Mortality trends and length of stays among hospitalized patients with COVID-19 in Ontario and Québec (Canada): a population-based cohort study of the first three epidemic waves

Yiqing Xia; Huiting Ma; David L Buckeridge; Marc Brisson; Beate Sander; Adrienne Chan; Aman Verma; Iris Ganser; Nadine Kronfli; Sharmistha Mishra; Mathieu Maheu-Giroux

International Journal of Infectious Diseases (Aug 2022)

Mortality trends and length of stays among hospitalized patients with COVID-19 in Ontario and Québec (Canada): a population-based cohort study of the first three epidemic waves

Yiqing Xia,
Huiting Ma,
David L Buckeridge,
Marc Brisson,
Beate Sander,
Adrienne Chan,
Aman Verma,
Iris Ganser,
Nadine Kronfli,
Sharmistha Mishra,
Mathieu Maheu-Giroux

Affiliations

Yiqing Xia: Department of Epidemiology and Biostatistics, School of Population and Global Health, McGill University, Montréal, QC, Canada
Huiting Ma: MAP Centre for Urban Health Solutions, St. Michael's Hospital, Unity Health Toronto, Toronto, ON, Canada
David L Buckeridge: Department of Epidemiology and Biostatistics, School of Population and Global Health, McGill University, Montréal, QC, Canada
Marc Brisson: Département de médecine sociale et préventive, Faculté de médecine, Université Laval, Québec, QC, Canada
Beate Sander: Institute of Health Policy, Management and Evaluation (IHPME), Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada; Toronto Health Economics and Technology Assessment (THETA) collaborative, University Health Network, Toronto, ON, Canada; Public Health Ontario, Toronto, ON, Canada; ICES, Toronto, ON, Canada
Adrienne Chan: Institute of Health Policy, Management and Evaluation (IHPME), Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada; Division of Infectious Diseases, Department of Medicine, University of Toronto, Toronto, ON, Canada
Aman Verma: Department of Epidemiology and Biostatistics, School of Population and Global Health, McGill University, Montréal, QC, Canada
Iris Ganser: Department of Epidemiology and Biostatistics, School of Population and Global Health, McGill University, Montréal, QC, Canada
Nadine Kronfli: Centre for Outcomes Research and Evaluation (CORE), Research Institute of the McGill University Health Centre, Montréal, QC, Canada; Department of Medicine, Division of Infectious Diseases and Chronic Viral Illness Service, McGill University Health Centre, Montréal, QC, Canada
Sharmistha Mishra: MAP Centre for Urban Health Solutions, St. Michael's Hospital, Unity Health Toronto, Toronto, ON, Canada; Institute of Health Policy, Management and Evaluation (IHPME), Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada; Division of Infectious Diseases, Department of Medicine, University of Toronto, Toronto, ON, Canada; Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada
Mathieu Maheu-Giroux: Department of Epidemiology and Biostatistics, School of Population and Global Health, McGill University, Montréal, QC, Canada; Corresponding author: Mathieu Maheu-Giroux, Department of Epidemiology and Biostatistics, School of Population and Global Health, McGill University, 2001 Avenue McGill College (Suite 1200), Montréal, QC, Canada, H3A 1G1, Phone: (+1) 514-398-5110.

Journal volume & issue: Vol. 121
pp. 1 – 10

Abstract

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Background: Epidemics of COVID-19 strained hospital resources. We describe temporal trends in mortality risk and length of stays in hospital and intensive care units (ICUs) among patients with COVID-19 hospitalized through the first three epidemic waves in Canada. Methods: We used population-based provincial hospitalization data from the epicenters of Canada's epidemics (Ontario and Québec). Adjusted estimates were obtained using marginal standardization of logistic regression models, accounting for patient-level and hospital-level determinants. Results: Using all hospitalizations from Ontario (N = 26,538) and Québec (N = 23,857), we found that unadjusted in-hospital mortality risks peaked at 31% in the first wave and was lowest at the end of the third wave at 6–7%. This general trend remained after adjustments. The odds of in-hospital mortality in the highest patient load quintile were 1.2-fold (95% CI: 1.0–1.4; Ontario) and 1.6-fold (95% CI: 1.3–1.9; Québec) that of the lowest quintile. Mean hospital and ICU length of stays decreased over time but ICU stays were consistently higher in Ontario than Québec. Conclusions: In-hospital mortality risks and length of ICU stays declined over time despite changing patient demographics. Continuous population-based monitoring of patient outcomes in an evolving epidemic is necessary for health system preparedness and response.

Published in International Journal of Infectious Diseases

ISSN: 1201-9712 (Print); 1878-3511 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Medicine: Internal medicine: Infectious and parasitic diseases
Website: http://www.journals.elsevier.com/international-journal-of-infectious-diseases/

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