Thursday, April 12, 2012

Is Acupuncture Just a “Meaningful Placebo”?

Acupuncture Recent examinations of acupuncture for various pain conditions suggest that influences other than needling may play essential roles in any efficacy of this modality. Yet, is that cause to cast it aside as a treatment for pain? Some would argue that acupuncture can still be a meaningful patient-centered option within the context of a multimodal approach to pain management.

Writing in the February 2012 edition of the Journal of Pain and Symptom Management, Edzard Ernst, MD, updates his earlier examination of Cochrane Reviews of acupuncture. Ernst — of Peninsula Medical School, University of Exeter, United Kingdom — has been a stern critic of acupuncture and his work has been discussed in prior Pain-Topics UPDATES [here] and [here].

Mixed Results in Acupuncture Reviews

In his earlier article [Ernst 2009], which included all 32 Cochrane Reviews up to 2007 that examined acupuncture for a variety of conditions, Ernst reported that most of the Reviews (25, or 78%) failed to demonstrate efficacy of acupuncture, 5 drew tentatively positive or positive conclusions, and 2 were inconclusive. The only pain condition solidly supported by evidence was idiopathic headache. Ernst concluded that the systematic reviews of research on acupuncture up to that time did not suggest that this treatment was effective for a wide range of conditions.

Negative findings for acupuncture in the Reviews typically denote that acupunture was demonstrated as no better than placebo or other comparative therapies. However, this is not to say that there were no improvements at all due to the treatments tested and, in some cases, acupuncture and certain other treatments (even placebo) may have produced worthwhile outcomes.

For his latest article, Ernst [2012] found that 21 further Cochrane Reviews of acupuncture became available since 2007. Eight of them were updates, and the new Reviews increasingly originated from China. He states that this “seems reasonable as most randomized controlled trials are from China and published in Chinese.” However, it meant that the referees for the Cochrane Reviews were unlikely to have access to primary data.

In total, 10 of the Cochrane Reviews since 2007 (48%) demonstrated negative findings for acupuncture, while 6 had positive or tentatively positive results, and 5 were inconclusive. Ernst observes that Chinese Review authors tend to include more Chinese studies that are invariably positive. In many instances, conclusions drawn by Cochrane Review authors stress the lack of data and a resulting uncertainty of the evidence. In such cases, Ernst suggests, “It is debatable whether it would not be preferable to be more blunt and express clearly that the evidence is simply not positive.”

Only 6 of the more recent Cochrane Reviews examined acupuncture for pain conditions. Positive or tentatively positive results were noted for migraine prophylaxis, tension-type headache, and osteoarthritis. There were negative findings for cancer pain, and inconclusive results for labor pain and endometriosis pain.

In a previous report in the journal PAIN [discussed in UPDATE here], Ernst and colleagues had examined 57 qualifying systematic reviews of acupuncture for pain published between 2000 and 2009, incorporating nearly 700 trials. They concluded that there is little convincing evidence that acupuncture is effective in reducing many types of pain. The treatment was somewhat effective for neck pain, low back pain, and osteoarthritis, but failed to benefit rheumatoid arthritis, fibromyalgia, migraine, and tension headache. In other conditions — eg, postoperative pain, shingles, and temporomandibular joint pain — outcomes were mixed or uncertain.

Nonspecific Effects of Acupuncture

Many of the controversies and concerns surrounding acupuncture for pain, expressed by Ernst and others, have focused on whether benefits of the treatment are largely due to placebo responses or some other aspect of the treatment, rather than the placement and insertion of needles. In a recent report, Peter White and colleagues from the University of Southampton in the UK, describe conducting a trial to more closely evaluate the nonspecific effects of acupuncture in osteoarthritic (OA) pain [White et al. 2012].

As noted in the reviews above, acupuncture for OA had been found to be of some benefit. This study by White and colleagues further examined differential effects of needling, the consultation process surrounding treatment, and differences among practitioners.

Writing in the journal PAIN, they describe a prospective randomized, single-blind, placebo-controlled, multifactorial trial that recruited 221 patients with OA awaiting joint replacement surgery. Interventions were acupuncture, Streitberger placebo acupuncture*, and mock electrical stimulation, each with either empathic or non-empathic consultations by the acupuncture practitioners. *The Streitberger Placebo–Needle mechanism is applied to the skin through a bandage strip to mask needle penetration. In placebo mode, the needle touches the skin but is retracted without penetrating the surface.

Eight 30-minute treatments were performed over 4 weeks, and the primary outcome was pain on a Visual Analog Scale at 1 week posttreatment. Face-to-face qualitative assessment interviews were conducted in 27 participants.

Results showed that improvements occurred from baseline for ALL interventions with no significant differences between real and placebo acupuncture (P = .40) or mock electrical stimulation (P = .25). Empathic consultations did not affect pain (P = .26), but one of the practitioners did achieve significantly greater analgesia in subjects than the others (P = .002).

Qualitative analyses of interviews indicated that patients’ beliefs about treatment authenticity and confidence in favorable outcomes were mutually linked. Interviews further revealed that the supportive nature of the trial overall may have diminished differences between empathic vs non-empathic consultation styles.

The authors conclude that improvements in pain did occur from baseline in all groups, but acupuncture had no specific efficacy over either placebo needling or mock electrical stimulation. They suggest that an unknown characteristic of the treating practitioner may predict outcome, as does a patient’s beliefs about treatment veracity; however, these poorly defined factors complicate and confound study interpretation.

COMMENTARY: Is Acupuncture a Hoax or a Help for Pain?

It is common for systematic reviews of acupuncture, like those examined by Ernst, and individual studies, like that of White et al., to be confounded by uncontrolled or nonspecific factors; not the least of which is small group size, a lack of proper blinding, questions about the veracity of sham procedures, qualities of practitioner-patient interaction, and other variables. In many cases, acupuncture demonstrates some benefits, but these are equivalent to placebo or other comparators, so the results are interpreted as negative.

So, what are we to think of the outcomes for acupuncture in pain management? Should this treatment modality be eschewed as worthless pseudoscience, or worse, as many critical skeptics would advise?

Certainly, appeals to the ancient roots of acupuncture and/or its current popularity for treating a variety of conditions as evidence of its validity are fallacious arguments, unless there also is confirming and valid scientific evidence of efficacy and safety. And, to date, the scientific evidence has been equivocal, inconsistent, or inconclusive in many cases.

Placebo responses, and unknown or poorly understood factors, appear to play major roles in any benefits of acupuncture; the acupuncture process is perhaps more dependent on psychology than biology. But, is this sufficient cause to cast it aside?

In a provocative editorial that appeared in the New England Journal of Medicine last year, Daniel Moerman, PhD, from the University of Michigan, Dearborn, Michigan, discusses how for a number of conditions both sham/placebo treatments and actual medical therapies have produced equivocal outcomes that are favorable when compared with no treatment [Moerman 2011]. He argues that for subjective and functional conditions, which would include most pain disorders, a patient-centered approach requires that patient-preferred outcomes trump the judgment of the physician. Under these conditions, inert pills can be as useful as ‘real’ ones; two inert pills can work better than one; colorful inert pills can work better than plain ones; and injections can work better than pills.

Moerman goes on to observe that, whether they are active or inert, all medical procedures are “meaningful”; that is, they represent something to the patient, and “meaning” exerts its own effects. The clinical environment takes on meaning, as does the demeanor of the practitioner, and meaning accumulates with increasing power regardless of what is in the pill or syringe; or, possibly in the case of acupuncture, regardless of where the needles are placed or whether they penetrate the skin.

Meanings create expectations, Moerman continues, which can significantly modify the effectiveness of even the most powerful proven treatment. This seemed evident in the trial conducted by White and colleagues; patients beliefs appeared to make a strong difference in acupuncture efficacy and, in that context, acupuncture — whether real or sham — may become a “meaningful placebo.”

Moerman wonders whether researchers should control for “meaning” in their clinical trials to know if a treatment is truly biologically active and effective. However, he concludes: Maybe it is sufficient simply to show that a treatment yields significant improvement for the patients, has reasonable cost, and has no negative effects over the short or long term.

If Moerman is correct, it seems prudent at this time to avoid the potentially false dichotomy of characterizing acupuncture as either bad or good, or a hoax or a help for pain. While skeptics may scoff at acupuncture as having no clearly delineated neurobiologic rationale, as yet, or consistent research evidence rising to the highest levels of proof, there could still be benefits of this modality from a patient-centered perspective.

An important caveat, however, is that other, possibly more effective and better-proven therapies for pain should not be ignored in favor of acupuncture. Acupuncture might best be viewed as but one adjunctive therapy in a multimodal approach to the management of select pain conditions.

REFERENCES:
> Ernst E. Acupuncture: What Does the Most Reliable Evidence Tell Us? An Update. J Pain Symptom Manage. 2012(Feb);43(2):e11-e13 [
access here].
> Ernst E. Acupuncture: What Does the Most Reliable Evidence Tell Us? J Pain Symptom Manage. 2009;37(4):709–714 [
abstract].
> Moerman DE. Meaningful Placebos — Controlling the Uncontrollable. NEJM. 2011(Jul);365:171-172 [
abstract].
> White P, Bishop FL, Prescott P, et al. Practice, practitioner, or placebo? A multifactorial, mixed-methods randomized controlled trial of acupuncture. PAIN. 2012(Feb);153(2):455-462 [
abstract].

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