Acupuncture originated in China more than 2,000 years ago. In 2002, acupuncture was used by an estimated 2.1 million U.S. adults.

Trial: Sufficient Rigor, Size, Duration

Conclusions of the study -- the longest and largest randomized, controlled phase III clinical trial of acupuncture ever conducted -- have been published in the December 21, 2004, issue of the Annals of Internal Medicine.

The multi-site study team, including rheumatologists and licensed acupuncturists, enrolled 570 patients, aged 50 or older with osteoarthritis of the knee. Participants had significant pain in their knee the month before joining the study, but had never experienced acupuncture, had not had knee surgery in the previous six months, and had not used steroid or similar injections.

Participants were randomly assigned to receive one of three treatments: acupuncture, sham acupuncture, or participation in a control group that followed the Arthritis Foundation's self-help course for managing their condition.

Patients continued to receive standard medical care from their primary physicians, including anti-inflammatory medications, such as COX-2 selective inhibitors, non-steroidal anti-inflammatory drugs, and opioid pain relievers.

"For the first time, a clinical trial with sufficient rigor, size and duration has shown that acupuncture reduces the pain and functional impairment of osteoarthritis of the knee," said Stephen E. Straus, M.D., NCCAM Director.

"These results also indicate that acupuncture can serve as an effective addition to a standard regimen of care and improve quality of life for knee osteoarthritis sufferers," Strauss said. "NCCAM has been building a portfolio of basic and clinical research that is now revealing the power and promise of applying stringent research methods to ancient practices like acupuncture."

Arthritis - Frequent Cause of Disability

"More than 20 million Americans have osteoarthritis. This disease is one of the most frequent causes of physical disability among adults," said Stephen I. Katz, M.D., Ph.D., NIAMS Director. "Thus, seeking an effective means of decreasing osteoarthritis pain and increasing function is of critical importance."

During the course of the study, led by Brian M. Berman, M.D., Director of the Center for Integrative Medicine and Professor of Family Medicine at the University of Maryland School of Medicine, Baltimore, Maryland, 190 patients received true acupuncture and 191 patients received sham acupuncture for 24 treatment sessions over 26 weeks.

Sham acupuncture is a procedure designed to prevent patients from being able to detect if needles are actually inserted at treatment points. In both the sham and true acupuncture procedures, a screen prevented patients from seeing the knee treatment area and learning which treatment they received. In the education control group, 189 participants attended six, two-hour group sessions over 12 weeks based on the Arthritis Foundation's Arthritis Self-Help Course -- a proven, effective model.

On joining the study, patients' pain and knee function were assessed using standard arthritis research survey instruments and measurement tools, such as the Western Ontario McMasters Osteoarthritis Index (WOMAC). Patients' progress was assessed at 4, 8, 14 and 26 weeks.

40% Less Pain, 40% More Functionality

Participants receiving acupuncture showed a significant increase in function by week 8 and a significant decrease in pain by week 14, compared with the sham and control groups. These results, shown by declining scores on the WOMAC index, held through week 26. Overall, those who received acupuncture had a 40 percent decrease in pain and a nearly 40 percent improvement in function compared to baseline assessments.

"This trial, which builds upon our previous NCCAM-funded research, establishes that acupuncture is an effective complement to conventional arthritis treatment and can be successfully employed as part of a multidisciplinary approach to treating the symptoms of osteoarthritis," said Dr. Berman.

Earlier Study Corroborated

Acupuncture originated in China more than 2,000 years ago. In 2002, acupuncture was used by an estimated 2.1 million U.S. adults, according to the 2002 National Health Interview Survey conducted by the Centers for Disease Control and Prevention.

The acupuncture technique that has been most studied scientifically involves penetrating the skin with thin, solid, metallic needles that are manipulated by the hands or by electrical stimulation. In recent years, scientific inquiry has begun to shed more light on acupuncture's possible mechanisms and potential benefits, especially in treating painful conditions, such as arthritis.

The results of a randomised controlled trial published in BMJ (British Medical Journal) earlier this year also point to acupuncture as an effective complementary therapy to the pharmacological treatment of osteoarthritis of the knee.