Abstract
BACKGROUND: Few studies have shown that smokers are more likely than non-smokers to have coronavirus disease 2019 (COVID-19), whereas some reports indicate that smokers are under-represented among those requiring hospital treatment for this illness. This study was designed and implemented for investigating the severity and outcome of COVID-19 based on smoking. MATERIALS AND METHODS: This was a cross-sectional study implemented in Tehran and Ahvaz with all COVID-19 hospitalization patients from February to June 2021. Four categories selected for severity and worst outcomes. They are admission in the intensive care unit (ICU), lung involvement more than 50%, using more than three medications, and death. A check list of demographic data and smoking history was completed and analyzed. RESULTS: A total of 11,112 patients were male (61.1%), and the mean age was 47.9 ± 11.3. A total of 1508 smokers (8.3%) were seen with any type of tobacco consumption. The frequency of ICU admission in the smokers is significantly higher than that in non-smokers (23.9% vs. 18.8%). A total of 668 (44.3%) smokers had more than 50% ground glass opacity in lungs, whereas 5340 non-smokers (32.1%) had so. Use of more than three medications in the smokers was significantly higher (70.6% vs. 52%). A comparison between patients based on smoking indicates that the death rate was significantly higher in smokers (31.6% vs. 25.6%). CONCLUSIONS: Although smoking rates in COVID-19 patients are lower than those in the general population, the consequences and mortality are higher in smokers.