Abstract
Background: There has been sizeable speculation regarding the association between the severe Acute breathing Syndrome Coronavirus 2 (SARS-CoV-2) pathogen, coronavirus disorder (COVID-19), and smoking. Aim: This work aims to determine the link between smoking and COVID-19 infection. Materials and Methods: A systematic search was performed over different medical databases to identify Internal Medicine studies, which studied the outcome of the Smokers group versus the Non-Smokers group of COVID-19 patients. Using the meta-analysis process, either with fixed or random-effects models, we conducted a meta-analysis on the prevalence of severe cases as a primary outcome, and on mortality rate as a secondary outcome. Results: Eleven studies were identified involving 146793 patients, 11973 in the Smokers group, and 134820 in the Non-Smokers group. The meta-analysis process revealed that the pooled prevalence of severity among COVID-19 patients was (27.7%), and there is a significant increase in COVID-19 severe cases in the Smokers group compared to the Non-Smokers group (OR=2.11, P=0.032). The pooled mortality rate among COVID-19 patients was (17.2%), and there is a significant increase in mortality in the Smokers group compared to the Non-Smokers group (OR=1.76, P=0.026). Conclusion: To conclude, Patients with any smoking history are vulnerable to severe COVID-19 and worse in-hospital outcomes. In the absence of current targeted therapies, preventative and supportive strategies to reduce morbidity and mortality in current and former smokers are crucial.