Delirium and Adverse Outcomes in Hospitalized Patients with COVID-19.

Background: Little is known about the association between acute mental changes and adverse outcomes in hospitalized adults with COVID-19.

Objectives: To investigate the occurrence of delirium in hospitalized patients with COVID-19 and explore its association with adverse outcomes.

Design: Longitudinal observational study.

Setting: Tertiary university hospital dedicated to the care of severe cases of COVID-19 in São Paulo, Brazil.

Participants: A total of 707 patients, aged 50 years or older, consecutively admitted to the hospital between March and May 2020.

Measurements: We completed detailed reviews of electronic medical records to collect our data. We identified delirium occurrence using the Chart-Based Delirium Identification Instrument (CHART-DEL). Trained physicians with a background in geriatric medicine completed all CHART-DEL assessments. We complemented our baseline clinical information using telephone interviews with participants or their proxy. Our outcomes of interest were in-hospital death, length of stay, admission to intensive care, and ventilator utilization. We adjusted all multivariable analyses for age, sex, clinical history, vital signs, and relevant laboratory biomarkers (lymphocyte count, C-reactive protein, glomerular filtration rate, D-dimer, and albumin).

Results: Overall, we identified delirium in 234 participants (33%). On admission, 86 (12%) were delirious. We observed 273 deaths (39%) in our sample, and in-hospital mortality reached 55% in patients who experienced delirium. Delirium was associated with in-hospital death, with an adjusted odds ratio of 1.75 (95% confidence interval = 1.15-2.66); the association held both in middle-aged and older adults. Delirium was also associated with increased length of stay, admission to intensive care, and ventilator utilization.

Conclusion: Delirium was independently associated with in-hospital death in adults aged 50 years and older with COVID-19. Despite the difficulties for patient care during the pandemic, clinicians should routinely monitor delirium when assessing severity and prognosis of COVID-19 patients.