Overview of current acupuncture scientific evidence

On November 3-5, 1997, the U.S. National Institute of Health Consensus Development Conference issued a statement from its independent panel of experts stating that “promising results have emerged showing efficacy of acupuncture in adult post-operative and chemotherapy nausea vomiting and post dental surgery pain”.  The panel also felt that acupuncture may be effective for other conditions, include addiction, stroke rehabilitation, headaches, menstrual cramps, tennis elbow, fibromyalgia, osteoarthritis, low back pain, carpal tunnel syndrome, and asthma.

A resolution passed at the 1998 Annual Representative Meeting of the British Medical Association stated that “the balance of evidence favours the use of acupuncture in back pain and neck pain. It seems to help in osteoarthritis (OA), although whether this is a specific effect remains unclear. Recurrent headache probably also responds, though as usual the evidence is not conclusive.”

In this review, the current scientific evidence for these conditions will be discussed.

Nausea and Vomiting
Vicker’s systematic review found 33 controlled trials in which the P6 acupuncture point was stimulated for treatment of nausea and/or vomiting associated with chemotherapy, pregnancy, and surgery. P6 acupuncture was equal or inferior to control in all four trials in which it was administered under anaesthesia; in 27 of the remaining 29 trials acupuncture was statistically superior.

Although P6 acupuncture point stimulation seems to be an effective antiemetic technique, except when administered under anaesthesia, the Cochrane review interpreted these findings as equivocal.

Nevertheless, the Canadian Society of Obstetric and Gynecology determined the results to be significant and safe, recommending P6 to be used as a conventional treatment for women with pregnancy related nausea in 1996.

Acute Dental Pain
A systematic review by Ernst and Pittler concluded that acupuncture can relieve dental pain.  Of 16 included controlled studies these, 11 trials were randomized with 7 positive trials.

Recently, Lao’s study evaluated the effectiveness of acupuncture to treat pain following oral surgery5.  This study indicated that acupuncture is superior to the placebo in preventing postoperative dental pain.

Headache
In a recent Cochrane review, 26 trials were analyzed.  Eight of 16 trials reported true acupuncture to be significantly superior for migraine and tension-type headaches.  Four trials reported a trend in favor of true acupuncture and two trials concluded there was no difference. The remaining 2 trials could not be interpreted. Ten additional 10 trials compared acupuncture with other forms of treatment and yielded contradictory results.

Although not fully convincing, the existing evidence supports the value of acupuncture for the treatment of idiopathic headaches.

Neck Pain
A review performed by my fellow colleagues in the Cervical Overview Group for the Cochrane review indicated that existing scientific testing was insufficient to clearly determine the effectiveness of other therapies. This includes treatments such as exercise, traction, acupuncture, heat/cold applications, electrotherapies, cervical orthoses for chronic pain, and cognitive behavioural rehabilitation strategies7.

My most recent update for the Cervical Overview Group found that there was some but limited evidence suggesting that acupuncture may provide short-term pain relief for patients with chronic mechanical neck pain compared to sham interventions and physiotherapeutic modalities.

Low Back Pain
There are 2 contradictory systematic reviews on acupuncture in the treatment of back pain.  Van Tulder used a qualitative review and concluded there was limited evidence that acupuncture is not more effective than placebo.  In contrast, Ernst’s meta-analysis provided statistical significance in favor of acupuncture over placebo.

Both groups are updating the review and the results are pending.

Elbow Pain
A review by Green et al concluded “needle acupuncture to be of short term benefit with respect to pain, but this finding was based on the results of 2 small trials, the results of which were not able to be combined in meta-analysis”.

Our most recent update identified 6 studies that met the inclusion criteria.   Due to clinical heterogeneity, we used the Best Evidence Synthesis Approach to analyze the data.  We concluded that there was strong evidence suggesting that acupuncture was effective for the short term relief of lateral epicondyle pain compared to various sham controls and ultrasound treatments.

Knee Pain
For rheumatoid arthritis, Casimiro’s et al. results suggested with caution that electroacupuncture might be beneficial to reduce symptomatic knee pain in patients 24 hours post treatment.

Ezzo et al identified 7 trials representing 393 patients with knee OA.  There was strong evidence that real acupuncture was more effective than sham acupuncture for pain. With regard to function, there was inconclusive evidence that real acupuncture was more effective than sham acupuncture.

Researchers in acupuncture often face various challenges similar to researchers in other fields, such as recruitment difficulties and heterogeneous samples etc.  There are some issues more specific to acupuncture research; namely, blinding issues and funding inadequacies.  Recent research has shown an improvement in methodology.  It is encouraging that there is an increasing interest in acupuncture research.

For a full copy of the article, please contact:

Dr. Kien (Ken) Vinh Trinh, MD, MSc
Assistant Clinical Professor, McMaster University, Faculty of Health Sciences
Programme Chair, Medical Acupuncture,
McMaster University Health Sciences Continuing Education
Director, Ancaster Sports Medicine Centre

Ancaster Sports Medicine & Rehabilitation Centre
1015 Golf Links Road
Ancaster, Ontario, Canada L9G 4S4
Telephone: 1 (905) 648-4425
Fax:  1 (905) 648-4426
Email: trinhk@mcmaster.ca