Impact of Tobacco Smoking Status on Morbidity and Mortality in Patients Hospitalized with COVID-19 Pneumonia: Observational study

Abstract

Background: Determine the impact of tobacco smoking status on patients hospitalized with COVID-19 pneumonia in the need for ICU care, mechanical ventilation and mortality. Methods: We performed a retrospective cohort study, that involved chart review. All adults 18 years or older with a diagnosis of COVID-19 pneumonia hospitalized from March 15th, 2020 to May 06th, 2020 with a positive reverse transcription polymerase chain reaction (RT-PCR) nasopharyngeal swab for COVID-19. We used chi-squared test for categorical variables and student t-tests or Wilcoxon rank sum tests for continuous variables. We further used adjusted and unadjusted logistic regression to assess risk factors for mortality and intubation. Results: Among 577 patients hospitalized with COVID-19 pneumonia, 268 (46.4%) had a history of smoking including 187 former and 81 active smokers. The former smokers when compared with non-smokers were predominantly older with more comorbidities. Also, when compared with never smokers D Dimer levels were elevated in active (p=0.05) and former smokers (p<0.01). The former smokers versus non-smokers required increased need for advanced non-invasive respiratory support on admission (p<0.05), ICU care (p<0.05) and had higher mortality [1.99 (CI 95% 1.03-3.85, p<0.05)]. Active smokers versus non-smokers received more mechanical ventilation [OR 2.11 (CI 95% 1.06-4.19, p<0.05)]. Conclusions: In our cohort of hospitalized patients with COVID-19 pneumonia, former smokers had higher need for non-invasive respiratory support on admission, ICU care, and mortality compared to non-smokers. Also, active smokers versus non-smokers needed more mechanical ventilation.