Hanzhang Xu, medical instructor; and co-investigator Wei Pan, associate professor; recently submitted their NIH/NIA R01 application entitled "Racial and Ethnic Differences in Trajectories of Subjective Memory and Objective Cognitive Function in U.S. Older Adults." Their application requests funds for a project period of April 1, 2020 until March 31, 2024.

Approximately 1-in-5 Americans age 65 and older suffer from cognitive impairment and among those experiencing some level of cognitive impairment, nearly 40% of them are currently living with Alzheimer’s disease and related dementias (ADRD). Studies have shown that the prevalence of ADRD is disproportionally higher in black and Hispanic older adults than in white older adults. Additionally, minority groups are more likely to access ADRD diagnostic and treatment services later than whites, which underscores the critical needs for early detection of ADRD in minority older adults. Increasing evidence now suggests that an individual’s perception of their memory problems (often referred to as subjective memory impairment) is one of the earliest noticeable symptoms of ADRD. Despite its promise to facilitate early identification of individuals who are at high risk of ADRD, the interrelationships among subjective memory, objective cognitive function, and diagnoses of ADRD across racial/ethnic groups are still largely unknown. To address this critical gap in knowledge, our interdisciplinary team with expertise in cognitive aging in the context of medical and social factors proposes to conduct a series of analyses using nationally representative longitudinal data from the Health and Retirement Study (HRS), HRS Genetic data, and Medicare claims. We aim to 1) identify trajectories of subjective memory and objective cognitive function in white, black, and Hispanic older adults using group-based trajectory models; 2) examine multidimensional factors (i.e., sociodemographic, psychosocial, behavioral, and physiological factors) associated with the dual-trajectory typologies of subjective memory and objective cognitive function; and 3) assess how dual-trajectory typologies are associated with clinical diagnosis of ADRD identified from Medicare claims in white, black, and Hispanic older adults. The objectives of this proposal are highly aligned with the National Institute on Aging’s (NIA) special emphasis on advancing innovative research on ADRD. Our proposal responds to this call by using multiple data sources from the largest national longitudinal study on aging in the U.S. to better understand racial/ethnic differences in cognitive aging over time. Completion of the proposed study will provide new insights into the age-related trajectories in subjective memory and objective cognitive function and how these age-related changes are associated with ADRD diagnoses in diverse older adults. Results from this project will provide much-needed evidence to address health disparities by incorporating subjective memory measures in clinical practice to facilitate early detection of ADRD, increasing self-awareness of symptoms related to ADRD in primary care or community settings, and developing novel interventions that target modifiable factors to delay and ultimately prevent the onset of ADRD.