OBJECTIVES: Despite an increase in countries reimbursing anti-obesity medications (AOMs) for selected populations, no AOMs are currently reimbursed in South Korea. We aimed to determine the budget impact of reimbursing AOMs compared with the annual cost of bariatric surgery in people with obesity in South Korea.

METHODS: A budget impact analysis was performed from the perspective of South Korea’s healthcare system, over a 1-year time horizon. The target population was people with BMI ≥35kg/m², or with BMI ≥30kg/m² with comorbidities. The population size was based on the Korean Society for the Study of Obesity and National Health Insurance data. The total annual cost of AOMs was calculated using the current out-of-pocket market price, the market share, the number of people and the non-responder rate at 12 weeks. Only liraglutide and orlistat were considered among currently available AOMs in South Korea, as they are reimbursed in many European countries. Non-responders were assumed to end treatment at 12 weeks, while responders were assumed to continue treatment for 52 weeks. The number of patients and annual cost of bariatric surgery were based on National Health Insurance claims data.

RESULTS: Of the 1.323 million people eligible for AOMs, it is expected that only 10,160 will receive AOMs, and 2,529 bariatric surgery. In our model, the total annual cost of bariatric surgery was 22,255 million KRW, assuming a patient co-payment of 20%. The total annual cost of AOMs, with co-payments of 30%, 50% or 80% was 13,974 million KRW, 9,981 million KRW and 3,993 million KRW, respectively.

CONCLUSIONS: The cost of AOM to treat people with obesity in South Korea is lower than that of bariatric surgery, regardless of the level of AOM co-payment and the larger population eligible for AOMs, with the potential for further cost reductions when AOMs undergo health technology assessment.