Associations of Individual- and Neighborhood-Level Factors with Racial and Ethnic Disparities in Timely Dementia Diagnosis

BACKGROUND: Underdiagnosis of dementia disproportionately affects racial and ethnic minority groups. As disease-modifying treatments and advances in dementia care models emerge, it is critical to ensure equitable, timely detection of dementia among older adults. OBJECTIVE: To examine racial and ethnic disparities in the timely diagnosis of dementia and determine what individual- and neighborhood-level factors explain most of these disparities. DESIGN: Retrospective observational study using 1998-2020 Medicare-linked survey data. PARTICIPANTS: U.S. adults aged ≥ 65 classified as having dementia in the Health and Retirement Study (HRS), linked to Medicare claims. MAIN MEASURES: Timely diagnosis of dementia, defined as a clinical diagnosis of dementia recorded in Medicare claims within 3 years before or 1 year after the month of the HRS interview at which dementia was first observed, was compared with delayed or missed dementia diagnosis. KEY RESULTS: In this population-based study of 3, 429 U.S. older adults classified as having dementia in the HRS, non-Hispanic Black (odds ratio, 0.71 [95% CI, 0.57 to 0.89]) and Hispanic individuals (odds ratio, 0.61 [95% CI, 0.44 to 0.85]) were less likely than non-Hispanic White individuals to receive a timely diagnosis after adjusting for non-modifiable demographics and health conditions. Educational attainment explained the largest share of the disparities (48.4% for non-Hispanic Black individuals and 61.9% for Hispanic individuals). Neighborhood affluence accounted for 27.3% and 17.8%, respectively, followed by densities of health practitioner offices (15.8% and 14.6%), physician offices (9.6% and 12.4%), and dementia specialist evaluation (6.6% and 5.5%). CONCLUSIONS: A large proportion of racial and ethnic disparities in timely diagnosis among older adults with dementia were explained by educational attainment, followed by neighborhood affluence, the densities of health practitioner offices, physician offices, and dementia specialist evaluation. The findings point to key directions for targeted interventions to improve dementia detection and advance equity in dementia care.