Findings from a systematic review showed low- to moderate-certainty evidence that yoga vs. non-exercise controls resulted in small to moderate improvements in back-related function at Months 3 and 6.
Current guidelines state that exercise may be beneficial for chronic low back pain. Yoga, a mind-body exercise, is sometimes used to relieve non-specific low back pain. A group of researchers set out to compare the effects of yoga for chronic non-specific low back pain vs. no treatment, minimal intervention (eg, education), or active treatment evaluating pain, function, and adverse events.
The team, led by L. Susan Wieland, searched various databases and trial registers up to March 11, 2016 for randomized controlled trials of yoga treatment in patients with chronic non-specific low back pain. Studies that compared yoga vs. any intervention or no intervention as well as studies comparing yoga as adjunct to other therapies vs. the other therapies were included. The overall certainty of evidence was categorized under the GRADE approach. A total of 12 trials (n=1,080) were identified for the review.
Most of the trials used lyengar, hatha, or Viniyoga forms of yoga. The trials compared yoga to no intervention or a non-exercise intervention such as education (7 trials), an exercise intervention (3 trials), or both exercise and non-exercise interventions (2 trials). All study outcomes were downgraded to “moderate certainty” due to the risk of bias and further downgraded if additional serious risk of bias, unexplained heterogeneity between studies, or imprecise analyses were present.
For yoga vs. non-exercise controls, there was low-certainty evidence that yoga resulted in small to moderate improvements in back-related function at 3–4 months (standardized mean difference [SMD], –0.4, 95% CI: –0.66 to –0.14). There was moderate-certainty evidence for small to moderate improvements at 6 months (SMD –0.44, 95% CI: –0.66 to –0.22). There was low-certainty evidence for small improvements at 12 months (SMD –0.26, 95% CI: –0.46 to –0.05). Study authors reported a very low- to moderate-certainty evidence that yoga was slightly better for pain at 3–4 months (MD –4.55, 95% CI: –7.04 to –2.06), 6 months (MD –7.81, 95% CI: –13.37 to –2.25), and 12 months (MD –5.4, 95% CI: –14.50 to –3.70); the pre-defined clinically significant changes in pain (≥15 points) was not met. Patients in the yoga cohort also had a higher risk of adverse pain (increased back pain) vs. those in the non-exercise controls (risk difference [RD] 5%, 95% CI: 2%–8%).
For yoga vs. non-yoga exercise controls, there was very low-certainty evidence for little or no difference in back-related function at 3 months (SMD –0.22, 95% CI: -0.65 to 0.20) and 6 months (SMD –0.20, 95% CI: –0.59, 0.19). There was also very low-certainty evidence for lower pain on a 0–100 scale at 7 months (MD –20.40, 95% CI: –25.48 to –15.32) and no information on pain at 3 months or after 7 months. Study authors concluded there was low-certainty evidence for no difference in the risk of adverse events when comparing yoga vs. non-yoga exercise controls.
For yoga as adjunct to exercise vs. exercise alone, there was very low-certainty evidence for little or no difference at Week 10 in back-related function (SMD –0.60, 95% CI: –1.42 to 0.22) or pain on a 0–100 scale (MD –3.20, 95% CI: –13.76 to 7.36).
Overall, low- to moderate-certainty evidence indicated that yoga led to small to moderate improvements in back-related function at 3 and 6 months compared to non-exercise controls. Yoga may also provide slightly more pain relief at 3 and 6 months though the effect size did not meet clinical significance. More high-quality research is needed to evaluate long-term outcomes, the authors added.
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