No studies evaluating the association between statins and outcomes of patients with seasonal influenza have been performed since the 2007-2008 and the 2009 pandemic H1N1 influenza seasons. All consecutive hospitalized patients between October 2017 and April 2018, diagnosed with laboratory-confirmed influenza A and B virus, were included. Patients were divided into two groups: statin and non-statin users. Outcomes were 30- and 90-day mortality, complications (pneumonia, myocarditis, encephalitis, intensive care unit (ICU) transfer, mechanical ventilation, vasopressor support), length of hospital stay, and readmission rates. A multivariate analysis was performed to adjust for mortality risk factors. To compare the groups, we matched patients to the nearest neighbor propensity score. Of the 526 patients ill with influenza A (201/526) and B (325/526), 36% (188/526) were statin users; 64% (338/526) were not. Statin users were older (78 vs.70; p = < 0.05) and suffered from more comorbidities (Charlson comorbidity scores of 6 vs.4; p < 0.005). The 30-day mortality rate among statin vs. non-statin users was 6% vs. 8% (p = 0.3). On multivariate analysis, statin use was not associated with mortality benefit (OR = 0.67 (0.29-1.36)). After propensity score matching, the results were unchanged (OR = 0.71 (0.29-1.71)). Statin users were diagnosed with less complicated diseases as they were less likely to receive vasopressor support, mechanical ventilation, and/or transfer to the ICU. Although statin users were significantly older and exhibited more comorbidities, 30-day mortality rates did not differ between statin users and non-users, which may signify a protective role of statins on seasonal influenza patients. Further studies performed during different influenza seasons and different subtypes are essential.
Keywords: Influenza; Mortality; Outcomes; Statins.