A randomized controlled trial on the effectiveness of a classification-based system for subacute and chronic low back pain

STUDY DESIGN: A randomized controlled trial. OBJECTIVE: To assess the effectiveness of Delitto's classification-based treatment approach compared with usual physical therapy care in patients with subacute or chronic low back pain. SUMMARY OF BACKGROUND DATA: No trial has evaluated this approach in patients with subacute and chronic low back pain. METHODS: Before randomization, all patients were classified by research physical therapists according to a modified version of Delitto's classification-based system. Randomization was computer-generated, with centralized allocation concealment. The statistician and the physical therapists were unblinded. Patients and assistants who collected follow-up questionnaires were blinded. Follow-up assessments were completed at 8, 26, and 52 weeks. The primary analysis was performed according to the intention-to-treat principle, using multilevel analysis. The main outcomes were global perceived effect, disability (Oswestry Disability Index, 0-100), and pain intensity (Numerical Rating Scale, 0-10). Secondary outcomes were quality of life, fear-avoidance beliefs, and psychosocial status. RESULTS.: A total of 156 patients were included (classification-based group, n = 74; usual physical therapy group, n = 82). There were no statistically significant differences between the treatment groups for any of the outcomes at any of the follow-up time points. After 8 weeks, patients in the classification-based group had greater global perceived effect scores; adjusted odds ratio of 1.01 (95% confidence interval [CI], 0.31 to 3.28), and higher adjusted Oswestry Disability Index and Numerical Rating Scale scores; mean adjusted differences of 0.48 points (95% CI, -4.59 to 3.63) and 0.49 points (95% CI, -1.34 to 0.37) respectively, but all differences were statistically nonsignificant. CONCLUSION: The classification-based system used in this study was not effective for improving physical therapy care outcomes in a population of patients with subacute and chronic low back pain