COVID-19 Disease Severity Correlates with Smoking Status

The novel COVID-19 disease is a contagious acute respiratory infectious disease whose causative agent has been demonstrated to be a new virus of the coronavirus family, SARS-CoV-2. Multiple studies have already reported that risk factors for severe disease include older age and the presence of at least one of several underlying health conditions. However, a recent physiopathological report and the French COVID-19 scientifific council have postulated a protective effect of tobacco smoking. We have been able to demonstrate the statistical signifificance in this regard of recent series from both China and in the US, reporting smoking status as well as disease severity (p-values of 2.27 × 10 3 and 11.7 × 10 15, respectively). Subsequently and using a Bayesian approach we have established that disease severity is positively associated with smoking status. Finally, we refute claims linking general population smoking status (N in O(108) or O(109)) to much smaller disease course series (N in O(103)). The latter point in particular is presented to stimulate academic discussion, and must be further investigated by well-designed studies.