Kim Y, Kim YJ, Kang YM, et al. - This study sought to evaluate severe exacerbations that required hospitalization or emergency room visits. Researchers examined the National Health Insurance Service-National Sample Cohort, version 2.0, data sampled between 2002 and 2015. Moreover, data from two years after the diagnosis of COPD for each participant were examined (N = 12,554, entire cohort). The data showed that in COPD patients, the number of comorbidities, certain comorbidities such as asthma, lung cancer, and heart failure, and low BMI were correlated with an elevated risk of severe exacerbation.