Relative contribution of overweight and obesity to rising public hospital in-patient expenditure in South Australia.

Objective Arguments to fund obesity prevention have often focused on the growing hospital costs of associated diseases. However, the relative contribution of overweight and obesity to public hospital expenditure growth is not well understood. This paper examines the effect of overweight and obesity on acute public hospital in-patient expenditure in South Australia over time compared with other expenditure drivers. Methods Annual inflation-adjusted acute public admitted expenditure attributable to a high body mass index was estimated for 2007-08 and 2011-12 and compared with other expenditure drivers. Results Expenditure attributable to overweight and obesity increased by A$45million, from 4.7% to 5.4% of total acute public in-patient expenditure. This increase accounted for 7.8% of the A$583million total expenditure growth, whereas the largest component of total growth (62.4%) was a real increase in the average cost per separation. Conclusions The relatively minor contribution of overweight and obesity to expenditure growth over the time period examined invites reflection on arguments to boost preventive spending that centre upon reducing hospital costs. These arguments may inadvertently detract attention from the considerable health and social burdens of overweight and obesity and from unrelated sources of expenditure growth that reduce opportunities for state governments to fund obesity prevention programs despite their comparative benefits to population health. What is known about the topic? Stand-alone estimates suggest that overweight and obesity are placing a considerable financial burden on the Australian public healthcare system. What does this paper add? Our findings challenge common perceptions about the relative importance of overweight and obesity in the context of rising public in-patient expenditure in Australia. What are the implications for practitioners? Consistent serial estimates of overweight- and obesity-attributable expenditure enable its tracking and comparison with other potentially controllable expenditure drivers that may also warrant attention. Explicit consideration of population health trade-offs in expenditure-related decisions, including in enterprise bargaining, would enhance transparency in priority setting.