Smoking Status, Nicotine Medication, Vaccination, and COVID-19 Hospital Outcomes: Findings from the COVID EHR Cohort at the University of Wisconsin (CEC-UW) Study
Authors: Piasecki Thomas M , Smith Stevens S , Baker Timothy B , Slutske Wendy S , Adsit Robert T , Bolt Daniel M , Conner Karen L , Bernstein Steven L , Eng Oliver D , Lazuk David , Gonzalez Alec , Jorenby Douglas E , D’Angelo Heather , Kirsch Julie A , Williams Brian S , Nolan Margaret B , Hayes-Birchler Todd , Kent Sean , Kim Hanna , Lubanski Stan , Yu Menggang , Suk Youmi , Cai Yuxin , Kashyap Nitu , Mathew Jomol P , McMahan Gabriel , Rolland Betsy , Tindle Hilary A , Warren Graham W , An Lawrence C , Boyd Andrew D , Brunzell Darlene H , Carrillo Victor , Chen Li-Shiun , Davis James M , Deshmukh Vikrant G , Dilip Deepika , Ellerbeck Edward F , Goldstein Adam O , Iturrate Eduardo , Jose Thulasee , Khanna Niharika , King Andrea , Klass Elizabeth , Mermelstein Robin J , Tong Elisa , Tsoh Janice Y , Wilson Karen M , Theobald Wendy E , Fiore Michael C 
Published: September 2022

Introduction

Available evidence is mixed concerning associations between smoking status and COVID-19 clinical outcomes. Effects of nicotine replacement therapy (NRT) and vaccination status on COVID-19 outcomes in smokers are unknown.

Methods

Electronic health record data from 104 590 COVID-19 patients hospitalized February 1, 2020 to September 30, 2021 in 21 U.S. health systems were analyzed to assess associations of smoking status, in-hospital NRT prescription, and vaccination status with in-hospital death and ICU admission.

Results

Current (n = 7764) and never smokers (n = 57 454) did not differ on outcomes after adjustment for age, sex, race, ethnicity, insurance, body mass index, and comorbidities. Former (vs never) smokers (n = 33 101) had higher adjusted odds of death (aOR, 1.11; 95% CI, 1.06–1.17) and ICU admission (aOR, 1.07; 95% CI, 1.04–1.11). Among current smokers, NRT prescription was associated with reduced mortality (aOR, 0.64; 95% CI, 0.50–0.82). Vaccination effects were significantly moderated by smoking status; vaccination was more strongly associated with reduced mortality among current (aOR, 0.29; 95% CI, 0.16–0.66) and former smokers (aOR, 0.47; 95% CI, 0.39–0.57) than for never smokers (aOR, 0.67; 95% CI, 0.57, 0.79). Vaccination was associated with reduced ICU admission more strongly among former (aOR, 0.74; 95% CI, 0.66–0.83) than never smokers (aOR, 0.87; 95% CI, 0.79–0.97).

Conclusions

Former but not current smokers hospitalized with COVID-19 are at higher risk for severe outcomes. SARS-CoV-2 vaccination is associated with better hospital outcomes in COVID-19 patients, especially current and former smokers. NRT during COVID-19 hospitalization may reduce mortality for current smokers.

Implications

Prior findings regarding associations between smoking and severe COVID-19 disease outcomes have been inconsistent. This large cohort study suggests potential beneficial effects of nicotine replacement therapy on COVID-19 outcomes in current smokers and outsized benefits of SARS-CoV-2 vaccination in current and former smokers. Such findings may influence clinical practice and prevention efforts and motivate additional research that explores mechanisms for these effects.