Delirium occurs often in older adults with COVID-19

Delirium represented a common symptom among older adults with COVID-19 presenting to U.S. EDs and was often seen in the absence of other typical signs or symptoms of the virus, according to findings published in JAMA.

“Anecdotally, I and many of my co-authors have seen older individuals with COVID-19 presenting with delirium and lacking the symptoms of COVID-19 that are described in the CDC case report form,” Maura Kennedy, MD, MPH, division chief of geriatric emergency medicine at Massachusetts General Hospital and assistant professor of emergency medicine at Harvard Medical School, told Healio Neurology. “There are also several case reports published that describe delirium as the sole symptom of COVID-19 infection among older individuals. Lack of provider recognition that delirium can be the sole symptom of COVID-19 could potentially contribute to a delay in diagnosis of COVID-19 infection.”

To assess how often adults aged 65 and older with COVID-19 presented to the ED with delirium, Kennedy and colleagues conducted a multicenter cohort study at 7 sites in the US. Participants included consecutive older adults presenting to the ED on or after March 13, 2020.

“We specifically wanted to understand how frequently delirium was a presenting symptom of COVID-19 infection,” Kennedy told Healio. “To do so, we focused on patients in the [ED], which is often the first point of contact a patient has with the health care system for an acute illness.”

Maura Kennedy

The researchers used a validated chart review tool to diagnose delirium, which Kennedy said “was necessary as most emergency departments do not routinely screen for delirium” and because research personnel could not screen for delirium due to COVID-19 restrictions. They noted that misclassification of delirium was possible with this method, but medical record reviewers received careful training, standardization, reliability assessments and adjudication of uncertain ratings. In addition, according to Kennedy, misclassification “typically underdiagnoses delirium.”

Among 817 older patients with COVID-19 (mean age, 77.7 years; men, 47%; white, 62%; Black, 27%; Hispanic or Latino, 7%), 226 (8%) exhibited signs of delirium at presentation; Kennedy told Healio that incidence of delirium in this study was “two to four times higher than most ED studies of delirium prior to the COVID-19 pandemic.” It was the primary symptom in 37 patients and occurred without fever, shortness of breath or other typical signs and symptoms of COVID-19 in 84 patients.

Factors that correlated with delirium included age over 75 years (adjusted RR [aRR] = 1.51; 95% CI, 1.17-1.95), living in a nursing home or assisted living facility (aRR = 1.23; 95% CI, .98-1.55), previous use of psychoactive medication (aRR = 1.42; 95% CI, 1.11-1.81), vision impairment (aRR = 1.98; 95% CI, 1.54-2.54), hearing impairment (aRR = 1.10; 95% CI, 0.78-1.55), stroke (aRR = 1.47; 95% CI, 1.15-1.88) and Parkinson’s disease (aRR = 1.88; 95% CI, 1.30-2.58).

The presence of delirium “was also predictive of worse clinical outcomes,” Kennedy told Healio, including admission to the ICU (aRR = 1.67; 95% CI, 1.30-2.15) and death (aRR = 1.24; 95% CI, 1.00-1.55).

“This study demonstrates that delirium is not only a common symptom of COVID-19, but also may be the leading and possibly sole symptom in older persons,” Sharon K. Inouye, MD, MPH, director of the Aging Brain Center at the Hinda and Arthur Marcus Institute for Aging Research in Boston, professor of medicine at Harvard Medical School and senior author of the paper, said in a press release. “Thus, delirium should be considered an important presenting symptom of COVID-19.”

While delirium occurred frequently in the study cohort, “it is not clear whether this is because COVID-19 infection is more likely to precipitate delirium than other disease processes or because our study had a large number of individuals at higher risk of developing delirium,” Kennedy said.

“I suspect it is a combination of these two factors,” she continued.

Kennedy also suggested that delirium should be added to the CDC case report form for COVID-19.

“If this is done, future research should be conducted to look at COVID-19 delirium in a larger sample and broader spectrum of health care settings,” she said.

References:

• Hebrew SeniorLife Hinda and Arthur Marcus Institute for Aging Research. Study shows delirium can signal presence of COVID-19 in asymptomatic older patients admitted to the emergency department. https://www.marcusinstituteforaging.org/press-room/article/study-shows-delirium-can-signal-presence-covid-19-asymptomatic-older-patients. Accessed Dec. 2, 2020.
• Kennedy M, et al. JAMA. 2020;doi:10.1001/jamanetworkopen.2020.29540.