Perception and reality in acupuncture

Last week, I wrote about an overhyped acupuncture study that purported to show (but didn’t, really) that acupuncture is more effective than “conventional” therapy in the treatment of low back pain. This story reverberated through the Internet and blogosphere as “proof” that acupuncture “works” when in reality the study was very weak evidence of any effect due to needles being placed into the skin and only showed that meridians are a meaningless concept (i.e., the finding that sham acupuncture was just as effective “real” acupuncture). If acupuncture does do anything, this study was pretty thin gruel to demonstrate it.

In my field, cancer, one common claim for acupuncture is that it is a useful adjunct that alleviates chemotherapy-induced nausea. It turns out that a study was recently presented at the European Cancer Conference in Barcelona last week that addresses this very question, and in doing so it sheds some light on the appeal of acupuncture:

Barcelona, Spain: Despite widespread belief among cancer patients and health care professionals that acupuncture helps relieve nausea caused by cancer treatment, new research in radiotherapy has found it does not.

The study, presented today (Wednesday) at the European Cancer Conference (ECCO 14) in Barcelona, evaluated the effectiveness of acupuncture in 215 patients with various types of cancer who got either active acupuncture or a sham treatment that involved an identical looking and feeling needle that retracted into the handle on contact with the skin.

The treatment, in the forearm, was given two or three times a week during the whole period of radiotherapy, which is a common schedule. The patients documented their nausea and vomiting in diaries and completed questionnaires during and after the radiotherapy course.

“Both groups of patients reported they believed the treatment had been invasive and effective in reducing nausea. However, 68 percent of patients who got the acupuncture experienced nausea for an average of 19 days during radiotherapy and 61 percent of the patients who got the sham treatment suffered nausea for an average of 17 days,” said the study’s lead researcher Anna Enblom, a physiotherapist and doctoral student at the Faculty of Health Sciences, Linköping University in Sweden.

Vomiting was experienced by 24 percent of the patients getting acupuncture and 28 percent of patients receiving the sham treatment, Enblom added.

Fifty-eight of the patients received chemotherapy in combination with radiotherapy. Among them, 82 percent of those in the acupuncture group developed nausea, compared with 80 percent of those treated with the sham needles.

“There was no statistically significant difference between the groups in the number of days with nausea or vomiting or in the intensity of the nausea, neither in the patients receiving radiotherapy alone, nor in those receiving a combination of chemotherapy and radiotherapy,” said Enblom. “Our study may indicate that attitudes and expectations play a major role in the experience of the effect of the treatment.”

Acupuncture is increasingly used in cancer care as an alternative to drugs to treat therapy side effects such as pain and nausea, despite unclear evidence that it has any real effect. The percentage of cancer patients using acupuncture for various kinds of symptoms, including nausea and pain, varies from two percent to 30 percent depending on the population.

My first thought was to marvel that this study actually used the sort of retractable needles suggested by Steve Novella as controls. This aspect of the study design alone, more than anything else, made it possible to actually blind the caregivers as well as the patients as to which treatment group they are in or dealing with. My second thought was that I’m not particularly surprised. Although it is theoretically possible that acupuncture works for pain control or nausea, a beneficial effect on chemotherapy-induced nausea due to acupuncture is less scientifically plausible than an effect on pain.

What is really interesting about this study is that it suggests a reason why so many people believe that alternative medicine, be it acupuncture, homeopathy, or whatever, works for them, even in the absence of any real objective evidence that it does anything. Here we have two groups of patients, one of which received “real” acupuncture and one did not, but who were truly blinded to which group they were in. Even though there was no objectively-measurable difference in the intensity or duration of chemotherapy-induced nausea and vomiting among the groups, the overwhelming majority of both groups thought acupuncture helped them and would like to use it again. My only quibble about this study is that it would have been strengthened by a third group receiving no treatment, although the addition of such a group could have altered the study by destroying its double-blind nature. Be that as it may, just the expectation that the treatment will work clearly led both groups to believe that it did, even though there was no objective evidence that either group did any better.

Certainly, this study won’t be the final word, and it will be interesting to see what the final manuscript shows, when all the details of the study design are presented. It turns out that the literature is all over the place regarding the use of acupuncture for chemotherapy-induced nausea, with the vast majority of studies tending to be of low quality and mostly negative or only weakly positive (like most alternative medicine studies). There is also a tendency to confuse electroacupuncture (acupuncture with electrical stimulation), for which there is some, albeit weak, evidence of efficacy in chemotherapy-induced nausea but which, I would argue, is a very different thing than acupuncture, given that the originators of acupuncture didn’t have electricity to run through their needles. (Maybe applying current is a better way of manipulating the flow of qi.)

One of the reasons that evaluating so many of these alternative therapies scientifically can be so difficult is because of this rose-colored view many patients have of their treatments, such that they look for every evidence of their efficacy and, even if there really isn’t any, still view the treatment as helpful, a phenomenon known as confirmation bias. This is a very difficult form of bias to overcome, both in patients and their caregivers. As the press release concludes:

In the study presented at ECCO, 66 percent of patients who got acupuncture and 71 percent who got the sham treatment said they would be highly interested in having acupuncture again if it turned out they needed another course of radiotherapy.

In Sweden, the cost of acupuncture is covered by the state healthcare system when given for indications where it is proven to work.

As long as the best possible available drug treatment for nausea is given to cancer patients receiving radiotherapy, the patient may be satisfied with a gentle and pain free acupuncture treatment and believe it helps. It is not recommended to give acupuncture if it produces pain or harm.

If I lived in Sweden, I’d say that I have no objection–as long as the patient pays for the acupuncture himself. After all, if there’s no scientific evidence that it objectively decreases the severity, duration, or intensity of nausea and vomiting, why should taxpayers be expected to pay for it? In a state-funded health care system, any money diverted to ineffective woo is money that doesn’t go to pay for effective treatments for other people. It’s exactly the same reason that, if I lived in the U.K., I’d be very upset that my tax money was being spent on homeopathy. It’s a zero sum game.