title: The relationship between disability-adjusted life years of cataracts and ambient erythemal ultraviolet radiation in China.
abstract: BACKGROUND
  Cataracts are one of the major public health problems worldwide. Ultraviolet radiation (UVR) is one of the risk factors for cataract development. We analyzed the relationship between disability-adjusted life year (DALY) rates of cataracts and UVR exposure in China.
  
  
  METHODS
  DALY rates of cataracts and UVR exposure in 31 regions of China were calculated based on data from the Second China National Sample Survey on Disability and the United States' National Aeronautics and Space Administration database. The relationship between the DALY rates of cataracts and UVR was estimated by Spearman rank correlation analysis and linear regression analysis.
  
  
  RESULTS
  The elderly (≥ 65 years) had higher DALY rates of cataracts than the whole population. The DALY rate of cataracts in the agricultural population was higher than that observed in the non-agricultural population. The DALY rates of cataracts were positively associated with UVR The DALY rates of cataracts in regions with higher UVR were higher than those in regions with lower UVR. An increase in the daily ambient erythemal UVR of 1000 J/m(2) was associated with an increase in the DALY rates of cataracts by 92 DALYs/100 000 (R(2) = 0.676) among the whole population, 34 DALYs/100 000 among the population < 65 years old (R(2) = 0.423), 607 DALYs/100 000 among the population aged 65-74 years (R(2) = 0.617), and by 1342 DALYs/100 000 among the population ≥ 75 years old (R(2) = 0.758).
  
  
  CONCLUSIONS
  DALY rates of cataracts increased with increases in UVR exposure in 31 regions of China. Greater exposure to UVR increases the disease burden of cataracts in the whole population, especially in the elderly and among the agricultural population.
authors.affiliation: School of Public Health, China Medical University.
authors.forename: Min
authors.initials: M
authors.lastname: Zhu
authors.forename: Jiaming
authors.initials: J
authors.lastname: Yu
authors.forename: Qian
authors.initials: Q
authors.lastname: Gao
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.forename: Liwen
authors.initials: L
authors.lastname: Hu
authors.forename: Yang
authors.initials: Y
authors.lastname: Zheng
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000383:Agriculture; D002386:Cataract / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D006233:Persons with Disabilities / Q000706:statistics & numerical data*; D004781:Environmental Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D004890:Erythema / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D019057:Quality-Adjusted Life Years; D012307:Risk Factors; D014466:Ultraviolet Rays / Q000009:adverse effects*; D055815:Young Adult