TY - JOUR T1 - Smoking quantitatively increases risk for COVID-19 JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.01273-2021 SP - 2101273 AU - Fuquan Zhang AU - Ancha Baranova Y1 - 2021/01/01 UR - http://erj.ersjournals.com/content/early/2021/07/21/13993003.01273-2021.abstract N2 - The COVID-19 pandemic has raised concern about the influence of smoking and alcohol drinking behavior on the susceptibility to coronavirus infection and its severity. Widely debated, the connection remains highly controversial. Conclusions derived from observational studies commonly suffer from limited ability to discern causes and effects.One SD increase in cigarettes per day is associated with 2.5-fold increased risk for very severe COVID-19 and 2-fold increased risk for hospitalised COVID-19.We thank members of the HGI and other teams, who generously shared the GWAS data. This work was supported by the National Natural Science Foundation of China (81471364). The funders had no role in the study design; in the collection, analysis, and interpretation of data; in the writing of the report; and in the decision to submit the article for publication. ER -