Placebo Response Seen In Acupuncture Trials

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Literature Review: Placebo Effect Sham Acupuncture

Section 1: Literature Review of 38 Journals.

The journals state that Sham acupuncture is used as a control in scientific studies that test the efficacy of acupuncture in the treatment of various illness or disorders. In an ideal controlled study, subjects would not know whether they were getting true or sham acupuncture. If true acupuncture is not significantly more effective than sham acupuncture, then the effect of acupuncture is most likely due to conditioning and the placebo effect. If true acupuncture works significantly better than sham acupuncture, then that would indicate that some mechanism other than conditioning and the placebo effect is at work. It should be noted that "placebo effect" is a broad term that includes many non-interventional or invasive elements in medical treatment. (Kaptchuk, 2002)

Other factors that might seem trivial, like the color of the treatment room or the color of the pill one is given, might affect patient expectancy. Other factors (called "false impressions of placebo effects" by G. S. Kienle and H. Kiene) may also contribute to the difficulty in measuring just how much of the effectiveness of a treatment like acupuncture is due to the sticking of needles in acupoints according to some traditional or idiosyncratic formula.

It should be noted that placebo and false placebo factors are problems for researchers in all areas of medical science and are not restricted to those studying the effects of acupuncture. Sometimes sham acupuncture is compared to another therapy, such as taking aspirin for back pain. If sham acupuncture is significantly more effective than the other therapy, it could well be because the subjects in the study have strong or weak expectancy of effectiveness based on their beliefs or past experience. The ritual of the sham acupuncture might contribute to its effectiveness. (Kaptchuk, 2002) The effect of being randomly assigned to the acupuncture group (the subjects would be deceived and think they were getting true acupuncture or they would know that they might be getting true acupuncture) might increase the expectancy of effectiveness for the group. The disappointment of being randomly assigned to the aspirin group might decrease the expectancy of effectiveness in that group.

Sometimes a third group receiving another kind of treatment is used in acupuncture studies and is compared to true and sham acupuncture groups. Some very well designed studies have found that true and sham acupuncture are about equally effective for some treatments and better than a conventional, science-based treatment. Such results would indicate that placebo factors explain all or a good part of the effectiveness of acupuncture.

The ideal double-blind control in an acupuncture study would mimic acupuncture treatment, but would not insert needles into the patient and the acupuncturist would not know whether he or she was doing true or sham acupuncture. So far, no one has devised a way for an acupuncturist to deliver acupuncture without knowing either where she is inserting the needle or whether she is inserting the needle beneath the ...