title: [Study on the changing structure of disabled population caused by birth defects in China].
abstract: OBJECTIVE
  To Compare the differences of classification and grading on disability between the TWO National Sample Surveys on Disability in 1987 and 2006, and to analyze the change of structure on disabled population with birth defects (BD).
  
  
  METHODS
  Quantitative analysis had been carried out based on the investigation of two national sample surveys.
  
  
  RESULTS
  (1) Prevalence rates of Disabilities caused by BD of 0 - 14, 15 - 64 and ≥ 65 age groups in 2006 were 0.1%, 0.28% and 1.15% respectively, all higher than those in 1987. There was significant difference among the age group of ≥ 65, between the two standard periods of survey. (2) The difference of prevalence rates on Disabilities caused by BD between males and females in 2006 was 0.03% higher than that of 1987 and the difference of proportion on Disability caused by BD between males and females in 2006 was 0.08%, which was lower than those data from the year 1987 (2006: χ(2) = 66.254, P < 0.001; 1987: χ(2) = 22.895, P < 0.001). (3) Prevalence rate of Disabilities caused by BD in rural area was 0.49% in 1987, and 0.74% in 2006 after standardization, which had an 50% increase during the past 19 years. Prevalence rate of Disabilities caused by BD in urban area was 0.35% in 1987 and 0.50% in 2006, which had an 43%. Increase during the past 19 years. (4) Percentage of grade 1 listen-speech disability caused by BD in 2006 deceased 17.35%, and the intelligent disability caused by BD increased 18.21% in 2006. (5) Compared with 1987, the difference of percentage on primary and higher education among disabled persons with BD disabled population and total population, became smaller in 2006.
  
  
  CONCLUSIONS
  To carry on a better study on disability, evaluation criteria of disability classification and grading standards should not only be taken into account on the continuity of the investigation, but also be better integrated with the international standards in terms of longitudinal comparison of data. Age structure of total population had a significant effect on the changing of structure on disabled persons caused by BD. Rural area was the high-risk area for disability caused by BD in China while female population should be viewed as the focus group of disability caused by BD.
authors.affiliation: Institute of Population Research, Peking University, Beijing 100871, China. Email: zhang.lei@pku.edu.cn.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Xiao-Ying
authors.initials: XY
authors.lastname: Zheng
authors.forename: Gong
authors.initials: G
authors.lastname: Chen
mesh_terms: D002681:China / Q000453:epidemiology; D006233:Persons with Disabilities; D006801:Humans; D015995:Prevalence; D011795:Surveys and Questionnaires