COVID-19-Related Delirium Associated with Increased Length of Stay and Mortality

We set out to determine the impact of delirium and COVID-19 on length of stay and mortality. For this study, we conducted a retrospective cohort study of patients aged >65 years admitted to the Owensboro Health Regional Hospital between August 2021 and December 2023. Delirium was determined based on a score of ≥2 on the Nurse Delirium Screening Scale (NuDESC) recorded on all admitted patients three times a day during nursing shift change. Multivariate logistic regression models were used to evaluate the association between delirium, COVID-19, or both on 30-day, 60-day, 90-day, 180-day, 360-day mortality, adjusting for age, sex, race, smoking status, diabetes, hypertension, dementia, COPD, obesity, heart failure, and heart disease. A total of 4872 hospitalized patients were included in the study. Of these, 698 (14.3%) were identified as having delirium and 4174 (85.7%) as without delirium. Patients with delirium were slightly older than those without (79.5 ± 8.6 years old vs. 77.0 ± 7.9). After adjusting for comorbidities, delirium was associated with an increase of 3.3 hospitalization days (8.6 ± 9.6 days vs. 5.3 ± 5.6 p < 0.01). Delirium was associated with higher 30-day, 60-day, 90-day, 180-day, and 360-day mortality rates. COVID-19-positive patients with delirium had 717% higher odds of 30-day mortality compared to the COVID-19-negative patients without delirium (aOR 8.17 95% CL 4.60–14.3).