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

Rosemary J Korda, Grace Joshy, Louisa R Jorm, James RG Butler and Emily Banks
Med J Aust 2012; 197 (11): 631-636. || doi: 10.5694/mja12.11035


Objectives: To investigate variation, and quantify socioeconomic inequalities, in the uptake of primary bariatric surgery in an obese population.

Design, setting and participants: 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%).17

Main outcome measures: Rates of bariatric surgery and adjusted rate ratios (RRs) in relation to health and sociodemographic characteristics.

Results: 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.

Conclusions: 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.

  • Rosemary J Korda1
  • Grace Joshy1
  • Louisa R Jorm2
  • James RG Butler1
  • Emily Banks1,3

  • 1 Australian National University, Canberra, ACT.
  • 2 Centre for Health Research, School of Medicine, University of Western Sydney, Sydney, NSW.
  • 3 Sax Institute, Sydney, NSW.


We thank the men and women participating in the 45 and Up Study. The 45 and Up Study is managed by the Sax Institute in collaboration with major partner Cancer Council NSW; and partners National Heart Foundation of Australia, NSW Ministry of Health; beyondblue: the national depression initiative; Ageing, Disability and Home Care, NSW Family and Community Services; UnitingCare Ageing; and the Australian Red Cross Blood Service. We also thank the Centre for Health Record Linkage. This project was supported by National Health and Medical Research Council (NHMRC) project grant 585402. The NHMRC had no role in the study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the article for publication.

Competing interests:

Emily Banks is supported by the NHMRC.

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