Epidemiological survey and risk factor analysis of asthma in children in urban districts of Zhengzhou, China

Abstract:

Objective To study the epidemiological features, treatment status, and risk factors for asthma in children in Zhengzhou, China. Methods Questionnaires for primary screening were issued using the method of multi-stage stratified sampling. Suspected asthmatic children were given a second questionnaire, physical examination, medical history review, and auxiliary examination to confirm the diagnosis. Age-and sex-matched non-asthmatic children were randomly recruited to the control group. Results The number of valid questionnaires was 10 616 (5 444 males and 5 172 females). There were 308 confirmed asthma cases and the overall prevalence was 2.90%. The prevalence in boys was higher than that in girls (3.4% vs 2.4%). The prevalence in children under 3 years of age was 10.2%, which was higher than that in other age groups. The top three triggers for asthma attack in children were respiratory infection (94.2%), weather changes (89.0%), and exercise (35.1%). The most common asthma attack was moderate (71.8%), followed by mild (22.7%). Inhaled corticosteroids, systemic corticosteroids, and antibiotics were applied to 94.8% (292 cases), 74.7% (230 cases), and 90.9% (280 cases) of all patients, respectively. Multivariate logistic regression analysis indicated the following major risk factors for asthma: history of allergic rhinitis (OR=150.285, 95% CI: 31.934-707.264), history of eczema (OR=10.600, 95% CI: 1.054-106.624), history of atopic dermatitis (OR=31.368, 95% CI: 3.339-294.683), food allergies (OR=27.373, 95% CI: 2.670-280.621), method of birth (OR=2.853, 95% CI: 1.311-6.208), age of first antibiotic use (OR=0.384, 95% CI: 0.172-0.857), frequency of antibiotic use within 1 year of age (OR=9.940, 95% CI: 6.246-15.820), use of wall decorating materials (OR=2.108, 95% CI: 1.464-3.036), and use of heat supply in winter (OR=6.046, 95% CI: 1.034-35.362). Conclusions The prevalence of childhood asthma is associated with age and gender in Zhengzhou. Most asthma attacks are moderate, often triggered by respiratory infection. Treatment of asthma has been standardized, but still needs further improvement. History of allergic rhinitis, eczema, atopic dermatitis and food allergies, cesarean delivery, frequent use of antibiotics within 1 year of age, use of decorating materials on the wall, and use of heating in winter may increase risk for asthma, and use of antibiotics in older age is a protective factor against asthma in children.