title: Prevalence and risk factors of childhood allergic diseases in eight metropolitan cities in China: a multicenter study.
abstract: BACKGROUND
  Several studies conducted during the past two decades suggested increasing trend of childhood allergic diseases in China. However, few studies have provided detailed description of geographic variation and explored risk factors of these diseases. This study investigated the pattern and risk factors of asthma, allergic rhinitis and eczema in eight metropolitan cities in China.
  
  
  METHODS
  We conducted a cross-sectional survey during November-December 2005 in eight metropolitan cities in China. A total of 23791 children aged 6-13 years participated in this survey. Questions from the standard questionnaire of the International Study of Asthma and Allergies in Children (ISAAC) were used to examine the pattern of current asthma, allergic rhinitis and eczema. Logistic regression analyses were performed to assess the risk factors for childhood allergies.
  
  
  RESULTS
  The average prevalence of childhood asthma, allergic rhinitis and eczema across the eight cities was 3.3% (95% Confidence interval (CI): 3.1%, 3.6%), 9.8% (95% CI: 9.4%, 10.2%) and 5.5% (95% CI: 5.2%, 5.8%), respectively. Factors related to lifestyle, mental health and socio-economic status were found to be associated with the prevalence of childhood allergies. These risk factors were unevenly distributed across cities and disproportionately affected the local prevalence.
  
  
  CONCLUSIONS
  There was apparent geographic variation of childhood allergies in China. Socio-environmental factors had strong impacts on the prevalence of childhood allergies; but these impacts differed across regions. Thus public health policies should specifically target at the local risk factors for each individual area.
authors.affiliation: Department of Developmental and Behavioral Pediatrics, Shanghai Institute of Pediatric Translational Medicine, Shanghai Jiaotong University, School of Medicine, Shanghai, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Li
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Zhou
authors.forename: Shenghui
authors.initials: S
authors.lastname: Li
authors.forename: Fan
authors.initials: F
authors.lastname: Jiang
authors.forename: Xingming
authors.initials: X
authors.lastname: Jin
authors.forename: Chonghuai
authors.initials: C
authors.lastname: Yan
authors.forename: Ying
authors.initials: Y
authors.lastname: Tian
authors.forename: Yiwen
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shilu
authors.initials: S
authors.lastname: Tong
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Shen
mesh_terms: D000293:Adolescent; D002648:Child; D002681:China / Q000453:epidemiology; D002947:Cities; D003430:Cross-Sectional Studies; D005260:Female; D006306:Health Surveys; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology* / Q000209:etiology*; D008297:Male; D012307:Risk Factors