Patients treated with 10 sessions of acupuncture over three months reported less pain at a 24-month follow-up than patients who did not get the therapy.
The difference between the two groups was small, however, with researchers concluding there was a "small benefit" at two years.
Study co-author Hugh MacPherson, PhD, characterized acupuncture's impact on the patients' pain as modest, but he tells WebMD that the ancient Chinese medical treatment has proven its worth as an adjunct to traditional therapies for nonspecific back pain.
"Acupuncture definitely has a role in the treatment of low back pain," he says. "And it seems to be associated with longer-term effects than anyone has realized."
Back Pain Hard to Treat
Chronic back pain is one the most common and difficult-to-treat medical problems in health care.
The costs in terms of lost productivity and workers' compensation are staggering.
Acupuncture has become an accepted treatment for the condition in both the United States and in Europe. But clinical evidence of its effectiveness has been equivocal.
In an analysis of 33 studies, published in 2005, acupuncture was found to be an effective short-term treatment for low back pain, even when compared with sham treatments using fake acupuncture, says Eric Manheimer, MS, of the Center for Integrative Medicine at the University of Maryland.
"Our analysis suggested that the benefits of acupuncture for low back pain are not due to a placebo effect," Manheimer tells WebMD.
But a large study published in February of this year showed otherwise.
Low back pain patients treated with acupuncture reported better pain control than those who got no acupuncture.
But they fared no better than patients treated with sham acupuncture, in which needles were placed superficially in the skin in areas not considered active acupuncture sites.
No Sham Group
The newly published study did not include a sham acupuncture control group because the point was to examine the treatment in a real-world clinical setting, MacPherson tells WebMD.
The study included 241 adults who had had nonspecific low back painback pain for four to 52 weeks.
Patients were randomly assigned to receive either standard care or acupuncture, along with individualized treatment administered by a general practitioner. Standard care included medications, back exercises, and physiotherapy (such as massage therapy).
Pain levels were assessed at 12 and 24 months. Also, the researchers measured use of pain medication and patient satisfaction with treatment at three, 12, and 24 months.
At three months, patients in the acupuncture group were much more likely to report being "very satisfied" with their treatment than those who did not get the therapy.
And at 24 months, the acupuncture group was more likely to report less worry about their back pain and less use of pain drugs.
They were also more likely to report having no pain for at least a year, leading the authors to conclude acupuncture provided long-lasting benefits.
"This was one of the most unexpected findings," MacPherson says.
In a separate analysis, acupuncture was also found to be cost effective compared with the usual treatment without acupuncture.
Evidence is mounting that acupuncture can help people with low back pain, but few studies have compared the treatment to other nonconventional therapies.
"There has been very little research comparing treatments head to head, so we can't say much about which ones work best," Manheimer says.