Raw Data

Two placebos face off.

By Jessica MarshallApr 27, 2006 5:00 AM


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THE STUDY: "Sham device v. inert pill: randomized controlled trial of two placebo treatments," published on February 1, 2006, in the journal BMJ (British Medical Journal). The purpose was to find out if doctors can manipulate the placebo effect. The National Institutes of Health ponied up $1,614,605 for the answer.

THE FINDINGS: Medical researcher Ted Kaptchuk pitted two types of fake medicine—sugar pills and pretend acupuncture—against each other to see which one worked better. He recruited 266 volunteers suffering from chronic arm pain, which they rated at least a 3 on a 10-point scale.

133 subjects received acupuncture with trick needles whose tips retract so they don't penetrate the skin. The other 133 subjects were prescribed blue cornstarch pills that resembled amitriptyline, an antidepressant often prescribed for repetitive strain injury.

25 percent of the acupuncture group experienced side effects from the nonexistent needle pricks, including 19 people who felt pain and 4 whose skin became red or swollen. 31 percent of the pill group experienced side effects from the make-believe drug, including dizziness, restlessness, rashes, headaches, nausea, and 4 cases of nightmares. Dry mouth and fatigue were the most common side effects, and 3 subjects withdrew from the study after reducing the dosage failed to control their symptoms. The reported side effects exactly matched those described by the doctors at the beginning of the study.

After 10 weeks, subjects taking sham pills said their pain decreased an average of 1.50 points on the 10-point scale. After 8 weeks, those receiving fake acupuncture reported a drop of 2.64 points. In other words, not receiving acupuncture reduces pain more than not taking drugs.

Kaptchuk says that the rituals of medicine explain the difference: Performing acupuncture is more elaborate than prescribing medicine. Other rituals that may make patients feel better include "white coats, and stethoscopes that you don't necessarily use, pictures on the wall, the way you reassure a patient, and the secretaries that sign you in." Careful manipulation of such rituals could make all types of treatment more effective, Kaptchuk suggests.

THE RESEARCHERS: Ted Kaptchuk grew up in Brooklyn but moved to Macao, China, to get a degree in Chinese medicine. He ended up running a pain unit at a hospital in Boston, where he prescribed acupuncture, meditation, and massage. It worked, but colleagues claimed the effect was purely psychological. And that was probably more interesting, he decided, so he started researching placebos at Harvard Medical School.

For this study he assembled an eclectic team, including a cardiologist, three statisticians, a neuroscientist, a psychologist, and a philosopher.

Kaptchuk's title is assistant professor of medicine. "It could have been 'quackery,' " he says, "but they didn't have a position in that."

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