Trends in characteristics, interventions, and outcomes of hospitalized patients with COVID-19 in Canada: a multicentre prospective cohort study

PurposeOur objective was to investigate the temporal trends in baseline characteristics, interventions, and clinical outcomes in patients hospitalized with COVID-19 in Canada over five pandemic waves.MethodsWe conducted a multicentre prospective cohort study enrolling adults and children admitted with COVID-19 from 47 Canadian hospitals. We compared characteristics, interventions, and outcomes of patients across five distinct pandemic waves.ResultsWe enrolled 5,285 patients between 2 January 2020 and 8 February 2022. The mean (standard deviation) age was 62.6 (21.0) yr; 41.2% (n = 2,176) were female, and 48% (n = 2,539) required admission to an intensive care unit (ICU), of whom 60.3% (n = 1,530) underwent invasive mechanical ventilation. The proportion of vaccinated patients increased over time. The proportion of vaccinated hospitalized patients progressing to require ICU admission fell over pandemic waves while the proportion of unvaccinated hospitalized patients progressing to require ICU admission did not. Patients were most commonly treated with corticosteroids (48.7%; n = 2,575); use of corticosteroids and other evidence-based treatments increased over time. Hospital mortality was 22.1% (n = 1,166) among all patients, 30.2% (n = 766) among those admitted to an ICU, and 37.9% (n = 580) among those requiring invasive mechanical ventilation. Younger age, absence of chronic cardiac or pulmonary disease, severity of illness at admission, and prior vaccination was associated with a lower mortality; however, pandemic wave itself was not.ConclusionAmong patients hospitalized in Canada with COVID-19, several clinical factors including prior vaccination were associated with lower mortality, but pandemic wave was not. ObjectifNotre objectif & eacute;tait d'& eacute;tudier les tendances temporelles des caract & eacute;ristiques de base, des interventions et des issues cliniques chez la patient & egrave;le hospitalis & eacute;e pour cause de COVID-19 au Canada au cours de cinq vagues de la pand & eacute;mie.M & eacute;thodeNous avons men & eacute; une & eacute;tude de cohorte prospective multicentrique aupr & egrave;s d'adultes et d'enfants admis<middle dot>es avec la COVID-19 dans 47 h & ocirc;pitaux canadiens. Nous avons compar & eacute; les caract & eacute;ristiques, les interventions et les issues des patient<middle dot>es sur cinq vagues pand & eacute;miques distinctes.R & eacute;sultatsNous avons recrut & eacute; 5285 patient<middle dot>es entre le 2 janvier 2020 et le 8 f & eacute;vrier 2022. L'& acirc;ge moyen (& eacute;cart type) & eacute;tait de 62,6 (21,0) ans; 41,2 % (n = 2176) & eacute;taient des femmes, et 48 % (n = 2539) ont d & ucirc; & ecirc;tre admis<middle dot>es & agrave; une unit & eacute; de soins intensifs (USI), dont 60,3 % (n = 1530) ont b & eacute;n & eacute;fici & eacute; de ventilation m & eacute;canique invasive. La proportion de patient<middle dot>es vaccin & eacute;<middle dot>es a augment & eacute; au fil du temps. La proportion de patient<middle dot>es hospitalis & eacute;<middle dot>es vaccin & eacute;<middle dot>es n & eacute;cessitant une admission aux soins intensifs a diminu & eacute; au cours des vagues pand & eacute;miques, tandis que la proportion de patient<middle dot>es hospitalis & eacute;<middle dot>es non vaccin & eacute;<middle dot>es n & eacute;cessitant une admission aux soins intensifs n'a pas diminu & eacute;. Les patient<middle dot>es & eacute;taient le plus souvent trait & eacute;<middle dot>es par corticost & eacute;ro & iuml;des (48,7 %; n = 2575); l'utilisation de corticost & eacute;ro & iuml;des et d'autres traitements fond & eacute;s sur des donn & eacute;es probantes a augment & eacute; au fil du temps. La mortalit & eacute; hospitali & egrave;re & eacute;tait de 22,1 % (n = 1166) parmi l'ensemble des patient<middle dot>es, 30,2 % (n = 766) chez les personnes admises & agrave; l'unit & eacute; de soins intensifs, et 37,9 % (n = 580) parmi les personnes n & eacute;cessitant une ventilation m & eacute;canique invasive. Le jeune & acirc;ge, l'absence de maladie cardiaque ou pulmonaire chronique, la gravit & eacute; de la maladie & agrave; l'admission et la vaccination ant & eacute;rieure & eacute;taient associ & eacute;s & agrave; une mortalit & eacute; plus faible; cependant, la vague pand & eacute;mique elle-m & ecirc;me ne l'& eacute;tait pas.ConclusionParmi les personnes hospitalis & eacute;es au Canada en raison de la COVID-19, plusieurs facteurs cliniques, y compris la vaccination ant & eacute;rieure, & eacute;taient associ & eacute;s & agrave; une mortalit & eacute; plus faible, mais pas la vague pand & eacute;mique.