Tuesday, August 04, 2009

The Hokey Pokey: Acupuncture, Placebo, and the Persistence of Bias

Title of the front page article in the July 2009 ACUPUNCTURE TODAY: “Acupuncture Found Effective for Back Pain: Study finds it superior to usual care.”

Title of a June 1, 2009 article in NEWSWEEK by science writer Sharon Begley: “Hooked on a Feeling: This is your brain on a placebo.”

Believe it or not, these articles report on the exact same recent acupuncture research. As their titles reveal, they reach basically opposite conclusions. The research in question, conducted by Daniel C. Cherkin et al and published in the Archives of Internal Medicine, May 11, 2009, under the title “A Randomized Trial Comparing Acupuncture, Simulated Acupuncture, and Usual Care for Chronic Low Back Pain,” utilized a cleverly constructed experiment to try to determine whether acupuncture was effective as a treatment for low back pain. 638 adults with chronic low back pain were split into three groups. One group received “individualized acupuncture,” in which the acupuncturist could use any points he or she wanted, as long as the patient was lying prone. The second group received “standardized acupuncture,” an eight-point combination consisting of the points Du-3, UB-23, UB-40, K-3, and a low back ashi point (an excellent prescription, though the ashi point, referring to a tender point, makes this “standardized acupuncture” somewhat individualized to my mind). The third group received “simulated acupuncture,” or, as acupuncture detractors prefer to call it, “sham acupuncture.” In this group, the patient would lie face down as in the other groups, and the acupuncturist would press an acupuncture needle guide tube against the same points used in the “standardized acupuncture” group, then simulate needle insertion by tapping a toothpick gently against the patient’s skin. None of the patients in any of the groups knew which group they were in, and, presumably, all thought they were receiving some kind of acupuncture. All patients received ten treatments over seven weeks, and outcomes were assessed after eight, twenty-six, and fifty-two weeks using the Roland-Morris Disability Questionnaire and a 0-10 range “symptom bothersomeness” scale.

Much to the delight of acupuncturists everywhere, the results showed that acupuncture “improved function and decreased symptoms,” and, furthermore, the improvement was significantly better than that resulting from usual care, even one year later. Interestingly - and here is the crux of the dispute between the pro- and anti-acupuncture camps – it didn’t make a difference whether a patient received “real acupuncture” of the individualized or standardized variety, or whether they received the non-penetrating “sham acupuncture.”

Now, this is food for thought. It is quite easy for the acupuncture-uneducated reader to leap to the conclusion, as NEWSWEEK’s Begley does, that “the most parsimonious explanation for that finding is inescapable: it is possible to think yourself out of pain.” In other words, if sham acupuncture works as well as real acupuncture, then all acupuncture must work because of the placebo effect.

Let me make my own bias clear: I am an acupuncturist. I believe that there is something going on other than mind over matter when I treat my patients and they get better. I think that acupuncture is a connective tissue therapy par excellence, and that the traditional East Asian approach to treating the human body’s ailments via the skin and connective tissue is far more sophisticated than the cutting edge of conventional medicine.

That said, I believe that there is also something to the whole placebo thing. Of course the placebo effect is part and parcel of how acupuncture works! Placebo effects are part of how any healing method works. It is a credit to the ancient Chinese doctors that they incorporated into their medicine methods that improve clinical outcomes through, to use the medical lingo, “nonspecific effects.” Yes, it helps patients to listen to them! It helps patients to palpate them, to look at them, to spend more than five minutes with them! My hope is that one of the outcomes of placebo research is that conventional medicine will reincorporate some of these things, to give it a softer edge, more compassion, less arrogance, and yes, better outcomes.

It appears to me that acupuncture has reached a tipping point in modern society. There are so many people who have benefited from acupuncture that it is simply getting accepted by the mainstream as a viable therapeutic method. Acupuncture poses a challenge only to those hardcore skeptics who cannot stand the thought that a method utilizing unscientific concepts like “qi,” “the five elements,” and “yin and yang” could possibly work. Their disbelief of acupuncture is akin to someone refusing to believe that a samurai sword can cut because their fundamentalist mind takes issue with the Shinto ritual that dictated the ancient swordmaker’s forging. Such people seize upon a study such as Cherkin’s as proof that acupuncture only works because patients believe that it does. They fail to consider alternate explanations, even though the authors of the study themselves spell out the possibility that “superficial acupuncture point stimulation directly stimulates physiological processes that ultimately lead to improved pain and function.” The research of MacPherson et al with functional magnetic resonance showing that superficial and deep needling elicit similar blood oxygen level-dependent responses in the brain suggest as much (Neuroscience Letters 434, 2008).

My strong suspicion is that acupuncture works not through a single mechanism but through multiple mechanisms. Something very physical happens when you insert a needle through the skin and tap at the surface of a myofascial trigger point until it releases with a palpable and visible fasciculation. Other acupuncture techniques are more “energetic” and mysterious but equally effective. There are entire schools of non-insertive acupuncture that rely on the practitioner feeling a pulsation or tingling where the needle meets the skin (the patient often feels something as well) to assess its effects during a treatment. I believe that this type of acupuncture is a means of interacting with a primitive electrical signaling system that utilizes the body’s connective tissue as a conductive direct current network. Deep needling may or may not utilize the same mechanism to produce its therapeutic effects. Ear acupuncture most likely utilizes yet a different mechanism – probably neural. For Sharon Begley or any other skeptic to decide for the public what “real acupuncture” is represents the height of arrogance. Perhaps there are many types of “real acupuncture,” and “sham acupuncture” is actually a type of real acupuncture!

There is an excellent quote in the book Herbal Emissaries by Steven Foster and Yue Chongxi, in which the authors state (about ginseng, not acupuncture): “Chinese researchers…have focused on how ginseng works, whereas western researchers focus on if it works. This reflects a fundamental difference in research approaches between the East and the West. In Asia, the efficacy of an herb is already established in a cultural context. In the West, we presuppose that traditional uses have no rational scientific basis.” The same could be said for acupuncture. There are already plenty of studies showing that acupuncture is effective for back pain, or nausea, or whatever. It’s great that these clinical studies are getting more sophisticated. But as the response to the Cherkin group’s research shows, people read into these studies what they already believe. The Acupuncture Today article never once uses the word “placebo” in discussing the possible interpretation of the results, and the NEWSWEEK article never once entertains the possibility that acupuncture works by a mechanism other than placebo.

I wish that instead of these sorts of studies, and in addition to better and more placebo research, scientists would do more basic research into how acupuncture actually, physically, works. It’s hard to argue with fMRI imaging that shows that the needling of points associated with the treatment of vision disturbances lights up the visual cortex of the brain (as Cho et al report in PNAS, vol. 95 no. 5, 1998), or that needle twirling at acupuncture points results in mechanical signal transduction in the connective tissue with far-ranging effects (Langevin, in the Journal of the Federation of American Societies for Experimental Biology 16:872-874, 2002).  I predict that the next generation of acupuncture research will demonstrate that acupuncture turns specific genes on or off to achieve its effects - and that these studies will be done on (presumably unbiased) non-human mammals.  I don’t feel any particular need to validate what I do to skeptics. I’m quite comfortable with the witch doctor element in what I do, and it’s good enough for me that my patients are satisfied with the care they receive. But I do realize that strong scientific evidence would ultimately result in more people benefiting from acupuncture. And I think that fundamental research in the biophysics and biochemistry of acupuncture would serve this end better than clinical research, which somehow just seems to strengthen one’s bias, whatever it might be. Perhaps I am being naïve, and no amount of studies will convince either camp that the other is wrong. For some reason acupuncture rubs some people the wrong way much like astrology or intelligent design do. But I predict that, with or without studies, acupuncture will continue to gain acceptance simply because more and more people are benefiting from it and its usefulness is becoming a matter of conventional wisdom in the same way that people accept the validity of many surgical procedures that have never been tested but continue to be used because of their self-evident efficacy.

If the placebo effect is hokey, then there is something hokey about acupuncture. The placement of needles at acupuncture points, with or without penetration of the skin, is certainly pokey. There is a magic that happens between the mind and the body, and between two interacting human beings, that unites and transcends the hokey and the pokey. That magic is called “healing.” When it comes to healing, maybe the Hokey Pokey IS what it’s all about. Just put your left hand out and I’d be happy to show you.

1 comment:

d. moll, l.ac. said...

An interesting post, and certainly a topic i ponder. I wonder if the efficacy of sham acupuncture would have been as successful with, say, digestive issues or chronic insomnia. As a note: I have had patients who gave me "credit" for healings when I was quite sure I had really done nothing......Hokey pokey, serve it up!