Outcomes of non-hospitalized patients with COVID-19 versus seasonal influenza during the fall-winter 2022-2023 period.

Abstract

Background: The comparability of outcomes for non-hospitalized COVID-19 outpatients during the Omicron wave to outpatients with influenza remains uncertain. This study aims to compare the outcomes of non-hospitalized outpatients with COVID-19 and seasonal influenza during the fall-winter of 2022-2023.

Methods: This is a retrospective cohort study using TriNetX, a collaborative clinical research platform. Non-hospitalized outpatients with COVID-19 and seasonal influenza between 01 October 2022 and 31 January 2023 were selected from TriNetX. Propensity score matching (PSM) was used to compare patients receiving corresponding outpatient antiviral treatments. Hazard ratios (HRs) with 95% confidence intervals (CIs) for the primary outcome-a composite of all-cause emergency department (ED) visits, hospitalizations, or mortality during the 30-day follow-up period-were calculated and compared.

Results: After PSM, two well-balanced groups of 9,030 patients each were identified. Non-hospitalized COVID-19 patients had a lower risk of primary composites outcomes including all-cause ED visits, hospitalization, or mortality (5.9% vs. 9.2%, HR, 0.661[95% CI, 0.593-0.737]) compared to the influenza group. In addition, the COVID-19 group demonstrated a reduced risk of all-cause ED visits (4.4% vs. 6.6%, HR 0.683[0.601-0.776]), hospitalization (1.7% vs. 2.9%, HR 0.605[0.495-0.739]) and mortality (0.1% vs. 0.2%, HR 0.176[0.052-0.597]), respectively.

Conclusions: This study indicates a lower risk of all-cause ED visits, hospitalization, and mortality in the non-hospitalized COVID-19 patients compared to the seasonal influenza group, supporting the current public health strategy of adjusting COVID-19 management based on approaches used for seasonal influenza.