Smoking Is Associated With COVID-19 Progression: A Meta-analysis

Smoking depresses pulmonary immune function and is a risk factor contracting other infectious diseases and more serious outcomes among people who become infected. This paper presents a meta-analysis of the association between smoking and progression of the infectious disease COVID-19.

PubMed was searched on April 28, 2020, with search terms "smoking", "smoker*", "characteristics", "risk factors", "outcomes", and "COVID-19", "COVID", "coronavirus", "sar cov-2", "sar cov 2". Studies reporting smoking behavior of COVID-19 patients and progression of disease were selected for the final analysis. The study outcome was progression of COVID-19 among people who already had the disease. A random effects meta-analysis was applied.