| Abstract: | Purpose: Medical care in Taiwan is well known for its low imbursement, high efficiency, high quality, excellent medical accessibility, and high equity. We investigate the trends in prevalence of diagnosed open angle glaucoma (OAG) and angle-closure glaucoma (ACG) during the period 2001-2010 and the trends in glaucoma medication expenditures under universal health insurance coverage from 1997 to 2010 in Taiwan.
Methods: A nationwide population-based retrospective longitudinal study based on records from the Longitudinal Health Insurance Database 2000. The study population comprised all patients with a diagnosis of OAG and ACG. Patients were stratified by gender and age; differences in prevalence and incidence were compared between the stratified groups. Besides, patients who had taken anti-glaucomatous agents were enrolled and stratified by gender, age, income and occupation. After adjusting for survey design and inflation using the 2011 inflation index, we analyzed the data of patients using glaucoma medication.
Results: Throughout the study period, the prevalence of diagnosed OAG and ACG increased. Before 2005, the prevalence of ACG was higher than that of OAG; however, from 2005 to 2010, the prevalence of OAG was higher than ACG. The incidence of diagnosed OAG increased insignificantly, but ACG decreased significantly. Elder people had higher prevalence and incidence of OAG and ACG. Female had higher prevalence and incidence rate of ACG during the study period. Annual medication expenditures increased from $0.21 million in 1997 to $0.63 million in 2010. Generalized estimating regression models showed that the expenditures for glaucoma medication during the study period increased year by year. In addition, patients older than 40 years, male patients and patients in the highest income bracket incurred higher medical expenditures, while blue collar workers had lower medical expenditures than the other working classes. Expenditures significantly increased for prostaglandin analogs (PGAs), α-agonists, and fixed combination drugs, but significantly decreased on ß-blockers and cholinergic agonists. The number of trabeculectomy shows two break points in 1999 and 2000 when PGAs were listed and reimbursed.
Conclusions: Women in Taiwan are at a higher risk of ACG. The reason for the change of prevalence between OAG and ACG after 2005 may be related to the increased high prevalence of myopia or to the rising number of cataract surgeries performed in Taiwan, or both. The cost of glaucoma drugs rose in Taiwan during the period 1997-2010. Factors responsible for such an increase include higher numbers of glaucoma patients, more frequent use of prostaglandin analogs, improved medical accessibility, and possibly more aggressive treatments for this disease. PGAs may have the effect of treatment expansion for trabeculectomy. These results also suggest socioeconomic disparities in glaucoma care, as well as understanding of the changes in the expenditure of glaucoma medications under such universal health insurance coverage system. |
