Background: Asthma presents with heterogeneous features, and patients show various phenotypes of differing severities. Therefore, it is necessary to define reliable predictable clinical factors that influence severity. To date, few large-scale studies have gathered clinical data on adult asthma patients in Asia.
Objectives: To establish an adult asthma cohort in Korea and to define significant factors associated with asthma severity and exacerbation.
Methods: Researchers from 11 university hospitals have established an asthma cohort termed the COhort for Reality and Evolution of adult Asthma in Korea (COREA). We classified the severity of asthma into 3 groups: mild, moderate, and severe. In this article, the first analysis of our cohort, we evaluate various clinical factors associated with the severity and exacerbation of asthma using data from 1,260 asthma patients.
Results: Physician-evaluated severity of asthma was associated with a history of asthma exacerbation (P < .001), a history of smoking (P < .001), symptom duration (P = .007), and treatment duration (P < .001). It was also significantly correlated with predicted forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) values and FEV1/FVC ratio (all P < .001). Previous exacerbation was associated with smoking (P = .02), predicted FVC and FEV1 values (both P < .001), FEV1/FVC ratio (P = .02), airway hyperresponsiveness (P = .002), and duration of disease (P < .001).
Conclusions: Previous exacerbation, duration of disease, and decrease in lung function were important clinical indices associated with asthma severity in the COREA study patients. Our long-term follow-up study is expected to soon yield more accurate and detailed outcomes.