Introduction Excess body weight is strongly associated with the risk of diabetes. In Australia, the latest data suggests that 11 million adults have overweight or obesity and 1.2 million adults have diabetes. The respective costs of obesity and diabetes were estimated previously, but the cost associated with both diabetes and obesity combined have not been reported in Australia.
Objective To assess and compare the total direct (healthcare plus non-healthcare) cost and government subsidies by body weight and diabetes status.
Methods The Australian Diabetes, Obesity and Lifestyle study collected health service utilisation and health related expenditure data at the 2004-05 and 2011-12 follow-up surveys. Costing data were available on 4409 participants aged ≥36 years in 2011-12. Unit costs for 2016-17 were used where available or were otherwise inflated to 2016-17 dollars. Age- and sex-adjusted costs per person were estimated using generalised linear models.
Results The annual total direct cost ranged from $1998 per person with normal weight to $2501 per person with obesity in participants without diabetes. For those with diabetes, total direct costs ranged from $2353 per person with normal weight to $3131 with obesity. Additional expenditure as government subsidies ranged from $5681 per person with normal weight and no diabetes to $8067 per person with obesity and diabetes. Compared to participants with costing data at both surveys, those with data in 2004-05 only were older, more likely to have diabetes and have died by the end of 2012, and had higher direct healthcare cost.
Conclusion The annual total excess cost was 26% for obesity alone and 46% with the addition of diabetes. Diabetes prevention programs targeting people with excess body weight may potentially reduce the financial burden for both individuals and the government.