Visual impairment and human development in Brazil

INTRODUCTION: Sight is responsible for about 80% of the perception of external stimuli. In Brazil, visual impairment was the most frequent disability reported to the 2010 Census. This study aims to investigate possible associations between the Human Development Index (HDI) and its components (income, longevity and education) to the prevalence of visual impairment.  

METHODS: An ecological study that used as territorial base the twenty-seven Brazilian states. The prevalence of visual impairment was the dependent variable. The HDI and its component variables were the independent variables. The analysis was performed in the free software R. Was used the Pearson correlation test and multiple linear regressions models, accepting the critical error of 5%.  

RESULTS: More than 35 million visually impaired were identified, of which 506,377 (1.4%) people were blind. The prevalence of visual impairment was 18.8%, ranging from 15.9% to 22.5% across states, being higher in the Northeast and lowest in the Southern region of the country. The HDI ranged from 0.63 to 0.82 among the states. A significant negative correlation with the prevalence of visual impairment and HDI (p < 0.01 Pearson = -0.66) was observed. In the multiple linear regression models, a significant association between the prevalence of visual impairment and the variables that make up the HDI was observed. In the triple model longevity was the variable that presented the strongest association (p = 0.05; R² = 0.50).  

CONCLUSIONS: There is an association between visual impairment and HDI in particular with the longevity variable, which along with income and education explained 50% of the variation in prevalence among Brazilian states.