The prevalence and nature of wheeze in preschool children: A questionnaire study.

The epidemiology of wheeze, asthma and recurrent cough was studied in preschool children using a parent-answered postal questionnaire. The influences of putative environmental factors and of a family history of wheeze/atopy on the nature and prevalence of wheeze and prevalences of asthma and recurrent cough were investigated. The study cohort was established from a population-based random sample of Leicestershire children ? 5 years. The questionnaire was designed for the target population. Questions were derived chiefly from previously tested or standardised questionnaires. Of 1650 questionnaires posted, 1422 (86.2%) were returned. Wheeze occurred in 15.6% and asthma in 11% of children, both with male predominance. Of the 222 children with reported wheeze, 125 (8.8%) were diagnosed as having asthma. Cumulative prevalence of asthma increased significantly with age. Recurrent cough was reported in 21.8% of children. The characteristics of wheeze were described using six severity variables, volunteered precipitants and seasonal and diurnal variation. Increasing age, number of wheezy episodes in the past year, severity of shortness of breath with attacks and precipitants other than colds were major determinants of the probability of a wheezy child being diagnosed as having asthma. The proportions of wheezy children who were under current medical review, had received medical attention (ever) or had been admitted to hospital for wheeze were 34.8%, 75.0% and 21.8% respectively. The likelihood of current or past treatment were related to wheeze frequency and exposure to inhaled precipitants whereas hospital admission was more likely where attacks caused shortness of breath and with decreasing frequency of attacks per year. Predominant factors influencing the prevalence of wheezy episodes in the past 12 months were previous respiratory tract infections, passive smoke exposure and a maternal history of asthma. Recurrent cough was associated with past history of bronchiolitis, bedroom sharing, damp in the home and parental smoking. This study established a cohort to study further the natural history of wheeze.