Classification Approaches for Treating Low Back Pain Have Small Effects That Are Not Clinically Meaningful: A Systematic Review With Meta-analysis

OBJECTIVE: To determine whether classification systems improve patient-reported outcomes for people with low back pain (LBP). DESIGN: Systematic review with meta-analysis. LITERATURE SEARCH: The MEDLINE, Embase, CINAHL, Web of Science Core Collection, and Cochrane Central Register of Controlled Trials databases were searched from inception to June 21, 2021. Reference lists of prior systematic reviews and included trials were screened. STUDY SELECTION CRITERIA: We included randomized trials comparing a classification system (eg, the McKenzie method or the STarT Back Tool) to any comparator. Studies evaluating participants with specific spinal conditions (eg, fractures or tumors) were excluded. DATA SYNTHESIS: Outcomes were patient-reported LBP intensity, leg pain intensity, and disability. We used the revised Cochrane Collaboration Risk of Bias Tool to assess risk of bias, and the Grading of Recommendations Assessment, Development and Evaluation approach to judge the certainty of evidence. We used random-effects meta-analysis, with the Hartung-Knapp-Sidik-Jonkman adjustment, to estimate the standardized mean difference (SMD; Hedges’ g) and 95% confidence interval (CI). Subgroup analyses explored classification system, comparator type, pain type, and pain duration. RESULTS: Twenty-four trials assessing classification systems and 34 assessing subclasses were included. There was low certainty of a small effect at the end of intervention for LBP intensity (SMD, –0.31; 95% CI: –0.54, –0.07; P = .014, n = 4416, n = 21 trials) and disability (SMD, –0.27; 95% CI: –0.46, –0.07; P = .011, n = 4809, n = 24 trials), favoring classified treatments compared to generalized interventions, but not for leg pain intensity. At the end of intervention, no specific type of classification system was superior to generalized interventions for improving pain intensity and disability. None of the estimates exceeded the effect size that one would consider clinically meaningful. CONCLUSION: For patient-reported pain intensity and disability, there is insufficient evidence supporting the use of classification systems over generalized interventions when managing LBP.