Cost-effectiveness analysis of interventions to reduce overweight and obesity in Australia.

Presenter: Megan Forster, University of Queensland

Abstract

Across the world, there is a trend to increasing levels of overweight and obesity. This is a public health problem because the condition increases the risk of morbidity and mortality from diseases such as heart disease and diabetes. This excess disease burden also places a large economic cost on the health care system. There is evidence that excess weight can be reduced. The most popular methods are through diet, exercise, pharmacotherapy and surgery.

Objectives: The objective of this paper is to determine whether interventions to reduce overweight and obesity are cost-effective in Australia.

Methodology: A model was developed in Excel using intervention costs and effects from the overweight and obesity literature and Australian data on disease epidemiology and treatment. Health outcomes are evaluated in Disability-Adjusted Life Years (DALYs), using a multi-state, multiple cohort life table approach. The model also accounts for the increasing trend to overweight and obesity and the typical maintenance pattern of induced weight loss.

There are nine diseases proven to be caused by overweight and obesity. The model calculates the decreased relative risk for each disease due to a one unit decrease in BMI and the corresponding decrease in morbidity, mortality and health system cost of treating these diseases. This information is compared to the cost of the intervention an Incremental Cost-Effectiveness Ratio (ICER) is calculated.

Results: Our analysis indicates that traditional interventions to reduce weight are not cost-effective. The main problem is that once weight is lost it is often regained. A further difficulty is that since the end of World War 2, there has been a trend to increasing overweight and obesity in the whole population. Many interventions only lead to a small amount of weight loss which has the potential to slow this trend but cannot not reverse it

Conclusions: To adequately address the problem of overweight and obesity, new interventions which lead to sustained, significant weight loss are needed.