In-hospital outcomes of healthcare-associated COVID-19 (Omicron) versus healthcare-associated influenza: a retrospective, nationwide cohort study in Switzerland
PhD Rebecca Grant, Marlieke E A De Kraker, Niccolò Buetti, Holly Jackson, Mohamed Abbas, Jonathan Aryeh Sobel, Rami Sommerstein, Marcus Eder, Carlo Balmelli, Nicolas Troillet, Peter W Schreiber, Philipp Jent, Laurence Senn, Domenica Flury, Sarah Tschudin-Sutter, Michael Buettcher, Maria Süveges, Laura Urbini, Olivia Keiser, Ursina Roder, Stephan Harbarth, Marie-Céline Zanella, Christoph Berger, Sara Bernhard-Stirnemann, Alexia Cusini, Ulrich Heininger, Anita Niederer-Loher, Yvonne Nussbaumer-Ochsner, Reto Stocker, Danielle Vuichard-Gysin, Petra Zimmermann, Franziska Zucol
Clinical Infectious Diseases, doi:10.1093/cid/ciae558
Background: As COVID-19 is integrated into existing infectious disease control programs, it is important to understand the comparative clinical impact of COVID-19 and other respiratory diseases. Methods: We conducted a retrospective cohort study of patients with symptomatic healthcareassociated COVID-19 or influenza reported to the nationwide, hospital-based surveillance system in Switzerland. Included patients were adults (≥18 years) hospitalized for ≥3 days in tertiary care and large regional hospitals. Patients had COVID-19 symptoms and a RT-PCR-confirmed SARS-CoV-2 infection ≥3 days after hospital admission between 1 February 2022 and 30 April 2023, or influenza symptoms and a RT-PCR-confirmed influenza A or B infection ≥3 days after hospital admission between 1 November 2018 and 30 April 2023. Primary and secondary outcomes were 30-day in-hospital mortality and admission to intensive care unit (ICU), respectively. Cox regression (Fine-Gray model) was used to account for time-dependency and competing events, with inverse probability weighting to adjust for confound ing. Results: We included 2901 patients with symptomatic healthcare-associated COVID-19 (Omicron) and 868 patients with symptomatic healthcare-associated influenza from nine hospitals. We found a similar case fatality ratio between healthcare-associated COVID-19 (Omicron) (6.2%) and healthcare-associated influenza (6.1%) patients; after adjustment, patients had a comparable subdistribution hazard ratio for 30-day in-hospital mortality (0.91, 95%CI 0.67-1.24). A similar proportion of patients were admitted to ICU (2.4% COVID-19; 2.6% influenza). Conclusions: COVID-19 and influenza continue to cause severe disease among hospitalized patients. Our results suggest that in-hospital mortality risk of healthcare-associated COVID-19 (Omicron) and healthcare-associated influenza are comparable.
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doi:10.1186/s12916-023-03070-8{ 'indexed': { 'date-parts': [[2024, 11, 14]],
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'abstract': '<jats:title>Abstract</jats:title>\n'
' <jats:sec>\n'
' <jats:title>Background</jats:title>\n'
' <jats:p>As COVID-19 is integrated into existing infectious disease control '
'programs, it is important to understand the comparative clinical impact of COVID-19 and other '
'respiratory diseases.</jats:p>\n'
' </jats:sec>\n'
' <jats:sec>\n'
' <jats:title>Methods</jats:title>\n'
' <jats:p>We conducted a retrospective cohort study of patients with '
'symptomatic healthcare-associated COVID-19 or influenza reported to the nationwide, '
'hospital-based surveillance system in Switzerland. Included patients were adults (≥18 years) '
'hospitalized for ≥3 days in tertiary care and large regional hospitals. Patients had COVID-19 '
'symptoms and a RT-PCR-confirmed SARS-CoV-2 infection ≥3 days after hospital admission between '
'1 February 2022 and 30 April 2023, or influenza symptoms and a RT-PCR-confirmed influenza A '
'or B infection ≥3 days after hospital admission between 1 November 2018 and 30 April 2023. '
'Primary and secondary outcomes were 30-day in-hospital mortality and admission to intensive '
'care unit (ICU), respectively. Cox regression (Fine-Gray model) was used to account for '
'time-dependency and competing events, with inverse probability weighting to adjust for '
'confounding.</jats:p>\n'
' </jats:sec>\n'
' <jats:sec>\n'
' <jats:title>Results</jats:title>\n'
' <jats:p>We included 2901 patients with symptomatic healthcare-associated '
'COVID-19 (Omicron) and 868 patients with symptomatic healthcare-associated influenza from '
'nine hospitals. We found a similar case fatality ratio between healthcare-associated COVID-19 '
'(Omicron) (6.2%) and healthcare-associated influenza (6.1%) patients; after adjustment, '
'patients had a comparable subdistribution hazard ratio for 30-day in-hospital mortality '
'(0.91, 95%CI 0.67-1.24). A similar proportion of patients were admitted to ICU (2.4% '
'COVID-19; 2.6% influenza).</jats:p>\n'
' </jats:sec>\n'
' <jats:sec>\n'
' <jats:title>Conclusions</jats:title>\n'
' <jats:p>COVID-19 and influenza continue to cause severe disease among '
'hospitalized patients. Our results suggest that in-hospital mortality risk of '
'healthcare-associated COVID-19 (Omicron) and healthcare-associated influenza are '
'comparable.</jats:p>\n'
' </jats:sec>',
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