Friday, April 1, 2011

Review Raises Doubts About Acupuncture for Pain

acupunctureAlthough acupuncture has been used for ages in pain management, a recent review of systematic reviews raises doubts about its effectiveness and safety. However, a close look reveals that the evidence in many cases does suggest benefits of this therapy and acupuncture might still be a viable alternative for select patients with pain.

Writing in the April 2011 edition of the journal Pain investigators from the Universities of Exeter & Plymouth (Exeter, UK) and the Korea Institute of Oriental Medicine (Daejeon, South Korea) collected and critically evaluated systematic reviews of acupuncture as a treatment for pain [Ernst et al. 2011]. After examining 57 qualifying reviews published between 2000 and 2009 that incorporated nearly 700 trials, the authors conclude there is little convincing evidence that acupuncture is effective in reducing many types of pain, and that reports in the literature of 95 serious adverse events associated with acupuncture are of great concern.

Overall, 44% (25) of the reviews arrived at positive conclusions favoring acupuncture; however, the reports were of variable quality. Many of the reviews did not present clear conclusions and Ernst and colleagues found it disconcerting that acupuncture was beneficial in reducing pain for but a few conditions and not for others. For example, it was somewhat effective for neck pain, low back pain, and osteoarthritis; however, acupuncture 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.

In an accompanying commentary, Harriet Hall, MD, observes that few of the conditions examined in the reviews had more than one study of decent quality favoring acupuncture, and the field appears to be riddled with inconsistencies, biases, and conflicting conclusions [Hall 2011]. She further asserts: "Importantly, when a treatment is truly effective, studies tend to produce more convincing results as time passes and the weight of evidence accumulates. When a treatment is extensively studied for decades and the evidence continues to be inconsistent, it becomes more and more likely that the treatment is not truly effective. This appears to be the case for acupuncture. In fact, taken as a whole, the published (and scientifically rigorous) evidence leads to the conclusion that acupuncture is no more effective than placebo."

Both Hall and Ernst et al. express apprehensions about reported cases of adverse events, which were grouped into three categories: infection (38 cases), trauma (42 cases), and others (13 cases). Most victims recovered fully, but there were 4 deaths due to pneumothorax (needle penetration of the chest wall). Ernst and colleagues contend, “One might argue that, in view of the popularity of acupuncture, the number of serious adverse events is minute. We would counter, however, that one avoidable adverse event is one too many.”

Hall concludes that evidence for the effectiveness of acupuncture is questionable and its use can be dangerous. “If the 57 systematic reviews [that were] surveyed had been for a prescription drug and a similar list of serious adverse effects had been reported for that drug, we would hesitate to prescribe that drug. Is there any reason not to hold acupuncture to the same standards?”

COMMENTARY: We have previously discussed research on acupuncture for pain in a series of UPDATES [here], noting evidence favoring its benefits as well as reports of strong placebo effects and seemingly conflicting outcomes. The papers by Ernst et al. and Hall, as much as anything, appear to emphasize the difficulties of doing research on acupuncture and the fact that its full appreciation may elude Western science.

Hall concedes in her commentary that acupuncture is not sufficiently standardized, making it difficult if not impossible to study objectively and reliably. “It is becoming increasingly clear,” she writes, “that the surrounding ritual, the beliefs of patient and practitioner, and the nonspecific effects of treatment are likely responsible for any reported benefits.” Further, she asks, “What would you think if a new pain pill was shown to relieve musculoskeletal pain in the arms but not in the legs?”

Comparing acupuncture to a molecular entity, such as a drug for pain, may reflect a Western bias regarding how medical treatments are expected to work. In an interesting overview article — appearing in a March 2011 supplement to the journal Pain — Ji-Sheng Han, from the Peking University Health Science Center, Beijing, China, provides a different perspective [Han 2011]. Traditional acupuncture practice revolves around the hypothetical flow of “Qi,” which regulates body function and becomes blocked in pain and illness. Inserting needles at one of 361 acupoints, followed by appropriate manipulation, can unblock the channels and restore the natural flow of Qi to relieve pain. Han concedes, however, that this hypothesis has not been validated by modern science.

Furthermore, Han observes, the rationale and process of acupuncture, based on theories of Traditional Chinese Medicine, usually cannot be completely understood and explained from perspectives of Western medicine. In fact, considering the many types of acupuncture and variations in technique, it might be considered as much an art as a science (Han refers to the field as “ART” — Acupuncture and Related Techniques). It is probably no coincidence that many positive trials of ART have come from China where the techniques have been practiced for centuries; whereas, studies conducted in other countries often use divergent forms of acupuncture that also may be hindered by poor or improper technique, such as using only a limited number of sites or incorrect acupoints.

Han also acknowledges that psychological components, such as patient expectation (eg, “belief”) and conditioning, play important roles in achieving ART-induced analgesia, and placebo effects to some extent may be an integral component of overall therapeutic effectiveness. Along with that, there are physiologic processes that have, thus far, eluded full elaboration by science. And, the interpersonal skills and communication style of the acupuncturist might be as important as knowing where to place needles and manipulate them for maximum effect. This sort of variability, and the many potentially confounding factors, can be difficult for Western science to accept and adequately test experimentally when it comes to establishing the validity of acupuncture.

Finally, concerns about the dangers of acupuncture expressed by Hall and Ernst et al. might reflect an overly negative bias. Considering the many millions of persons receiving acupuncture therapy each year, the 95 adverse events reported in the literature would represent a miniscule incidence rate, even allowing for a probable underreporting of such cases. The events were not intrinsic to acupuncture; rather, they resulted from carelessness, lack of sanitation, and acupuncturist errors. The solution is relatively easy; the training and competency level of the acupuncturist should be considered before considering this therapeutic option.

It would seem, as Hall proposed, that sufficient time has passed with adequate clinical experimentation to either establish or denounce the validity of acupuncture as a viable therapy for pain relief. However, as with many other CAM (Complementary and Alternative Medicine) approaches, the problem of validity may be due to our lack of understanding and/or ability to adequately assess effectiveness, rather than with the modality itself. Considering the multitude of patients worldwide who have benefitted from acupuncture in one way or another, it still appears premature to broadly dismiss it as being of little or no value for pain relief.

> Ernst E, Lee MS, Choi T-Y. Acupuncture: Does it alleviate pain and are there serious risks? A review of reviews. Pain. 2011;152(4):755-764 [abstract here].
> Hall H. Acupuncture's claims punctured: Not proven effective for pain, not harmless. Pain. 2011;152(4):711-712 [access by subscription].
> Han J-S. Acupuncture analgesia: Areas of consensus and controversy. Pain. 2011;152(suppl 3):S41-S48 [access by subscription].
[A note of apology to readers: While we always try to provide links to resources cited in UPDATES, the respective journals do not always allow free access to the full articles — this is beyond our control.]