Scientific article
Open access

Hospital outcomes of community-acquired COVID-19 versus influenza: Insights from the Swiss hospital-based surveillance of influenza and COVID-19

Published inEuro surveillance, vol. 27, no. 1, no. 2001848
Publication date2022-01

Background: Since the onset of the COVID-19 pandemic, the disease has frequently been compared with seasonal influenza, but this comparison is based on little empirical data.AimThis study compares in-hospital outcomes for patients with community-acquired COVID-19 and patients with community-acquired influenza in Switzerland.MethodsThis retrospective multi-centre cohort study includes patients > 18 years admitted for COVID-19 or influenza A/B infection determined by RT-PCR. Primary and secondary outcomes were in-hospital mortality and intensive care unit (ICU) admission for patients with COVID-19 or influenza. We used Cox regression (cause-specific and Fine-Gray subdistribution hazard models) to account for time-dependency and competing events with inverse probability weighting to adjust for confounders.

Results: 2020, 2,843 patients with COVID-19 from 14 centres were included. Between 2018 and 2020, 1,381 patients with influenza from seven centres were included; 1,722 (61%) of the patients with COVID-19 and 666 (48%) of the patients with influenza were male (p < 0.001). The patients with COVID-19 were younger (median 67 years; interquartile range (IQR): 54-78) than the patients with influenza (median 74 years; IQR: 61-84) (p < 0.001). A larger percentage of patients with COVID-19 (12.8%) than patients with influenza (4.4%) died in hospital (p < 0.001). The final adjusted subdistribution hazard ratio for mortality was 3.01 (95% CI: 2.22-4.09; p < 0.001) for COVID-19 compared with influenza and 2.44 (95% CI: 2.00-3.00, p < 0.001) for ICU admission.

Conclusion: Community-acquired COVID-19 was associated with worse outcomes compared with community-acquired influenza, as the hazards of ICU admission and in-hospital death were about two-fold to three-fold higher.

  • COVID-19
  • ICU
  • Influenza
  • Switzerland
  • Air-borne infections
  • Clinic
  • Epidemiology
  • Influenza
  • Influenza virus
  • Mortality
  • Severe acute respiratory syndrome – SARS
  • Surveillance
  • Viral infections
  • COVID-19
  • Cohort Studies
  • Hospital Mortality
  • Hospitalization
  • Hospitals
  • Humans
  • Influenza, Human / diagnosis
  • Influenza, Human / epidemiology
  • Intensive Care Units
  • Male
  • Pandemics
  • Retrospective Studies
  • SARS-CoV-2
  • Switzerland / epidemiology
  • European Commission - Combatting Bacterial Resistance in Europe [115523]
Citation (ISO format)
FRÖHLICH, Georg Marcus et al. Hospital outcomes of community-acquired COVID-19 versus influenza: Insights from the Swiss hospital-based surveillance of influenza and COVID-19. In: Euro surveillance, 2022, vol. 27, n° 1. doi: 10.2807/1560-7917.ES.2022.27.1.2001848
Main files (1)
Article (Published version)
Secondary files (1)
ISSN of the journal1025-496X

Technical informations

Creation03/02/2022 2:04:00 PM
First validation03/02/2022 2:04:00 PM
Update time03/16/2023 7:09:11 AM
Status update03/16/2023 7:09:08 AM
Last indexation05/06/2024 11:20:21 AM
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