Comparing Clinical Outcomes of COVID-19 and Influenza-Induced Acute Respiratory Distress Syndrome: A Propensity-Matched Analysis

Acute respiratory distress syndrome (ARDS) is one the leading causes of mortality and morbidity in patients with COVID-19 and Influenza, with only small number of studies comparing these two viral illnesses in the setting of ARDS. Given the pathogenic differences in the two viruses, this study shows trends in national hospitalization and outcomes associated with COVID-19- and Influenza-related ARDS. To evaluate and compare the risk factors and rates of the adverse clinical outcomes in patients with COVID-19 associated ARDS (C-ARDS) relative to Influenza-related ARDS (I-ARDS), we utilized the National Inpatient Sample (NIS) database 2020. Our sample includes 106,720 patients hospitalized with either C-ARDS or I-ARDS between January and December 2020, of which 103,845 (97.3%) had C-ARDS and 2875 (2.7%) had I-ARDS. Propensity-matched analysis demonstrated a significantly higher in-hospital mortality (aOR 3.2, 95% CI 2.5-4.2, p < 0.001), longer mean length of stay (18.7 days vs. 14.5 days, p < 0.001), higher likelihood of requiring vasopressors (aOR 1.7, 95% CI 2.5-4.2) and invasive mechanical ventilation (IMV) (aOR 1.6, 95% CI 1.3-2.1) in C-ARDS patients. Our study shows that COVID-19-related ARDS patients had a higher rate of complications, including higher in-hospital mortality and a higher need for vasopressors and invasive mechanical ventilation relative to Influenza-related ARDS; however, it also showed an increased utilization of mechanical circulatory support and non-invasive ventilation in Influenza-related ARDS. It emphasizes the need for early detection and management of COVID-19.