University of Wisconsin–Madison Medical College of Wisconsin

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

Yilu Dong, PhD; Ryan Hanson, MS; Annie C. Penlesky, MPH; Ann B. Nattinger, MD, MPH; Thomas W. Heinrich, MD; Liliana E. Pezzin, PhD, JD

WMJ. 2023;122(5):319-324

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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.

Author Affiliations: Collaborative for Healthcare Delivery Science, Medical College of Wisconsin, Milwaukee, Wisconsin (Dong, Hanson, Penlesky, Nattinger, Heinrich, Pezzin).
Corresponding Author: Yilu Dong, PhD, Collaborative for Healthcare Delivery Science, Medical College of Wisconsin, 999 N 92nd St, Milwaukee, WI 53226; phone 414.337.7706; email; ORCID ID 0000-0001-6859-9759
Funding/Support: None declared.
Financial Disclosures: None declared.
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