Effectiveness and cost-effectiveness of shortening rehabilitation programs for patients with chronic musculoskeletal pain; Design of a RCT

Background and Aims: Pain Rehabilitation Programs (PRP's) are proven effective for patients with chronic musculoskeletal pain (CMP). Evidence about the relationship of dose on the effect of PRP however, is unavailable. We hypothesized that shortening PRP will not be inferior to care as usual. The aim of the RCT is to analyse the effect of shortening duration of PRP on effectiveness and cost effectiveness of PRP. Methods: The study will be a single blind, 2 armed, randomized controlled clinical trial, with a non inferiority design. A total of 264 patients with CMP referred to outpatient multidisciplinary PRP will be included for the study. The control intervention will be care as usual. Three programs will be applied with durations of 12, 16 or 20 weeks, depending on the complexity The experimental group will receive PRP in 4 weeks less than care as usual, while the experimental intervention will not differ in content. Pain related disability, measured with the Pain Disability Index (PDI), will be the main outcome. The non-inferiority margin is predefined as 4 points difference on PDI to tolerate as non-inferior. For cost-effectiveness direct and indirect costs will be calculated. Patients will complete questionnaires at baseline, end of PRP and at 3 and 12 months follow up. Inclusion: 2 years starting September 2011. Results: Not available. Conclusions: This will be the first RCT ever in the PRP field to study dose variables