Background: The COVID-19 pandemic has affected older adults disproportionately, and delirium is a concerning consequence; however, the relationship between delirium and corticosteroid use is uncertain. The objective of the present study was to describe patient characteristics, treatments and outcomes among older adults hospitalized with COVID-19, with a focus on dexamethasone use and delirium incidence.

Methods: We completed this retrospective cohort study at 7 sites (including acute care, rehabilitation and long-term care settings) in Toronto, Ontario, Canada. We included adults aged 65 years or older, consecutively hospitalized with confirmed SARS-CoV-2 infection, between Mar. 11, 2020, and Apr. 30, 2021. We abstracted patient characteristics and outcomes from charts and analyzed them descriptively. We used a logistic regression model to determine the association between dexamethasone use and delirium incidence.

Results: During the study period, 927 patients were admitted to the acute care hospitals with COVID-19. Patients' median age was 79.0 years (interquartile range [IQR] 72.0-87.0), and 417 (45.0%) were female. Most patients were frail (61.9%), based on a Clinical Frailty Scale score of 5 or greater. The prevalence of delirium was 53.6%, and the incidence was 33.1%. Use of restraints was documented in 20.4% of patients. In rehabilitation and long-term care settings (n = 115), patients' median age was 86.0 years (IQR 78.5-91.0), 72 (62.6%) were female and delirium occurred in 17 patients (14.8%). In patients admitted to acute care during wave 2 of the pandemic (Aug. 1, 2020, to Feb. 20, 2021), dexamethasone use had a nonsignificant association with delirium incidence (adjusted odds ratio 1.38, 95% confidence interval 0.77-2.50). Overall, in-hospital death occurred in 262 (28.4%) patients in acute care settings and 28 (24.3%) patients in rehabilitation or long-term care settings.

Interpretation: In-hospital death, delirium and use of restraints were common in older adults admitted to hospital with COVID-19. Further research should be directed to improving the quality of care for this population with known vulnerabilities during continued waves of the COVID-19 pandemic.