Changes in Perceived Stress After Yoga, Physical Therapy, and Education Interventions for Chronic Low Back Pain: A Secondary Analysis of a Randomized Controlled Trial

Objective Perceived stress and musculoskeletal pain are common, especially in low-income populations. Studies evaluating treatments to reduce stress in patients with chronic pain are lacking. We aimed to quantify the effect of two evidence-based interventions for chronic low back pain (cLBP), yoga and physical therapy (PT), on perceived stress in adults with cLBP. Methods We used data from an assessor-blinded, parallel-group randomized controlled trial, which recruited predominantly low-income and racially diverse adults with cLBP. Participants (N = 320) were randomly assigned to 12 weeks of yoga, PT, or back pain education. We compared changes in the 10-item Perceived Stress Scale (PSS-10) from baseline to 12- and 52-week follow-up among yoga and PT participants with those receiving education. Subanalyses were conducted for participants with elevated pre-intervention perceived stress (PSS-10 score ≥17). We conducted sensitivity analyses using various imputation methods to account for potential biases in our estimates due to missing data. Results Among 248 participants (mean age = 46.4 years, 80% nonwhite) completing all three surveys, yoga and PT showed greater reductions in PSS-10 scores compared with education at 12 weeks (mean between-group difference = −2.6, 95% confidence interval [CI] = −4.5 to −0.66, and mean between-group difference = −2.4, 95% CI = −4.4 to −0.48, respectively). This effect was stronger among participants with elevated pre-intervention perceived stress. Between-group effects had attenuated by 52 weeks. Results were similar in sensitivity analyses. Conclusions Yoga and PT were more effective than back pain education for reducing perceived stress among low-income adults with cLBP.