Cost-utility analysis for bariatric surgery compared with usual care for the treatment of obesity in Australia

Abstract

Background: The uptake of bariatric surgery in Australia has been hampered by the lack of funding and lack of evidence on relative value for money.

Objectives: To determine the cost-effectiveness of adjustable gastric banding (AGB), Roux-En-Y gastric bypass (RYGB), and sleeve gastrectomy (SG) versus usual care (UC).

Setting: Perspective of the Australian public healthcare system.

Methods: A Markov model was constructed to simulate the costs and outcomes for 4 approaches to managing obesity. The base-case was a 30-year-old Australian female with a body-mass index>35. Subgroup analysis was conducted to account for the effect of diabetes as well as various differences in cohort characteristics. Uncertainty was characterised by one-way and probabilistic sensitivity analyses.

Results: All bariatric surgeries were effective. The incremental cost-effectiveness ratios were similar at $24,454 for AGB, $22,645 for RYGB, and $27,523 for SG, compared with UC. At a willingness to pay threshold of $70,000 per quality-adjusted life year, the probabilities of being cost-effective were 64%, 75%, and 71% for AGB, RYGB, and SG, respectively. Subgroup analysis showed that bariatric procedures are less cost-effective for older cohorts. For those with diabetes, all the procedures were dominant in comparison with UC.

Conclusion: This model shows that all bariatric procedures are a cost-effective treatment for the management of obese patients. When given to a subgroup with diabetes, bariatric interventions become cost-saving.

Keywords: Bariatric; Cost-effectiveness; Cost-utility; Markov; Obesity.