title: [Influence of smoking on the prevalence of chronic diseases among people with different income levels].
abstract: OBJECTIVE
  To explore the influence of smoking on chronic diseases among people with various income levels in China.
  
  
  METHODS
  Cross-sectional study on smoking behavior, chronic disease and income level was performed using database of the Second National Health Service Study (1998) provided by the Ministry of Health in China.
  
  
  RESULTS
  Compared to never-smokers, smokers (including current smokers and former smokers) had a higher rate of having chronic diseases, after adjusted in age, income, educational level, employment status and type of jobs with corresponding countryside (OR = 1.185, 95% CI: 1.121 - 1.253 and town OR = 1.083, 95% CI: 1.010 - 1.161). Smoking had a more serious effect on having chronic illness in males from the countryside (former-smoker OR = 2.764, 95% CI: 2.471 - 3.092) than in town (former-smoker OR = 2.112, 95% CI: 1.844 - 2.419). Smokers at the lowest income level had a higher possibility of having chronic illness (town OR = 2.076, 95% CI: 1.551 - 2.780; countryside OR = 2.903, 95% CI: 2.248 - 3.749) than those at the highest income level (town OR = 1.785, 95% CI: 1.285 - 2.479 in the countryside OR = 2.466, 95% CI: 1.941 - 3.134).
  
  
  CONCLUSIONS
  Smoking might cause more serious health problems to people at lower income level in China.
authors.affiliation: Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Wei-rong
authors.initials: WR
authors.lastname: Yan
authors.forename: Ke-qin
authors.initials: KQ
authors.lastname: Rao
authors.forename: Zeng-zhen
authors.initials: ZZ
authors.lastname: Wang
authors.forename: Peng
authors.initials: P
authors.lastname: Ran
mesh_terms: D002681:China / Q000453:epidemiology; D002908:Chronic Disease / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007182:Income; D008297:Male; D012907:Smoking / Q000009:adverse effects*; D012923:Social Class