The impact of COPD and smoking history on the severity of COVID‐19: A systemic review and meta‐analysis

Comorbidities are associated with the severity of coronavirus disease 2019 (COVID-19). This meta-analysis aimed to explore the risk of severe COVID-19 in patients with pre-existing chronic obstructive pulmonary disease (COPD) and ongoing smoking history. A comprehensive systematic literature search was carried out to find studies published from December 2019 to 22 March 2020 from five databases. The languages of literature included English and Chinese. The point prevalence of severe COVID-19 in patients with pre-existing COPD and those with ongoing smoking was evaluated with this meta-analysis. Overall 11 case series, published either in Chinese or English language with a total of 2002 cases, were included in…