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 classifi cation-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 (classifi cation-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 classifi cation-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 classifi cation-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.