A recent study analyzed medical claims data from over 5 million Medicare beneficiaries aged 66 and older to assess the incidence and prevalence of dementia across different races, sexes, and levels of neighborhood deprivation.

Published in The BMJ, the study found that while new cases of dementia in the United States declined from 2015 to 2021, the number of individuals living with dementia increased, largely due to an aging population.

Specifically, the overall incidence of dementia decreased from 3.5% in 2015 to 2.8% in 2021, while prevalence rose from 10.5% to 11.8% during the same period.

In 2015, the incidence of dementia was higher among male beneficiaries compared to females, and this gap widened by 2021, with women representing 60% of dementia cases in that year.

The burden of dementia was particularly pronounced among Black beneficiaries and those residing in socioeconomically deprived neighborhoods, with the highest incidence rates noted in both 2015 and 2021.

These findings underscore the greater burden of dementia in marginalized and low-resource communities, highlighting the urgent need for equitable dementia care policies.

The authors of the study call for further research to explore the underlying mechanisms behind these disparities and to promote health equity measures across various demographics.

Possible explanations for the observed decline in incidence include improved management of cardiovascular risk factors and increased COVID-19 fatalities among individuals who might have been diagnosed with dementia.

Looking ahead, dementia cases are projected to more than double to nearly 14 million by 2060, raising significant social and economic concerns.

In 2021, nearly 2.9 million traditional Medicare beneficiaries, approximately 12%, were diagnosed with dementia, illustrating the widespread impact of this condition.

However, the study cautions that marginalized minorities may be underrepresented in Medicare plans, potentially obscuring true inequalities in dementia prevalence.

Limitations of the study include potential inaccuracies in Medicare claims data and a limited classification of race and ethnicity, which may not fully represent patients with different insurance types.