Rural versus Urban Residence in Adulthood and Incident Cognitive Impairment.

Introduction: Rural versus urban living is a social determinant of cognitive health. We estimated the association of rural versus urban residence in the USA with incident cognitive impairment (ICI) and assessed effect heterogeneity by sociodemographic, behavioral, and clinical factors.

Methods: The Reasons for Geographic and Racial Differences in Stroke Study (REGARDS) is a population-based prospective observational cohort of 30,239 adults, 57% female, 36% Black, aged 45+ years, sampled from 48 contiguous states in the USA in 2003-2007.

Cross-national harmonization of cognitive measures across HRS HCAP (USA) and LASI-DAD (India).

Background: As global populations age, cross-national comparisons of cognitive health and dementia risk are increasingly valuable. It remains unclear, however, whether country-level differences in cognitive function are attributable to population differences or bias due to incommensurate measurement. To demonstrate an effective method for cross-national comparison studies, we aimed to statistically harmonize measures of episodic memory and language function across two population-based cohorts of older adults in the United States (HRS HCAP) and India (LASI-DAD).

Education differentially contributes to cognitive reserve across racial/ethnic groups.

Introduction: We examined whether educational attainment differentially contributes to cognitive reserve (CR) across race/ethnicity.

Methods: A total of 1553 non-Hispanic Whites (Whites), non-Hispanic Blacks (Blacks), and Hispanics in the Washington Heights-Inwood Columbia Aging Project (WHICAP) completed structural magnetic resonance imaging. Mixture growth curve modeling was used to examine whether the effect of brain integrity indicators (hippocampal volume, cortical thickness, and white matter hyperintensity [WMH] volumes) on memory and language trajectories was modified by education across racial/ethnic groups.

Illiteracy, dementia risk, and cognitive trajectories among older adults with low education.

Objective: To investigate whether illiteracy was associated with greater risk of prevalent and incident dementia and more rapid cognitive decline among older adults with low education.

Methods: Analyses included 983 adults (≥65 years old, ≤4 years of schooling) who participated in a longitudinal community aging study. Literacy was self-reported ("Did you ever learn to read or write?").

Secular trends in cognitive trajectories of diverse older adults.

Introduction: This study aimed to determine if later birth year influences trajectory of age-related cognitive decline across racial/ethnic groups and to test whether years of school, childhood socioeconomic status, and cardiovascular disease burden explain such secular trends.

Methods: We compared cognitive trajectories of global cognition and subdomains in two successive racially/ethnically and educationally diverse birth cohorts of a prospective cohort study.

Results: Later birth year was associated with higher initial cognitive levels for Whites and Blacks, but not Hispanics.

Sex/gender differences in cognitive trajectories vary as a function of race/ethnicity.

Introduction: The present study sought to determine whether cognitive trajectories differ between men and women across and within racial/ethnic groups.

Methods: Participants were 5258 non-Hispanic White (NHW), Black, and Hispanic men and women in the Washington/Hamilton Heights-Inwood Columbia Aging Project who were administered neuropsychological tests of memory, language, and visuospatial abilities at 18- to 24-month intervals for up to 25 years. Multiple-group latent growth curve modeling examined trajectories across sex/gender by race/ethnicity.

Measurement invariance of neuropsychological measures of cognitive aging across race/ethnicity by sex/gender groups.

Objective: The purpose of this study was to evaluate the measurement invariance of a neuropsychological battery across race/ethnicity by sex/gender subgroups over repeated measurements.

Method: Participants were 6,057 non-Hispanic White (NHW), Black, and Hispanic men and women in the Washington/Hamilton Heights Inwood Columbia Aging Project (WHICAP) who were administered neuropsychological tests of memory, language, and visuospatial abilities at 18 to 24-month intervals for up to 25 years. Invariance analyses were conducted on the three-factor model across sex/gender, racial/ethnic, and sex/gender by racial/ethnic subgroups, as well as across five assessment timepoints.

Predictors of Episodic Memory Performance Across Educational Strata: Multiple-Group Comparisons.

Objectives: Low educational attainment is a risk factor for more rapid cognitive aging, but there is substantial variability in cognitive trajectories within educational groups. The aim of this study was to determine the factors that confer resilience to memory decline within educational strata.

Methods: We selected 2573 initially nondemented White, African American, and Hispanic participants from the longitudinal community-based Washington Heights/Inwood Columbia Aging Project who had at least two visits.

Normative data for Farsi-speaking Iranians in the United States on measures of executive functioning.

As the Farsi-speaking Iranian population continues to grow in the United States, examination of their cognitive performance is an imperative first step to providing this group with culturally competent services. Thirty-six healthy primarily Farsi-speaking Iranian adults completed Farsi-translated and adapted versions of three frequently used measures of executive/subcortical functioning: Wisconsin Card Sorting Test (WCST), Trail Making Test (TMT), and Color Trails Test (CTT). Participants' performance on each measure was compared to published normative data resulting in 0-85% of cognitively and medically healthy individuals being classified as impaired depending on the executive/subcortical test score examined, with the highest impairment rates for specific WCST outcome scores.