Study of >61 million US electronic health records reveals that people with dementia are at significantly increased risk of COVID-19

09/02/2021

On 9 February, a team of researchers led by Prof. Rong Xu of Case Western Reserve University (Cleveland, USA) published a study in Alzheimer's & Dementia, evaluating the risk of COVID-19 in people with dementia and their unaffected peers. The results of this study indicate that people with dementia are, on average, twice as likely to get COVID-19 compared to their unaffected peers.

This case-control study employed the electronic health records of 61.9 million adults in the US, aiming to assess how race and other demographic factors such as age and sex affect the risk of COVID-19 in people with different types of dementia.  Over 1 million adults in the population analysed had a dementia diagnosis, including over 350,000 with Alzheimer's disease and 117,000 with vascular dementia. Focusing on the risk of COVID-19 in people with different types of dementia, the highest risk was observed in people with vascular dementia, who were over 3 times as likely to have COVID-19 compared to peers without dementia (an average Odds Ratio of 3.17).  In comparison, the Odds Ratio for COVID-19 risk in people with Alzheimer's disease was 1.86, indicating that their risk of COVID-19 was similar to the broader dementia population. Overall, the researchers estimated that people with dementia had double the risk of COVID-19, corresponding to an average Odds Ratio of 2.00.

Focusing on race and ethnicity, Black people with dementia were almost three times more likely to be affected by COVID-19 compared to their White peers, even after adjusting for age, sex and other COVID-19 risk factors. COVID-19 hospitalisation rates were also much higher for Black people with dementia, with over 73% requiring hospitalisation compared to 53.8% of White people with dementia. A higher proportion of Black people with dementia died from COVID-19 (23.08%) compared to their White peers (19.23% dying from COVID-19). Overall, mortality risk from COVID-19 was substantially higher for people with dementia (20.99% mortality rate) compared to people unaffected by dementia (4.81%). Together, these results consistently identify a significantly increased risk of COVID-19 in people with dementia, especially those who are Black.  This highlights the need to protect people with dementia during the COVID-19 pandemic, to ensure their risk of COVID-19 morbidity and mortality is minimised.

https://doi.org/10.1002/alz.12296