Economic Evaluation of the Metabolic and Bariatric Surgery Initiative for Patients With Obesity and Comorbid Diabetes in Queensland.

Background: Metabolic and bariatric surgery is the most effective long-term treatment for patients with obesity; however, access to publicly funded surgery in Australia has been limited despite strong evidence of clinical benefit. The Bariatric Surgery Initiative (BSI) was established to improve equitable access for people with obesity and type 2 diabetes, but its long-term economic value has not been evaluated. This study assessed the cost-effectiveness of metabolic and bariatric surgery compared with usual medical care to inform health-system decision-making. Methods: A Markov model was developed to simulate health outcomes and costs over the rest of life for patients with BSI. The model had five health states representing BMI classes. Costs obtained from the BSI for the surgical procedure were used and long-term costs for BMI classes were drawn from the literature. Quality of life (utility) weights were obtained from the BSI as were outcomes at 12 months following surgery. A Usual Care comparison group was developed from the literature and long-term costs were applied to both groups depending on the BMI class. Incremental cost-effectiveness ratios were estimated and sensitivity analyses were undertaken from the perspective of the Australian public health system. Results: The base-case analysis demonstrated that MBS was the preferred strategy that is, better health outcomes (2.5 QALYs gained) and lower costs (cost-savings of $67,000). Scenario analyses identified that younger age groups have greater health benefits and higher BMI classes have greater cost-savings. Conclusions: MBS is a cost-effective intervention for patients with obesity class 2 and diabetes. The BSI was an efficient service that provided the necessary information to develop the local evidence.