Cost-utility Analysis of Primary Open-angle Glaucoma according to Follow-up Observation Period

Purpose: To evaluate the cost-utility based on the quantitative relationship between glaucoma follow-up and glaucoma progression. Methods: The Markov model was constructed and analyzed to determine the cost-effectiveness of primary open-angle glaucoma. The Markov model set up a virtual cohort of Korean over 40 years of age with early glaucoma. The costs associated with glaucoma treatment were assessed from a social point of view, and the utility was calculated using the quality adjusted life years according to the glaucoma states. Glaucoma health status was divided into 5 stages (early, middle, late, unilateral, bilateral blindness). The transition probability was set in one direction from mild to severe, and the length of each cycle was set at one year. The incremental cost effectiveness ratio (ICER) was calculated and compared with each other different follow-up periods. Sensitivity analysis was conducted to determine how the uncertainty of the variables used in this study affected the outcome. Results: ICER of 3-month follow-up was 28,244,398 won/quality adjusted life years (QALY) compared 6-month follow-up, and ICER of 6-month follow-up was 13,615,443 won/QALY compared to 12-month follow-up. If the probability of progression of glaucoma in 6-months follow-up observations increases by more than 10% over 3-month periodic follow-up and the progression probability of 12-month follow-up increases by more than 15% follow-up compared to 3-months follow-up, 3-months follow-up was found to be a cost-effective strategy. On the other hand, 6-month follow-up was found to be cost-effective if probability of progression of 6-month follow-up was less than 10% increase of 3-month follow-up and 15% increase of 6-months follow-up. Conclusions: Cost-effective follow-up strategies differed according to the probability of progression of glaucoma, and 3-month or 6-month follow-up strategies were cost-effective and acceptable in Korea's health care system.