Cost analysis of bariatric surgery in Denmark made with a decision-analytic model

Introduction: Bariatric surgery offers effective obesity treatment. The aim of this study was to evaluate the cost-effectiveness of bariatric surgery in Denmark from a third-party payer perspective in the mid-(ten years) and long-term (lifetime). Methods: A state-transition Markov model was developed in which patients may experience surgery, post-surgery complications, diabetes mellitus type 2, cardiovascular diseases or die. Transition probabilities, costs and utilities were informed by the literature. Three types of surgery were included: gastric bypass, sleeve gastrectomy and adjustable gastric banding. The impact of different surgical methods on BMI level was informed by the Danish Obesity Surgery Registry (Dansk Fedmekirurgiregister). Results: In the ten-year base-case analysis, bariatric surgery led to a cost increment of 19,332 DKK and generated an additional 1.1 quality-adjusted life years (QALYs). In the course of a lifetime, surgery leads to savings of 36,403 DKK, an additional 0.7 life years and 2.9 QALYs. Bariatric surgery was cost-effective at ten years with an incremental cost-effectiveness ratio of 17,818 DKK per QALY and was dominant over conservative management in the course of a lifetime. Up to three years of delay in the provision of surgery resulted in a reduction of life years, a lower QALY gain and a minor decrease in healthcare costs. Conclusions: In Denmark, bariatric surgery is cost-effective at ten years and may produce a significant reduction in healthcare costs over the course of a lifetime in persons with severe obesity.