Inequalities in bariatric surgery in Australia: findings from 49 364 obese participants in a prospective cohort study

Abstract

To investigate variation, and quantify socioeconomic inequalities, in the uptake of primary bariatric surgery in an obese population. Prospective population-based cohort study of 49,364 individuals aged 45-74 years with body mass index (BMI)≥30 kg/m2. Data from questionnaires (distributed from 1 January 2006 to 31 December 2008) were linked to hospital and death data to 30 June 2010. The sample was drawn from the 45 and Up Study (approximately 10% of New South Wales population aged 45 included, response rate approximately 18%). Rates of bariatric surgery and adjusted rate ratios (RRs) in relation to health and sociodemographic characteristics. Over 111,757 person-years (py) of follow-up, 312 participants had bariatric surgery, a rate of 27.92 per 10,000 py (95% CI, 24.91-31.19). Rates were highest in women, those living in major cities and those with diabetes, and increased significantly with a higher BMI and number of chronic health conditions. Adjusted RRs were 5.27 (95% CI, 3.18-8.73) for those with annual household income≥ $70 000 versus those with household income<$20,000, and 4.01 (95% CI, 2.41-6.67) for those living in areas in the least disadvantaged quintile versus those in the most disadvantaged quintile. Having versus not having private health insurance (age- and sex-adjusted RR, 9.25; 95% CI, 5.70-15.00) partially explained the observed inequalities. Bariatric surgery has been shown to be cost-effective in treating severe obesity and associated illnesses. While bariatric surgery rates in Australia are higher in those with health problems, large socioeconomic inequalities are apparent. Our findings suggest these procedures are largely available to those who can afford private health insurance and associated out-of-pocket costs, with poor access in populations who are most in need. Continuing inequalities in access are likely to exacerbate existing inequalities in obesity and related health problems.