impact of smoking on the mortality of hospitalized patients with covid-19, iran: a cross-sectional study

Background: there are inconsistent data about the association of smoking with the prognosis of hospitalized patients with covid-19. this inconsistency is so huge that some investigators have suggested some protective roles for smoking against covid-19 disease. objective: this study was designed to investigate the association of smoking with mortality in hospitalized patients with covid-19. methods: this cross-sectional study was conducted on 493 adult patients with covid-19 disease. other underlying diseases, clinical and laboratory findings, and mortality rates were compared between smoking and non-smoking patients using univariate and multivariate analyses. results: the prevalence of current smoking among hospitalized patients was 6.1%. clinical complaints and disease severity at admission were similar between smokers and non-smokers. leukocyte count and blood sugar were higher in smokers compared to non-smokers (p=0.003, p=0.018, respectively). the rate of icu admission and days of hospitalization were comparable between smokers and non-smokers. however, smokers had a significantly higher mortality rate than non-smokers (36.7% vs 13.8%, respectively, p=0.001). after adjusting for significantly different variables in univariate analysis, smoking was associated with a 3.78 times higher mortality rate (or=3.78, 95% ci: 1.48-9.67, p=0.005). conclusion: smoking is an independent predictor of mortality in hospitalized patients with covid-19.