Reference Summary of the study Conclusions Frost et al., 2007 [25 ] Investigating the relation of mortality risk and survival time with statin therapy in influenza and COPD patients. Moderate dosage of statin treatment (≤4 mg/d) significantly reduced the mortality rate and survival time ( Kwong et al., 2009 [26 ] A cohort study of association between statins and pneumonia and influenza hospitalizations in elderly patients using data from ten influenza seasons in Ontario, Canada. No considerable reduction in morbidity and mortality of influenza has been observed in statin-treated patients. Fleming et al., 2010 [27 ] Prospective study of the effects of statin on acute respiratory infections in primary care. No beneficiary effects of statins on respiratory diseases have been observed. However, there was a kind of synergistic relation between statins and influenza vaccines. Carrillo-Esper et al., 2011 [28 ] Retrospective study of 26 patients with severe influenza in H1N1 influenza virus outbreak in 2009. Combination treatments with methyl prednisolone, activated protein C, and statins had significantly increased the survival ( Viasus et al., 2011 [29 ] Cohort study of patients in pandemic influenza A (H1N1), 2009, complicated by pneumonia. None of the therapies (corticosteroids, macrolides, and statins) were found effective to reduce the risk of severe disease. Makris et al., 2011 [30 ] A randomized controlled trial of ventilator associated pneumonia with oral pravastatin sodium. This study evidenced that pravastatin may ameliorate the frequency of viral pneumonia. Yende et al., 2011 [31 ] Association of statin usage on clinical outcome and circulating biomarkers of community-acquired pneumonia patients. Only a modest change in circulating biomarkers has been observed in statin-treated patients. Vandermeer et al., 2012 [32 ] Investigating the relation of statin therapy with influenza related death in laboratory confirmed patients of 59 countries in 10 states. Statins may have beneficiary effects on reducing mortality in hospitalized influenza patients. Papazian et al., 2013 [33 ] A randomized controlled trial of ventilator associated pneumonia with simvastatin. The result of this study does not support positive effects of simvastatin against ventilator associated pneumonia patients. Kruger et al., 2013 [34 ] A randomized controlled trial of the effects of atorvastatin on critically ill sepsis patients. This cohort study showed that continuation of atorvastatin is associated with survival improvement.
