After eliminating duplicate records and further consideration of eligibility criteria, 53 studies with 658,073 patients were included in the final analysis. In the initial search, 722 articles were identified. A comprehensive literature search was performed using five international search engines. In this systematic review and meta-analysis, we aimed to examine in detail whether the underlying chronic obstructive pulmonary diseases (COPD), asthma and chronic respiratory diseases (CRDs) were associated with an increased risk of more severe COVID-19. Persistent questions remain about the relationship between the severity of COVID-19 and comorbid diseases, as well as other chronic pulmonary conditions. Coronavirus disease 2019 (COVID-19) caused by infection with severe acute respiratory syndrome coronavirus 2 was first detected in Wuhan, China, in late 2019 and continues to spread worldwide.
