[Epidemiological survey on bronchial asthma in Henan province].

Objective: To survey asthma prevalence, correlation factors for prevention, treatment, and for policy decision of asthma control.
Methods: Done with TB epidemiological survey synchronously, sampling by stratified-cluster-random method. 43 points were selected and distributed in all 18 prefectures in Henan province. Sampling population was 75 134, and 65 033 (97.0%) were investigated actually.
Results: In this survey, 682 asthma patients were found. The total prevalence rate was 1.05%, the rate for children was 1.71%, and that for adult was 0.82%; the rates for male and female were 1.16%, 0.94% respectively. The ratio of male to female was 1.23:1. When asthmatic chronic bronchitis cases were regarded as asthma cases and included in total asthma cases, the overall prevalence rate of asthma would increase up to 1.73%, raised by 65%. The higher prevalence were in 0 approximately 3 years old age group (4.48%) and >/= 65 years old age group (1.43%), the lowest prevalence was in 15 approximately 24 years old age group (0.36%). For 90% of asthmatic children, the initiative age of asthma was before 7 years old, and for 1/3 adult patient, it was in childhood. The prevalence of asthma in rural area was higher than that of urban area. Cold air, common cold, stimulation of smoking and cooking, and room dust were the 4 main inducing factors. Seasonal attack of asthma accounted for 67.2%, and that in winter and spring was 65.4%. 60.6% of asthma cases showed history of allergic diseases including allergic rhinitis, dermatitis, and drug allergy; 34.3% asthma family history.
Conclusions: The rate of prevalence and inducing factors of asthma in Henan province were gained in this survey. The results may basically reflect the present status and be provided for asthma control as reference. According to the prevalence, asthma cases would be up to 0.98 approximately 1.6 million in whole Henan province and more attention should be paid to this situation.