The prevalence of comorbid respiratory disease among COVID-19 patients, and mortality during the first wave in Japan: A nationwide survey by the Japanese Respiratory Society

There is a concern that persons with underlying respiratory disease may have increased susceptibility to COVID-19 and/or increased severity/mortality if infected. However, information regarding such patients during the first wave of the epidemic is lacking in Japan. We surveyed chest physicians nationwide, and collected anonymous data concerning 1444 patients. Among COVID-19 patients, the prevalence of asthma, chronic obstructive pulmonary disease (COPD), and interstitial lung diseases (ILD) was 3.4%, 4.8%, and 1.5%, respectively. Among COVID-19 patients with these 3 comorbidities, exacerbation of the comorbidity occurred in 12.2%, 18.8%, and 36.4%, respectively, and mortality (6.2% overall) was 4.1%, 13.0%, and 31.8%, respectively. The prevalence of asthma among COVID-19 patients was not higher than that for the general population, and mortality in COVID-19 patients with asthma was not higher than mortality in COVID-19 patients without underlying respiratory disease. COVID-19 patients having COPD or ILD had relatively high mortality, especially for ILD.