RESUMO
<p><b>OBJECTIVE</b>To study the prevalence, epidemiological characteristics, and risk factors for childhood asthma in Yichang City, China and to collect evidence for the early diagnosis and preventive treatment of asthma.</p><p><b>METHODS</b>Preliminary screening questionnaires were distributed to more than 90% of children in 5 kindergartens, 10 primary and secondary schools, and 5 communities in Yichang City to detect children with suspected asthma. These surveyed children were selected by cluster random sampling. A further questionnaire survey was conducted for suspected cases. Meanwhile, a similar number of sex- and age-matched non-asthmatic children were selected for the case-control study. Information from returned questionnaires was entered into a database for statistical analysis.</p><p><b>RESULTS</b>A total of 11 000 questionnaires were distributed, and 10 456 (95.1%) questionnaires were returned. The prevalence rate of asthma among children in Yichang was 3.47%, significantly higher in boys than in girls (P<0.05). A total of 107 out of 363 children with asthma had a history of drug allergy, and 152 cases had a family history of allergy. The majority of asthmatic children had irregular onset-prone seasons and hours. Respiratory tract infections were the most common trigger of asthma attacks, accounting for 93.1% of all onsets; family history of allergy, history of early use of antibiotics, history of housing renovation, and history of passive smoking were the major risk factors for asthma.</p><p><b>CONCLUSIONS</b>Prevention of respiratory tract infections may reduce the frequency of asthma attacks; reducing the use of antibiotics during early childhood, decreasing the frequency of housing renovation, and advocating for smoking cessation among parents have preventive effects on asthma.</p>