Cost-effectiveness of Bariatric Surgery for People with Morbid Obesity in South Korea

Objective: This study aimed to evaluate the cost-effectiveness of bariatric surgery (BS) compared to non-surgical treatment (NST) in Korean people with morbid obesity according to comorbidities and body mass index (BMI) severity. Methods: The target cohort was people with morbid obesity, defined as BMI of ≥ 35 kg/m², or obese people with BMI of 30–34.9 kg/m² having obesity-related comorbidities. A decision-tree model for 1-year obesity treatment and Markov model for the rest of life were used. In the decision-tree model, the comorbidity remission rate and BMI change after 1-year treatment were decided based on a prospective clinical trial. In the Markov model, the transition probabilities were calculated considering the BMI level and age. The starting age of 20 years, a cycle length of 1 year, a time horizon of 80 years, and a 5% discount rate were applied for the base case from the healthcare system perspective. Results: In the base case, BS improved quality-adjusted life years (QALYs) and was the cost-effective option in total cohort (incremental cost-effectiveness ratio of BS vs. NST was 674 USD/QALY). It was shown to be cost-effective in all subgroup analyses based on BMI level. In particular, BS was a dominant alternative for the subgroup with basal BMI of 35.0–37.4 kg/m². Various sensitivity analyses showed the robustness of results indicating the cost-effectiveness of BS. Conclusion: BS at BMI of > 30 kg/m² was more effective than NST for a reduction in BMI and remission of obesity-related comorbidities and was cost-effective in Korea.