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Archive for November 17th, 2008

On the dangers of using valid placebo controls in clinical trials of acupuncture

ResearchBlogging.orgI don’t recall if I’ve ever mentioned this before on this blog, but there was a time when I was less skeptical of acupuncture than I am now. It’s true. Don’t get me wrong, though. I never for a minute considered that the whole rigamarole about “unblocking” or “redirecting” the flow of that mystical life force known as qi had anything to do with whether or not acupuncture did or did not have efficacy treating disease or other conditions. That was clearly a holdover from the pre-scientific medicine times in which most beliefs about the causes of disease involved either the wrath of the gods or vitalism, the latter of which is, when you come right down to it, the philosophical basis upon which many “complementary and alternative” (CAM) modalities are based, especially the so-called “energy healing” modalities, such as reiki, therapeutic touch, and, of course, acupuncture.

However, because unlike so many other “energy healing” methods, acupuncture involved an actual physical action upon the body, namely the insertion of thin needles into the skin to specified depths, it did not seem to me entirely unreasonable that there might be some sort of physiological effect that might produce a therapeutic result. At least, that’s what I used to think until I actually started paying attention to the scientific literature on acupuncture. That’s when I started to realize that “there’s no ‘there’ there,” if you know what I mean. Horribly designed studies with either no controls or utterly inadequate controls tend to be the norm in the acupuncture “literature” (if you can call it that). Moreover, acupuncture was touted as having value for conditions and procedures for which there is no plausible (or even mildly plausible) physiological mechanism by which it could be reasonably postulated to have an effect. Arthritis, allergies, headache, back pain, gastroesophageal reflux disease (GERD), Parkinson’s disease, post-operative nausea, hot flashes in breast cancer patients caused by the anti-estrogen drugs they have to take, infertility, it doesn’t matter. Seemingly acupuncture can do it all; it’s the Swiss Army knife of CAM therapies. Moreover, the “explanations” given to explain “how acupuncture works” seemed increasingly less plausible to me. Most of these explanations involve counterirritation or the release of opioids, and I’ve had an increasingly hard time believing that, even if these mechanisms are at play, they could have anything other than nonspecific effects, with no mechanism to explain how acupuncture could possibly do all things attributed to it. One rule of medical skepticism is that you should be very skeptical of modalities that are touted to be useful for a wide variety of medical conditions that have very different pathophysiology. Indeed, a funny thing happens when rigorous placebo controls are introduced, and that’s sometimes the placebo control does better than the “true” acupuncture; i.e., the evidence for acupuncture, taken in its totality, is completely compatible with placebo effect.

As Harriet Hall put it in her excellent analysis of a study purporting to show that acupuncture is useful for GERD:

This study falls into the category of what I call Tooth Fairy science. You could measure how much money the Tooth Fairy leaves under the pillow, whether she leaves more cash for the first or last tooth, whether the payoff is greater if you leave the tooth in a plastic baggie versus wrapped in Kleenex. You can get all kinds of good data that is reproducible and statistically significant. Yes, you have learned something. But you haven’t learned what you think you’ve learned, because you haven’t bothered to establish whether the Tooth Fairy really exists.

One area that acupuncturists keep needling away at is infertility. Somehow, in the CAM community it’s become conventional wisdom that acupuncture can somehow increase the chance of success for couples undergoing in vitro fertilization (IVF). Indeed, early this year I wrote about a meta-analysis that concluded that acupuncture did actually increase the success rate of IVF and why it did not show what its authors thought it showed. Tooth fairy science, indeed.

Now comes yet another study being publicized in the media that examines once again the question of whether sticking needles into women before they undergo IVF can increase their chances of conceiving. I could not help but be extremely amused by the title given to the ScienceDaily story about it: Placebo Acupuncture Is Associated With Higher Pregnancy Rate After IVF Than Real Acupuncture. You have to love a headline like that, and opening paragraphs like this:
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Posted in: Acupuncture, Clinical Trials, Medical Academia, Science and the Media

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