Association Between COVID-19 and Delirium Development in the General Medical Units at an Academic Medical Center

Abstract

Introduction: Evidence suggests that inpatients who develop delirium experience worse outcomes. Although there is reason to believe that COVID-positive patients may be at a higher risk for developing delirium, little is known about the association between COVID-19 and delirium among hospitalized patients outside the intensive care unit (ICU). This study aimed to examine (1) the independent association between COVID-19 infection and the development of delirium among all non-ICU patients and (2) the risk factors associated with developing delirium among patients admitted with COVID-19, with a special focus on presenting symptoms.

Methods: Using electronic health record (EHR) data of adults admitted to any general medical unit at a large academic medical center from July 2020 through February 2021, we used a cross-sectional multivariable logistic regression to estimate the associations, while adjusting for patients' sociodemographic, clinical characteristics, delirium-free length of stay, as well as time fixed effects.

Results: Multivariable regression estimates applied to 20 509 patients hospitalized during the study period indicate that COVID-19-positive patients had 72% higher relative risk (odds ratio 1.72; 95% CI, 1.31 - 2.26; P < 0.001) of developing delirium than the COVID-19-negative patients. However, among the subset of patients admitted with COVID-19, having any COVID-19-specific symptoms was not associated with elevated odds of developing delirium compared to those who were asymptomatic, after controlling for potential confounders.

Conclusions: COVID-19 positivity was associated with higher odds of developing delirium among patients during their non-ICU hospitalization. These findings may be helpful in targeting the use of delirium prevention strategies among non-ICU patients.