Respiratory symptoms and duration of residence in immigrant teenagers living in Melbourne, Australia.

Abstract

Examination of the relation between respiratory symptoms and time since arrival in Australia in immigrant teenagers living in Melbourne. Two stage, stratified, cross sectional survey. High schools (n = 51). 9794 people aged 13-19 years. Prevalence of wheeze during a 12 month period, region of birth, duration of residence in Australia. The estimated population 12 month period prevalence of wheeze was 18.9% (95% confidence interval (CI), 18.0 to 19.9). In subjects born outside Australia, residence for five to nine years in Australia was associated with a 2.1-fold (CI, 1.1 to 4.0) increase in the odds of self reported wheeze; after 10-14 years, this risk increased 3.4-fold (CI, 1.8 to 6.7). There was no difference in severity of wheeze, measured by reported frequency of attacks, between Australian born and non-Australian born subjects. The notion of a continued secular increase in the prevalence of wheezing is not supported. There is a time dose effect on the prevalence of symptoms in subjects born outside Australia and now living in Melbourne, which is independent of age and country of birth.