People with dementia have a significantly higher risk of contracting the coronavirus, and are much more likely to be hospitalized and die from it than people without dementia, a new study of millions of medical records in the United States found.
Their risk can not be fully explained by features common to people with dementia, which are known risk factors for Covid-19: age, in a nursing home and conditions such as obesity, asthma, diabetes and cardiovascular disease. After researchers adjusted for these factors, Americans with dementia were twice as likely to get Covid-19 as late summer.
“It’s pretty convincing to suggest that there is something about dementia that makes you more vulnerable,” said Dr. Kristine Yaffe, a professor of neurology and psychiatry at the University of California, San Francisco, said, who was not involved in the study.
The study found that black people with dementia were almost three times more likely to infect white people with dementia with the virus, a finding that experts say probably reflects the fact that colored people were generally excessively disadvantaged during the pandemic.
“This study highlights the need to protect patients with dementia, especially those who are black,” the authors wrote.
Maria Carrillo, chief scientific officer of the Alzheimer’s Association, which runs the journal that published the study, Alzheimer’s and dementia, said in an interview: ‘One of the things that came out of this situation of Covid’s is that we have this should show differences. ”
The study was led by researchers from Case Western Reserve University who analyzed electronic health records of 61.9 million people aged 18 and older in the United States from February 1 to August 21, 2020. The data collected by IBM Watson Health Explorys The authors said 360 hospitals and 317,000 healthcare providers in all 50 countries participated.
Rong Xu, a professor of biomedical informatics at Case Western and the senior author of the study, said there were speculations as to whether people with dementia are more likely to be infected and harmed by Covid-19.
“We thought, ‘We have the data, we can just test this hypothesis,'” he said. Xu said.
The researchers found that out of 15,770 patients with Covid-19 in the analysis records, 810 of them also had dementia. When the researchers adjusted for common demographic factors – age, gender and race – they found that people with dementia were more than three times more likely to get Covid-19. When they adjusted for Covid-specific risk factors such as nursing home stay and underlying physical conditions, the gap widened somewhat, but people with dementia were still twice as infected.
Experts and the study authors said that the reasons for this vulnerability may include cognitive and physiological factors.
“People with dementia are more dependent on those around them to do the safety equipment, to remember to wear a mask, to keep people away by social distance,” said Dr Kenneth Langa, a professor of medicine at the University of Michigan, said was not involved in the study. “There is the cognitive impairment and the fact that they are more socially at risk,” he said.
Dr. Yaffe said there could also be a “fragility” for people with dementia, including a lack of mobility and muscle tone, which could affect their resilience to infections.
Dr. Carrillo noted that coronavirus infection is associated with an inflammatory response that has been shown to affect blood vessels and other aspects of blood circulation. Many people with dementia already have vascular disability, which can be exacerbated or exacerbated by Covid-19.
Indeed, the authors of the study subdivided patients according to the type of dementia listed in the electronic records and found that people designated as vascular dementia have a greater risk of infection than people who have Alzheimer’s disease or other types.
But dr. Langa and dr. Yaffe warns that there is a significant overlap between types of dementia. Many patients have both Alzheimer’s pathology and vascular pathology, they said, and doctors who are not specialists may not distinguish subtypes in providing codes for electronic records.
In investigating the risk of hospitalization and death for Covid patients with dementia, the researchers did not adjust for demographics such as age or whether they lived in nursing homes or had underlying medical conditions. They found that Covid patients with dementia were 2.6 times as likely to be hospitalized during the first six months of the pandemic as those without dementia. They were 4.4 times as likely to die.
Black people with Covid-19 and dementia were significantly more likely to be admitted to the hospital than white people who both had diseases. The authors did not find a significant difference in the mortality rate for black and white coronavirus patients with dementia, although they wrote that the number of deaths analyzed was 170 too small to give a thorough conclusion about it.
Experts noted that one limitation to the study was that researchers did not have access to socio-economic information, which could provide a greater understanding of patients’ risk factors.
Dr Langa also noted that the data only reflect people who interacted with the healthcare system, and therefore do not include “more isolated and poorer patients who have more difficulty getting to doctors.”
Consequently, he says, the study is possibly an underestimation of the greater risk of Covid infection for those with dementia. ‘