IDEAS and New IDEAS: Amyloid PET in diverse populations

Abstract

AbstractBackgroundImaging biomarkers for neurodegenerative disease are understudied in diverse populations. The completed Imaging Dementia‐Evidence for Amyloid Scanning (IDEAS) and recently launched New IDEAS studies evaluate the clinical impact of amyloid PET in large samples of Medicare beneficiaries across the U.S. with MCI or dementia, enabling comparisons between patients from different racial and ethnic backgrounds.MethodAmyloid PET was performed in 18,295 IDEAS Study participants recruited from 590 clinical sites between 2016‐2018. Dementia specialists completed pre‐ and post‐PET case report forms. Medicare claims were followed for 12 months. New IDEAS will enroll 7000 Medicare beneficiaries (minimum 2000 African Americans and 2000 Latinos) with MCI or dementia at ∼350 memory clinics across the US between 2020‐2023, following analogous procedures. Quantified social determinants of health (quality of education, midlife/current income, marital status and living arrangement) will be measured. A team involving Vanderbilt University, University of North Carolina and the Alzheimer’s Association will use community engaged research principles (community stakeholders as study champions, tailored recruitment strategies) to ensure cohort diversity.ResultRecruitment in IDEAS included a low proportion of minority participants (83.9% White (N=15,568), 3.4% African American (N=639), 4.6% Hispanic (N=848), 1.8% Asian (N=328)). The proportion of positive amyloid scans was lower for African Americans (53.8%), Hispanics (54%) and Asians (45.1%) compared to Whites (62.7%). African Americans (52%), Hispanics (56%) and Asians (47%) presented more frequently with dementia (as opposed to MCI) than Whites (37%). There were disparities in vascular risk factors (hypertension/diabetes: 68%/28% African Americans, 55%/26% Hispanics, 48%/25% Asians, 50%/15% Whites) and lower educational attainment for African Americans and Hispanics. New IDEAS will examine the impact of amyloid PET on health outcomes and patient management in the total cohort and individual racial groups. A biorepository of banked plasma and DNA from 5000 participants will be established.ConclusionIDEAS demonstrated baseline differences in disease stage, risk factors and etiologies across racial and ethnic groups. New IDEAS will employ a multi‐pronged approach to improve participation of under‐represented populations and evaluate the clinical utility of amyloid PET and its relationship with social determinants of health in a diverse population of patients with cognitive impairment.