Tehran University of Medical Sciences Journal of Biostatistics and Epidemiology 2383-4196 8 4 2022 12 15 410 441 Dorsa Moharerzadeh Kurd Department of Clinical Biochemistry, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran. Ali Seidkhani nahal Department of Clinical Biochemistry, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran. Ali Noori-zadeh Department of Clinical Biochemistry, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran. Atiye Sheikhabbasi Department of Clinical Biochemistry, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran Fatemeh Heydari Department of Epidemiology, Faculty of Health, Ilam University of Medical Sciences, Ilam, Iran. Iraj Pakzad Department of Medical Bacteriology, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran. Reza Pakzad 0000-0001-8133-3664 2022 08 15 2023 01 01 Background: Statins is a class of lipid-lowering drugs and our previous investigations showed that statins have antiviral effects and have a wound healing effect in the lung. This systematic review and meta-analysis aimed to evaluate the effects of statin therapy on mortality and clinical outcomes in COVID-19 patients. Methods: A comprehensive search was conducted in international databases, including MEDLINE, Scopus, Web of Science, and Embase from December 1, 2019 until January 26, 2022 without any restriction in language. The random-effects model was used to estimate the pooled odds ratio (OR). Results: The statin therapy overally was associated with decrease in odds of ventilation [pooled OR (95% CI): 0.85 (0.70 to 0.99)] and mortality [pooled OR (95% CI): 0.73 (0.66 to 0.81)] but had no effects on the  ICU admission [pooled OR (95% CI):  0.93 (0.77 to 1.12)], oxygen therapy [pooled OR (95% CI): 0.85 (0.70 to 0.99)], recovery [pooled OR (95% CI): 1.85 (0.35 to 9.92)], kidney failure [pooled OR (95% CI): 1.01 (0.73 to 1.40)], hospitalization [pooled OR (95% CI): 1.45 (0.88 to 2.36)], asymptomatic disease [pooled OR (95% CI): 1.33 (0.24 to 7.44)], and ARDS [pooled OR (95% CI): 1.15 (0.88 to 1.49)]. Conclusions: The present meta-analysis showed that statin therapy was associated with a reduced risk of mortality and ventilation in patients with COVID-19 but had no effects on other clinical outcomes. https://jbe.tums.ac.ir/index.php/jbe/article/view/1021 https://jbe.tums.ac.ir/index.php/jbe/article/download/1021/423