given treatment (eg, endorphin release after acupuncture,
pharmacologic actions of herbal constituents), or by factors not
directly related to the therapy (eg, empathy, time spent
with the patient, expectation, etc). Each of the two elements can vary
in size from 0% to approximately 100% of the total therapeutic
effect.,6 It seems obvious that rigorous research should
differentiate the nonspecific from the specific effects, because in the
final analysis, this is in the interest of the asthma patient.