Cost-effectiveness of laser peripheral iridotomy in the treatment of primary angle closure suspect in China: a Markov model

PURPOSE: Conduct a cost-effectiveness analysis (CEA) and a cost-utility analysis (CUA) for prophylactic laser peripheral iridotomy (LPI) to prevent primary angle closure suspects (PACS) from developing primary angle-closure glaucoma (PACG). DESIGN: A Markov model was utilized with 10,000 iterations over a 30-year lifespan for each strategy to ensure robustness in the analysis. PARTICIPANTS: The study cohort consists of individuals aged 50 years or older who have been diagnosed with PACS. METHODS: In patients with PACS who develop PACG, the mean deviation of visual field loss starts at − 2 dB. This is referenced in the Asymptomatic Narrow Angles Laser Iridotomy Study (ANA-LIS). As the patients’ mean deviation of the visual field deteriorated, their health state was stratified as follows: mild (≥-6dB), moderate (-6dB to ≥-12dB), severe glaucoma (-12dB to ≥ 20dB), and blindness. For each health state, we determined the direct costs of treatment and examinations, as well as the associated health utilities. Additionally, we considered the societal indirect costs associated with blindness. Incremental cost-effectiveness ratios (ICER) and incremental cost-utility ratios (ICUR) were determined through probabilistic sensitivity analysis (PSA) and Monte Carlo simulation techniques. Effectiveness was defined as the rate of suffering from PACG over 30 years, while utility was defined as quality-adjusted life years (QALYs). Additionally, one-way sensitivity analyses and PSA were performed to assess the impact of varying key parameters, including progression rates from PACS to AAC or PAC or moderate-stage PACG, and PAC to mild-stage PACG, costs, utilities, and other critical inputs. The national gross domestic product (GDP) in China was approximately $13447.89 (roughly $1 = ¥7.12) in 2024; therefore, we set the willingness to pay at one to three times the GDP ($13447.89 and $40343.67). ICER and ICUR under One-time GPD were considered very cost-effectiveness. PRIMARY OUTCOME MEASURE: ICER/ICUR. RESULTS: In our base-case analysis for treating PACS with LPI compared to the NO LPI strategy over 30 years, LPI dominated the NO LPI strategy, being both less costly and more effective. According to the results from ICUR, the cost of a PACS with LPI over 30 years was $189.16, and the cost of the NO LPI strategy was $219.23. Additionally, the PACS with LPI resulted in a higher QALYs, totaling 13.54, compared to 13.49 QALYs in the NO LPI strategy. The ICER results indicated that the avoided glaucoma rate was 6.39% for PACS with LPI over 30 years, significantly lower than the rate for the NO LPI strategy, which was 12.19%. In the one-way sensitivity analysis, we identified that the moderate utility, the cost of follow-up, and the progression rate from PAC to PACG were the three main factors influencing ICER and ICUR. The PSA showed that LPI strategy dominated NO LPI strategy, both in ICUR and ICER analysis. CONCLUSIONS: LPI as an intervention for PACS is projected to be very cost-effectiveness to prevent AAC or PACG compared to PACS without LPI over 30 years. CLINICAL TRIAL NUMBER: Not applicable.