PROJECT SUMMARY The number of people impacted by Alzheimer’s Disease and Alzheimer’s Disease Related Dementias (ADRD) is 5 million in the US alone and is expected to grow, especially in Black communities. Black older adults have a 40-80% higher incidence of ADRD and approximately double the risk of underdiagnosis. Innovative use of survey-Medicare Claims linked data holds promise to advance our understanding of disparities in timely ADRD diagnosis and their contributing factors. However, no prior research has validated this approach. Also, prior research on risk factors for delayed ADRD diagnosis has focused on individual-level characteristics that are difficult to modify. I seek to fill this gap by validating the measure of timeliness of ADRD diagnosis with respect to the survival benefits and examining placed-based structural factors associated with disparities in timely ADRD diagnosis. Residential racial segregation and geographic features of health care access are important to consider together. While unequal distribution of health care resources in segregated areas may be the primary driver of the racial disparities in timely diagnosis, residential segregation may capture unobserved features of structural racism influencing health care utilization patterns by race. These factors can be mutually reinforcing drivers of poor diagnosis in the Black population. In the K99 phase, I will conduct a robust epidemiological analysis to examine the timeliness of ADRD diagnosis related to survival using the Health and Retirement Study and the National Health and Aging Trends Study. In the R00 phase, I will examine the association between residential racial segregation or health care access features and racial disparities in the timeliness of ADRD diagnosis while extending my inquiry to the cohort from the Reasons for Geographic and Racial Disparities in Stroke study. I will also examine how the magnitude of the association between health service characteristics and timely ADRD diagnosis differs by small-area characteristics (e.g., area deprivation) and individual characteristics (e.g., education). This research plan is complemented by a training plan that builds on my background in social work and sociology, and includes new training in (1) neurodegenerative diseases, clinical assessment, and diagnostic pathways; (2) application of algorithm-based dementia assessment in surveys; (3) utilization of Medicare claims data, and (4) gaining additional sociological knowledge in linking data in residential segregation, health care access, and racial disparities related to timely ADRD diagnosis. The combined research and training plans will prepare me for a successful independent research career focused on identifying modifiable determinants of Alzheimer’s disease and related dementias, and study of the effects of policies and interventions to reduce racial disparities in ADRD. Together, these have the potential to improve prevention and care in ADRD. My mentorsh...