Seasonal characteristics of patients hospitalized for asthma exacerbation in China

Objective To study the seasonal characteristics of patients hospitalized for asthma exacerbation in China. Methods This was a retrospective study which involved patients hospitalized for asthma exacerbation in 29 hospitals throughout mainland China during 2013—2014. The number of patients hospitalized for asthma exacerbation in each hospital was calculated, as well as the ratio of asthmatic patients to all the hospitalized patients. The analysis by month was conducted. The number and ratio of asthmatic patients in the northern and southern cities were calculated respectively. Results During the study period, there were 6 480 patients hospitalized for asthma exacerbation, accounting for 3.14% (6 480/206 135) of all the hospitalized patients of the respiratory department in 29 hospitals. The analysis by month showed that the ratio of patients hospitalized for asthma exacerbation was highest in March (3.49%), then declined from April to June, then rose again from July, reaching a second peak at September (3.28%), and then declined again from October to December. The ratio of asthmatic patients in every month was higher in northern cities than in southern cities. Conclusions The ratio of patients hospitalized for asthma exacerbation in China fluctuates with the changes of seasons, and March and September are the two peak months. Northern cities have a higher ratio of asthmatic patients than southern cities. Key words: Asthma; Hospitalization; Seasons; Disease attributes