Cost-effectiveness of subsidy for physical activity counselling in general practice, Perth, Western Australia

Presenter: Anura Amarasinghe, University of Western Australia

Abstract

Rationale: Physical inactivity is a major risk factor for many chronic diseases including diabetes, cardiovascular diseases, depression and some cancers. It is estimated that, in Australia, physical inactivity contributes to 13,500 annual deaths and incurs an annual cost of AU$ 21 billion to the health care system. The cost of physical inactivity to the Western Australian (WA) economy is estimated to be about AU $ 2.1 billion. Increased burden of physical inactivity has motivated health professionals to seek cost effective intervention to promote physical activity. One such strategy is encouraging general practitioner (GP) to address the health needs of patients who are at high risk of developing chronic diseases associated with physical inactivity.

Objective: Recent reviews of physical inactivity and obesity have indicated that setting individually focussed specific interventions to promote physical activity can be a successful strategy. This study intends to investigate this hypothesis by evaluating the cost-effectiveness of a subsidy program for GP advice to promote physical activity.

Methodology: The percentage of population that could potentially move from insufficiently active to sufficiently active, on GP advice, were quantified from the adult physical activity task force (PATF) survey of WA in 2006. Population impact fractions (PIFs) were then used to translate this percentage increase in physical activity into an expected difference in the burden avoided for five major diseases where physical activity is risk factor. The potential burden avoided for each disease was assessed in terms of disability adjusted life years (DALYs) and health care expenditure saved. Burden avoided was also allowed to vary with different compliance rates (i.e., % of people who adhere to GP advice). Health care expenditure saved was used to estimate the net cost of intervention for varying subsidy rates. Finally, the cost-effectiveness of subsidy programs were evaluated in terms of cost per DALY saved at different compliance rates.

Results: Results showed that GP advice could potentially reduce the burden of physical inactivity. However success of a subsidy program for GP advice depends on the fraction of population who comply with GP advice. With a 50% adherence to GP advice, an annual health care cost of AU $ 24 million could be potentially saved to the WA economy. A DALY can be saved at a cost of AU $ 11,000 with a $ 25 subsidy at a 50% compliance rate. Cost effectiveness of such a subsidy program decreases at higher subsidy and lower compliance rates. If higher compliance rates can be achieved, even a higher subsidy rate would be worth considering. These results will be helpful in allocating healthcare resources for cost-effective intervention strategies in order to promote physical activity and public health.