Oral Presentation Australian & New Zealand Obesity Society 2016 Annual Scientific Meeting

The impact of weight-loss interventions on health expenditure in Australia: evidence from a microsimulation model of obesity and chronic disease (#62)

Sharyn Lymer 1 , Deborah Schofield 1 2 3 , Stephen Colagiuri 4 , Rupendra Shrestha 1 , Crystal Lee 4 5
  1. Pharmacy, University of Sydney, Sydney, NSW, Australia
  2. Murdoch Children's Research Institute, Melbourne, Victoria, Australia
  3. Garvin Institute of Medical Research, Sydney, NSW, Australia
  4. Boden Institute, University of Sydney, Sydney, NSW, Australia
  5. School of Public Health, Curtin University, Perth, WA, Australia

Obesity is a costly health issue within the Australian context. It is a major risk factor for multiple chronic diseases, significantly contributing to Australia’s burden of disease and health system costs. This study describes potential health system savings and productivity gains in the older working population across three interventions: usual care of general practitioner advice, commercial weight loss programmes by doctor referral and bariatric surgery.

This study is based on a microsimulation model, NCDMod, focused on obesity, its inter-relationship with other health risk factors and chronic disease (cardio-vascular disease and diabetes). The model uses the ABS 2005 National Health Survey as the base file and projects out to 2025 in 5 year increments. BMI transition equations operate by changing an individual’s weight over time as their risk factors change. The model allows the comparison of various health outcomes. The projected CVD prevalence are then input into Health&WealthMOD2030 to obtain productivity impact measures including productive years of life lost.   

The modelling included simulation of approximately 300,000 participants in the commercial weight loss programme scenario and 30 000 individuals in the bariatric surgery scenario. Under the model assumptions, commercial weight loss programme scenario projected 3500 adverted cases of diabetes, 7500 averted CVD incidents and 2000 CVD deaths avoided over 10 years. Bariatric surgery scenario projected 2500 averted cases of diabetes, 2000 averted CVD events and 30 averted CVD deaths. To the health system, the commercial weight loss programme projected $Au 2200 million savings to the health system whilst the bariatric surgery projected approximately $Au 150 million in savings to the health system in the 10 year period.     

Interventions such as a commercial weight loss programme, with potential wider reach, though not as effective at the individual level for weight loss, have potential population level impact offering meaningful prevention of chronic disease and health system savings.