Evolution of Positive SARS-CoV-2 Tobacco Consumer Patients From March-December 2020: Retrospective Cohort

Abstract

Background:

Smoking is a risk factor for unfavorable outcomes for other respiratory infections. This study attempts to show associations between tobacco smoking and the development of severe disease in positive SARS-CoV-2 patients. Besides determining the prevalence of smokers who are positive for SARS-CoV-2, another goal of this study was to raise awareness about the adverse effects caused by smoking on human health. We inferred that smokers with COVID-19 were at greater risk for hospitalization, ventilator requirement, oxygen requirement, and ICU admission as well as increased length of stay and duration in the mentioned therapies when compared to non-smokers.

Methods:

We analyzed 2,990 EMRs from patients who tested positive to SARS-CoV-2 from HGPS evaluated in the ER. We identified n = 75 patients with a history of smoking (S = smokers) and n = 75 non-smokers (NS = non smokers) which were matched for age, sex, and comorbidities. The hospital length of stay, incidence of admission and duration in ICU, use and duration of oxygen therapy, use and duration of mechanical ventilation, and mortality rate were obtained. It was analyzed using JASP, SPSS for relative risk (RR) and t-tests. Ethics committee approval was obtained prior to the study.

Results:

Group S was associated with longer hospital stay [mean (x) = 8.87 days] compared to group NS (x = 6.49 days) P = .032. Smokers were not at higher risk for oxygen requirement [RR = 0.98 (95% CI: 0.7675—1.2492, P = 0.877)]. There was no significant difference between S (x = 7.34 days) and NS (x = 6.19 days) in the duration of oxygen therapy (P = .38). Smokers did not show a higher risk for ICU admission [RR = 0.92 (95% CI: 0.62-1.39 P = .61)] but there was an increase in length of stay in the ICU for the S (x = 10.96 days) compared to the NS (x = 5.47 days) (P = .002). Smokers were not at higher risk for requiring mechanical ventilation [RR = 1.25 (95% CI: 0.63-2.49 P = .52)]. An increase in duration of mechanical ventilation was found in S (x = 21.93 days) compared with NS (x = 3.92) (P = .016). There was no increased risk of mortality in S compared to NS [RR = 1.75 (95% CI: 0.93-3.29) P = .083].

Conclusions:

The history of smoking significantly increased the total duration of hospitalization, ICU stay, and duration of mechanical ventilation. No significant difference was found in the risk of admission to the ICU, requirement of oxygen, ventilator requirement, or mortality. Studies with larger samples and multi-center settings are recommended.