Another pointless “acupuncture” study misinterpreted

ResearchBlogging.orgAt the risk of once again irritating long time readers who’ve hear me say this before, I can’t resist pointing out that, of all the various forms of “alternative medicine” other than herbal medicines (many of which are drugs, just adulterated, impure drugs), acupuncture was the one treatment that, or so I thought, might actually have a real therapeutic effect. Don’t get me wrong; I never bought magical mystical mumbo-jumbo about “meridians” and “unblocking the flow of qi” (that magical mystical life energy that can’t be detected by scientists but that practitioners of woo claim to be able to manipulate for therapeutic intent). The point is (sorry, couldn’t resist) that acupuncture actually involves doing something physicial to the body, namely inserting thin needles into it. Shorn of its trappings of prescientific Eastern mysticism, acupuncture struck me as something that might have something to it.

Five years ago.

Since I started actually studying acupuncture and acupuncture studies, I’ve become acutely aware that my previous assessment was incorrect, and my pointing that out from time to time sometimes results in comments along the lines of, “We don’t need to hear this again.” Tough. For the benefit of new readers and readers who might not have read some of my previous posts on acupuncture before, I consider it important to reinforce that I have, in fact, undergone a bit of a change of heart. I have reviewed studies that showed that sham acupuncture works as well or even better than “true” acupuncture, with the needles placed right where those fancy acupuncture charts say they should be placed and that you don’t even need needles. Toothpicks with their points twirled against the skin will do. I’ve also come to realize that many of the explanations postulated by acupuncturists and doctors who believe in acupuncture are actually far less interesting than actual scientific results that they produce in their search for “proof” that “acupuncture works.” Sometimes, acupuncturists substitute active sorts of treatment for acupuncture and call it something else, like “electroacupuncture, which involves hooking up a weak electrical current to acupuncture needles. Electroacupuncture is in essence nothing more than transcutaneous electrical nerve stimulation (TENS), an accepted modality to treat pain.

Add to the evidence pile yet another study demonstrating that acupuncture is placebo medicine, reported in Arthritis Care & Research by a team of investigators based primarily at the M.D. Anderson Cancer Center that I heard about via the TIME Magazine Wellness Blog. The study, entitled A Randomized controlled trial of acupuncture for osteoarthritis of the knee: Effects of patient-provider communication, demonstrates about as unequivocally as one can imagine that one form of so-called “acupuncture” is, as far as can be detected, virtually all placebo. What is surprising about this study is not so much that it shows that acupuncture doesn’t work. In fact, it doesn’t actually show that, because what is being used is not acupuncture. What is being used is “electroacupuncture, which is in essence nothing more than TENS! More amazingly, no one whom I’ve yet seen seems to be mentioning this. In essence, the results of this study are entirely consistent with the hypothesis that it doesn’t matter whether you place TENS needles on acupuncture points or not. Will wonders never cease? Actually, that’s not quite the right interpretation, as we shall soon see.

Let’s, as they say, go to the tape. Rather, let’s go to the study.

The study was actually a rather straightforward nested randomized design. First, certified acupuncturists were trained to communicate in one of two styles, either “high expectation” or “neutral expectation. I’ll only mention in passing all the description about how all the acupuncturists were licensed in Texas (who cares, given that it’s licensing woo?) and that they all had at least two years of experience. 455 patients were randomized first to acupuncturists using one of these two styles of communication, after which they were randomized in a nested fashion to “sham” or “real” acupuncture, the latter of which was called “traditional Chinese acupuncture” or TCA. I don’t understand how TCA can be called TCA, given that there weren’t electrical sources to hook up to needles 2,000 years ago, but that’s what it’s called in he paper. Thus, the experimental groups were as follows:

  • High expectation/TCA
  • High expectation/sham
  • Low expectation/TCA
  • Low expectation/sham
  • Waiting list control

More importantly, acupuncturists were trained thusly:

Because the individual communication patterns of each acupuncturist could be different in the first half of the study, the acupuncturists were randomized, three to interact with a high expectations style and the other three in a more uncertain, neutral fashion. In the second half of the study, the high expectations acupuncturists were retrained to act neutrally and viceversa. One acupuncturist had to leave the study towards the end of the first half of the trial, so in order to maintain a balanced design, only 4 acupuncturists participated in the second half.

  1. High expectations. Acupuncturists conveyed high expectations of improvement, using positive utterances such as “I think this will work for you,” “I’ve had a lot of success with treating knee pain,” “Most of my patients get better.” A high expectations brochure was developed and given to patients. The research coordinator assisting with these patients was also trained to interact with a high expectations style.
  2. Neutral expectations. Acupuncturists conveyed uncertainty with utterances such as “It may or may not work for you,” “It really depends on the patient,” We’re uncertain, and that’s why we are doing the study.” and words like “uncertain”. A neutral expectations brochure was given to patients. The research coordinator for this group was trained to interact with a neutral style.

Training materials were developed for each style. Before the trial started, acupuncturists participated in two 2-day training sessions including didactic instruction, one-on-one coaching, and group role play to practice the assigned style, with video-recording to provide feedback. After completion of the first half of the trial acupuncturists were retrained.

As I said, this was a rather clever design, and, in general scientifically sound. But what were the exact natures of the “treatments” offered. TCA consisted of acupuncture needles placed in the “right place” along meridians, placed to the “proper” depth and then hooked up to the juice:

For TCA, TENS was set to emit a dense disperse (DD) wave impulse at 50Hz, dispersing at 15Hz, 20 cycles/minute. Voltage was increased slowly from 5V to 60V until maximal tolerance was achieved. Patients rested for 20′ with continuing TENS

That doesn’t sound like an ancient Chinese practice to me. Be that as it may, the “sham” points were chosen outside the “correct” locations along meridians. Thsese needles were not placed as deeply, and they got a different amount of juice:

For sham, instead of DD, a 40Hz adjustable (ADJ) wave was used. Voltage was increased until the patient could feel it and then immediately turned off. Patients rested for 20′ with the needles retained, but without TENS stimulation.

Well, there you go. Change the location, change the depth, change the juice, and you have a perfect ancient placebo. Actually, right here, I feel obligated to be very explicit with what the TCA and sham groups really were, because you won’t find it in any of the descriptions of this study I’ve seen thus far:

  • “True acupuncture” in meridians, electricity cranked up to 60 V for 20 minutes
  • Sham acupuncture, electricity with enough voltage just long enough for the patient to feel it, then stop. Leave needles in for 20 minutes.

So what were the results? Not surprisingly, both the TCA and “sham” groups reported significant improvements in their pain scores compared to the poor bastards on the waiting list control, and there were no detectable differences between the TCA and sham groups. Surprise, surprise. It wasn’t even a surprise that it didn’t matter whether the TENS electrodes (which, let’s face it, is all that these needles were) are placed along acupuncture meridians or not.

Now here’s where things get interesting. What we have here is a study that failed to have a proper control for what it was doing (TENS) because the investigators designed their control for what they thought they were doing (acupuncture), but they still managed to come up with an interesting result! The study was intentionally designed to be able to analyze the effect of using “high expectation” versus “neutral” language in describing acupuncture to patients. So that’s what the investigators did. What they found is that patients in the “high expectation” group had statistically significant (in some cases highly statistically significant) improvements in four different pain scores and that another pain score almost achieved statistical significance (p = 0.07). The effects were not huge (0.25), but they did appear to be real.

Sadly, instead of looking at the real finding of their research, the investigators spend much of the Discussion section trying to rationalize it away and ignore the true finding, namely yet another result showing that patient expectation and practitioner attitude influence the placebo effect, in this case using what is in essence TENS. Instead, we’re treated to passages like this:

Our study used a sham procedure with superficial needling in non-meridian points and minimal electric stimulation. While the procedure was minimally invasive, it was sufficient to allow successful blinding, as compared to some recent studies where blinding was unsuccessful. Our sham procedure may have had an analgesic effect from superficial needling such as release of endorphins, yet, this effect is also observed with oral pain placebo. Meridian point insertion following TCA practices did not have an additional effect. Furthermore, using continuous electrical stimulation in the TCA group (compared to a few seconds in the sham group) was also ineffective. Whereas the improvement observed in both TCA and sham groups is due to needling (deep or superficial) or to the placebo effects of participating in a study with frequent contact with research staff, cannot be easily established.

Nonesense. In this study, both the sham and TCA used active treatment, namely electricity. In reality, it could reasonably be argued that this study suggests that TENS works primarily through placebo effects, given that it didn’t matter whether current was applied for the whole 20 minutes or just for a brief period of time. Unfortunately, we can’t say that for sure because it could well be that meridians chosen represent crappy locations for TENS electrodes. We’d have to do the same experiment with and without electricity using the same electrode needle locations. We can, however, say that placebo effects did appear to play a significant role in both groups, even if based on this experiment we can’t say much else.

Right on cue, as epected, we’re seeing the usual apologia that inevitably appears whenever results of this sort are published about acupuncture, with bloggers getting it wrong in their rush to try to downplay just how little the results of this study support the efficacy of acupuncture. For example, although Laura Blue at TIME gets it right when she entitles her post Acupuncture: A 2,000-year tradition of placebo effect? (although, like almost everyone else, she failed to notice that this study was not really about acupuncture but TENS), Tara Parker-Pope unfortunately stumbles badly when she writes:

The results don’t mean acupuncture doesn’t work, but they do suggest that the benefits of both real and fake acupuncture may have something to do with the way the body transmits or processes pain signals. Other studies have suggested that the prick of a needle around the area of injury or pain could create a “super-placebo” effect that alters the way the brain perceives and responds to pain.

The study design may also have blurred the lines between real and fake acupuncture, muting the effects of the real thing. For instance, in traditional Chinese acupuncture, the needle insertion points are along specific areas called meridians, but the exact point of insertion is decided on a patient-by-patient basis, depending on the patient’s body and area of pain. In the study, however, a standard map was used so that the needle insertion point was the same for every patient. In addition, trained acupuncturists also were asked to administer the fake treatment and insert needles at specific points outside of traditional meridians. Although researchers sometimes stepped into treatment sessions to check on the location of the needles, it’s possible that some of the sham treatments were similar to real acupuncture.

Ms. Parker-Pope should be careful. She’ll hurt herself contorting herself to justify acupuncture using the time-dishonored trope that the treatments weren’t sufficiently “individualized” and that standardization somehow kept the magic from working. Even worse, she didn’t seem to notice that what was being studied was not acupuncture, but rather TENS, even though the authors refer to it as “acupuncture.” It’s a rather obvious rookie, although when I see journalists analyzing “alt-med” studies, rookie mistakes seem to continually plague even experienced reporters. Let’s finish with how the authors finished:

This is the first study examining TCA and sham acupuncture in knee OA that also included experimental manipulation of the acupuncturists’ communication style. In summary, TCA was not superior to sham acupuncture, and needling of meridian points was not more effective than use of sham points. Continuous electrical stimulus or increased needle penetration in the TCA group did not improve response. Acupuncturists’ communication style had a small but statistically significant effect in pain reduction and satisfaction suggesting that the perceived benefits of acupuncture may be partially mediated through placebo effects related to the acupuncturists’ behavior.

This study is a mess, as I pointed out before, but, for the sake of argument, let’s assume that the control was actually a valid control for what was being done and that this really was a study of TCA versus sham acupuncture, rather than a trial of 20 minutes of TENS on acupuncture meridians versus less than a minute of weaker TENS away from acupuncture meridians. In other words, let’s use the authors’ own assumptions behind their design of the study. What do you call a procedure in which it doesn’t matter if you place the needles in the “correct” spots or not and doesn’t matter whether there’s any juice turned on or not, but does matter how optimistic the practitioners’ communication style is?

A placebo. I call it a placebo.

REFERENCE

Suarez-Almazor, M., Looney, C., Liu, Y., Cox, V., Pietz, K., Marcus, D., & Street, R. (2010). A Randomized controlled trial of acupuncture for osteoarthritis of the knee: Effects of patient-provider communication Arthritis Care & Research DOI: 10.1002/acr.20225