R ecent data suggest that almost 60% of the adult Australian population is overweight or obese. 1 In mid-age, being overweight or obese is associated with common health problems, including cardiovascular disease, type 2 diabetes and some forms of cancer, 2,3 as well as symptoms such as backache and surgical procedures such as cholecystectomy. [4][5][6][7] It has been estimated that the costs of obesity in Australia increased from $0.84 billion in 1992/93 to $1.52 billion in 2003. These costs include direct health care costs as well as indirect costs associated with lost production due to premature death and absenteeism. 8 In 1999, physical inactivity was identified as the leading contributor to the overall burden of disease in Australian women. 9 It is independently associated with many of the obesity-related health problems described above 3 and exacerbates the metabolic, structural and functional declines of ageing. 10 In 2002, the annual direct health care costs of inactivity-related health problems in Australia were conservatively estimated to be $0.38 billion per year. 11 In the United States (US), it has been shown that health care costs are inversely associated with PA, after adjustment for Body Mass Index (BMI), 12 and it is estimated that health care costs are $US300 per person per year less for regularly active than for sedentary adults. 13 As it is now well established that weightrelated health problems are ameliorated by regular PA 14 17 As 78.5% of the participants in that study were men, the cost savings for women are less clear. The aims of this study were therefore to quantify relationships between PA, BMI and Medicare costs in a cohort of midage Australian women and to estimate the potential population cost savings associated with increasing PA and decreasing BMI in sedentary women.
Methods
The Australian Longitudinal Study on Women's Health (ALSWH)The ALSWH is a prospective study of three age-based cohorts of women who were selected randomly from the national Medicare health insurance database (which includes all citizens and permanent residents of Australia, as well as some temporary residents and refugees) with intentional over-representation of women living in rural
ConcernsArticle