Osteoarthritis (OA) affects around 40% of adults >45 years, resulting in an enormous economic and disability burden on individuals and society. As prevalence increases with age, both the burden of disease and economic costs are rising rapidly with population ageing. Despite best practice guidelines recommending a multidisciplinary, multimodal approach, this is seldom delivered in New Zealand. This study aims to: 1) estimate the impact of rising prevalence of OA on the New Zealand health system and society, and; 2) investigate the cost-effectiveness of a range of intervention strategies for OA in New Zealand, compared with current practice. We will use sophisticated multi-criteria decision-analysis software to facilitate consensus among a panel of experts to prioritise the most promising and feasible strategies for the New Zealand health system, and we will use validated computer simulation modeling to compare the costs and benefits of those potential strategies for managing the growing burden of OA in New Zealand.