higher for Chinese males (around 50%, against around 3% for females) (Guan et al., 2020a; Wang et al., 2020). Tobacco use was associated with a more severe form of the disease (16.9% of tobacco use in severe cases vs 11.8% in less severe cases) (Guan et al., 2020a). On the other hand, in a large US sample, current smoking was almost ten times lower than the prevalence in the general population (CDCMMWR, 2020), consistent with data from China (Farsalinos et al., 2020b). Low smoking prevalence among hospitalized COVID-19 patients in China were consistent across all studies and in agreement with case series from USA (Farsalinos et al., 2020b). The estimated prevalence of tobacco smoking in hospitalized patients is around 7% according to different meta analyses (Emami et al., 2020; Farsalinos et al., 2020b; Tindle et al., 2020). Still, recent US data report that tobacco is associated with the risk of hospitalization(Killerby et al., 2020).
