Comparison Between Influenza and COVID-19 at a Tertiary Care Center

ABSTRACT

BackgroundWidespread reports suggest the characteristics and disease course of coronavirus disease 2019 (COVID-19) and influenza differ, yet detailed comparisons of their clinical manifestations are lacking. ObjectiveComparison of the epidemiology and clinical characteristics of COVID-19 patients with those of influenza patients in previous seasons at the same hospital DesignAdmission rates, clinical measurements, and clinical outcomes from confirmed COVID-19 cases between March 1 and April 30, 2020 were compared with those from confirmed influenza cases in the previous five influenza seasons (8 months each) beginning September 1, 2014. SettingLarge tertiary care teaching hospital in Boston, Massachusetts ParticipantsLaboratory-confirmed COVID-19 and influenza inpatients MeasurementsPatient demographics and medical history, mortality, incidence and duration of mechanical ventilation, incidences of vasopressor support and renal replacement therapy, hospital and intensive care admissions. ResultsData was abstracted from medical records of 1052 influenza patients and 583 COVID-19 patients. An average of 210 hospital admissions for influenza occurred per 8-month season compared to 583 COVID-19 admissions over two months. The median weekly number of COVID-19 patients requiring mechanical ventilation was 17 (IQR 4, 34) compared to a weekly median of 1 (IQR 0, 2) influenza patient (p=0.001). COVID-19 patients were significantly more likely to require mechanical ventilation (31% vs 8%), and had significantly higher mortality (20% vs. 3%; p<0.001 for all). Relatively more COVID-19 patients on mechanical ventilation lacked pre-existing conditions compared with mechanically ventilated influenza patients (25% vs 4%, p<0.001). LimitationThis is a single-center study which could limit generalization. ConclusionCOVID-19 resulted in more hospitalizations, higher morbidity, and higher mortality than influenza at the same hospital.