Moderators and Nonspecific Predictors of Treatment Benefits in a Randomized Trial of Mindfulness-Based Stress Reduction vs Cognitive-Behavioral Therapy vs Usual Care for Chronic Low Back Pain.

Both mindfulness-based stress reduction (MBSR) and cognitive-behavioral therapy (CBT) are effective for chronic low back pain (CLBP), but little is known regarding who might benefit more from one than the other. Using data from a randomized trial comparing MBSR, CBT, and usual care (UC) for adults aged 20 to 70 years with CLBP (N = 297), we examined baseline characteristics that moderated treatment effects or were associated with improvement regardless of treatment. Outcomes included 8-week function (modified Roland Disability Questionnaire), pain bothersomeness (0-10 numerical rating scale), and depression (Patient Health Questionnaire-8). There were differences in the effects of CBT versus MBSR on pain based on participant gender (P = .03) and baseline depressive symptoms (P = .01), but the only statistically significant moderator after Bonferroni correction was the nonjudging dimension of mindfulness. Scores on this measure moderated the effects of CBT versus MBSR on both function (P = .001) and pain (P = .04). Pain control beliefs (P <.001) and lower anxiety (P < .001) predicted improvement regardless of treatment. Replication of these findings is needed to guide treatment decision-making for CLBP. TRIAL REGISTRATION: The trial and analysis plan were preregistered in ClinicalTrials.gov (Identifier: NCT01467843). PERSPECTIVE: Although few potential moderators and nonspecific predictors of benefits from CBT or MBSR for CLBP were statistically significant after adjustment for multiple comparisons, these findings suggest potentially fruitful directions for confirmatory research while providing reassurance that patients could reasonably expect to benefit from either treatment.