Spine April 2014. Menke M.
Meta-analysis methodology was extended to derive comparative effectiveness information on spinal manipulation for low back pain.
Of 84% acute pain variance, 81% was from nonspecific factors and 3% from treatment. No treatment for acute pain exceeded sham’s effectiveness. Most acute results were within 95% confidence that predicted by natural history alone. For chronic pain, 66% of 98% was nonspecific, but treatments influenced 32% of outcomes. Chronic pain treatments also fit within 95% confidence bands as predicted by natural history. Though the evidential support for treating chronic back pain as compared with sham groups was weak, chronic pain seemed to respond to SMT, whereas whole systems of clinical management did not.
Meta-analyses can extract comparative effectiveness information from existing literature. The relatively small portion of outcomes attributable to treatment explains why past research results fail to converge on stable estimates. The probability of treatment superiority matched a binomial random process. Treatments serve to motivate, reassure, and calibrate patient expectations–-features that might reduce medicalization and augment self-care. Exercise with authoritative support is an effective strategy for acute and chronic low back pain.