The relationship of per capita gross national product to the prevalence ofsymptoms of asthma and other atopic diseases in children (ISAAC)

Background Increasing prevalence and worldwide variation in asthma and othe r atopic diseases suggest the influence of environmental factors, at least one possibly related to socioeconomic wellbeing. This paper examines the re lationship of symptoms of asthma, rhinitis and enema with gross national pr oduct per capita (GNP per capita). Methods The prevalences of atopic symptoms in 6-7- and 13-14-year-old child ren were assessed in 91 centres (from 38 countries) and 155 centres (from 5 6 countries), respectively, in the International Study of Asthma and Allerg y in Childhood (ISAAC). These symptoms were related to 1993 GNP per capita for each country as reported by the World Bank. The relationships between s ymptoms of atopic diseases and infant mortality, the human development inde x and 1982 GNP per capita were also considered. Results The countries in the lowest quartile of GNP per capita have the low est median positive responses to all the questions on symptoms of asthma, r hinitis and eczema. There was a statistically significant positive associat ion between wheeze in the last 12 months and GNP per capita in the 13-14-ye ar 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 sym ptoms being of only moderate strength suggests that the environmental facto rs are not just related to the wealth of the country.