Low rate of daily smokers in patients with symptomatic COVID-19

Background Identification of prognostic factors in COVID-19 remains a global challenge. The role of smoking is still controversial. Objective To evaluate the rate of daily smokers in patients with COVID-19. Methods COVID-19 in-and outpatients from a large French university hospital were systematically interviewed for their smoking status, use of e-cigarette and nicotinic substitutes. The rates of daily smokers in in-and outpatients were compared to those in the 2019 French general population, after standardization for sex and age. Results The inpatient group was composed of 340 patients, median age 66 years: 203 men (59.7%) and 137 women (40.3%), median age for both 66 years, with a daily smokers rate of 4.1 % CI95% [2.3–6.9] (5.4% of men, 2.2% of women). The outpatient group was composed of 139 patients, median age 44 years: 62 men (44.6%, median age 43 years), and 77 women (55.4%, median age 44 years). The daily smoker rate was 6.1 % CI 95% [2.7 - 11.6] (5.1% of men, 6.8% of women). In the 2019 French population, the daily smoker rate was 24.0% (27.5% of men, 20.7% of women). Among inpatients, daily smokers represented 2.2% and 3.4% of the 45 dead patients and of the 29 patients transferred to ICU, respectively. The rate of daily smokers was significantly lower in COVID-19 patients, as compared to that in the French general population after standardization by age and sex, with Standardized Incidence Ratios of 0.24 [0.12-0.48] for outpatients and 0.24 [0.14-0.40] for inpatients. Conclusion Daily smokers rate in patients with symptomatic COVID-19 is lower as compared to the general population