Compared with usual care, individualized acupuncture, standardized acupuncture, and simulated acupuncture had beneficial and persisting effects on chronic back pain. These treatments resulted in clinically meaningful improvements in function. Substantial adverse experiences with needle insertion were infrequent (1/315 participants). Self-reported medication use in the real and simulated acupuncture groups decreased significantly more than in the usual care group and remained lower through the one year follow-up. However, the 8–10 acupuncture treatments received by most participants (which would cost between $600 and $1200) did not result in cost savings to the health plan during the year after randomization.
This trial differs from our earlier study--which found similar effects for acupuncture and a more rigorous educational intervention—in having a usual care group, subjects with more chronic pain, and participants who were all acupuncture-naïve. 25
However, our findings are consistent with those of recent high quality trials. One German trial found both real acupuncture and sham acupuncture (superficial needling at non-acupuncture points) to have similar effects that were superior to those of guideline-based conventional medical treatment.10
A second German trial found both real and sham acupuncture superior to a wait list control group, but not significantly different from each other.9
Finally, a British trial found traditional acupuncture care delivered in a primary care setting to have modestly superior results to usual care after 2 years.12
Our trial extends these studies, by demonstrating that needle insertion is not necessary to achieve therapeutic benefits and by measuring longer term outcomes.
Collectively, these recent trials provide strong and consistent evidence that real acupuncture needling using the Chinese meridian system is no more effective for chronic back pain than various purported forms of “sham” acupuncture. However, both real and sham acupuncture appear superior to usual care. Possible explanations for these findings are: 1) superficial acupoint stimulation directly stimulates physiological processes that ultimately lead to improved pain and function, or, 2) participants’ improved functioning resulted from non-specific effects such as therapist conviction, patient enthusiasm, or receiving a treatment believed to be helpful.
The appropriateness of using minimal, superficial, or sham control groups in trials of acupuncture remains controversial. 28
In fact, the use of blunt needles that did not penetrate the skin was described two thousand year-old ago in the classic book on acupuncture needling. 29
A study using functional magnetic resonance imaging found that superficial and deep needling of an acupuncture point elicited similar blood oxygen level dependent responses. 30
Another study demonstrated that light touch of the skin can stimulate mechanoreceptors that induce emotional and hormonal reactions which in turn alleviate the affective component of pain. 31
This could explain why trials evaluating acupuncture for pain have failed to find real acupuncture superior to sham or superficial control treatments and raises questions about whether sham treatments truly serve as inactive controls.
The possibility that an acupuncture treatment “experience” could be beneficial due to non-specific effects is also credible. 32
A recent acupuncture trial for irritable bowel syndrome reported that non-specific effects (especially the patient-clinician relationship) produced statistically and clinically significant outcomes. 33,34
The potency of non-specific effects has also been noted in placebo-controlled randomized trials of surgical interventions for pain conditions. 35,36
The main strengths of this trial are its size, high compliance and follow-up rates, long-term follow-up, inclusion of a simulated acupuncture control, and effective masking. Limitations include restricting treatment to a single component (needling) of normal Traditional Chinese Medicine acupuncture; 37
pre-specification of the number and duration of treatments; limited conversation between acupuncturists and participants; and, exclusion of a medical attention control group. However, a recent trial using a similar number and duration of visits for both the acupuncture and medical care control groups, also found acupuncture superior.10
Our results have important implications for key stakeholders. For clinicians and patients seeking a relatively safe 38,39
and effective treatment for a condition for which conventional treatments are often ineffective, various methods of acupuncture point stimulation appear to be reasonable options, even though the mechanism of action remains unclear. Furthermore, the reduction in chronic exposure to the potential side effects of medications is an important benefit that may enhance the safety of conventional medical care. The number of patients that would need to be treated with insertive or superficial acupuncture stimulation to result in one person achieving meaningful improvement in function ranges from 5 (for short term benefits) to 8 (for persisting benefits).
In conclusion, acupuncture-like treatments significantly improved function in persons with chronic low back pain. However, the finding that benefits of real acupuncture needling were no greater than those of non-insertive stimulation raises questions about acupuncture’s purported mechanism of action. Future research is needed to determine the relative contributions of the physiologic effects of non-insertive stimulation, patient expectations, and other non-specific effects.