The prevalence of asthma and respiratory symptoms among young adults: is it increasing in Australia?

The objective of this study was to determine the prevalence of self-reported asthma and respiratory symptoms among young adults and whether there had been any change since a previous survey. A cross-sectional postal community survey was conducted in three parliamentary electorates in the inner South East region of Melbourne, Australia. A total of 4500 individuals aged between 20 and 44 years were randomly selected from the electoral roll. After three mailings and telephone follow-up, an adjusted response rate of 79% was achieved. No intervention was performed. Self-reported asthma and respiratory symptoms were recorded from the European Community Respiratory Health Survey screening questionnaire. Respondents were most likely to report nasal allergies (41%), nocturnal cough (28.6%), and wheeze in the last 12 months (28.1%). Nocturnal cough was more common in females than males. The prevalence of wheeze, nocturnal chest tightness, and use of asthma medications decreased with age. An attack of asthma in the last 12 months was reported by 9.7% of young adults, and this fell to 8.2% after correction for nonresponse bias. The prevalence of current asthma had not increased significantly since a previous postal survey in 1990. However the prevalence of nocturnal chest tightness, nocturnal cough, and use of asthma medications had increased significantly over a 2-year period. Further research is required to investigate why asthma is so prevalent in Australia and why some features are increasing in prevalence.