A study of factors related to asthma exacerbation using a questionnaire survey in Niigata Prefecture, Japan

As indices of asthma control, exacerbations are equally important with symptoms and respiratory function. Thus, it is critical to recognize the risk factors of exacerbation. We conducted a questionnaire survey of asthma patients in Niigata Prefecture to clarify the factors involved in asthma exacerbation. The questionnaire survey was carried out in patients and their physicians from September to October 2014. In 2015, the same sample population also received a questionnaire about current asthma control and exacerbation. One hundred patients experienced asthma exacerbation during the 1-year period. There were significant differences in age, sex, history of hospitalization due to asthma, smoking history, Asthma Control Test, treatment step, and transient steroid treatment history in the previous year between the exacerbation group and non-exacerbation group. On multivariate analysis, there was a significant difference in history of transient steroid therapy, history of hospitalization associated with asthma attacks, and nonsmoking history. Cluster analysis of cases with exacerbation was classified into three clusters. Cluster 1 comprised slightly older cases with smoking history, Cluster 2 had more females, non-smoking and nonatopic cases with uncontrolled symptoms, and Cluster 3 had more females, non-smoking and mild atopic cases. Our findings suggest that patients with asthma exacerbation in the previous year and nonsmoking females are important targets for the study of asthma exacerbation. The adequate treatment of women patients might be important for the prevention of asthma exacerbation.