Hospitalization Due to Asthma Exacerbation: A China Asthma Research Network (CARN) Retrospective Study in 29 Provinces Across Mainland China

PURPOSE: Details of patients hospitalized for asthma exacerbation in mainland China are lacking. To improve disease control and reduce economic burden, a large sample survey among this patient population is indispensable. This study aimed to investigate the clinical characteristics and outcomes of such patients.METHODS: A retrospective study was conducted on patients hospitalized for asthma exacerbation in 29 hospitals of 29 regions in mainland China during the period 2013 to 2014. Demographic features, pre-admission conditions, exacerbation details, and outcomes were summarized. Risk factors for exacerbation severity were analyzed.RESULTS: There were 3,240 asthmatic patients included in this study (57.7% females, 42.3% males). Only 28.0% used daily controller medications; 1,287 (39.7%) patients were not currently on inhaled corticosteroids. Acute upper airway infection was the most common trigger of exacerbation (42.3%). Patients with severe to life-threatening exacerbation tended to have a longer disease course, a smoking history, and had comorbidities such as hypertension, chronic obstructive pulmonary disease (COPD), and food allergy. The multivariate analysis showed that smoking history, comorbidities of hypertension, COPD, and food allergy were independent risk factors for more severe exacerbation. The number of patients hospitalized for asthma exacerbation varied with seasons, peaking in March and September. Eight patients died during the study period (mortality 0.25%).CONCLUSIONS: Despite enhanced education on asthma self-management in China during recent years, few patients were using daily controller medications before the onset of their exacerbation, indicating that more educational efforts and considerations are needed. The findings of this study may improve our understanding of hospital admission for asthma exacerbation in mainland China and provide evidence for decision-making.

Seasonal distribution of patient hospitalization due to asthma exacerbation in 7 geographic areas in China / 中华流行病学杂志

Objective To understand the seasonal distribution of patient hospitalization due to asthma exacerbation in 7 geographic areas in China.Methods This was a retrospective study which involved patients hospitalized for asthma exacerbation in 29 hospitals throughout 7 geographic areas in the mainland of China (northeast,north,central,east,south,northwest and southwest).The numbers of asthmatic patients and total inpatients of the respiratory department of each hospital were recorded.The monthly ratio of asthmatic patients to the total inpatients in every area was calculated and compared.Results During the study period,6 480 patients were admitted for asthma exacerbation,accounting for 3.14％ of all the 206 135 patients admitted to the respiratory departments in the 29 hospitals.The ratio of asthmatic patients to total inpatients in the northeast area (5.61％) was highest,and the ratio in east area was lowest (1.97％).Statistical analysis showed that the difference among different areas was significant (P＜0.000 1).In most areas,both the number and proportion of hospitalized asthmatic patients peaked in spring (February-April) and autumn (September-October).In the northeast area,east area and south area,the peaks in spring were more obvious,while in the north area and southwest area,the peaks in autumn were more obvious.In the northwest area the peaks occurred in winter (December-January) and summer (June-August),respectively.The differences in hospitalization due to asthma among different months were significant in the northeast,north,and southwest areas (P＜0.005).Conclusion The number of patients hospitalized for asthma exacerbation fluctuated with season in different areas in China.In most areas,more asthmatic patients were admitted to hospitals in spring and autumn.

Seasonal distribution of patient hospitalization due to asthma exacerbation in 7 geographic areas in China / 中华流行病学杂志

Objective To understand the seasonal distribution of patient hospitalization due to asthma exacerbation in 7 geographic areas in China.Methods This was a retrospective study which involved patients hospitalized for asthma exacerbation in 29 hospitals throughout 7 geographic areas in the mainland of China (northeast,north,central,east,south,northwest and southwest).The numbers of asthmatic patients and total inpatients of the respiratory department of each hospital were recorded.The monthly ratio of asthmatic patients to the total inpatients in every area was calculated and compared.Results During the study period,6 480 patients were admitted for asthma exacerbation,accounting for 3.14％ of all the 206 135 patients admitted to the respiratory departments in the 29 hospitals.The ratio of asthmatic patients to total inpatients in the northeast area (5.61％) was highest,and the ratio in east area was lowest (1.97％).Statistical analysis showed that the difference among different areas was significant (P＜0.000 1).In most areas,both the number and proportion of hospitalized asthmatic patients peaked in spring (February-April) and autumn (September-October).In the northeast area,east area and south area,the peaks in spring were more obvious,while in the north area and southwest area,the peaks in autumn were more obvious.In the northwest area the peaks occurred in winter (December-January) and summer (June-August),respectively.The differences in hospitalization due to asthma among different months were significant in the northeast,north,and southwest areas (P＜0.005).Conclusion The number of patients hospitalized for asthma exacerbation fluctuated with season in different areas in China.In most areas,more asthmatic patients were admitted to hospitals in spring and autumn.

A retrospective study of the inducing factors and clinical characteristics of patients hospitalized for asthma exacerbation in China in 2013-2014 / 中华内科杂志

Objective To study the inducing factors and clinical characteristics of patients hospitalized for asthma exacerbation in China. Methods Patients hospitalized for asthma exacerbation at 29 hospitals in China were retrospectively recruited during 2013-2014. Results Clinical data of 3 240 asthmatic patients were collected and analyzed including 1 369(42.3%) males and 1 871(57.7%)females. The patients hospitalized for asthma exacerbation counted for 2.95% (6 375/215 955) of all patients hospitalized during the same period. The leading six inducing factors, in sequence, were acute upper respiratory tract infection[42.3%(1 370/3 240)],changes of weather[22.8%(738/3 240)],noxious gas[(4.3% (140/3 240), allergy challenges [3.5%(115/3 240)], strenuous exercise [1.8%(57/3 240)], and air pollution [1.5%(49/3 240)].In older patients,more exacerbations were induced by weather changes,yet less sensitive to allergy challenges. As to middle-aged patients, they were less sensitive to upper respiratory tract infections,however the difference was not statistically significant(P>0.05).In winter more asthma patients were induced by upper respiratory tract infections,while in autumn more patients were induced by weather changes,strenuous exercise and air pollution.In spring and summer more patients were induced by allergy challenges, but the differences failed to achieve statistical significance (P>0.05). In northern cities more patients were induced by upper respiratory infections, whereas in southern cities more by noxious gases. Allergy challenges and air pollution tended to affect more patients in northern cities,but the difference was of no significance (P>0.05). The differences of inducing factors among patients of different gender, with or without a smoking history, and with different exacerbation severity didn't show any statistical significance. The patients with severe and life-threatening exacerbations counted for 20.1%(652/3 240).The percentage of patients older than 60 years was higher in patients with severe or life-threatening exacerbations than in whose with mild or moderate exacerbations,so did the percentage of male patients,of patients with disease duration longer than 10 years, with smoking history, and with a history of hospitalization or emergency department visits due to asthma exacerbation during the last year.Conclusion The acute upper respiratory tract infection ranks top among all the inducing factors. Senility, male gender, long duration of disease, smoking history, and a history of frequent hospital visits might be the risk factors for severe or life-threatening asthma exacerbations.