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