Background: Many treatments are recommended for chronic low back pain (cLBP), but comparative effectiveness and adaptive interventions have not been adequately studied.
Objective: To compare the effectiveness of physical therapy (PT) and cognitive behavioral therapy (CBT) as first-stage treatment and switching treatments versus mindfulness as second-stage treatment.
Design: Multisite sequential, multiple-assignment, randomized trial with 52-week follow-up. (ClinicalTrials.gov: NCT03859713).
Setting: Three health care systems.
Participants: Adults with cLBP.
Intervention: Eight weeks of PT or CBT in stage I. Nonresponders were randomly assigned again to 8 weeks of stage II treatment.
Measurements: Co-primary outcomes were function measured with the Oswestry Disability Index (ODI; range, 0 to 100) and pain intensity (range, 0 to 10) at 10 (stage I), 26, and 52 (stage II) weeks.
Results: The sample comprised 749 participants. After 10 weeks, there was greater improvement in function in the PT group (adjusted mean ODI difference, 2.8 [96% CI, 0.38 to 5.1]) and no difference in pain intensity (adjusted mean difference, 0.32 [99% CI, -0.07 to 0.71]). The mean difference in ODI was below the minimum important difference of 6. After 52 weeks, there were no differences in stage II treatments for nonresponders for either function (adjusted mean ODI difference, 0.43 [96% CI, -0.29 to 2.4]) or pain intensity (adjusted mean difference, -0.05 [96% CI, -0.58 to 0.48]).
Limitations: Treatment initiation was lower than expected, particularly for CBT and for nonresponders. Participants were not blinded. Sample size was reduced due to the COVID-19 pandemic.
Conclusion: Patients with cLBP may benefit from PT as first-line treatment. Among nonresponders, there were no differences in second-stage treatment with mindfulness or switching.
Primary funding source: Patient-Centered Outcomes Research Institute (PCORI).