Disparities Among Older Adults in Measures of Cognitive Function by Race or Ethnicity

Establishment, Prediction, and Validation of a Nomogram for Cognitive Impairment in Elderly Patients With Diabetes

Objective: The purpose of this study is to establish a predictive model of cognitive impairment in elderly people with diabetes. Methods: We analyzed a total of 878 elderly patients with diabetes who were part of the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2014. The data were randomly divided into training and validation cohorts at a ratio of 6:4. The least absolute shrinkage and selection operator (LASSO) logistic regression analysis to identify independent risk factors and construct a prediction nomogram for cognitive impairment. The performance of the nomogram was assessed using receiver operating characteristic (ROC) curve and calibration curve. Decision curve analysis (DCA) was performed to evaluate the clinical utility of the nomogram. Results: LASSO logistic regression was used to screen eight variables, age, race, education, poverty income ratio (PIR), aspartate aminotransferase (AST), blood urea nitrogen (BUN), serum uric acid (SUA), and heart failure (HF). A nomogram model was built based on these predictors. The ROC analysis of our training set yielded an area under the curve (AUC) of 0.786, while the validation set showed an AUC of 0.777. The calibration curve demonstrated a good fit between the two groups. Furthermore, the DCA indicated that the model has a favorable net benefit when the risk threshold exceeds 0.2. Conclusion: The newly developed nomogram has proved to be an important tool for accurately predicting cognitive impairment in elderly patients with diabetes, providing important information for targeted prevention and intervention measures.

Measurement invariance of a neuropsychological battery across urban and rural older adults in Costa Rica

This study evaluated the measurement invariance of a neuropsychological battery across rural and urban older adults from Costa Rica. Rural and urban older adults (N = 295) from the Epidemiology and Development of Alzheimer's Disease (EDAD) study in Costa Rica were assessed. The baseline factor model for the EDAD neuropsychological measures was identified with nine neuropsychological measures and three cognitive constructs: Verbal Memory, Spatial Reasoning, and Cognitive Flexibility. Measurement and structural invariance were established, and, then, group comparisons of the latent cognitive factors were conducted to explore regional disparities. The findings showed that most of the neuropsychological tests in EDAD can be directly compared across the groups, allowing for cognitive constructs comparisons. The rural sample showed a disadvantage in the Spatial Reasoning and Cognitive Flexibility abilities. When age and education were included in the models, differences between the regions disappeared. Having more years of education was associated with higher cognitive abilities, with a larger effect for the rural group. Norms for Costa Rican older adults should consider age and education adjustments. This study contributes to the growing area of measurement invariance in neuropsychological assessment as it highlights the importance of examining the comparability of assessment measures across different cultural groups.

Robust reference group normative data for neuropsychological tests accounting for primary language use in Asian American older adults

OBJECTIVE

The present study aimed to develop neuropsychological norms for older Asian Americans with English as a primary or secondary language, using data from the National Alzheimer's Coordinating Center (NACC).

METHOD

A normative sample of Asian American participants was derived from the NACC database using robust criteria: participants were cognitively unimpaired at baseline (i.e., no MCI or dementia) and remained cognitively unimpaired at 1-year follow-up. Clinical and demographic characteristics were compared between Primary and Secondary English speakers using analyses of variance for continuous measures and chi-square tests for categorical variables. Linear regression models compared neuropsychological performance between the groups, adjusting for demographics (age, sex, and education). Regression models were developed for clinical application to compute demographically adjusted z-scores.

RESULTS

Secondary English speakers were younger than Primary English speakers (p < .001). There were significant differences between the groups on measures of mental status (Mini-Mental State Examination, p = .002), attention (Trail Making Test A, Digit Span Forward Total Score, p <.001), language (Boston Naming Test, Animal Fluency, Vegetable Fluency, p < .001), and executive function (Trail Making Test B, p = .02).

CONCLUSIONS

Separate normative data are needed for Primary vs. Secondary English speakers from Asian American backgrounds. We provide normative data on older Asian Americans to enable clinicians to account for English use in the interpretation of neuropsychological assessment scores.

The Mediating Effects of Education and Occupational Complexity Between Race and Longitudinal Change in Late Life Cognition in ACTIVE

This study examined educational and occupational inequality as two aspects of social determinants of health that might mediate the longitudinal relationship between racialization and late life cognitive level and change. Participants were 2371 individuals racialized as Black and White from the ACTIVE study who provided occupational data. Data were analyzed from baseline and five assessments over 10-years using structural equation modeling. Black/White race served as the predictor, occupational complexity (OC) and years of education as mediators, and cognitive (memory, reasoning, and speed of processing) intercept, linear slope, and quadratic slope as the dependent variables. Black/White race showed significant indirect associations through education and OC on level of performance in cognition, linear change in reasoning and memory, and quadratic change in reasoning. Education and OC accounted for 11-16% of the association between race and cognitive level and represent modifiable social determinants of health that are associated with disparities in cognitive aging.

Epigenetic age and socioeconomic status contribute to racial disparities in cognitive and functional aging between Black and White older Americans

Epigenetic age, a biological aging marker measured by DNA methylation, is a potential mechanism by which social factors drive disparities in age-related health. Epigenetic age gap is the residual between epigenetic age measures and chronological age. Previous studies showed associations between epigenetic age gap and age-related outcomes including cognitive capacity and performance on some functional measures, but whether epigenetic age gap contributes to disparities in these outcomes is unknown. We use data from the Health and Retirement Study to examine the role of epigenetic age gap in racial disparities in cognitive and functional outcomes and consider the role of socioeconomic status (SES). Epigenetic age measures are GrimAge or Dunedin Pace of Aging methylation (DPoAm). Cognitive outcomes are cross-sectional score and two-year change in Telephone Interview for Cognitive Status (TICS). Functional outcomes are prevalence and incidence of limitations performing Instrumental Activities of Daily Living (IADLs). We find, relative to White participants, Black participants have lower scores and greater decline in TICS, higher prevalence and incidence rates of IADL limitations, and higher epigenetic age gap. Age- and gender-adjusted analyses reveal that higher GrimAge and DPoAm gap are both associated with worse cognitive and functional outcomes and mediate 6-11% of racial disparities in cognitive outcomes and 19-39% of disparities in functional outcomes. Adjusting for SES attenuates most DPoAm associations and most mediation effects. These results support that epigenetic age gap contributes to racial disparities in cognition and functioning and may be an important mechanism linking social factors to disparities in health outcomes.

Rates of Undiagnosed Cognitive Impairment and Performance on the Montreal Cognitive Assessment Among Older Adults in Primary Care

BACKGROUND

The number of adults in the USA with cognitive impairment is increasing; however, few studies report prevalence rates of undiagnosed cognitive impairment among older adults in primary care.

OBJECTIVE

To determine the prevalence of undiagnosed cognitive impairment among adults ages 55 years and older in primary care settings and provide normative data for the Montreal Cognitive Assessment in this context.

DESIGN

Single interview, observational study.

PARTICIPANTS

English-speaking adults ages 55 years and older without diagnoses of cognitive impairment recruited from primary care practices in New York City, NY, and Chicago, IL (n = 872).

MAIN MEASURES

Montreal Cognitive Assessment (MoCA). Undiagnosed cognitive impairment was defined by age and education adjusted z-scores more than 1.0 and 1.5 standard deviations below published norms, corresponding to mild or moderate to severe cognitive impairment, respectively.

KEY RESULTS

The mean age was 66.8 (8.0) years, 44.7% were male, 32.9% were Black or African-American, and 29.1% were Latinx. Undiagnosed cognitive impairment was identified in 20.8% of subjects (mild impairment, 10.5%; moderate-severe impairment, 10.3%). Impairment at any level of severity was associated in bivariate analyses with several patient characteristics, most notably for race and ethnicity (White, non-Latinx, 6.9% vs. Black, non-Latinx, 26.8%, Latinx, 28.2%, other race, 21.9%; p < 0.0001), place of birth (US 17.5% vs. non-US 30.7%, p < 0.0001), depression (33.1% vs. no depression, 18.1%; p < 0.0001), and impairment in activities of daily living (≥ 1 ADL impairment, 34.0% vs. no ADL impairment, 18.2%; p < 0.0001).

CONCLUSIONS

Undiagnosed cognitive impairment is common among urban dwelling older adults attending primary care practices, and was associated with several patient characteristics, including non-White race and ethnicity and depression. Normative data for the MoCA from this study may serve as a useful resource for studies of similar patient populations.

Cognitive and Functional Improvement via Novel Skill Learning for Low-Income Minoritized Middle-Aged and Older Adults

Prior research has demonstrated beneficial outcomes for learning new skills in older adulthood, including increased cognitive and functional abilities, which help prevent age-related declines and foster healthy aging. However, these studies largely have included participants not typically considered at risk for cognitive and functional decline (i.e., White, highly educated, higher income). Cognitive and functional disparities exist among minoritized racial and ethnic individuals, particularly Black and Latinx populations, because of a lifetime of inequalities associated with low socioeconomic status, low education, and discrimination. This theoretical paper proposes a potential pathway in which such disparities could be mitigated by increasing cognitive and functional abilities via novel skill learning in these at-risk populations in middle and later life to prevent decline. We also discuss indirect barriers (e.g., financial and health issues), direct barriers (e.g., limited learning opportunities), and motivational barriers (e.g., self-beliefs, values) that these adults may encounter. We further highlight that addressing these barriers to novel skill learning by providing appropriate resources is necessary to maximize the feasibility and potential effectiveness of this pathway. Lastly, we encourage future research to test this pathway and help inform policymakers and existing learning programs to implement better ways of promoting lifelong learning in an inclusive and equitable manner to prevent decline.

Measurement of Prevalent Versus Incident Dementia Cases in Epidemiologic Studies

Because dementia is progressive, incident cases are on average milder than prevalent cases, affecting the performance of cognitive tests and questions on functional limitations (i.e., cognition/functional limitation items) used for dementia assessment. Longitudinal studies assess incident cases, while cross-sectional studies assess prevalent cases, but differences are not typically considered when researchers select items to include in studies. We used longitudinal data from the Religious Orders Study and Memory and Aging Project (ROSMAP) (n = 3,446) collected between 1994 and 2021 to characterize differences in associations between items (cognition: 35 items; functional limitations: 14 items) and incident or prevalent dementia using multinomial regression models with generalized estimating equations, controlling for ROSMAP cohort (Religious Orders Study or Memory and Aging Project), age, sex, race, and education. The association between a given item and incident dementia was significantly weaker than the association between the same item and prevalent dementia for 46 of 49 items. However, there was variability, with larger differences for some items, including naming a pencil (prevalence odds ratio = 0.02 (95% confidence interval: 0.02, 0.03); incidence odds ratio = 0.10 (95% confidence interval: 0.06, 0.17); P for difference < 0.001). Important differences exist in the performance of cognition/functional limitation items for measurement of incident versus prevalent dementia. Differences can inform the choice of items for cross-sectional studies of prevalent cases or longitudinal studies of incident cases, leading to reduced misclassification and increased statistical power.

Socioeconomic Status, Race/Ethnicity, and Unexpected Variation in Dementia Classification in Longitudinal Survey Data

OBJECTIVES

As dementia affects a growing number of older adults, it is important to understand its detection and progression. We identified patterns in dementia classification over time using a longitudinal, nationally representative sample of older adults. We examined the relationship between socioeconomic status and race/ethnicity, and patterns in dementia classification.

METHODS

Data for 7,218 Medicare beneficiaries from the 2011-2017 National Health and Aging Trends Study (NHATS) were classified into five categories: consistently no dementia, consistently cognitive impairment, "typical" dementia progression, "expected" variation, and "unexpected" variation. Multivariable multinomial logistic regression assessed relative risk of dementia classification by sociodemographic and health factors.

RESULTS

Among NHATS respondents, 59.5% consistently were recorded as having no dementia, 7% consistently cognitively impaired, 13% as having typical progression, 15% as having expected variation, and 5.5% as having unexpected variation. In multivariable models, compared with consistent dementia classification, less education, Medicare-Medicaid-dual enrollment, and identifying as non-Hispanic Black were associated with increased likelihood of unexpected variation (e.g., non-Hispanic Black adjusted risk ratio: 2.12, 95% CI: 1.61-2.78, p < .0001).

DISCUSSION

A significant minority of individuals have unexpected patterns of dementia classification over time, particularly individuals with low socioeconomic status and identifying as non-Hispanic Black. Dementia classification uncertainty may make it challenging to activate resources (e.g., health care, caregiving) for effective disease management, underscoring the need to support persons from at-risk groups and to carefully evaluate cognitive assessment tools to ensure they are equally reliable across groups to avoid magnifying disparities.

The Role of Incarceration as a Risk Factor for Cognitive Impairment

OBJECTIVES

The objective of this study was to understand disparities in cognitive impairment between middle-aged formerly incarcerated (FI) and nonincarcerated individuals.

METHODS

The 1979 National Longitudinal Survey of Youth is a nationally representative longitudinal data set containing information on incarceration, cognitive functioning, and other health conditions. Using a modified version of the Telephone Interview for Cognitive Status (TICS-m), adapted from the Health and Retirement Study, we analyzed the association between incarceration and cognitive impairment, cognitive impairment-not dementia and dementia. Multivariable regression models were estimated, including prior incarceration status and covariates associated with incarceration and cognitive functioning.

RESULTS

FI individuals had lower unadjusted scores on TICS-m (-2.5, p < .001) and had significantly greater unadjusted odds ratios (OR) for scoring in the cognitive impairment (OR = 2.4, p < .001) and dementia (OR = 2.7, p < .001) range. Differences were largely explained by a combination of risk factors associated with incarceration and cognition. Education and premorbid cognition (measured by Armed Forces Qualification Test) separately and completely explained differences in the odds of dementia. Regardless of incarceration status, Blacks and Hispanics had significantly greater odds of cognitive impairment and dementia relative to Whites, holding other factors constant.

DISCUSSION

The association between prior incarceration and cognitive impairment in middle age was largely explained by differences in educational attainment and premorbid cognitive functioning, supporting the cognitive reserve hypothesis. Greater prevalence of cognitive impairment and dementia among the FI could create challenges and should be considered in reentry planning. Structural and institutional factors should be considered when addressing health disparities in Alzheimer's Disease and Related Dementias.

Psychiatric history and later-life cognitive change: effect modification by sex, race and ethnicity

Objective: We explored associations between psychiatric history and cognitive functioning, and differences by sex and race/ethnicity (SRE) in 20,155 Health and Retirement Study (1995-2014) participants aged 65 or older.Methods: Multi-level growth curve models examined cognition scores and their trajectories over time by SRE.Results: A history of psychiatric, emotional, or nervous problems was significantly related to cognition scores and rates of decline. Hispanic and Black participants had significantly lower cognition scores at age 75 and steeper rates of decline than White females, and Black race and the Hispanic race/ethnicity-sex interaction erased the protective effects of being female.Conclusions: Future research should include specific psychiatric diagnoses. Population level findings as reported here, along with aggregate findings from similar studies, can inform interventions and policies regarding support for populations that are vulnerable to mental illness and to subsequent cognitive decline.

The effect of missing data and imputation on the detection of bias in cognitive testing using differential item functioning methods

Background

Item response theory (IRT) methods for addressing differential item functioning (DIF) can detect group differences in responses to individual items (e.g., bias). IRT and DIF-detection methods have been used increasingly often to identify bias in cognitive test performance by characteristics (DIF grouping variables) such as hearing impairment, race, and educational attainment. Previous analyses have not considered the effect of missing data on inferences, although levels of missing cognitive data can be substantial in epidemiologic studies.

Methods

We used data from Visit 6 (2016–2017) of the Atherosclerosis Risk in Communities Neurocognitive Study (N = 3,580) to explicate the effect of artificially imposed missing data patterns and imputation on DIF detection.

Results

When missing data was imposed among individuals in a specific DIF group but was unrelated to cognitive test performance, there was no systematic error. However, when missing data was related to cognitive test performance and DIF group membership, there was systematic error in DIF detection. Given this missing data pattern, the median DIF detection error associated with 10%, 30%, and 50% missingness was -0.03, -0.08, and -0.14 standard deviation (SD) units without imputation, but this decreased to -0.02, -0.04, and -0.08 SD units with multiple imputation.

Conclusions

Incorrect inferences in DIF testing have downstream consequences for the use of cognitive tests in research. It is therefore crucial to consider the effect and reasons behind missing data when evaluating bias in cognitive testing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01572-2.

Blood Pressure and Later-Life Cognition in Hispanic and White Adults (BP-COG): A Pooled Cohort Analysis of ARIC, CARDIA, CHS, FOS, MESA, and NOMAS

BACKGROUND

Ethnic differences in cognitive decline have been reported. Whether they can be explained by differences in systolic blood pressure (SBP) is uncertain.

OBJECTIVE

Determine whether cumulative mean SBP levels explain differences in cognitive decline between Hispanic and White individuals.

METHODS

Pooled cohort study of individual participant data from six cohorts (1971-2017). The present study reports results on SBP and cognition among Hispanic and White individuals. Outcomes were changes in global cognition (GC) (primary), executive function (EF) (secondary), and memory standardized as t-scores (mean [SD], 50 [10]); a 1-point difference represents a 0.1 SD difference in cognition. Median follow-up was 7.7 (Q1-Q3, 5.2-20.1) years.

RESULTS

We included 24,570 participants free of stroke and dementia: 2,475 Hispanic individuals (median age, cumulative mean SBP at first cognitive assessment, 67 years, 132.5 mmHg; 40.8% men) and 22,095 White individuals (60 years,134 mmHg; 47.3% men). Hispanic individuals had slower declines in GC, EF, and memory than White individuals when all six cohorts were examined. Two cohorts recruited Hispanic individuals by design. In a sensitivity analysis, Hispanic individuals in these cohorts had faster decline in GC, similar decline in EF, and slower decline in memory than White individuals. Higher time-varying cumulative mean SBP was associated with faster declines in GC, EF, and memory in all analyses. After adjusting for time-varying cumulative mean SBP, differences in cognitive slopes between Hispanic and White individuals did not change.

CONCLUSION

We found no evidence that cumulative mean SBP differences explained differences in cognitive decline between Hispanic and White individuals.

Alzheimer disease in African American individuals: increased incidence or not enough data?

Research on racial differences in Alzheimer disease (AD) dementia has increased in recent years. Older African American individuals bear a disproportionate burden of AD and cognitive impairment compared with non-Latino white individuals. Tremendous progress has been made over the past two decades in our understanding of the neurobiological substrates of AD. However, owing to well-documented challenges of study participant recruitment and a persistent lack of biological data in the African American population, knowledge of the drivers of these racial disparities has lagged behind. Therapeutic targets and effective interventions for AD are increasingly sought, but without a better understanding of the disease in African American individuals, any identified treatments and/or cures will evade this rapidly growing at-risk population. In this Perspective, I introduce three key obstacles to progress in understanding racial differences in AD: uncertainty about diagnostic criteria, disparate cross-sectional and longitudinal findings; and a dearth of neuropathological data. I also highlight evidence-informed strategies to move the field forward.

In this Perspective, Barnes introduces three key obstacles to progress in our understanding of racial differences in Alzheimer disease and highlights evidence-informed strategies that can move the field forward.

Differences in Subjective Memory Impairment, Depressive Symptoms, Sleep, and Physical Activity in African American and Asian American Elderly

Background: Subjective memory impairment (SMI) is associated with negative health outcomes including mild cognitive impairment and Alzheimer's disease. However, ethnic differences in SMI and disparities in risk factors associated with SMI among minority populations are understudied. The study examined the ethnic differences in SMI, whether SMI was associated with depressive symptoms, sleep, and physical activity (PA), and whether the associations vary across racial/ethnic groups. Methods: Participants included 243 African and Asian Americans (including Chinese, Vietnamese, and Korean Americans) aged 50 or older. Demographic information, SMI, depressive symptoms, daily sleeping hours, and PA levels were assessed. Results: Vietnamese Americans reported the highest SMI score. Depressive symptoms, sleeping hours, and PA levels were significantly associated with SMI. Depressive symptoms were the only significant factor across all ethnic groups. Significant interaction effects were found between ethnicity and health behaviors in predicting SMI. In particular, Vietnamese American participants with greater depressive symptoms and physical inactivity were significantly more likely to experience SMI compared to other ethnic groups Conclusions: Our findings demonstrate ethnic differences in SMI and its association with depressive symptoms, sleep, and PA, which highlight the importance of considering the unique cultural and historical backgrounds across different racial/ethnic groups when examining cognitive functioning in elderly.

Senior WISE intervention: Gender differences in bodily pain and trait anxiety

PURPOSE

In this secondary analysis we tested whether 12 h of Senior WISE (Wisdom Is Simply Exploration) memory or health training with older adults would produce better outcomes by gender in perceptions of anxiety and bodily pain and whether the effects of the Senior WISE training on pain were mediated by anxiety.

DESIGN

An implemented Phase III randomized clinical trial with follow up for 24 months in Central Texas. The sample was mostly female (79%), 71% Caucasian, 17% Hispanic, and 12% African American with an average age of 75 and 13 years of education.

RESULTS

The effects of the memory intervention on anxiety were consistent across time, with effects present for males but not females at post-treatment and end-of-study. Although males had more anxiety in the health promotion group, the memory training reduced males' anxiety such that no gender difference was present in this group. The Senior WISE intervention reduced pain for both males and females at post-intervention but not at end-of-study. Although gender differences did not depend on the treatment group for pain, females reported somewhat, but not significantly, less pain at post-treatment and end-of-study. Mediation analysis indicated that, for males, the memory intervention indirectly affected pain at post-treatment, in part, by reducing anxiety, which lowered pain. However, at end-of-study, no indirect effect was present. Males responded to memory training. Training tailored to gender may increase the efficacy of the programs and "buy-in" from male participants, especially if tailored to anxiety and pain.

The Impact of the BAILAMOS™ Dance Program on Brain Functional Connectivity and Cognition in Older Latino Adults: A Pilot Study

Dance is a culturally salient form of physical activity (PA) for older Latinos. Resting-state functional connectivity (FC) is a putative biomarker for age-related cognitive decline. We aimed to investigate the impact of the BAILAMOS™ dance program on FC in three brain functional networks (Default Mode [DMN], Frontoparietal [FPN], and Salience [SAL] networks), and cognition. Ten cognitively healthy older Latinos participated in the four-month BAILAMOS™ dance program. We assessed PA levels (self-reported and device-assessed) and estimated cardiorespiratory fitness, cognition, and resting-state FC via functional magnetic resonance imaging at baseline and post-intervention. We performed paired t-tests and Pearson correlations. Given the pilot nature of the study, significance levels were set at p < 0.05 and effect sizes are reported. We observed a significant increase in self-reported moderate leisure-time PA from pre- to post-intervention (t(9) = 3.16, p = 0.011, d = 0.66). FC within-FPN regions of interest (ROIs) significantly increased pre- to post-intervention (t(9) = 2.35, p = 0.043, d = 0.70). DMN ROIs showed an increase, with a moderate effect size, in the integration with other networks' ROIs (t(9) = 1.96, p = 0.081, d = 0.64) post-intervention. Increases in moderate leisure-time PA at post-intervention were associated with increases in the FC within-FPN (R = 0.79, p = 0.006). Our results suggest that dance might be a promising approach for improving age-related disruption of FC within- and between-networks commonly associated with cognitive decline.

Gender Differences in Cognitive Function among Older Mexican Immigrants

This paper uses data from the Health and Retirement Study (HRS) and the Mexican Health and Aging Study (MHAS) to study the cognitive function of Mexican-born older adults residing in the United States (Mexican immigrants). We find that, once differences in socioeconomic factors are accounted for, the cognitive function of male Mexican immigrants is statistically indistinguishable from that of male non-Hispanic (NH) whites, but the cognitive scores of female Mexican immigrants remain significantly below those of their NH white counterparts. We explore four potential hypotheses that may explain the cognition gap for female Mexican immigrants. Namely, we investigate whether the relative incidence of risk factors for dementia, when compared to NH whites, is higher for female than for male Mexican immigrants (the "risk factor hypothesis"); whether the mortality rate of male Mexican immigrants with low cognition is higher, relative to their white counterparts, than that of female Mexican immigrants (the "survival bias hypothesis"); whether female Mexican immigrants are less positively selected than their male counterparts in terms of predisposition to cognitive decline when compared with either the non-migrant Mexican population or the population of return migrants (the "differential selection hypothesis"); and whether male immigrants are better acculturated to life in the United States than female immigrants (the "acculturation hypothesis). We find no support for the risk-factor, survival, or acculturation hypotheses but we find evidence suggesting that the differential selection hypothesis may explain part of the female cognitive gap. Our results imply that older Mexican females currently residing in the U.S. may be at elevated risk for dementia and should be targeted by campaigns aimed at preventing or diagnosing the condition.

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.

RESULTS

After adjusting for age and education, the largest baseline differences were between NHW men and Hispanic women on visuospatial and language, and between NHW women and Black men on memory. Memory and visuospatial decline was steeper for Black women compared with Hispanic men and NHW women, respectively.

DISCUSSION

This study takes an important first step in understanding interactions between race/ethnicity and sex/gender on cognitive trajectories by demonstrating variability in sex/gender differences across race/ethnicity.

A Framework of Minority Stress: From Physiological Manifestations to Cognitive Outcomes

Cognitive impairment and dementia continue to threaten the aging population. Although no one is immune, certain groups, namely black older persons, are more likely to have a diagnosis of certain dementias. Because researchers have not found a purely biological reason for this disparity, they have turned to a biopsychosocial model. Specifically, black persons in the United States are more likely to live with social conditions that affect their stress levels which in turn affect physiological regulation leading to conditions that result in higher levels of cognitive impairment or dementia. Here we discuss some of these social conditions such as discrimination, education, and socioeconomic status, and how physiological dysregulation, namely allostatic load that can lead to cognitive impairment and dementia in black persons especially.

Trends in Memory Problems and Race/Ethnicity in the National Health and Examination Survey, 1999-2014

Background

Little data exist to describe serial population-level trends in cognitive impairment- especially among minority communities. Because memory problems are among the first warning signs of cognitive impairment, they provide a potential method for monitoring changes in cognitive health at the population level. This exploratory study aimed to: 1) estimate prevalence of memory problems among US residents by race/ethnicity, age category; and 2) examine whether racial/ethnic differences in subjective cognitive concerns (memory problems) varied across recent time periods.

Design and Setting

Serial cross-sectional analysis of self-reported data from the National Health and Examination Survey (NHANES), 1999-2014.

Participants

20,585 participants aged ≥45 years during 1999-2014, who reported race/ethnicity as non-Hispanic White (NHW), non-Hispanic Black (NHB), and Latino/Hispanic.

Measurements

The outcome of interest was subjective cognitive concerns, identified as self-reported memory problems. The frequencies of memory problems were examined for each 4-year period, across racial/ethnic groups.

Results

In adjusted analyses, compared with older (aged ≥ 65 years) NHWs, disparities in subjective cognitive concerns were observed for older Latinos for most periods (range of AOR: 1.43 - 2.01, P<.05). Additionally, Latinos without a high school education had significantly higher odds of reporting memory problems than NHW in multiple periods (range of AOR: 1.95 - 2.17, P<.005), while Latino high school graduates did not. There were no significant changes in racial/ethnic differences in subjective cognitive concerns over time.

Conclusions

The prevalence of subjective cognitive concerns across time periods points to a need to engage patients - particularly older and less-educated Latinos - about warning signs for cognitive impairment. The impact of education on subjective cognitive concerns in older Latinos may be related to acculturation and warrant further investigation.

The effect of social network on the physical activity-cognitive function nexus in late life

ABSTRACTBackground:To examine the contribution of vigorous physical activity to subsequent cognitive functioning, taking into account the effect of social network.

METHODS

The sample included respondents aged 65 years and older who participated in both the fourth and sixth waves of Survey of Health, Ageing and Retirement in Europe (n = 17,104). Cognitive functioning in Wave 6, measured as the average of standardized scores for recall, fluency, and numeracy, was regressed on the extent of vigorous physical activity, social network size, and several confounders in Wave 4 (including the corresponding cognition score at baseline). Interaction terms for physical activity and network size were also considered.

RESULTS

Moderate and high levels of vigorous physical activity, as well as social network size, were related to the cognition outcome after controlling for the confounders. Introduction of the interaction terms showed a direct and positive association of both moderate and high physical activity with the cognition outcome scores as social network size increased. However, among respondents in small- (0-1 members) and moderate-sized networks (2-3 members), greater physical activity was unrelated to the cognition score at follow-up. Only the interaction of high social connectedness (4-7 network members) and vigorous physical activity was significant.

CONCLUSIONS

Vigorous physical activity is, indeed, related to subsequent cognitive functioning. However, the relationship is tempered by social network size. Therefore, interventions that increase both social connectedness and physical activity, especially among older people who are isolated and sedentary, are warranted.

Cognitive Training for Ethnic Minority Older Adults in the United States: A Review

Purpose of the Study

Interest in cognitive training for healthy older adults to reduce cognitive decline has grown considerably over the past few decades. Given the shift toward a more diverse society, the purpose of this review is to examine the extent of race/ethnic minority participation in cognitive training studies and characteristics of studies that included race/ethnic minority participants.

Design and Methods

This review considered peer-reviewed studies reporting cognitive training studies for cognitively healthy, community-dwelling older adults (age 55+) in the United States published in English before December 31, 2015. A total of 31 articles published between 1986 and 2015 meeting inclusion criteria were identified and included in the review.

Results

A total of 6,432 participants were recruited across all of the studies, and ranged in age from 55 to 99 years. Across all studies examined, 39% reported racial/ethnic background information. Only 3 of these studies included a substantial number of minorities (26.7% in the ACTIVE study; 28.4% in the SeniorWISE study; 22.7% in the TEAM study). Race/ethnic minority older adults were disproportionately underrepresented in cognitive training studies.

Implications

Further research should aim to enroll participants representative of various race/ethnic minority populations. Strategies for recruitment and retention of ethnic minority participants in cognitive training research are discussed, which could lead to the development of more culturally appropriate and perhaps more effective cognitive interventions.

Black-white mental status trajectories: What ages do differences emerge?

OBJECTIVES

Studies of older U.S. adults have consistently found that African Americans perform worse on cognitive measures than whites, but there are inconsistencies as to whether these findings hold over time. Moreover, studies have focused on adults 51 and older, without considering younger ages; thus it is unclear the age at which these disparities surface. The present study examines black-white disparities in mental status trajectories among adults as young as 25 years over a 25-year period.

METHOD

Data come from the Americans' Changing Lives Study (ACL) (n = 3,617). Participants, ranging from ages 25-100 years old at baseline, were followed from 1986 to 2011 over 5 waves. Mental status was assessed at each wave using a 5-item Short Portable Mental Status Questionnaire. Growth models were used to estimate the associations between age, race, baseline status, and longitudinal changes in mental status, controlling for sociodemographic (e.g., education, income) and other health risk factors (diabetes, stroke, tobacco use, depression).

RESULTS

Racial disparities were seen beginning in midlife and this relationship was curvilinear. Specifically, blacks had a steeper rate of mental status decline than whites and these disparities persisted after accounting for social and health risk factors (b = 0.0090, p < 0.0001).

DISCUSSION

Study findings demonstrate disparities emerge at middles ages and worsen as age increases. This finding highlights the importance of addressing racial disparities in cognition across a larger part of the adult life course. By doing so, we may better be able to capture early-life exposures that influence later-life cognitive outcomes and ultimately lead to disparities.

Cognitive Aging in Black and White Americans: Cognition, Cognitive Decline, and Incidence of Alzheimer Disease Dementia

BACKGROUND

US-based studies have reported that older blacks perform worse than older whites on cognitive tests and have higher risk of Alzheimer disease dementia (AD). It is unclear whether these findings reflect differences in cognitive decline.

METHODS

The Chicago Health and Aging Project followed individuals, 65+ years old (64% black, 36% white), for up to 18 years. Participants underwent triennial cognitive assessments; stratified randomized samples underwent assessments for AD. We compared black and white participants' cognitive performance, cognitive decline rate (N = 7,735), and AD incidence (N = 2,144), adjusting for age and sex.

RESULTS

Black participants performed worse than white participants on the cognitive tests; 441 participants developed AD. Black participants' incident AD risk was twice that of whites (RR = 1.9; 95% CI, 1.4, 2.7), with 58 excess cases/1,000 occurring among blacks (95% CI, 28, 88). Among noncarriers of APOE ε4, blacks had 2.3 times the AD risk (95% CI, 1.5, 3.6), but among carriers, race was not associated with risk (RR = 1.1; 95% CI, 0.6, 2.0; Pinteraction = 0.05). However, cognitive decline was not faster among blacks: the black-white difference in 5-year change in global cognitive score was 0.007 standard unit (95% CI, -0.034, 0.047). Years of education accounted for a sizable portion of racial disparities in cognitive level and AD risk, in analyses using a counterfactual approach.

CONCLUSIONS

The higher risk of AD among blacks may stem from lower level of cognitive test performance persisting throughout the observation period rather than faster rate of late-life cognitive decline. Disparities in educational attainment may contribute to these performance disparities. See video abstract at, http://links.lww.com/EDE/B299.

Terminal decline of episodic memory and perceptual speed in a biracial population

We compared trajectories of terminal cognitive decline in older Black (n = 3372) and White (n = 1756) persons from a defined population who completed tests of episodic memory and perceptual speed at 3-year intervals for up to 18 years. During a mean of 9.9 years of observation, 1608 Black persons and 902 White persons died. Preterminal decline of episodic memory did not differ by race. Terminal episodic memory decline began earlier in Black persons (mean of 4.3 years before death) than in White persons (mean = 3.9 years) and progressed more slowly. By contrast, terminal decline of perceptual speed began earlier in White persons (mean = 5.0 years) than in Black persons (mean = 4.5 years). Rate of perceptual speed decline was more rapid in White persons than in Black persons in both the preterminal and terminal periods. The results indicate that terminal cognitive decline occurs in Black persons but suggest that the rate of cognitive decline during the terminal period is less rapid in Black persons than in White persons.

Self-Reported Cognitive Impairment Across Racial/Ethnic Groups in the United States, National Health Interview Survey, 1997-2015

INTRODUCTION

The primary objectives of this study were 1) to examine trends of self-reported cognitive impairment among 5 major racial/ethnic groups during 1997-2015 in the United States and 2) to examine differences in the trends across these groups.

METHODS

Data were from the National Health Interview Survey (NHIS). The sample consisted of 155,682 people aged 60 or older. Respondents were asked to report whether any family member was "limited in any way because of difficulty remembering or because of experiencing periods of confusion." Race/ethnicity categories were non-Hispanic white, non-Hispanic black, Native American, Hispanic, and Asian. We applied hierarchical age-period-cohort cross-classified random-effects models for the trend analysis. All analyses accounted for the complex survey design of NHIS.

RESULTS

The overall rate of self-reported cognitive impairment increased from 5.7% in 1997 to 6.7% in 2015 (P for trend <.001). Among non-Hispanic white respondents, the rate increased from 5.2% in 1997 to 6.1% in 2015 (slope = 0.14, P for trend <.001). We observed no significant trend in rate of cognitive impairment in other groups. After we controlled for covariates, we found that Asian (B = 0.31), non-Hispanic black (B = 0.37), Hispanic (B = 0.25), and Native American (B = 0.87) respondents were more likely than non-Hispanic white respondents to report cognitive impairment (P <.001 for all).

CONCLUSION

We found an increased rate of self-reported cognitive impairment in older adults of 5 major racial/ethnic groups from 1997 through 2015 in the United States. However, the rate of self-reported cognitive impairment was low, which may suggest underreporting. There is a need to further promote awareness of the disease among individuals, family members, and health care providers.

Biopsychosocial Predictors of Fall Events Among Older African Americans

This study identifies risk and protective factors for falls among older, community-dwelling African Americans. Drawing upon the biopsychosocial perspective, we conducted a series of sex- and age-adjusted multinomial logistic regression analyses to identify the correlates of fall events among older African Americans. Our sample consisted of 1,442 community-dwelling African Americans aged 65 and older, participating in the 2010-2012 rounds of the Health and Retirement Study. Biophysical characteristics associated with greater relative risk of experiencing single and/or multiple falls included greater functional limitations, poorer self-rated health, poorer self-rated vision, chronic illnesses (high blood pressure, diabetes, cancer, lung disease, heart problems, stroke, and arthritis), greater chronic illness comorbidity, older age, and female sex. Physical activity was negatively associated with recurrent falls. Among the examined psychosocial characteristics, greater depressive symptoms were associated with greater relative risk of experiencing single and multiple fall events. Implications for clinicians and future studies are discussed.

A Cognitive Turning Point in Development of Clinical Alzheimer's Disease Dementia and Mild Cognitive Impairment: A Biracial Population Study

Background

Cognitive changes during the preclinical phase of Alzheimer's disease (AD) dementia have been characterized among European Americans (EAs), but studies of preclinical changes among African Americans (AAs) are notably absent.

Methods

Preclinical changes in cognition before the development of AD dementia and mild cognitive impairment over a period of 18 years were examined using change points in a biracial sample of 2,125 older adults.

Results

Of 2,125 participants, 442 (21%) developed AD dementia and 661 (31%) developed mild cognitive impairment. A cognitive change point occurred between 4 and 5 years before the clinical diagnosis of AD dementia. Differences between AAs and EAs were observed: EAs had a higher starting level of composite cognitive function, and a change point occurred 4.3 years before AD dementia among AAs and 4.7 years among EAs. The slope of cognitive decline after the change point among those developing clinical AD dementia was significantly greater among EAs (0.233 units/y) than among AAs (0.171 units/y; p < .001). This difference in slope of cognitive decline persisted after diagnosis of AD dementia so that at the conclusion of observation the difference in average cognitive level was reversed. AAs without cognitive impairment had a lower average baseline of cognition than EAs, but the slopes of cognitive decline were similar.

Conclusions

A prominent change to a steeper slope of cognitive decline occurs between 4 and 5 years prior to the diagnosis of AD dementia. The slope of cognitive decline after the change point is steeper among EAs than AAs.

Socioeconomic, health, and psychosocial mediators of racial disparities in cognition in early, middle, and late adulthood

Racial disparities in cognitive performance exist across the life course, but it is not known whether mediators of disparities differ by age. Understanding sources of cognitive disparities at different ages can inform policies and interventions. Data were obtained for non-Hispanic Black and White respondents to The National Survey of Midlife Development in the United States from 3 age groups: 28-44 (N = 1210; 20% Black); 45-64 (N = 2693; 15% Black); and 65-85 (N = 1298; 11% Black). Moderated mediation models characterized direct and indirect effects of race on episodic memory and executive function composite scores through economic, health, and psychosocial variables as a function of age group. Education, income, chronic health conditions, and external locus of control mediated cognitive disparities across the life course, although income was a stronger mediator at younger ages. Perceived discrimination was a weaker mediator among young adults due to an absence of racial differences in perceived discrimination in that group. Despite multiple indirect effects, there were still significant unexplained effects of race on cognition that were not moderated by age group. Interventional work is needed to determine whether increasing educational attainment and income, and reducing chronic health conditions and perceived constraints among Blacks, reduce cognitive disparities. Targeting income inequality and discrimination (or buffering the impact of those variables) may be differently effective at reducing cognitive disparities at different stages of the adult life course. (PsycINFO Database Record

Racial and ethnic differences in cognitive function among older adults in the USA

OBJECTIVE

Examine differences in cognition between Hispanic, non-Hispanic black (NHB), and non-Hispanic white (NHW) older adults in the United States.

DATA/METHODS

The final sample includes 18 982 participants aged 51 or older who received a modified version of the Telephone Interview for Cognitive Status during the 2010 Health and Retirement Study follow-up. Ordinary least squares will be used to examine differences in overall cognition according to race/ethnicity.

RESULTS

Hispanics and NHB had lower cognition than NHW for all age groups (51-59, 60-69, 70-79, 80+). Hispanics had higher cognition than NHB for all age groups but these differences were all within one point. The lower cognition among NHB compared to NHW remained significant after controlling for age, gender, and education, whereas the differences in cognition between Hispanics and NHW were no longer significant after controlling for these covariates. Cognitive scores increased with greater educational attainment for all race/ethnic groups, but Hispanics exhibited the least benefit.

DISCUSSION

Our results highlight the role of education in race/ethnic differences in cognitive function during old age. Education seems beneficial for cognition in old age for all race/ethnic groups, but Hispanics appear to receive a lower benefit compared to other race/ethnic groups. Further research is needed on the racial and ethnic differences in the pathways of the benefits of educational attainment for late-life cognitive function. Copyright © 2016 John Wiley & Sons, Ltd.

Racial-ethnic related clinical and neurocognitive differences in adults with gambling disorder

Recent epidemiological data suggest that the lifetime prevalence of gambling problems differs depending on race-ethnicity. Understanding variations in disease presentation in blacks and whites, and relationships with biological and sociocultural factors, may have implications for selecting appropriate prevention strategies. 62 non-treatment seeking volunteers (18-29 years, n=18 [29.0%] female) with gambling disorder were recruited from the general community. Black (n=36) and White (n=26) participants were compared on demographic, clinical and cognitive measures. Young black adults with gambling disorder reported more symptoms of gambling disorder and greater scores on a measure of compulsivity. In addition they exhibited significantly higher total errors on a set-shifting task, less risk adjustment on a gambling task, greater delay aversion on a gambling task, and more total errors on a working memory task. These findings suggest that the clinical and neurocognitive presentation of gambling disorder different between racial-ethnic groups.

Neighborhood Predictors of Cognitive Training Outcomes and Trajectories in ACTIVE

We examined the influence of neighborhood socioeconomic position (SEP), racial/ethnic composition, and living in a major city on cognitive trajectories and intervention outcomes. Data came from the Advanced Cognitive Training for Independent and Vital Elderly study ( N = 2,438). Mixed effects analyses examined the associations between neighborhood variables and memory, reasoning, speed of processing, and everyday cognition, estimating differences in initial gains (potentially related to practice) and long-term rate of change over 10 years. The effect of reasoning training on initial gain was weaker for individuals in a major city. For everyday cognition, there was a stronger initial gain for memory-trained and control participants in areas with more racial/ethnic minorities and for speed-trained and control individuals in higher SEP areas. The racial/ethnic minority effect was no longer significant after adjustment for multiple comparisons. Neighborhood factors may be more important in practice-related improvement than in long-term change.

Factors related to racial differences in late-life level of cognitive function

OBJECTIVE

The study aim was to identify factors associated with racial differences in level of cognitive function in old age.

METHOD

Older Black (n = 5,950) and White (n = 3,469) residents of a geographically defined urban community were randomly split into exploratory and confirmatory subgroups. A global measure of cognition was derived from 4 brief performance tests, and potential correlates of cognition (candidates) were selected from demographic, health-related, and experiential measures. In the exploratory subgroup, using a stepwise search algorithm, we examined the cognitive difference by race and then allowed candidate measures and Race × Candidate Measure interactions to enter the model.

RESULTS

The cognitive score in the exploratory subgroup (M = 0.257, SD = 0.714) was a mean of 0.403 unit lower in Black persons than White persons (SE = 0.021, p < .001), and race accounted for 7% of cognitive variability. After the candidate selection process, 16 measures were retained, including 12 candidate measures and the 2-way interactions of race with education, age, reading/cognitive activity, and neuroticism. In this model, which accounted for 45% of the variability in global cognition, race was no longer associated with global cognition (coefficient = 0.012, SE = 0.110, p = .912). Findings were replicated in the confirmatory subgroup.

CONCLUSION

These cross-sectional analyses suggest that consideration of demographic, health-related, and experiential factors greatly attenuates racial differences in late-life level of cognition. (PsycINFO Database Record

Examination of the Factor Structure of a Global Cognitive Function Battery across Race and Time

Older African Americans tend to perform more poorly on cognitive function tests than older Whites. One possible explanation for their poorer performance is that the tests used to assess cognition may not reflect the same construct in African Americans and Whites. Therefore, we tested measurement invariance, by race and over time, of a structured 18-test cognitive battery used in three epidemiologic cohort studies of diverse older adults. Multi-group confirmatory factor analyses were carried out with full-information maximum likelihood estimation in all models to capture as much information as was present in the observed data. Four different aspects of the data were fit to each model: comparative fit index (CFI), standardized root mean square residuals (SRMR), root mean square error of approximation (RMSEA), and model $$\chi ^{2} $$ . We found that the most constrained model fit the data well (CFI=0.950; SRMR=0.051; RMSEA=0.057 (90% confidence interval: 0.056, 0.059); the model $$\chi ^{2} $$ =4600.68 on 862 df), supporting the characterization of this model of cognitive test scores as invariant over time and racial group. These results support the conclusion that the cognitive test battery used in the three studies is invariant across race and time and can be used to assess cognition among African Americans and Whites in longitudinal studies. Furthermore, the lower performance of African Americans on these tests is not due to bias in the tests themselves but rather likely reflect differences in social and environmental experiences over the life course. (JINS, 2016, 22, 66-75).

Effects of education and race on cognitive decline: An integrative study of generalizability versus study-specific results

The objective of the study was to examine variability across multiple prospective cohort studies in level and rate of cognitive decline by race/ethnicity and years of education. We compare data across studies, we harmonized estimates of common latent factors representing overall or general cognitive performance, memory, and executive function derived from the: (a) Washington Heights, Hamilton Heights, Inwood Columbia Aging Project (N = 4,115), (b) Spanish and English Neuropsychological Assessment Scales (N = 525), (c) Duke Memory, Health, and Aging study (N = 578), and (d) Neurocognitive Outcomes of Depression in the Elderly (N = 585). We modeled cognitive change over age for cognitive outcomes by race, education, and study. We adjusted models for sex, dementia status, and study-specific characteristics. The results found that for baseline levels of overall cognitive performance, memory, and executive function, differences in race and education tended to be larger than between-study differences and consistent across studies. This pattern did not hold for rate of cognitive decline: effects of education and race/ethnicity on cognitive change were not consistently observed across studies, and when present were small, with racial/ethnic minorities and those with lower education declining at faster rates. In this diverse set of datasets, non-Hispanic Whites and those with higher education had substantially higher baseline cognitive test scores. However, differences in the rate of cognitive decline by race/ethnicity and education did not follow this pattern. This study suggests that baseline test scores and longitudinal change have different determinants, and future studies to examine similarities and differences of causes of cognitive decline in racially/ethnically and educationally diverse older groups is needed.

Role of Place in Explaining Racial Heterogeneity in Cognitive Outcomes among Older Adults

Racially patterned disadvantage in Southern states, especially during the formative years of primary school, may contribute to enduring disparities in adult cognitive outcomes. Drawing on a lifecourse perspective, we examine whether state of school attendance affects cognitive outcomes in older adults and partially contributes to persistent racial disparities. Using data from older African American and white participants in the national Health and Retirement Study (HRS) and the New York based Washington Heights Inwood Cognitive Aging Project (WHICAP), we estimated age-and gender-adjusted multilevel models with random effects for states predicting years of education and cognitive outcomes (e.g., memory and vocabulary). We summarized the proportion of variation in outcomes attributable to state of school attendance and compared the magnitude of racial disparities across states. Among WHICAP African Americans, state of school attendance accounted for 9% of the variance in years of schooling, 6% of memory, and 12% of language. Among HRS African Americans, state of school attendance accounted for 13% of the variance in years of schooling and also contributed to variance in cognitive function (7%), memory (2%), and vocabulary (12%). Random slope models indicated state-level African American and white disparities in every Census region, with the largest racial differences in the South. State of school attendance may contribute to racial disparities in cognitive outcomes among older Americans. Despite tremendous within-state heterogeneity, state of school attendance also accounted for some variability in cognitive outcomes. Racial disparities in older Americans may reflect historical patterns of segregation and differential access to resources such as education.

External locus of control contributes to racial disparities in memory and reasoning training gains in ACTIVE

Racial disparities in cognitive outcomes may be partly explained by differences in locus of control. African Americans report more external locus of control than non-Hispanic Whites, and external locus of control is associated with poorer health and cognition. The aims of this study were to compare cognitive training gains between African American and non-Hispanic White participants in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study and determine whether racial differences in training gains are mediated by locus of control. The sample comprised 2,062 (26% African American) adults aged 65 and older who participated in memory, reasoning, or speed training. Latent growth curve models evaluated predictors of 10-year cognitive trajectories separately by training group. Multiple group modeling examined associations between training gains and locus of control across racial groups. Compared to non-Hispanic Whites, African Americans evidenced less improvement in memory and reasoning performance after training. These effects were partially mediated by locus of control, controlling for age, sex, education, health, depression, testing site, and initial cognitive ability. African Americans reported more external locus of control, which was associated with smaller training gains. External locus of control also had a stronger negative association with reasoning training gain for African Americans than for Whites. No racial difference in training gain was identified for speed training. Future intervention research with African Americans should test whether explicitly targeting external locus of control leads to greater cognitive improvement following cognitive training.

The role of early-life educational quality and literacy in explaining racial disparities in cognition in late life

OBJECTIVES

Racial disparities in late-life cognition persist even after accounting for educational attainment. We examined whether early-life educational quality and literacy in later life help explain these disparities.

METHOD

We used longitudinal data from the Washington Heights-Inwood Columbia Aging Project (WHICAP). Educational quality (percent white students; urban/rural school; combined grades in classroom) was operationalized using canonical correlation analysis. Late-life literacy (reading comprehension and ability, writing) was operationalized using confirmatory factor analysis. We examined whether these factors attenuated race-related differences in late-life cognition.

RESULTS

The sample consisted of 1,679 U.S.-born, non-Hispanic, community-living adults aged 65-102 (71% black, 29% white; 70% women). Accounting for educational quality and literacy reduced disparities by 29% for general cognitive functioning, 26% for memory, and 32% for executive functioning but did not predict differences in rate of cognitive change.

DISCUSSION

Early-life educational quality and literacy in late life explain a substantial portion of race-related disparities in late-life cognitive function.

Cognitive aging in older Black and White persons

During a mean of 5.2 years of annual follow-up, older Black (n = 647) and White (n = 647) persons of equivalent age and education completed a battery of 17 cognitive tests from which composite measures of 5 abilities were derived. Baseline level of each ability was lower in the Black subgroup. Decline in episodic and working memory was not related to race. Decline in semantic memory, perceptual speed, and visuospatial ability was slower in Black persons than White persons, and in semantic memory and perceptual speed this effect was stronger in older than younger participants. Racial differences persisted after adjustment for retest effects. The results suggest subtle cognitive aging differences between Black persons and White persons.

Measurement Invariance of Cognitive Abilities Across Ethnicity, Gender, and Time Among Older Americans

OBJECTIVES

The aim of this research was to test the invariance of the cognitive variables in the Health and Retirement Study/Asset Health Dynamics Among the Oldest Old studies (HRS/AHEAD) across ethnicity, gender, and time.

METHOD

Analyses were conducted using a selected subsample of the HRS/AHEAD data set. The cognitive performance tests measuring episodic memory and mental status were used, and invariance of a two-factor structure was tested using confirmatory factor analyses and multilevel modeling for longitudinal data.

RESULTS

Results provided some support for "strict" factorial invariance of the episodic memory and mental status measures across ethnicity and gender. Further support of weak ("metric") measurement invariance was found across time.

DISCUSSION

Results of the research further our understanding of invariance of the HRS/AHEAD cognitive ability measures. Further implications are discussed.

Becoming centenarians: disease and functioning trajectories of older US Adults as they survive to 100

BACKGROUND

Little is known about the health and functioning of individuals who become centenarians in the years prior to reaching age 100. We examined long-term trajectories of disease, disability, and cognitive function in a sample of U.S. centenarians to determine how their aging experience differs from their nonsurviving cohort counterparts, and if there is heterogeneity in the aging experience of centenarians.

METHODS

Data are from the 1993-2010 waves of the nationally representative Health and Retirement Study. Among those who had the potential to become centenarians, we identified 1,045 respondents who died before reaching age 100 and 96 who survived to their 100th birthday. Respondents, or their proxies, reported on diagnosis of six major diseases (hypertension, heart disease, lung disease, stroke, cancer, and diabetes), limitations in activities of daily living, and cognitive function.

RESULTS

As they age to 100, centenarians are generally healthier than nonsurviving members of their cohort, and a number of individuals who become centenarians reach 100 with no self-reported diseases or functional impairments. About 23% of centenarians reached age 100 with no major chronic disease and approximately the same number had no disability (18%). Over half (55%) reached 100 without cognitive impairment. Disease and functioning trajectories of centenarians differ by sex, education, and marital status.

CONCLUSIONS

While some centenarians have poor health and functioning upon reaching age 100, others are able to achieve exceptional longevity in relatively good health and without loss of functioning. This study underscores the importance of examining variation in the growing centenarian population.

Veteran Status and Men’s Later-Life Cognitive Trajectories

Objective: The aim of this study is to determine the extent to which men’s later-life cognitive trajectories vary by veteran status. Method: We use Health and Retirement Study (HRS) data to estimate growth curve models examining men’s later-life cognitive trajectories by veteran status, war service status, and period of service. Analyses control for early-life characteristics that influence selection into military service and later-life cognition, and mid- to late-life characteristics that potentially mediate the relationship between military service and later-life cognition. Results: Veterans have higher cognition scores relative to nonveterans around retirement age, but their cognition scores decline more rapidly with increasing age, such that cognition scores are similar in both groups among the oldest old. Veterans who served during the Korean War have lower cognition scores around retirement age, but less steep age-related declines, than veterans who served during World War II. Discussion: Findings are discussed in relation to the extant literature, future research, potential service needs, and study limitations.

A longitudinal analysis of the influence of race on cognitive performance

OBJECTIVES

Whether there are racial and ethnic disparities in the rate of cognitive decline among older adults is not clear. The purpose of this study was to determine if there are differences in cognitive decline among racial and ethnic older adults.

METHOD

Data were from the Health and Retirement Study, waves 1998-2010. Participants were community dwelling at baseline (n = 9,492), mostly female participants (58.8%), ranged in age from 65 to 105 years (M = 74.41, SD = 6.97), and had education levels that averaged less than high school (M = 11.7, SD = 3.4). Cognition was examined using a combined score from word recall, Serial 7's, backward counting, and naming tasks. To determine changes in cognition across 12 years, we utilized mixed effects models.

RESULTS

Results indicated that after adjusting for covariates, race or ethnicity was unrelated to changes in cognitive performance, but there were significant differences in baseline cognition and these differences were more pronounced after adjusting for age, gender, education, poverty, heart disease, diabetes, high blood pressure.

DISCUSSION

It is evident that there are significant differences in baseline cognition, although the rate of cognitive decline across 12 years did not vary significantly by race. These findings support previous assertions that the rate of cognitive decline is not associated with race and suggest that it is likely that baseline cognitive performance is a better indicator of performance over time.

The rationale, design, and baseline characteristics of the Women's Health Initiative Memory Study of Younger Women (WHIMS-Y)

The Women's Health Initiative Memory Study-Younger (WHIMS-Y) was designed to assess the effect of prior random assignment to hormone therapy (HT) (conjugated equine estrogen (CEE) alone or CEE plus medroxyprogesterone acetate (MPA)) on global cognitive function in younger middle-aged women relative to placebo. WHIMS-Y was an ancillary study to the Women's Health Initiative (WHI) HT trial and enrolled 1361 women who were aged 50-55 years and postmenopausal at WHI enrollment. WHIMS-Y will examine whether an average of 5.4 years of HT during early menopause has longer term protective effects on global cognitive function and if these effects vary by regimen, time between menopause and study initiation, and prior use of HT. We present the study rationale and design. We describe enrollment, adherence to assigned WHI therapy, and compare risk factor characteristics of the WHIMS-Y cohort at the time of WHI enrollment to similar aged women in the WHI HT who did not enroll in WHIMS-Y. Challenges of WHIMS-Y include lower than expected and differential enrollment. Strengths of WHIMS-Y include balance in baseline risk factors between treatment groups, standardized and masked data collection, and high rates of retention and on-trial adherence and exposure. In addition, the telephone-administered cognitive battery showed adequate construct validity. WHIMS-Y provided an unprecedented chance to examine the hypothesis that HT may have protective effects on cognition in younger postmenopausal women aged 50-55 years. Integrated into the WHI, WHIMS-Y optimized the experience of WHI investigators to ensure high retention and excellent quality assurance across sites. This article is part of a Special Issue entitled Hormone Therapy.

Demographic predictors of cognitive change in ethnically diverse older persons

The purpose of this study was to evaluate how demographic variables relate to cognitive change and address whether cross-sectional demographic effects on cognitive tests are mirrored in differences in longitudinal trajectories of cognitive decline. We hypothesized that race and ethnicity, education, and language of test administration would relate to cross-sectional status and that the rate of cognitive decline would differ among African Americans, Hispanics, and Caucasians, across levels of educational attainment, and according to linguistic background. Participants were 404 educationally, ethnically, and cognitively diverse older adults enrolled in an ongoing longitudinal study of cognition. Mixed-effects regression analysis was used to measure baseline status and longitudinal change in episodic memory, executive functioning, and semantic memory. Results showed that ethnicity and education were strongly associated with baseline scores, but were, at most, weakly associated with change in cognition over time after accounting for confounding variables. There was evidence that the episodic-memory scores of Spanish-speaking Hispanic participants with limited education underestimated their true abilities in the initial evaluation, which may reflect lack of familiarity with the testing environment. These results--consistent with other reports in the literature--suggest that cross-sectional effects of demographic variables on cognitive-test scores result from differences in life experiences that directly influence test performance and do not indicate greater disease effects on cognition in minorities and those with limited education.

Changes in the prevalence of cognitive impairment among older Americans, 1993-2004: overall trends and differences by race/ethnicity

The authors used data from 6 waves of the Health and Retirement Study to evaluate changes in the prevalence of cognitive impairment among adults 70 years of age or older from 1993 to 2004. Having sampling weights for each wave enabled the authors to create merged waves that represented cross-sections of the community-dwelling older population for that year. Logistic regression analyses with year as the predictor were used to estimate trends and determine the contribution of sociodemographic and health status variables to decreasing trends in the prevalence of cognitive impairment over time (score ≤8 on a modified Telephone Interview Cognitive Screen). Results showed an annual decline in the prevalence of cognitive impairment of 3.4% after adjustment for age, gender, and prior test exposure (odds ratio (OR) = 0.966, 95% confidence interval (CI): 0.941, 0.992). The addition of socioeconomic variables to the model attenuated the trend by 72.1%. The annual percentage of decline in impairment was larger for blacks (OR = 0.943, 95% CI: 0.914, 0.973) and Hispanics (OR = 0.954, 95% CI: 0.912, 0.997) than for whites (OR = 0.971, 95% CI: 0.936, 1.006), although the differences were not statistically significant. Linear probability models used in secondary analyses showed larger percentage-point declines for blacks and Hispanics. Improvements in educational level contributed to declines in cognitive impairment among older adults-particularly blacks and Hispanics-in the United States.

Differential benefits of memory training for minority older adults in the SeniorWISE study

PURPOSE

Cognitive training improves mental abilities in older adults, but the benefit to minority elders is unclear. We conducted a subgroup analysis of subjects in the SeniorWISE (Wisdom Is Simply Exploration) trial to examine this issue.

DESIGN AND METHODS

SeniorWISE was a Phase 3 randomized trial that enrolled 265 nondemented community-dwelling older adults aged 65 years and older between 2001 and 2006. Participants were randomly assigned to 12 hr of either memory or health training.

RESULTS

The sample was 79% female, 71% Caucasian, 17% Hispanic, and 12% African American. On the Rivermead Behavioural Memory Test (RBMT), 28% of the sample scored normal, 47% scored poor, and 25% impaired. Memory performance changed differently over time depending on the demographic characteristics of participants. Both Hispanics and Blacks performed better than Whites on visual memory, and Blacks performed better over time on instrumental activities of daily living. On all performance measures, lower pretest scores were associated with relatively greater improvements over time.

IMPLICATIONS

Our analyses suggested that minority participants received differential benefits from the memory training; however, this remains speculative because the 3 ethnic groups in the sample were not equivalent in size. The question of why Black and Hispanic participants often made greater improvements needs further exploration.