Low incidence of daily active tobacco smoking in patients with symptomatic COVID-19 infection
Makoto Miyara, Florence Tubach, Zahir Amoura
Abstract
Importance: As the pandemic of COVID-19 is still under progression, identification of prognostic factors is a global challenge. Among epidemiological risk factors, the role of smoking, to date, is unclear. Objective: To accurately evaluate a possible correlation of daily smoking with an increased susceptibility to SARS-CoV-2 infection. Participants: We estimated the rates of daily current smokers in COVID-19-infected patients in a large French university hospital between February 28th 2020 and March 30th 2020 for outpatients and from March 23rd till April 9th 2020 for inpatients. Design: The rates from both groups were compared to those of daily current smokers in the 2018 French general population, established in 2018, after standardization of the data for sex and age. Results: The inpatient group was composed of 343 patients, median age 65 yr: 206 men (60.1%, median age 66 yr) and 137 women (39.9%, median age 65 yr) with a rate of daily smokers of 4.4% (5.4% of men and 2.9% of women).The outpatient group was composed of 139 patients, median age 44 yr: 62 men (44.6 %, median age 43 yr, and 77 women (55.4 %, median age 44). The daily smokers rate was 5.3% (5.1% of men and 5.5 % of women). In the French population, the daily smokers rate is 25.4% (28.2% of men and 22.9% of women). The rate of current daily smokers was significantly lower in COVID-19 outpatients and inpatients (80.3% and 75.4%, respectively), as compared to that in the French general population with standardized incidence ratios according to sex and age of 0.197 [0.094 - 0.41] and 0.246 [0.148 - 0.408]. These ratios did not significantly differ between the two groups (P=0.63). Conclusions and relevance: Our study highlights for the first time a dramatic decreased prevalence of daily current smokers both in COVID-19 outpatients and inpatients as compared to the general population.