Export Objective: Although smoking is a major known risk factor for respiratory disease, the effect of smoking on coronavirus disease 2019 (COVID-19) is to be studied. The aim of this study was to determine the effect of smoking on the clinical progress of patients with COVID-19 infection. Methods: This was a cohort prospective study including 125 who had an infection with SARS-CoV-2, admitted according to WHO guidelines to Al-Kindy Teaching Hospital during the period from 1st April to 1st September 2021. Patients were categorized into three groups according to their smoking status: never-smokers (50 patients), current smokers (50 patients), and ex-smokers (25 patients). Patients were followed-up until they were discharged from the hospital or entered the respiratory care unit (RCU). Results: Out of 125 included patients, 24 patients (19.2%) required RCU admission. Such admission was more common among current smokers (28%) and ex-smokers (24%) compared with nonsmokers (8%), with significant differences. The mean SpO2 in nonsmokers was 93.0%±4.53%, which was significantly higher than that of current smokers (89.26%±5.59%) and ex/smokers (90.12%±4.82%). Two clinical symptoms were significantly associated with smoking. The frequency of shortness of breath and cough in nonsmokers was 64% and 62%, respectively, compared with 82% and 86%, respectively, in current smokers and 92% and 80%, respectively, in ex-smokers with a significant difference, the difference is mainly between the nonsmokers on one side and the current and ex-smokers on the other side while the difference between the current and ex-smokers is not significant. Conclusions: About one-fifth of patients with COVID-19 need for RCU admission regardless of their smoking status. However, the requirement for RCU admission is significantly more common in current and ex-smoker patients compared with nonsmoker. Smoking (whether current or previous) is associated with lower SpO2 and more common need for NRBM and CPAP ventilations.
Hussein et al. (Sun,) studied this question.