Representation of Older Latinxs in Cohort Studies at the Rush Alzheimer’s Disease Center

Abstract

The Rush Alzheimer’s Disease Center (RADC) conducts 5 harmonized prospective clinical-pathologic cohort studies of aging – with 1 study, the Latino Core, focused exclusively on Latinxs, 2 studies consisting of mostly non-Latinx whites, and 2 studies of mostly non-Latinx blacks. This paper contextualizes the Latino Core within the other 4 harmonized RADC cohort studies. The overall aim of the paper is to provide information from the RADC, so that researchers can learn from our participants and procedures to better advance the science of Alzheimer’s disease and related dementias in Latinxs. We describe an annual clinical evaluation that assesses risk factors for Alzheimer’s dementia among older adults without known dementia at enrollment. As all RADC cohort studies offer brain donation as a part of research participation, we discuss our approach to brain donation and subsequent participant decision-making among older Latinxs. We also summarize baseline characteristics of older Latinxs across the 5 RADC cohort studies in relation to the baseline characteristics of non-Latinx blacks and non-Latinx whites. Finally, we outline challenges and considerations as well as potential next steps in cognitive aging research with older Latinxs.

Stability and change in acculturation‐related characteristics in older Latinos: Implications for culturally compatible ADRD research

“…As previously discussed, 19 , 20 participants were self‐identified Latinos enrolled in one of three ongoing longitudinal community‐based cohort studies of aging: the Rush Memory and Aging Project (MAP; 1997 to present), 21 the RADC Latino Core (2015 to present), 20 or the Religious Orders Study (ROS; 1994 to present). These studies are identical in essential details (e.g., a harmonized protocol that includes the same acculturation measures) and enroll older Latinos free of known dementia at baseline who agree to annual, in‐home, evaluations.…”

“…As previously discussed, 19,20 At the time of these analyses, 332 Latinos had completed a baseline evaluation including our acculturation metrics (introduced at the RADC in 2016). We excluded eight participants diagnosed with dementia at baseline using a uniform structured clinical evaluation 22 and National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association criteria.…”

A Longitudinal Study of Acculturation in Context and Cardiovascular Health and Their Effects on Cognition Among Older Latino Adults

“…Participants were self‐identified Latino adults enrolled in either the Rush MAP (Memory and Aging Project) 30 or the Rush Alzheimer's Disease Center Latino Core. 31 These ongoing longitudinal cohort studies began in 1997 and 2015, respectively, as community‐based studies of aging recruiting from a variety of settings in and around Chicago. Both studies are identical in essential details (eg, overlapping and standardized evaluations of acculturation in context, cardiovascular health, and cognition).…”

“…All participants underwent a cognitive evaluation administered in an identical fashion at annual evaluations and conducted in the participant's preferred language, Spanish or English. 31 Nineteen tests assessed the following 5 cognitive domains: episodic memory, semantic memory, working memory, perceptual speed, and visuospatial ability. In addition to domain‐specific Z scores derived by converting all raw test scores to standard scores using the baseline mean and SD of the entire cohort and then averaging the Z scores of all tests for each domain, we created a global cognitive function score averaging an individual's standard scores across all 19 test scores.…”

ARTS: A novel In-vivo classifier of arteriolosclerosis for the older adult brain

“…All participants underwent cognitive function testing at least annually. In this work, performance of MAP, ROS, CC, and MARS participants in five cognitive domains (episodic memory, semantic memory, working memory, perceptual speed, visuospatial ability) was assessed using 19 cognitive tests that were common across the four studies ( Marquez et al, 2020 ). The raw scores from individual tests were first converted to z-scores: , where and are a participant’s z-score and raw score for test i , and , are the mean and standard deviation of the raw scores across participants, and the resulting z-scores were averaged into a composite score for each cognitive domain, and also averaged across all tests to obtain a composite score of global cognition ( Wilson et al, 2015 ): , where j,k are indices of the first and last tests included in a composite, and n is the number of tests included in that composite.…”