Population estimates and characteristics of Australians potentially eligible for bariatric surgery: findings from the 2011–13 Australian Health Survey
Authors: Sharman Melanie J. , Breslin Monique C. , Kuzminov Alexandr , Palmer Andrew J. , Blizzard Leigh , Hensher Martin , Venn Alison J. 
Published: June 2017

Objective
The aim of the present study was to determine the potential demand for publicly and privately funded bariatric surgery in Australia.

Methods
Nationally representative data from the 2011–13 Australian Health Survey were used to estimate the numbers and characteristics of Australians meeting specific eligibility criteria as recommended in National Health and Medical Research Council guidelines for the management of overweight and obesity.

Results
Of the 3 352 037 adult Australians (aged 18–65 years) estimated to be obese in 2011–13, 882 441 (26.3%; 95% confidence interval (CI) 23.0–29.6) were potentially eligible for bariatric surgery (accounting for 6.2% (95% CI 5.4–7.1) of the adult population aged 18–65 years (n = 14 122 020)). Of these, 396 856 (45.0%; 95% CI 40.4–49.5) had Class 3 obesity (body mass index (BMI) ≥40 kg m–2), 470945 (53.4%; 95% CI 49.0–57.7) had Class 2 obesity (BMI 35–39.9 kg m–2) with obesity-related comorbidities or risk factors and 14 640 (1.7%; 95% CI 0.6–2.7) had Class 1 obesity (BMI 30–34.9 kg m–2) with poorly controlled type 2 diabetes and increased cardiovascular risk; 458 869 (52.0%; 95% CI 46.4–57.6) were female, 404 594 (45.8%; 95% CI 37.3–54.4) had no private health insurance and 309 983 (35.1%; 95% CI 28.8–41.4) resided outside a major city.

Conclusion
Even if only 5% of Australian adults estimated to be eligible for bariatric surgery sought this intervention, the demand, particularly in the public health system and outside major cities, would far outstrip current capacity. Better guidance on patient prioritisation and greater resourcing of public surgery are needed.

What is known about this topic?
In the period 2011–13, 4 million Australian adults were estimated to be obese, with obesity disproportionately more prevalent in areas of socioeconomic disadvantage. Bariatric surgery is considered to be cost-effective and the most effective treatment for adults with obesity, but is mainly privately funded in Australia (>90%), with 16 650 primary privately funded procedures performed in 2015. The extent to which the supply of bariatric surgery is falling short of demand in Australia is unknown.

What does this paper add?
The present study provides important information for health service planners. For the first time, population estimates and characteristics of those potentially eligible for bariatric surgery in Australia have been described based on the best available evidence, using categories that best approximate the national recommended eligibility criteria.

What are the implications for practitioners?
Even if only 5% of those estimated to be potentially eligible for bariatric surgery in Australia sought a surgical pathway (44 122 of 882 441), the potential demand, particularly in the public health system and outside major cities, would still far outstrip current capacity, underscoring the immediate need for better guidance on patient prioritisation. The findings of the present study provide a strong signal that more funding of public surgery and other effective interventions to assist this population group are necessary.