A study published today in JAMA Network Open/Emergency Medicine supports evidence that older persons admitted to emergency departments (ED), and subsequently diagnosed positive for COVID-19, often present with delirium when they show no other typical COVID-19 symptoms, such as fever and cough. Sharon K. Inouye, MD, MPH, Director of the Aging Brain Center in the Hinda and Arthur Marcus Institute for Aging Research at Hebrew SeniorLife and Professor of Medicine at Harvard Medical School, is senior author on the study.

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Although COVID-19 poses a risk at all ages, adults aged 65 years and older are at greatest risk of severe disease, hospitalization, intensive care use, and death. Persons older than 65 years comprise 16% of the United States population yet have accounted for more than 80% of deaths in the U.S.

Delirium is an acute state of confusion, characterized by an altered level of consciousness, disorientation, inattention, and other cognitive disturbances. Beyond COVID-19, delirium is known to be a common symptom in older adults with severe disease in the ED and is associated with extended hospitalization, and increased morbidity and mortality. Despite the threat delirium poses to older ED patients, it is undetected in two-thirds of cases.

Researchers involved in the study examined 817 patients 65 or older admitted to the ED and who were diagnosed with COVID-19. They found almost a third had delirium at the time they were seen in the ED. A delirium diagnosis was the main presenting symptom for 16 percent of those patients, and 37 percent had no typical COVID-19 symptoms; delirium was the sixth most common presenting symptoms in all patients. These findings suggest the clinical importance of including delirium on checklists of presenting signs and symptoms of COVID-19 that guide screening, testing, and evaluation.

According to Dr. Inouye, "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. Thus, delirium should be considered an important presenting symptom of COVID-19."

—Hebrew SeniorLife Hinda and Arthur Marcus Institute for Aging Research