title: The relationship of per capita gross national product to the prevalence of symptoms of asthma and other atopic diseases in children (ISAAC).
abstract: BACKGROUND
  Increasing prevalence and worldwide variation in asthma and other atopic diseases suggest the influence of environmental factors, at least one possibly related to socioeconomic wellbeing. This paper examines the relationship of symptoms of asthma, rhinitis and eczema with gross national product per capita (GNP per capita).
  
  
  METHODS
  The prevalences of atopic symptoms in 6-7- and 13-14-year-old children were assessed in 91 centres (from 38 countries) and 155 centres (from 56 countries), respectively, in the International Study of Asthma and Allergy in Childhood (ISAAC). These symptoms were related to 1993 GNP per capita for each country as reported by the World Bank. The relationships between symptoms of atopic diseases and infant mortality, the human development index and 1982 GNP per capita were also considered.
  
  
  RESULTS
  The countries in the lowest quartile of GNP per capita have the lowest median positive responses to all the questions on symptoms of asthma, rhinitis and eczema. There was a statistically significant positive association between wheeze in the last 12 months and GNP per capita in the 13-14-year age group, but not in the 6-7-year age group. There was also a positive association between GNP per capita and eczema in both age groups.
  
  
  CONCLUSIONS
  The positive associations between GNP per capita and atopic symptoms being of only moderate strength suggests that the environmental factors are not just related to the wealth of the country.
authors.affiliation: Department of Community Health, University of Auckland, Auckland, New Zealand. aw.stewart@auckland.ac.nz
authors.forename: A W
authors.initials: AW
authors.lastname: Stewart
authors.forename: E A
authors.initials: EA
authors.lastname: Mitchell
authors.forename: N
authors.initials: N
authors.lastname: Pearce
authors.forename: D P
authors.initials: DP
authors.lastname: Strachan
authors.forename: S K
authors.initials: SK
authors.lastname: Weiland
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000453:epidemiology*; D002648:Child; D004467:Economics; D004485:Eczema / Q000453:epidemiology*; D014943:Global Health; D006801:Humans; D015995:Prevalence; D012220:Rhinitis / Q000453:epidemiology*; D012923:Social Class; D012924:Social Conditions / Q000191:economics