Epidemiological survey of children asthma prevalence in Lanzhou urban area

Objective To explore the prevalence,diagnosis and management of childhood asthma in Lanzhou urban area. Methods Multi-stage,stratified and random cluster sampling was used to recruit children born during July 1st,1996 to July 1st,2010 from Lanzhou or other provinces but resided in Lanzhou for over half a year.The same screening questionnaires for the Third National Epidemiological Survey of Childrenu0027s Asthma were distributed to parents of children at schools,kindergartens and communities.Asthmatic children were picked among the screening-positive children based on on-the-spot inquiries,physical examinations,medical records and supporting test results.Further survey of asthmatics was carried out to investigate the diagnosis and treatment status of childhood asthma and other associated allergic diseases.All data required double entry by Epi-Info 3.5.3software and were processed by SPSS 19.0. Results Among a total of 11 068 questionnaires,10 566 were completed with a response rate of 95.46%.And 298(2.82%)children were diagnosed with typical(n=265,2.51%)and cough variant(n=33,0.31%)asthma.Among them,54.36%(162/298)had been previously diagnosed with asthma.The prevalence of asthma was higher in boys than in girls[3.31%(180/5 440)vs 2.30%(118/5 126),χ2=9.761,P0.01].The asthma prevalence of preschoolers(3~7years old)was the highest(4.31%(116/2 690)).In the past two years,the symptoms of 84.90%(253/298)children persisted and the current two-year prevalence of asthma was2.39%(253/10 566).Among the 162 children with previous asthma,87.65%(142/162)received inhaled corticosteroids according to the Global Initiative for Asthma(GINA)and 87.04%(141/162)of them used antibiotics. Conclusions The prevalence of asthma is 2.82%in children under 14 years old in Lanzhou urban area,increased significantly over the past ten years,and it varied in children with different genders and ages.A considerable number of children are not diagnosed or treated properly,and the management of asthma requires further improvement.