Its effectiveness was most obvious among those who stayed with the yoga, says Robert B. Saper, MD, director of integrative medicine at Boston Medical Center. He presented his study at the American Academy of Pain Management 2016 Annual Meeting.
"We know that yoga is effective, we know that PT is effective, but we don't know their comparative effectiveness," says Saper. "To get a complementary health practice into mainstream health care, I would say that (at minimum) it has to be as effective as the conventional therapy, and perhaps offer other benefits, like cost-effectiveness."
For this new study, researchers enrolled 320 adult patients from Boston-area community health centers who had chronic back pain with no obvious anatomic cause, such as spinal stenosis. The patients had "quite high" pain scores (average of 7 out of 10 on a pain scale) and were "quite disabled" in terms of their back pain, says Saper. Almost three-quarters were using pain medication, with about 20% taking opioids.
"We had absolutely no problem recruiting patients" for this study, he says. "That's because people are suffering with chronic pain and their needs are not being met."
Patients were randomly assigned to one of three groups: yoga, PT, or education.
The yoga group had a 75-minute weekly class with a very low student-to-teacher ratio.
The classes began with a short segment on yoga philosophy (nonviolence, moderation, self-acceptance). Participants were then given mats on which to do the simple yoga poses. They received a DVD to practice these at home.
Some patients did have difficulty, especially those who were obese, Saper says. "But these classes go slow and gentle; the first class may be just getting people on the floor, knees to chest, or in a table position."
The PT group had 15 one-on-one 60-minute sessions that included aerobic exercise. The education group got a comprehensive book on back pain.
Both the PT and yoga sessions continued for 12 weeks, after which patients were followed to 52 weeks. During this time, patients in both the yoga and PT groups were randomly assigned to maintenance (drop-in yoga classes or more PT sessions) or just at-home practice.
The study showed that the yoga and PT groups reported about the same function. ”They are not terribly different from education at 12 weeks," Saper says.
Overall, though, patients didn’t attend many yoga classes or PT sessions: about seven during the initial phase. And looking at just those patients who actually went to the yoga classes, Saper says, "you see yoga and PT are still quite similar, but the difference with education is quite high."
There were similar results for pain scores.
And a similar number of yoga and PT subjects reported being "very improved" and "very satisfied," Saper says.
Yoga proved to be safe, with only mild, usually temporary worsening of back pain.
In addition to the low adherence rate, another possible limitation of the study is that "this was a very structured standardized yoga program," Saper says. "We don't know how patients will do if they go to the yoga studio down the street."
Larger studies are needed to develop better ways to ensure that people in the studies stick to their guidelines, he said.
Researchers will now analyze costs involved with yoga, Saper says.
There's also evidence that yoga has a positive impact on the brain, says M. Catherine Bushnell, PhD, of the National Center for Complementary and Integrative Health, National Institutes of Health, who also presented at the conference.
There seems to be "quite a robust" relationship between how long a person has done yoga and positive brain changes, she said.
These findings were presented at a medical conference. They should be considered preliminary, as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data before publication in a medical journal.