RESUMO
OBJECTIVE: We evaluated exercise interventions for cognitive appraisal of chronic low back pain (cLBP) in an underserved population. METHODS: We conducted a secondary analysis of the Back to Health Trial, showing yoga to be noninferior to physical therapy (PT) for pain and function outcomes among adults with cLBP (n = 320) recruited from primary care clinics with predominantly low-income patients. Participants were randomized to 12 weeks of yoga, PT, or education. Cognitive appraisal was assessed with the Pain Self-Efficacy Questionnaire (PSEQ), Coping Strategies Questionnaire (CSQ), and Fear-Avoidance Beliefs Questionnaire (FABQ). Using multiple imputation and linear regression, we estimated within- and between-group changes in cognitive appraisal at 12 and 52 weeks, with baseline and the education group as references. RESULTS: Participants (mean age = 46 years) were majority female (64%) and majority Black (57%), and 54% had an annual household income <$30,000. All three groups showed improvements in PSEQ (range 0-60) at 12 weeks (yoga, mean difference [MD] = 7.0, 95% confidence interval [CI]: 4.9, 9.0; PT, MD = 6.9, 95% CI: 4.7 to 9.1; and education, MD = 3.4, 95% CI: 0.54 to 6.3), with yoga and PT improvements being clinically meaningful. At 12 weeks, improvements in catastrophizing (CSQ, range 0-36) were largest in the yoga and PT groups (MD = -3.0, 95% CI: -4.4 to -1.6; MD = -2.7, 95% CI: -4.2 to -1.2, respectively). Changes in FABQ were small. No statistically significant between-group differences were observed on PSEQ, CSQ, or FABQ at either time point. Many of the changes observed at 12 weeks were sustained at 52 weeks. CONCLUSION: All three interventions were associated with improvements in self-efficacy and catastrophizing among low-income, racially diverse adults with cLBP. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT01343927.