[Epidemiological survey of childhood asthma in Kunming City, China].

Objective: To investigate the prevalence of childhood asthma, and to find the distribution characteristics, precipitating factors, diagnosis and treatment status, and to provide scientific data for improving the prevention and management of asthma in children in Kunming City, China.

Methods: Children were selected by random cluster sampling. A standardized preliminary questionnaire was used for screening out possible patients in the survey. Diagnosis of asthma was confirmed by diagnostic criteria in suspected asthmatic children. Asthmatic children were further asked for past diagnosis and treatment with the questionnaire of asthma in children.

Results: The total asthma incidence rate was 1.40%. The prevalence of asthma in male and female children was 1.89% and 0.88% respectively (P<0.05). Children aged 0-5 years old had a higher prevalence of asthma (1.69%) than that of school-age children (6-14 years old, 1.21%). In all asthmatic children, 51.3% were previously diagnosed with classical asthma or cough variant asthma, 26.0% were suffered attacks from December to February, and 54.0% were suffered attacks at midnight or dawn. Respiratory tract infection (87.3%) was the most common triggers of asthma exacerbation. Antibiotics were used in 80.0%, bronchodilators in 66.0%, inhaled corticosteroid in 64.0%. A peak flow meter for monitoring lung function was used in 17% of asthmatic children over 5 years old.

Conclusions: The prevalence of asthma is associated with age and gender in children aged 0-14 years old in Kunming City. Acute asthma attack occurs mostly in winter and at midnight or dawn. Respiratory tract infection is the most common trigger of asthma exacerbation. Nearly a half of patients with asthma had not been diagnosed with asthma in the early stage. Most asthmatic children use antibiotics and only two-thirds use bronchodilators or inhaled corticosteroid in the treatment. The treatment and management of asthma in children awaits improvement as well.