Cognitive Trajectories and Associated Social and Behavioral Determinants Among Racial/Ethnic Minority Older Adults in the United States.

Background and objectives: Despite higher risks of developing Alzheimer's disease and Alzheimer's disease-related dementias (AD/ADRD) among racial/ethnic minority populations, some maintain good cognition until old age. This study aimed to investigate heterogeneous cognitive trajectories among non-Hispanic Black and Hispanic older adults, examine cognitive impairment prevalence across trajectory classes, and identify associated social and behavioral determinants.

Research design and methods: Using 11 waves of data from the Health and Retirement Study (1996-2016), 1,322 non-Hispanic Black and 747 Hispanic adults aged 50 + with normal cognition in 1996 were included. Latent class growth modeling and multinomial logistic regressions were performed to examine cognitive trajectories and associated determinants.

Results: For both racial/ethnic groups, three trajectory classes were identified: high, medium, and low cognition. In the low cognition class, 87% and 100% of non-Hispanic Black and Hispanic participants developed cognitive impairment. For both racial/ethnic groups, older age and living in rural areas during school time increased the likelihood of being in the low cognition class, while more education was associated with a lower likelihood. Unique risk and protective determinants for non-Hispanic Black and Hispanic participants were also identified.

Discussion and implications: This study reveals the heterogeneity of cognitive trajectories among racial/ethnic minority older adults and various associated social and behavioral determinants. More prevention interventions and accessible, affordable diagnosis and treatment should be provided to older racial/ethnic minorities with these characteristics to reduce disparities. More research is needed to further explore associations between unique determinants and cognition in racial/ethnic minority populations to better inform interventions.