Socioeconomic disparities in the global burden of glaucoma: an analysis of trends from 1990 to 2016

Purpose To assess the global burden of glaucoma by year, age, sex, regions, socioeconomic development, and mean years of schooling (MYS) by using disability-adjusted life year (DALY), then to explore the health inequality with socioeconomic status in glaucoma. Methods Global, national, and regional DALY data of glaucoma by year, age, and sex were extracted from the Global Health Data Exchange. Human development index (HDI) and national MYS in 2015 were obtained from the Human Development Report (HDR) 2016. Mann-Whitney U test was performed to explore the sexual difference in global DALYs. Kruskal-Wallis tests were performed to explore the difference of age-standardized DALY rates across WHO regions and HDI-related country groups. Linear regression analyses were performed to explore the association between age-standardized DALY rates with HDI and MYS. Health-related Gini coefficients and concentration indexes were calculated to evaluate the trends in health inequality of glaucoma since 1990. Results DALY numbers, crude DALY rates, and age-standardized DALY rates increased by 118.0%, 55.22%, and 12.12%, respectively, since 1990. Global DALY numbers and crude DALY rates increased with age, and Mann-Whitney U test revealed no significant sex difference in global DALY numbers (P = 0.807) and global crude DALYs rates (P = 0.976) for each age group in 2016. Africa and Eastern Mediterranean had higher age-standardized DALY rates than the global one in 2016. Kruskal-Wallis test indicated significant difference in age-standardized DALY rates across WHO regions (chi(2) = 94.227, P < 0.001). Linear regression analysis indicated that HDI (adjusted R-2 = 0.079; F = 16.722, P < 0.001) and MYS (adjusted R-2 = 0.108; F = 23.048, P < 0.001) had a significant effect on age-standardized DALY rates. Gini coefficients rose from 0.290 in 1990 to 0.292 in 2015 with a peak value 0.299 in 2005, concentration index declined from 1990 (- 0.099) to 2000 (- 0.077) with reaching a low peak value, then rapidly increased to - 0.097 in 2015. Conclusions With population growth and aging, global burden of glaucoma is increasing and older age, lower socioeconomic status, and lower MYS are associated with higher glaucoma burden. Our results help to gain a better understanding of glaucoma and guide future health policies tailored for public.