title: Prevalence and severity of childhood asthma and allergic sensitisation in seven climatic regions of New South Wales.
abstract: OBJECTIVE
  To compare the prevalence and severity of asthma and of allergic sensitisation in children in different regions. We hypothesised that regions with different standardised hospital admission rates would have different prevalences of childhood asthma and that diverse climates would result in a range of sensitisations to different allergens.
  
  
  METHODS
  We studied large random population samples of children in seven regions in New South Wales (NSW) in 1991-1993. Hospitalisation rates were obtained from NSW Department of Health data.
  
  
  METHODS
  6394 children aged 8-11 years.
  
  
  METHODS
  History of respiratory symptoms by self-administered questionnaire; airway hyperresponsiveness by histamine inhalation test; and sensitisation to allergens by skin-prick tests.
  
  
  RESULTS
  Children in all regions had a high prevalence of recent wheeze (22%-27%), of diagnosed asthma (24%-38%) and of use of asthma medications (22%-30%), but no region was consistently higher or lower for all measurements. The prevalence of current asthma in children living in three coastal regions (where sensitisation to house-dust mites was high) and in the far west (where sensitisation to alternaria was high) was 12%-13%, which was significantly higher than the prevalence of 7%-10% in children living in three inland regions (where sensitisation to these allergens was lower) (P < 0.01).
  
  
  CONCLUSIONS
  We found significant variations in the prevalence and severity of childhood asthma in NSW. The prevalence of hospitalisations, diagnosed asthma, recent symptoms and medication use may relate to different regional diagnostic patterns, whereas current asthma prevalence may relate to different levels of allergic sensitisation.
authors.affiliation: Department of Medicine, University of Sydney, NSW.
authors.forename: J K
authors.initials: JK
authors.lastname: Peat
authors.forename: B G
authors.initials: BG
authors.lastname: Toelle
authors.forename: E J
authors.initials: EJ
authors.lastname: Gray
authors.forename: M M
authors.initials: MM
authors.lastname: Haby
authors.forename: E
authors.initials: E
authors.lastname: Belousova
authors.forename: C M
authors.initials: CM
authors.lastname: Mellis
authors.forename: A J
authors.initials: AJ
authors.lastname: Woolcock
mesh_terms: D001249:Asthma / Q000453:epidemiology* / Q000503:physiopathology; D002648:Child; D002980:Climate; D003710:Demography; D005843:Geography; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology* / Q000503:physiopathology; D009517:New South Wales / Q000453:epidemiology; D015995:Prevalence; D012720:Severity of Illness Index