CWRU Study: Dementia Patients Twice As Likely To Get COVID-19

Dementia patients are twice as likely to contract COVID-19 and are at a significantly higher risk for severe outcomes and death, according to a new Case Western Reserve University (CWRU) study released Tuesday.

An analysis of nearly 62 million electronic medical records found those with dementia were two times as likely to become infected with COVID-19, and vascular dementiapatients are three times as likely.

The findings are not a total surprise because dementia patients commonly have comorbidities also associated with more severe outcomes of COVID-19, such as hypertension, high blood pressure, and diabetes, said Rong Xu, the study’s co-author and a professor of biomedical informatics at CWRU.

However, even when these factors were controlled for in the analysis, dementia patients were still significantly at higher risk, said Dr. Pamela Davis, co-author and professor of general medical sciences.

“The key finding was that, over and above the shared risk factors for COVID and dementia, dementia was an independent risk factor for contracting COVID, and doing worse,” Davis said.

Racial disparities are revealed through the data as well, Davis said. Not only were African American dementia patients three times more likely than white patients to contract the virus, but also more likely to be hospitalized and die from it.

“That is consistent with other studies in COVID infections, that African Americans are more likely to acquire SARS-CoV-2, and also do worse once they get it. It’s certainly a vulnerable population, and one that’s important to protect,” Davis said.

An estimated 5.8 million Americans age 65 and older are living with Alzheimer's and other types of dementia, according to the Alzheimer’s Association. Caretakers and loved ones of dementia patients should take extra precautions to prevent them from getting the virus because of this increased risk, Davis said.

“In the absence of sufficient vaccine, those families need to be assiduous with masking and distancing and cleaning, and cleaning hands, and all that, I think even more so than the rest of us,” she said.

While more follow-up research is needed to determine exactly why dementia patients had much higher rates of infection and severe outcomes, Xu and Davis speculate there are multiple reasons behind the numbers.

One possible explanation is that many dementia patients live in congregate settings, which have struggled to contain COVID-19 outbreaks, Davis said.

In Ohio, nursing homes and other congregate living facilities were prioritized in the first group for the COVID-19 vaccine, but about 60 percent of nursing home employees reportedly declined to get the shot, Davis said. The dementia study re-emphasizes the importance of nursing home staff members getting the vaccine, Davis said.

“It would be really helpful to encourage that as much as possible, to protect the vulnerable people,” she said.

Another possible reason for the increased COVID-19 risk in patients is that dementia impacts short-term memory, which could cause patients to forget to take precautions such as washing their hands and wearing masks, Davis said.

Also, dementia damages a person’s blood-brain barrier, which is made up of cells that protect the body from circulating toxins and pathogens. This might make it easier for COVID-19 to enter the patient’s body, she said.

In addition to learning more about the factors behind the increased risk, researchers also want to examine whether the long-term effects of COVID-19 could impact a person’s dementia, Davis said.

“We don’t know yet whether the dementia will accelerate with the COVID, so I think it’s very important to keep an eye on this population,” she said.

The database used by researchers for the study included medical records from 360 hospitals and 317,000 providers across the nation, representing 20 percent of the U.S. population, Xu said. More than one million people in the study had dementia, 15,770 had COVID-19 and 810 had both.

The study was published Tuesday in the peer-reviewed medical journal Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.