Yawn…another overhyped acupuncture study

Blogging on Peer-Reviewed ResearchNever let it be said that Orac doesn’t give the people what they want.

Well, most of the time, anyway.

What I’m referring to is a recent German study about acupuncture for low back pain that’s been making its way around the media. I had actually been planning on commenting about it yesterday, but Iranian President (and Holocaust denier) Mahmoud Ahmadinejad’s speech at Columbia University intervened and took me on one of my occasional diversions away from science and medicine into the history of the Holocaust, Holocaust denial, and politics. In just that two day interval, I’ve been deluged with e-mail about this particular study (well, I did get several, anyway), making me think that I’d better answer the call and give my readers what they want.

What’s most annoying about this study is not so much the study itself but rather how it’s being represented. For example, look at these headlines:

Not surprisingly, these stories completely miss the point.

For example, here’s what the BBC (which really should know better) says:

Acupuncture – real or sham – is more effective at treating back pain than conventional therapies, research suggests.

A German team found almost half the patients treated with acupuncture felt pain relief.

But the Archives of Internal Medicine study also suggests fake acupuncture works nearly as well as the real thing.

In contrast, only about a quarter who received drugs and other Western therapies felt better.

The researchers, from the Ruhr University Bochum, say their findings suggest that the body may react positively to any thin needle prick – or that acupuncture may simply trigger a placebo effect.

One theory is that pain messages to the brain can be blocked by competing stimuli.

Researcher Dr Heinz Endres said: “Acupuncture represents a highly promising and effective treatment option for chronic back pain.

Here’s what MedPage Today (which really, really should know better) said:

BOCHUM, Germany, Sept. 24 — Acupuncture offers an effective alternative to conventional therapy for low-back pain, investigators here reported.

Almost twice as many patients responded to acupuncture versus conventional therapy, Heinz G. Endres, M.D., of Ruhr-University Bochum, and colleagues, reported in the Sept. 24 issue of Archives of Internal Medicine.

However, sham acupuncture worked just as well as verum, or true, acupuncture, they reported.

“Acupuncture constitutes a strong alternative to multimodal conventional therapy,” the authors concluded. “Acupuncture gives physicians a promising and effective treatment option for chronic low-back pain, with few adverse effects or contraindications.”

Notice how both articles completely gloss over a key observation: That “sham” acupuncture was seemingly just as effective as “real” acupuncture. Why is this important? Remember that acupuncture as a discipline claims that the insertion of needles in specific points in the body can relieve pain and have therapeutic effect. These points on the body are known as “meridians” and placing needles into these meridians is claimed to “unblock” or restore the “flow” of qi or the “life force.” Never mind that there is no anatomic or physiologic basis for meridians, nor can ;em>qi be detected or measured, much less any change in the flow of qi due to sticking thin needles into specific points on the skin. “Sham” acupuncture, which, as I’ve discussed before, is an absolutely necessary control in any serious clinical trials to test acupuncture, is the placement of needles in locations other than the correct meridians.

So why is this key observation that sham acupuncture is as effective as acupuncture? Simple! The fact that it doesn’t matter where the needles are placed is clear evidence that the entire “theoretical” underpinning of traditional Chinese medicine underlying acupuncture is a load of fetid dingo’s kidneys. If it doesn’t matter where needles are placed, then, as expected, meridians have no anatomical or physiological meaning. As Ben Goldacre put it:

But even more interestingly, the pretend acupuncture group, where they just bunged needles in any old place with a bit of ceremony, did just as well as the people having proper, posh, theatrical, genuine acupuncture.

In other words, if sticking needles into the skin has any effect on low back pain, it is not due to any magic–like qi. It has to be due to a physiological mechanism that good, old-fashioned, materialistic reductionist science can work out if given sufficient time and resources. In fact, it seems inappropriate even to call this acupuncture, because it doesn’t at all depend on the traditional Chinese medicine concepts that underlie acupuncture. Of course, only some news reports are emphasizing this point properly. Instead, what we are treated with are truly silly statements like this:

Dr James Young, of Chicago’s Rush University, said: “We don’t understand the mechanisms of these so-called alternative treatments, but that doesn’t mean they don’t work.”

It doesn’t mean that they do “work” either. This study is weak evidence at best supporting a therapeutic effect due to sticking needles into the skin in terms of reducing the pain from chronic low back conditions. Let’s take a look. Here’s the abstract:

Background To our knowledge, verum acupuncture has never been directly compared with sham acupuncture and guideline-based conventional therapy in patients with chronic low back pain.

Methods A patient- and observer-blinded randomized controlled trial conducted in Germany involving 340 outpatient practices, including 1162 patients aged 18 to 86 years (mean ± SD age, 50 ± 15 years) with a history of chronic low back pain for a mean of 8 years. Patients underwent ten 30-minute sessions, generally 2 sessions per week, of verum acupuncture (n = 387) according to principles of traditional Chinese medicine; sham acupuncture (n = 387) consisting of superficial needling at nonacupuncture points; or conventional therapy, a combination of drugs, physical therapy, and exercise (n = 388). Five additional sessions were offered to patients who had a partial response to treatment (10%-50% reduction in pain intensity). Primary outcome was response after 6 months, defined as 33% improvement or better on 3 pain-related items on the Von Korff Chronic Pain Grade Scale questionnaire or 12% improvement or better on the back-specific Hanover Functional Ability Questionnaire. Patients who were unblinded or had recourse to other than permitted concomitant therapies during follow-up were classified as nonresponders regardless of symptom improvement.

Results At 6 months, response rate was 47.6% in the verum acupuncture group, 44.2% in the sham acupuncture group, and 27.4% in the conventional therapy group. Differences among groups were as follows: verum vs sham, 3.4% (95% confidence interval, -3.7% to 10.3%; P = .39); verum vs conventional therapy, 20.2% (95% confidence interval, 13.4% to 26.7%; P < .001); and sham vs conventional therapy, 16.8% (95% confidence interval, 10.1% to 23.4%; P < .001. Conclusions Low back pain improved after acupuncture treatment for at least 6 months. Effectiveness of acupuncture, either verum or sham, was almost twice that of conventional therapy.

As in all studies, particularly studies of alternative medicine modalities, pay very close attention to the inclusion and exclusion criteria:

Main inclusion criteria were as follows: age 18 years or older, clinical diagnosis of chronic low back pain for 6 months or longer, mean Von Korff Chronic Pain Grade score7 of grade 1 or higher and a Hanover Functional Ability Questionnaire score of less than 70%, no previous acupuncture for treatment of chronic low back pain, and signed informed consent. Primary exclusion criteria were previous spinal surgery; previous spinal fractures, infectious, or tumorous spondylopathy; and chronic pain caused by other diseases.

One point that leaps right off the page is that the patient population studied had had chronic low back pain for at least 6 months and, based on that duration and the patients’ willingness to try acupuncture, we can reasonably infer that their pain probably wasn’t responding particularly well to conventional therapy. This makes it unsurprising that the reported response rate in the standard therapy group was so low, given that it was just getting more of the same treatment. Other exclusion criteria included sciatica from other disease, infections, abuse of pain medication. In other words, none of the patients in the study had a clear, anatomic cause for their pain that could be corrected. I must emphasize that this in no way means that their pain isn’t real; much if not most back pain doesn’t reveal an obvious anatomical cause. What it does say is that, if you have chronic back pain that’s due to a herniated disc, spondylosis, an injury causing a fracture (even if that fracture healed) a systemic disorder like rheumatoid arthritis, or other anatomic or physiologic causes that can be detected by radiological studies or other objective tests, the results of this study do not apply to you, at least not very well, anyway. (Remember my recent post about evidence-based guidelines and how guidelines based on evidence from studies that didn’t study a relevant population are less reliable?) From my perspective, then, you’d be better off using surgery or other conventional, evidence-based therapies. And that’s a big point right off the bat that you won’t find in any of the news reports.

Then, there’s a real question about the blinding in this study. Obviously, the patients in the conventional group knew what they were getting. Among the two groups of acupuncture patients, the “real” acupuncture were inserted 5 to 40 mm (yikes–40 mm = 1.57 inches!), while “sham” acupuncture needles were inserted only 3 mm. The outcome measures are also a bit dicey, as the response rate was defined without much justification as 33% improvement or better on 3 pain-related items on the Von Korff Chronic Pain Grade Scale or a 12% improvement or better on back-specific functional status measured by the Hanover Functional Ability Questionnaire and measured at 1.5, 3, and 6 months. Moreover, there is a group of patients who were excluded from the analysis for using “proscribed” treatments (for the acupuncture group, nonsteroidal antiinflammatory drugs for no more than two days a week; for the “conventional therapy” group, not well specified). As described in Pyjamas in Bananas:

But more intriguing is the requirement that no proscribed therapy be used, or the patient is then assigned to the unresponsive category.

The initial figures are 58%, 68%, and 71% responders for conventional, sham, and verum acupuncture respectively. Yet, once those who took “proscribed” treatments (we are not clearly told what these “proscribed treatments” might be for conventional therapy, for acupuncture it is anything other than rescue treatment for acute episodes of pain with nonsteroidal anti-inflammatory drugs to be taken on no more than two days per week up to the maximum daily dose during the therapy period and only one day per week during follow-up) are classed as non-responders, and those who missed the 6 month assessment, these figures were 27%, 44%, and 47%.

Since failure to attend follow-up was 6%, 3%, 3%, this suggests a whopping quarter of all patients were classified as non-responders for using proscribed therapies. Now given the generous allowance of painkillers allowed to the acupuncture groups we might think this is just fine since their acupuncture clearly wasn’t working for them, but what were the conventional therapy subjects being excluded for?

The bottom line appears to be:

So what we have here is a study comparing sticking needles into patients versus conventional therapy (presumably delivered by the same doctors) where only the interviewers (assessing outcome) were blinded, and where somehow, only half of patients were given analgesics in the conventional therapy group, where the acupuncture therapy group were allowed analgesics two days a week, and where half of conventional therapy responders were excluded for having ‘proscribed’ treatment that is never defined or quantified.

This analysis looks as though it is based primarily on a close reading of Table 5 in the paper and appears to be correct, but it’s even worse than that. These excluded patients were moved to the “nonresponder” group. After correcting for the use of “proscribed” treatments, over 50% of responders to conventional therapy were moved to the nonresponder group, whereas only around 35% of responders from the sham acupuncture and 33% of responders to acupuncture were moved to the nonresponder group. At the very least, this certainly accentuated the difference between the conventional therapy group and the acupuncture groups, which were not so large in the first analysis, making a relatively small difference into a large difference. What should have been done is that these patients using “proscribed” treatments should have been excluded from the analysis altogether, rather than moved to the “nonresponder” group.

That all puts a rather different spin on the whole study that the media reports don’t tell you about, doesn’t it?

When I first read about this study and scanned the abstract the other day, I started out rather impressed. True, the study definitely did not support the theoretical framework that is claimed to support acupuncture as a discipline, but it did seem to indicate that sticking 14-20 needles in the skin could relieve low back pain better than conventional therapy. After a careful reading I’m not so sure that this is true anymore or that this isn’t just another example of how elaborate procedures and rituals can produce strong placebo effects.

At least the study results forced the authors to admit this much:

The comparison of sham vs verum acupuncture was intended to differentiate the physiologic (specific) from the psychologic (nonspecific) effects of acupuncture. Among the nonspecific effects for both forms of acupuncture are positive patient expectations about acupuncture paired with negative expectations about conventional medicine, more intensive physician contact, and the experience of an invasive technique (needling). Given that the 2 forms of acupuncture are indistinguishable to the patient, any differences in outcomes between the 2 forms must be attributable to specific treatment effects. However, the 2 forms did not differ insofar as the primary outcome. This cannot be explained solely by positing the existence of additional,previously unknown acupuncture points or regions because in the sham acupuncture, needles were inserted only very shallowly and without elicitation of Qi. Several other hypotheses must be considered instead: (1) there are no specific acupuncture effects at all; (2) the specific acupuncture effect is very small and is overlaid by nonspecific effects; and (3) there exist specific acupuncture effects, the nature of which is still unknown,that lead to symptom improvement independent of point selection and depth of needling.

Or you could conclude that the whole concept of meridians and qi is a crock.

I’ve said before that I’m not as hostile to acupuncture as I am to woo like homeopathy. This is because there may well be physiological explanation for any effects observed, where such cannot be true for homeopathy, which is nothing more than the administration of water or other diluent with no active ingredient. That being said, this article is not nearly as strong evidence for the efficacy of acupuncture to treat low back pain as it has been made out to be in the press, while it is a very strong piece of evidence against concepts underlying traditional Chinese medicine.

ADDENDUM: Steve Novella has also done a nice analysis. I particularly like his suggestion for special needles that would blind the practitioner to whether or not the needle was inserted or not.