An epidemiological study of bronchial asthma in Qinghai Province

Abstract

To study the prevalence of asthma in Qinghai Province between 2006 to 2007. According to the geographical location and the altitude (1920 - 4500 m), stratified-cluster-random sampling was use for this study. A total of 27 851 individuals were investigated by household survey at 49 locations in 4 autonomous prefectures, Xining Municipal City and Haidong Administrative District. The questionnaire included respiratory symptoms, personal history, allergic history, and family medical history. Chest X-ray and pulmonary function tests (ventilation function and bronchodilatation test) were performed. Diagnosis of bronchial asthma was made according to the criteria in the Guidelines for Asthma Management by Chinese Respiratory Society. The overall prevalence of asthma was 0.38% (105/27 851). The prevalence of asthma in females was [0.45% (61/13 433)], which was higher than that in males [0.31% (44/14 418)]. The prevalence of asthma in children [0.85% (30/3510)] was higher than that in adults [0.31% (75/24 341)]. The prevalence of asthma in different occupational populations was as follows: farmers [0.61% (46/7524)], government officials and employees [0.23% (12/5252)], half farmers and half herdsmen [0.22% (4/1792)], inhabitants [0.20% (12/5865)], factory workers [0.06% (1/1808)] and herdsmen [0% (0/2100)]. The prevalence of asthma in farmers was higher than those in other occupations. The prevalence of asthma was also different in geographical locations and altitudes, 0.45% (91/20 314) in population living at 1920 - 3000 m above sea level, 0.29% (13/4462) at 3001 - 3500 m above sea level and 0.03% at greater than 3500 m above sea level. The prevalence of asthma in rural, urban, half farming and half herding areas and the pastoral areas was 0.64% (65/10 119), 0.27% (37/13 933), 0.15% (2/1310) and 0.04% (1/2489) respectively; the highest in rural areas and the lowest in the pastoral areas. The overall prevalence of asthma in Qinghai Province was lower than that in the nation as a whole. The prevalence of asthma in higher altitudes was lower than that in the lower altitudes, and was lower in herdsmen as compared to other occupational populations.