Investigating the Association Between Smoking and Death in Patients With COVID-19 in Iran: A Meta-analysis Study

With reducing the immune function of the pulmonary, smoking is considered a risk factor for contracting other infections with more severe outcomes. The present study investigates a meta-analysis of the association between smoking and the progression of COVID-19 infection in Iran.

The online databases of PubMed/MEDLINE and Web of Science were searched on August 23, 2022, with the following terms: (‘‘COVID-19’’ OR ‘‘SARS-CoV-2’’ OR ‘‘Coronavirus’’), AND (‘‘smoking’’ OR ‘‘smoker*’’), AND (“Iran”). In this review, we included the studies with molecular-confirmed cases of COVID-19 and the outcome of death. The Mantel-Hensel meta-analysis method with random effects was used to investigate the relationship in the data.

We identified 8 papers with a total of 9199 COVID-19 patients, of whom 1861(20.2%) had the outcome of death, and 1105(12%) had a history of smoking. A total of 274 patients with a history of smoking (24.7%) were dead. The meta-analysis showed a significant association between smoking and death related to COVID-19 (odds ratio=1.22, 95% confidence interval [1.03-1.44], P=0.001). Therefore, the probability of death in COVID-19 patients with a history of smoking is about 22% higher than other people.

Smoking is a risk factor for the progression of COVID-19, with smokers having higher odds of COVID-19 progression than non-smokers.