Association of Smoking Status with Severe COVID-19

Rationale. The association between smoking status and severe Coronavirus Disease-2019 (COVID-19) remains controversial. To assess the risk of 14-day hospitalization, as a marker of severe COVID-19, in patients who are ever-smokers and tested positive for the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) compared to those who are never smokers and tested positive for the virus in a single academic health system in the United States. Methods. We conducted a retrospective cohort study of patients who tested positive for SARS-CoV-2 in the University of Texas Medical Branch Health System between March 1st and October 30th 2020 to identify the risk of 14-day hospitalization in ever-smokers compared to non-smokers. Results. In our study period, we identified 5,738 patients who met the inclusion criteria and had documentation of smoking habits. Out of this group, 636 (11%) were consider to be ever-smokers. One hundred and ninety one patients were current smokers and 445 were former smokers. Of the 5,738 patients, 35.1% were male, average age was 43.8 (SD± 17.6), 37.4% were Caucasian, 51.5% were obese (BMI≥30), 3.19 % had vaping history, and 76.5% had at least one comorbidity. We identified 624 (10.8%) patients who were admitted in 14 days and 49(0.8%) who died in 14 days during hospitalization. The percentage of ever smokers admitted in 14 days was greater than that of never smokers (17.9% vs 10%, p<0.0001). In addition, the percentage of smokers who died in 14 days was greater than that of never smokers (2.8% vs 0.6%, p<0.0001). However, after adjusting for other covariates the odds for 14-day hospitalization among ever smokers with COVID-19 was not significant (OR 0.96, 95% CI 0.7-1.2). Conclusions. In our single center study, smoking status was not associated with severe COVID-19 infection.