Evolution of COVID-19 mortality over time: results from the Swiss hospital surveillance system (CH-SUR)

Article Article scientifique Article Evolution of COVID-19 mortality over time: results from the Swiss hospital surveillance system (CH-SUR) eng 2021-11-24 2021-11-24 author Roelens Maroussia 828632 author Martin Alexis 752309 author Friker Brian author Sousa Filipe Maximiano author Thiabaud Amaury 901139 author Vidondo Beatriz author Buchter Valentin author Gardiol Céline author Vonlanthen Jasmin author Balmelli Carlo author Battegay Manuel author Berger Christoph author Buettcher Michael author Cusini Alexia author Flury Domenica author Heininger Ulrich author Niederer-Loher Anita author Riedel Thomas author Schreiber Peter W author Sommerstein Rami author Troillet Nicolas author Tschudin-Sutter Sarah author Vetter Pauline 673142 author Bernhard-Stirnemann Sara author Corti Natascia author Gaudenz Roman author Marschall Jonas author Nussbaumer-Ochsner Yvonne author Senn Laurence author Vuichard-Gysin Danielle author Zimmermann Petra author Zucol Franziska author Iten Anne Clemence Marie 31054 author Keiser Olivia 0000-0001-8191-2789 873427 CH-SUR study group w30105 10.4414/smw.2021.w30105 34843180 1424-7860 https://smw.ch/article/doi/smw.2021.w30105 Background: When the periods of time during and after the first wave of the ongoing SARS-CoV-2/COVID-19 pandemic in Europe are compared, the associated COVID-19 mortality seems to have decreased substantially. Various factors could explain this trend, including changes in demographic characteristics of infected persons and the improvement of case management. To date, no study has been performed to investigate the evolution of COVID-19 in-hospital mortality in Switzerland, while also accounting for risk factors. Methods: We investigated the trends in COVID-19-related mortality (in-hospital and in-intermediate/intensive-care) over time in Switzerland, from February 2020 to June 2021, comparing in particular the first and the second wave. We used data from the COVID-19 Hospital-based Surveillance (CH-SUR) database. We performed survival analyses adjusting for well-known risk factors of COVID-19 mortality (age, sex and comorbidities) and accounting for competing risk. Results: Our analysis included 16,984 patients recorded in CH-SUR, with 2201 reported deaths due to COVID-19 (13.0%). We found that overall in-hospital mortality was lower during the second wave of COVID-19 than in the first wave (hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.63- 0.78; p<0.001), a decrease apparently not explained by changes in demographic characteristics of patients. In contrast, mortality in intermediate and intensive care significantly increased in the second wave compared with the first wave (HR 1.25, 95% CI 1.05-1.49; p = 0.029), with significant changes in the course of hospitalisation between the first and the second wave. Conclusion: We found that, in Switzerland, COVID-19 mortality decreased among hospitalised persons, whereas it increased among patients admitted to intermediate or intensive care, when comparing the second wave to the first wave. We put our findings in perspective with changes over time in case management, treatment strategy, hospital burden and non-pharmaceutical interventions. Further analyses of the potential effect of virus variants and of vaccination on mortality would be crucial to have a complete overview of COVID-19 mortality trends throughout the different phases of the pandemic. COVID-19 Hospital Mortality Hospitals Humans Pandemics SARS-CoV-2 Switzerland / epidemiology Dewey 613 66 Institut de santé globale 22A1 false 1246 Maladies infectieuses et modèles mathématiques 988 Swiss medical weekly 151 22bd1c12-1637-4818-bdaf-760af3526b56 Article (Published version) Public Roelens_smw_151_w30105.pdf 2448368 application/pdf CC BY-NC-SA-4.0 openAccess Faculté de médecine / Section de médecine clinique / Département de santé et médecine communautaires / Institut de santé globale

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Evolution of COVID-19 mortality over time: results from the Swiss hospital surveillance system (CH-SUR)	Swiss medical weekly			2021	421	175

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Martin, Alexis