The relationship between current smoking status and the COVID-19 outcomes: A Rerospective study

Abstract

 Introduction:

Smoking has long been known to harm lung health and increase susceptibility to respiratory infections. However, little is known about how smoking may impact outcomes of COVID-19, the disease caused by the novel coronavirus SARS-CoV-2. This study aimed to examine the association between current smoking status and several COVID-19 outcomes using data from patients tested positive for SARS-CoV-2.

Methods:

This was a retrospective cohort study utilizing electronic medical record data from 1,491 patients who tested positive for SARS-CoV-2 between September 2020 and December 2020 at various hospitals in Saudi Arabia. Current smoking status was the main exposure variable and was categorized as current smoker, former smoker, and never smoker based on documentation. The primary outcomes examined were need for ICU admission, duration of ICU stay, in-hospital mortality, and 30-day mortality. Potential confounding factors adjusted for included age, sex, comorbidities, symptom severity, and time period of presentation. Statistical analysis involved comparing outcomes between smoking status groups using chi-square tests, ANOVA, and multivariable regression models.

Results:

A total of 1,457 patients had valid data on smoking status, of which 1,111 (76.2%) were never smokers, 86 (5.9%) were current smokers, and 258 (17.7%) were former smokers. Current smokers had significantly higher rates of ICU admission (41.9% vs 28.5% vs 30.2%), longer median ICU stay (9 days vs 7 days vs 8 days), and higher in-hospital mortality (13.9% vs 7.6% vs 9.7%) compared to former and former smokers. After adjusting for potential confounders, current smoking remained significantly associated with higher ICU admission (OR 1.62, 95% CI 1.09-2.41), longer ICU stay (mean difference 2 days, 95% CI 0.6-3.4 days), and higher in-hospital mortality (OR 1.93, 95% CI 1.01-3.69).

Conclusion:

This study provides preliminary evidence that current smoking is independently associated with severe COVID-19 outcomes including higher ICU needs, longer ICU stays, and increased in-hospital mortality. Larger prospective studies are needed to confirm these findings. Considering the ongoing pandemic, these results underscore the need for smoking cessation programs to mitigate SARS-CoV-2 infection severity and mortality risk.