OBJECTIVETo 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.

METHODSPreliminary 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.

RESULTSA 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.

CONCLUSIONSPrevention 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.