JMIR Publications

ABSTRACT

Background:

Exudative age-related macular degeneration (AMD), one of the leading causes of blindness, requires expensive drugs such as anti-vascular endothelial growth factor (VEGF) agents. However, there is no study on the long-term patient-centered economic burden of exudative AMD after reimbursement of anti-VEGF.

Objective:

This retrospective cohort study aims to evaluate the patient-centered economic burden of exudative AMD for 2 years, including non-reimbursement and out-of-pocket costs, compared to non-exudative AMD patients who did not receive anti-VEGF treatment, using the observational medical outcomes partnership-common data model (OMOP-CDM).

Methods:

This retrospective cohort study was conducted using the OMOP-CDM which included 2,006,478 patients who visited Seoul National University Bundang Hospital from June 2003 to July 2019. We defined the exudative AMD group as patients with a diagnosis of exudative AMD and a prescription of anti-VEGF or verteporfin over 50 years of age. The control group was defined as patients without diagnosis of exudative AMD, prescription of anti-VEGF, or verteporfin over 50 years of age. Controls were matched using propensity scores using regularized logistic regression with a Laplace prior to adjusting selection bias. We measured any medical cost occurring in the hospital as the economic burden of exudative AMD during a two-year follow-up by four categories: total medical cost, reimbursement cost, non-reimbursement cost, and out-of-pocket cost. We estimated the incremental costs of the exudative AMD group in comparison with those of the non-exudative AMD group. To estimate the average cost by adjusting the confounding variable and overcoming the positive skewness of costs, we used an exponential conditional model (ECM) using a generalized linear model.

Results:

We identified 931 exudative AMD patients and matched 783 exudative AMD patients with 2,918 non-exudative AMD patients. In the ECM, the incremental cost for total medical, reimbursement, non-reimbursement, and out-of-pocket cost were estimated as $3,426, $3,130, $366, and $561, respectively in the first year and $1,829, $1,461, $373, and $507, respectively in the second year. All incremental costs in the exudative AMD group were 1.89–4.25 and 3.50–5.09 times higher in the first and second year, respectively than that in the controls (all P<0.001).

Conclusions:

The exudative AMD had a significantly greater economic impact for 2 years on reimbursement, non-reimbursement, and out-of-pocket costs than those in patients with non-exudative AMD after adjusting for baseline demographic and clinical characteristics using OMOP-CDM. Although economic policies could relieve the economic burden of patients with exudative AMD over time, the out-of-pocket cost of exudative AMD was still higher than that of non-exudative AMD for 2 years. Our findings support the need for expanding reimbursement strategies for exudative AMD patients to alleviate their economic burden, given the significant economic burden faced by patients with incurable and fatal diseases, both in South Korea and globally.