Epidemiological study of wheeze, doctor diagnosed asthma, and cough in preschool children in Leicestershire.

Abstract

OBJECTIVE--To determine the cumulative prevalences of wheeze and doctor diagnosed asthma and the point prevalences of recurrent cough and wheeze in children aged 5 years and under. DESIGN--Questionnaire survey of population based random sample of children registered on regional authority's child health index for immunisation; questionnaire completed by parents. SETTING--Leicestershire. SUBJECTS--1650 white children born in 1985-9 who were surveyed in 1990. MAIN OUTCOME MEASURES--Cumulative prevalences of wheeze and doctor diagnosed asthma and point prevalences of recurrent cough and wheeze by age and sex. RESULTS--There were 1422 replies (86.2%; 726 for boys, 696 for girls). Overall, 11.0% (95% confidence interval 9.4% to 12.6%) of children had formally been diagnosed as having asthma, the cumulative prevalence in boys (12.7%) being somewhat higher than in girls (9.2%) (age adjusted odds ratio 1.47, p = 0.03). As expected, the cumulative prevalence of asthma increased significantly with age (7.5% (13/173) in children under 1 year, 15.9% (61/383) in children of 4 years and over; p < 0.001). The cumulative prevalence of wheeze overall was 15.6% (13.7% to 17.5%), being higher in boys (17.6%) than in girls (13.5%) (odds ratio 1.38, p = 0.03). The overall prevalence of recurrent cough without colds was 21.8% (19.6% to 23.9%), with a non-significant excess in boys (23.1% v 20.4%). The overall prevalence of wheezing attacks during the previous 12 months was 13.0% (11.3% to 14.8%) with a non-significant excess in boys (14.5% v 11.5%). CONCLUSIONS--These findings are baseline results and emphasise the importance of studying the age group of interest rather than relying on the recall of parents of school age children.