This study investigated the optimal strategy to minimize budgetary constraints on National Health Insurance (NHI) services, while maximizing the number of diabetic macular edema (DME) patients who receive anti-vascular endothelial growth factor (anti-VEGF) therapy.

We estimated the potential budget impact of anti-VEGF treatments in DME patients based on perceived upcoming changes in reimbursement fees over the next 5 years (2018–2022). Four scenarios were evaluated: (1) current anti-VEGF treatment patterns, (2) the hypothetical reimbursement fee, (3) the introduction of a new molecule similar to current anti-VEGF treatments, and (4) the prescription of an off-label drug, bevacizumab. The number of patients, anti-VEGF treatments, and medical costs for each scenario were calculated using claims data from the Korean NHI system and anti-VEGF prescription data from a single hospital.

The potential budget impact of anti-VEGF injections in patients with DME over the next 5 years was estimated to be about 97.7 billion and 106.2 billion KRW for scenarios 1 and 2, respectively. In scenario 3, in which a biosimilar product to anti- VEGF is used, the estimated budget of the NHI system would be approximately 98.4 billion KRW. If an off-label drug is reimbursed, roughly 79.5 billion KRW will be required for the NHI system's budget.

If the revised fee structure for AMD patients is similarly applied to anti-VEGF injections for DME patients, the NHI fiscal requirements will increase disproportionately over the next 5 years compared to current reimbursement conditions. Given the growth of DME patients in toda's patient population, the use of a biosimilar or off-label drug is a financially viable alternative to reduce the overall burden on the NHI system.