[Epidemiological survey of children asthma prevalence in Beijing urban area]

To explore the prevalence, diagnosis and management of childhood asthma in Beijing urban area.

Multi-stage, stratified and random cluster sampling was used to recruit children born during November 1, 1995 to October 31, 2010 from Beijing or other provinces but residing in Beijing for over half a year. The same screening questionnaires for the third national epidemiological survey of children's asthma were distributed to parents of children at schools, kindergartens and communities during October 2010 to March 2011. 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 3.5.3 software and were processed by SPSS 19.0.

Among a total of 14 085 questionnaires, 13 513 were completed with a response rate of 95.94%. And 497 (3.68%) children were diagnosed with typical (n = 451, 3.34%) and cough variant (n = 46, 0.34%) asthma. Among them, 40.64% (202/497) were newly diagnosed and 59.36% (295/497) had been previously diagnosed with asthma. The prevalence of asthma was higher in boys than in girls (4.80% (345/1790) vs 2.40% (152/6323), χ(2) = 54.446, P < 0.01). The asthma prevalence of preschoolers (3 - < 7 years old) was the highest (5.05% (180/3563)). In the past two years, the symptoms of 69.42% (345/497) children persisted and the current two-year prevalence of asthma was 2.55% (345/13513). Among the 295 children with previous asthma, only 46.44% (137/295) received inhaled corticosteroids according to the Global Initiative for Asthma (GINA) and 82.37% (243/295) of them used antibiotics.

The prevalence of asthma is 3.68% in children under 14 years old in Beijing urban area and it varies 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.