The Effects of Previous Asthma and COPD on the Susceptibility to and Severity of COVID-19: A Nationwide Cohort Study in South Korea

Background: There is controversial evidence of the associations of asthma and chronic obstructive pulmonary disease (COPD) with the risk and outcomes of Coronavirus Disease 2019 (COVID-19). We aimed to evaluate the effects of asthma and COPD on the susceptibility to and severity of COVID-19. Methods: Data from a nationwide COVID-19 cohort database by the Korea National Health Insurance Corporation were utilized. A total of 4066 COVID-19 patients (1 January 2020 through 4 June 2020) were 1:4 matched with 16,264 controls with regard to age, sex, and income. Asthma and COPD were defined as diagnostic codes (ICD-10) and medication claim codes. Conditional and unconditional multivariate logistic regression were applied to analyze the susceptibility to and severity of COVID-19 associated with asthma and COPD. Results: The prevalence of mild and severe asthma/COPD did not differ between the COVID-19 and control patients in the multivariate analyses. Among the total 4066 COVID-19 patients, 343 (8.4%) had severe COVID-19, of whom 132 (3.2% of the total COVID-19 patients) died. Regarding the outcomes of COVID-19, neither mild nor severe asthma were associated with the severity or mortality of COVID-19 after adjusting for other variables. However, severe COPD was a significant risk factor for severe COVID-19 (odds ratio (OR) = 2.23, 95% confidence intervals (CI): 1.08–4.60, p = 0.030) and the mortality of COVID-19 in the multivariate analyses (OR = 3.06, 95% CI: 1.14–8.2, p = 0.026). Conclusions: In a Korean nationwide cohort, neither asthma nor COPD were associated with COVID-19, but severe COPD was associated with the severity and mortality of COVID-19.