ASSOCIATION BETWEEN COVID-19 AND DELIRIUM DEVELOPMENT IN ACUTE CARE UNITS AT AN ACADEMIC MEDICAL CENTER

ABSTRACT

BACKGROUND: In studies of COVID-19 patients, delirium is associated with functional impairments, increased length of stay (LOS), and mortality, though the condition is often under-detected. To date, no research has examined the impact of COVID-19 on the likelihood of developing delirium while hospitalized. Using a validated delirium screening tool, we examined 1) the association between COVID-19 diagnosis and incidence of delirium among patients admitted to acute care units at a large, urban academic hospital, and 2) factors associated with the incidence of delirium among patients admitted with COVID-19. METHODS: The study population consists of all adult patients admitted to acute care units at Froedtert & the Medical College of Wisconsin from July 2020 to February 2021. Patients were excluded if they had delirium at admission, were admitted from an ICU, or had history of a psychiatric diagnosis. Delirium was assessed using Nursing Delirium Screening Scale (NuDESC). Screening occurred every 8 hours;patients scoring ≥ 2 were considered delirious. COVID-positivity was assessed via Polymerase Chain Reaction (PCR) test prior to admission or after admission but prior to delirium onset. A multivariate logistic regression was used to estimate the association between COVID-19 status and odds of developing deliriumduring the hospital stay, adjusting for demographics, financial vulnerability (uninsured or Medicaid enrollees), comorbidities, and time fixed effects. RESULTS: 20,509 patients were included. The mean age was 55.6 (SD=19.7), with 9,768 (47.6%) >60. 11,553 (56.3%) were female. 4,351 (21.2%) were considered financially vulnerable. 374 patients (1.8%) tested positive for COVID-19. 2,278 patients (11.1%) developed delirium. Of COVID-positive patients, the incidence rate of developing delirium rose to 18.2%.On average, COVID-positive patients had 62%higher relative risk (OR 1.62, 95% CI 1.24-2.14, p=.001) of developing delirium than COVID-negative patients. This result persisted in sensitivity analyses where we also controlled for patients' LOS. Development of delirium was associated with male sex (OR 1.30, 95%CI 1.18-1.42, p=.000), Black race (OR 1.62, 95%CI 1.18-1.42, p=.000), Hispanic ethnicity (OR 1.33, 95%CI 1.05-1.69, p=.017), financial vulnerability (OR 1.63, 95%CI 1.42-1.89, p=.000), and age >40. Among COVID-positive patients, development of delirium was associated with male sex (OR 2.39, 95%CI 1.41-4.06, p=.000), and age >60. We found no evidence that the presence of specific COVID-19 symptom(s) increased the odds of developing delirium compared to asymptomatic COVID-19-positive patients. CONCLUSIONS: Patients with COVID-19 were significantly more likely to develop delirium during their hospital stay than their COVID-19 negative counterparts, even after controlling for confounding. Among COVID-19 positive patients, patients >60 are especially vulnerable. Providers should proactively assess delirium among COVID-19 patients, with a particular focus on the elderly.