Global disease burden of uncorrected refractive error among adolescents from 1990 to 2019

Abstract

Background: To estimate the global disease burden of uncorrected refractive error (URE) among adolescents and assess the contributions of various risk factors to disability-adjusted life-years (DALYs) due to URE.

Methods: Global, regional and country-level DALY numbers and rates due to URE among adolescents were acquired from the Global Burden of Disease Study 2019 database. Human Development Index (HDI), Socio-Demographic Index (SDI) and other country-level data were obtained from other open databases as potential indicators. Regression analysis was used to evaluate associations between DALY rates among adolescents and potential predictors.

Results: Global DALYs due to URE among adolescents rose by 8% between 1990 and 2019 but moderately decreased by 4.8% during this period after adjusting for population size. Female adolescents showed higher DALY rates. DALY rates sharply increased from 5 to 9 years of age, then rose more slowly, reaching a plateau before 20 years of age. Country-level DALY rates in 2019 were positively associated with HDI, SDI, and urbanization rates but negatively correlated with primary school dropout rates. Higher disease burden of adolescents visually impaired from URE was associated with lower primary school dropout rates (β = - 0.257, 95% CI - 0.376 to - 0.138, P < 0.001) and higher urbanization rates (β = 0.257, 95% CI 0.067 to 0.256, P = 0.001).

Conclusions: Higher socioeconomic status, urbanization rates and education levels are associated with a heavier disease burden of URE among adolescents. The findings of this study can provide a reference for policy making on resource allocation for URE prevention and control in teenagers.

Keywords: Adolescents; Disability-adjusted life years; Education; Socioeconomic; Uncorrected refractive error; Urbanization.

Fig. 1

Time trends of global health burden and prevalence of URE among adolescents in 1990–2019. Panel A. DALY numbers. Panel B. DALY rates. Panel C. Prevalence numbers. Panel D. Prevalence rates. Dashed lines represent 95% CIs; DALY, disability-adjusted life year; URE, uncorrected refractive error

Fig. 2

The distribution of global burden due to URE among adolescents by age and sex. Panel A. Sex-specific DALY numbers. Panel B. Sex-specific DALY rates. Panel C. Age-specific and sex-specific DALY numbers in 2019. Panel D. Age-specific and sex-specific DALY rates in 2019. DALY, disability-adjusted life year; URE, uncorrected refractive error

Fig. 3

Global map of the disease burden of adolescents visually impaired from URE. Global maps were generated from a data visualization tool available from the Global Health Data Exchange (GHDx) repository (https://vizhub.healthdata.org/gbd-compare/). Panel A. DALY numbers. Panel B. DALY rates. Panel C. The 10 countries with the highest DALY numbers. Panel D. The 10 countries with the highest DALY rates. DALY, disability-adjusted life years; URE, uncorrected refractive error

Fig. 4

Global health burden distribution of URE among adolescents in different regions. Panel A. WHO regions. Panel B. Different SDI-level regions. All estimated GBD 2019 locations are divided into five groups referring to SDI quintile values: High SDI (0.805–1), High-middle SDI (0.690–0.805), Middle SDI (0.608–0.690), Low-middle SDI (0.455–0.608), Low SDI (0–0.455). Panel C. Different income-level regions. All estimated GBD 2019 locations are divided into four income groups according to GNI per capita, calculated using the World Bank Atlas method: High income ($12,696 or more), Upper middle income ($4096–$12,695), Lower middle income ($1046–$4095), Low income ($1045 or less). WHO, World Health Organization; SDI, Socio-Demographic Index; GNI, gross national income; URE, uncorrected refractive error

Fig. 5

Relationship between the disease burden of URE among adolescents and country-level indicators. Panel A. SDI. The SDI is the geometric mean of total fertility rate for those younger than 25 years old (TFU25), mean education for those 15 years old (EDU15+) and lag-distributed income (LDI) per capita. Panel B. HDI. The HDI is the geometric mean of life expectancy at birth, gross national income (GNI) per capita and average and expected years of schooling. Panel C. Primary school dropout rates. It is calculated as the percentage of students from a given cohort who have enrolled in primary school but who drop out before reaching the last grade of primary education. Panel D. Urbanization rates. It is calculated as the proportion of population living in the areas classified as urban according to the criteria used by each country or area. HDI, Human Development Index; SDI, Socio-Demographic Index