OA06.04. Dose-response of spinal manipulation for chronic low back pain: pain and disability outcomes from a randomized controlled trial

Methods We randomized 400 patients with cLBP to receive one of four dose levels of care: 0, 6, 12, or 18 sessions of lumbar spinal manipulation from a chiropractor. All participants were scheduled for three visits per week for six weeks at one of eight clinics. Care was rendered at each visit, either the index intervention or light massage control. The primary outcomes were low back pain intensity and functional disability at 12 and 24 weeks (100-point scales). Secondary outcomes included days with pain and functional disability, pain unpleasantness, global perceived improvement, and general health status. Outcomes were assessed at baseline and at 6, 12, 18, 24, 39, and 52 weeks. Linear dose effects and group comparisons (efficacy) were evaluated using covariateadjusted simultaneous regression for continuous data (primary analysis). Binomial regression was performed in a responder analysis of 50% improvement (secondary analysis).