Efficacy of the Flinders chronic condition management program in obese patients with hip or knee osteoarthritis: A study rationale and protocol

Background Obesity is a risk factor for osteoarthritis and total hip/knee joint replacement and can also lead to poorer outcomes following surgical interventions. Self-management programs are a recommended approach for addressing clinical features of osteoarthritis and obesity. Aims This study investigates the relative efficacy of the Flinders chronic condition self-management program versus treatment as usual in obese patients with hip or knee osteoarthritis on a knee/hip joint replacement waiting list. Methods Obese (Body Mass Index or BMI≥30) osteoarthritis patients on a knee/hip joint replacement waiting list will be assessed for study eligibility. 95 consented patients will provide 80 per cent power to detect an effect size of 0.6 in the primary outcome measure of quality of life at 6 months and 10 months, at α=10 per cent level. A randomised sequence, stratified by gender and obesity class will be generated and administered by a computer-based system. Health-related quality of life outcomes will be collected using Short Form SF-36 and OAKHQOL at 6 and 10 months pre-and post-operatively. The main analysis will investigate differences in SF-36 scores between the intervention and treatment as usual groups on an intention-to-treat basis. Linear mixed effect models will be used to analyse outcome data. Conclusion This study is designed to provide robust and transparent findings including randomisation sequence generation, allocation concealment and implementation and will therefore provide much needed quality evidence in the field of self-management and osteoarthritis.1 The Flinders Program has not been used in this type of patient cohort before and since it has been proven a successful self-management tool for other chronic conditions in Australian communities, the results of this study will add valuable knowledge to the chronic condition management.