Socioeconomic disparity in global burden of cataract: an analysis for 2013 with time trends since 1990

Purpose To assess socioeconomic disparity in global burden of cataract, by using disability-adjusted life years (DALYs). Design International, comparative burden-of-disease study. Methods Published data on national age-standardized DALY rates caused by cataract and human development index (HDI) between 1990 and 2013 were obtained. The association between age-standardized DALY rates and HDI in 2013 was analyzed. The health-related Gini coefficients and the concentration indexes were calculated to explore the trends in between-country inequality in cataract burden from 1990 to 2013. Results Multiple comparison revealed that lower HDI countries had higher age-standardized DALY rates caused by cataract. Age-standardized DALY rates were inversely associated with HDI ( β = -0.522, P < 0.01). From 1990 to 2013, global age-standardized DALY rates showed a trend of decline, whereas the Gini coefficients increased from 0.409 to 0.439. The concentration indexes indicated that socioeconomic associated inequality declined in the 1990s and subsequently increased since 2000, with values of -0.259 in 1990, -0.244 in 2000, and -0.273 in 2013. Conclusions Global health progress in cataract was accompanied by widening inequality, with cataract burden being more concentrated in countries with lower socioeconomic status. The findings highlight the need to provide more cataract services for developing countries, to combat global vision loss caused by cataract.