A large retrospective analysis showed differences in incident dementia among five racial and ethnic groups in older adult U.S. veterans.

Given the diversity of the U.S. population, researchers in this study analyzed retrospective data to determine if the incidence of dementia varied by race and ethnicity within the Veterans Health Administration (VHA) system. Data from 1.9 million participants ≥55 years (mean age, 69 years; 2% women) who were dementia-free at baseline were included. Self-reported racial and ethnicity data were obtained from a national database, and participants were divided into 10 U.S. regions based on residential zip code data. Demographics included age, sex, and education. Comorbid conditions included hypertension, obesity, stroke or transient ischemic attack, diabetes, traumatic brain injury, post-traumatic stress disorder, and alcohol use disorder. Dementia diagnosis was determined by inpatient and outpatient diagnosis codes.

There were 0.4% American Indian or Alaska Native, 0.5% Asian, 9.5% Black, 1.0% Hispanic, and 88.6% white participants. After a mean follow-up of 10 years, 13% developed dementia. The age-adjusted incidence of dementia per 1000 person-years was 20.7 for Hispanics (95% CI, 20.1–21.3), 19.4 (95% CI, 19.2–19.6) for Blacks, 14.2 (95% CI, 13.3–15.1) for American Indians or Alaska Natives, 12.4 (95% CI, 11.7–13.1) for Asians, and 11.5 (95% CI, 11.4–11.6) for whites. Compared with whites, the increase in dementia risk was 5% in American Indians or Alaska Natives (nonsignificant), 20% in Asians, 54% in Blacks, and 92% in Hispanics in fully adjusted models. The age-adjusted dementia incidence rates were highest for Blacks and Hispanics across most U.S. regions.

COMMENT

Incident dementia rates vary by race and ethnicity within the U.S. VHA system, with Blacks and Hispanics at higher risk. Future studies are needed to determine the contributing factors associated with these differences, including the causes of dementia among these groups.