The landmark study, which concluded that the incidence of the brain disorder to be the lowest among Asian Americans, has compared six ethnic and racial groups within the same geographic population and found significant variation in dementia incidence among them.
According to the lead author Elizabeth Rose Mayeda, postdoctoral fellow at University of California, San Francisco, “This is the only research that directly compares dementia for these six racial and ethnic groups, representing the true ageing demographic of the United States in a single study population”. This is the first study to look at dementia risk in a large population representing the diversity of the United States, also the largest and longest study thus far of ethnic disparities in dementia risk.
The researchers found dementia incidence to be highest in Blacks and American Indian/Alaska Natives, lowest among Asian Americans, and intermediate among Latinos, Pacific Islanders and Whites. The researchers found that dementia incidence over the study period ranged from an average annual rate of 26.6 cases per 1,000 for Blacks, and 22.2 cases per 1,000 for American Indians/Alaskan Natives, to 15.2 cases per 1,000 for Asian Americans.
The study population included over 274,000 Northern California members of Kaiser Permanente, the nation’s largest private integrated health care system with over 10 million members.
The researchers used electronic health records covering patient visits over 14 years , from the period (January 2000 through December 2013), to identify participants diagnosed with dementia, as well as their race and ethnicity.
The results were published online in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.