Educational attainment is an important factor in the interpretation of cognitive test scores but years of education are not necessarily synonymous with educational quality among racial/ethnic minority populations. This study investigated the comparability of educational attainment with reading level and examined whether discrepancies in education and reading level accounted for differences in neuropsychological test performance between HIV+ racial/ethnic minority and nonminority participants. Study participants (N = 200) were derived from the Manhattan HIV Brain Bank (MHBB) where 50% of the cohort had ≤8th grade reading level but only 5% had ≤8 years of education. Significantly lower reading ability and education was found among African Americans and Hispanics, and these participants were more likely to have discrepant reading and education levels compared to non-Hispanic Whites. Discrepancy in reading and education level was associated with worse neuropsychological performance while racial/ethnic minority status was not. As years of schooling overestimated racial/ethnic minority participants’ educational quality, standard norms based on education may inflate impairment rates among racial/ethnic minorities. Identifying appropriate normative standards is and will continue to be important in the detection of cognitive impairment in racial/ethnic minorities with HIV.
Literacy; Education; Ethnicity; HIV; Neuropsychology; Premorbid IQ
A critical focus of neuropsychological research is to identify unbiased ways to compare heterogeneous groups on background variables relevant to neuropsychological performance. While recent work has pointed to single word reading as a less culturally biased measure of educational experience than years of education, the extent to which reading score captures a broad range of educational experience, and does so consistently across ethnic and language groups is unknown. The current study evaluated reading in relation to years of education in English-speaking Caucasian, African American, and Hispanic elders, and Spanish-speaking Hispanic elders (n=342). Consistent with previous work, reading scores at each grade level were lower in English speaking ethnic minorities than in Caucasians, supporting the idea that variables related to lifetime educational experience are often confounded with ethnicity. Standardized reading scores were highest in the Spanish speakers; however, interpretation of this difference is limited as scores were necessarily derived using separate normative samples. Importantly, the slopes of reading score by years of education were comparable across all groups. That is, reading scores rose consistently with years of education independently of ethnicity or language, suggesting that such scores can be treated comparably for theoretical and statistical purposes in multiethnic and multilingual samples.
Neuropsychological Testing; Ethnicity; English; Spanish; Culture; Language
Neuropsychological tests generally require adjustments for years of education when determining the presence of neurocognitive impairment. However, evidence indicates that educational quality, as assessed with reading tests, may be a better reflection of educational attainment among African Americans. Thus, African Americans with poor educational quality may be incorrectly classified with neurocognitive impairment based on neuropsychological tests. We compared the accuracy of neuropsychological test scores standardized using reading grade-equivalent versus years of education in predicting neurocognitive impairment among a sample of Whites and African-American adults who were HIV+. Participants were examined by a neurologist and classified with or without HIV-associated neurocognitive disorders according to accepted criteria. Participants were also classified as impaired versus not impaired based on their neuropsychological test scores standardized by 1) self-reported education or 2) WRAT-3 reading grade-level. Cross tabulation tables were used to determine agreement of the two methods in detecting impairment. Among African-Americans, standardized scores derived from reading scores had greater specificity than those derived from years of education (84.1% vs. 77.3). Among the Whites, correction based on years of education had both greater specificity and sensitivity. The results suggest that reading tests may be a useful alternative for determining NCI among African Americans.
HIV; Dementia; Neuropsychology; WRAT-3; Education; Reading
This study examined factors associated with brain donation program participation among African-American and White elders. By postal mail, participants were recruited from an Alzheimer’s research registry (all of whom had been invited to participate in the Center’s brain donation program) and asked to complete surveys assessing brain donation knowledge, trust in healthcare systems, and religiousness. African-American respondents completed a cultural mistrust inventory. Demographic, brain donation status, and literacy data (as assessed by the Wide Range Achievement Test-3 Reading subtest) were compiled from the respondents’ most recent registry visit. The survey response rate was 60% (n=184 White and n=49 Black respondents). Logistic regression, comparing religiousness, trust in healthcare institutions, and educational attainment, identified a single predictor (ie, religiousness) in the prediction of donation status among White respondents (P=0.008), whereas no predictors were observed for donation status among the Black respondents. Using all African-American donors and nondonors from the registry (n=68), comparisons revealed Wide Range Achievement Test-3 Reading score differences for African-American donors (46.8±5.9) and nondonors (42.8±8.4, P=0.02). Results suggest that increased religiousness is related to White elders’ decisions not to donate, whereas lower reading ability might be related to African-American participants’ decisions not to donate.
African-American; brain donation; cultural mistrust; religiousness; research participation
We aimed to whether the abnormally high amyloid-β (Aβ) level in the brain among apparently healthy elders is related with subtle cognitive deficits and/or accelerated cognitive decline.
A total of 116 dementia-free participants (mean age 84.5 years) of the Washington Heights Inwood Columbia Aging Project completed 18F-Florbetaben PET imaging. Positive or negative cerebral Aβ deposition was assessed visually. Quantitative cerebral Aβ burden was calculated as the standardized uptake value ratio in pre-established regions of interest using cerebellar cortex as the reference region. Cognition was determined using a neuropsychological battery and selected tests scores were combined into four composite scores (memory, language, executive/speed, and visuospatial) using exploratory factor analysis. We examined the relationship between cerebral Aβ level and longitudinal cognition change up to 20 years before the PET scan using latent growth curve models, controlling for age, education, ethnicity, and Apolipoprotein E (APOE) genotype.
Positive reading of Aβ was found in 41 of 116 (35%) individuals. Cognitive scores at scan time was not related with Aβ. All cognitive scores declined over time. Aβ positive reading (B = -0.034, p = 0.02) and higher Aβ burden in temporal region (B = -0.080, p = 0.02) were associated with faster decline in executive/speed. Stratified analyses showed that higher Aβ deposition was associated with faster longitudinal declines in mean cognition, language, and executive/speed in African-Americans or in APOE ε4 carriers, and with faster memory decline in APOE ε4 carriers. The associations remained significant after excluding mild cognitive impairment participants.
High Aβ deposition in healthy elders was associated with decline in executive/speed in the decade before neuroimaging, and the association was observed primarily in African-Americans and APOE ε4 carriers. Our results suggest that measuring cerebral Aβ may give us important insights into the cognitive profile in the years prior to the scan in cognitively normal elders.
Ethnically diverse examinees tend to perform lower on neuropsychological tests. The practice of adjusting normative comparisons for the education level and/or race to prevent overpathologizing low scores is problematic. Education quality, as measured by reading recognition, appears to be a more accurate benchmark for premorbid functioning in certain populations. The present study aimed to extend this line of research to traumatic brain injury (TBI). We hypothesized that a measure of reading recognition, the Wechsler Test of Adult Reading (WTAR), would account for racial differences in neuropsychological performance after TBI. Fifty participants (72% African American, 28% Caucasian) with moderate to severe TBI underwent neuropsychological testing at 1-year post-injury. Reading recognition accounted for all the same variance in neuropsychological performance as race and education (together), as well as considerable additional variance. Estimation of premorbid functioning in African Americans with TBI could be refined by considering reading recognition.
traumatic brain injury; premorbid functioning; racial differences; neuropsychological testing; psychometrics
Memory and executive functioning are two important components of clinical neuropsychological (NP) practice and research. Multiple demographic factors are known to affect performance differentially on most NP tests, but adequate normative corrections, inclusive of race/ethnicity, are not available for many widely used instruments. This study compared demographic contributions for widely used tests of verbal and visual learning and memory (Brief Visual Memory Test-Revised, Hopkins Verbal Memory Test-Revised), and executive functioning (Stroop Color and Word Test, Wisconsin Card Sorting Test-64) in groups of healthy Caucasians (n = 143) and African-Americans (n = 103). Demographic factors of age, education, gender, and race/ethnicity were found to be significant factors on some indices of all four tests. The magnitude of demographic contributions (especially age) was greater for African-Americans than Caucasians on most measures. New, demographically corrected T-score formulas were calculated for each race/ethnicity. The rates of NP impairment using previously published normative standards significantly overestimated NP impairment in African-Americans. Utilizing the new demographic corrections developed and presented herein, NP impairment rates were comparable between the two race/ethnicities and unrelated to the other demographic characteristics (age, education, gender) in either race/ethnicity group. Findings support the need to consider extended demographic contributions to neuropsychological test performance in clinical and research settings.
To examine the relationship that international medical school graduates (IMGs) in comparison with United States medical school graduates (USMGs) have on health care-seeking behavior and satisfaction with medical care among African-American and white elderly.
Secondary data analysis of the 1986–1998 Piedmont Health Survey of the Elderly, Established Populations for the Epidemiological Study of the Elderly, a racially oversampled urban and rural cohort of elders in five North Carolina counties.
Primary focus of analyses examined the impact of the combination of elder race and physician graduate status across time using a linear model for repeated measures analyses and χ2 tests. Separate analyses using generalized estimating equations were conducted for each measure of elder characteristic and health behavior. The analytic cohort included 341 physicians and 3,250 elders (65 years old and older) in 1986; by 1998, 211 physicians and 1,222 elders.
Data Collection/Extraction Methods
Trained personnel collected baseline measures on 4,162 elders (about 80 percent responses) through 90-minute in-home interviews.
Over time, IMGs treated more African-American elders, and those who had less education, lower incomes, less insurance, were in poorer health, and who lived in rural areas. White elders with IMGs delayed care more than those with USMGs. Both races indicated being unsure about where to go for medical care. White elders with IMGs were less satisfied than those with USMGs. Both races had perceptions of IMGs that relate to issues of communication, cultural competency, ageism, and unnecessary expenses.
IMGs do provide necessary and needed access to medical care for underserved African Americans and rural populations. However, it is unclear whether concerns regarding cultural competency, communication and the quality of care undermine the contribution IMGs make to these populations.
African-American elderly; international medical school graduate physicians; United States medical school graduate physicians; satisfaction with medical care; health care-seeking behavior
To assess the neuropsychological and anatomical correlates of anti-saccade (AS) task performance in normal elders.
The AS task correlates with neuropsychological measures of executive function and frontal lobe volume in neurological diseases, but has not been studied in a well-characterized normal elderly population. Because executive dysfunction can indicate an increased risk for cognitive decline in cognitively normal elders, we hypothesized that AS performance might be a sensitive test of age-related processes that impair cognition.
The percentage of correct AS responses was evaluated in forty-eight normal elderly subjects and compared with neuropsychological test performance using linear regression analysis and gray matter volume measured on MRI scans using voxel-based morphometry.
The percentage of correct AS responses was associated with measures of executive function, including modified trails, design fluency, Stroop inhibition, abstraction, and backward digit span, and correlated with gray matter volume in two brain regions involved in inhibitory control: the left inferior frontal junction and the right supplementary eye field. The association of AS correct responses with neuropsychological measures of executive function was strongest in individuals with fewer years of education.
The AS task is sensitive to executive dysfunction and frontal lobe structural alterations in normal elders.
anti-saccade; normal aging; executive function; frontal lobe; cognitive reserve
To investigate whether demographic (age and education) adjustments for the Mini-Mental State Examination (MMSE) attenuate mean score discrepancies between African American and Caucasian adults, and to determine whether demographically-adjusted MMSE scores improve the diagnostic classification accuracy of dementia in African American adults when compared to unadjusted MMSE scores.
Community-dwelling adults participating in the Mayo Clinic Alzheimer’s Disease Patient Registry (ADPR) and Alzheimer’s Disease Research Center (ADRC).
Three thousand two hundred fifty-four adults (2819 Caucasian, 435 African American) aged 60 and older.
MMSE at study entry.
African American adults obtained significantly lower unadjusted MMSE scores (23.0 ± 7.4) compared to Caucasian adults (25.3 ± 5.4). This discrepancy persisted despite adjustment of MMSE scores for age and years of education using established regression weights or newly-derived weights. However, controlling for dementia severity at baseline and adjusting MMSE scores for age and quality of education attenuated this discrepancy. Among African American adults, an age- and education-adjusted MMSE cut score of 23/24 provided optimal dementia classification accuracy, but this represented only a modest improvement over an unadjusted MMSE cut score of 22/23. The posterior probability of dementia in African American adults is presented for various unadjusted MMSE cut scores and prevalence rates of dementia.
Age, dementia severity at study entry, and quality of educational experience are important explanatory factors to understand the existing discrepancies in MMSE performance between Caucasian and African American adults. Our findings support the use of unadjusted MMSE scores when screening African American elders for dementia, with an unadjusted MMSE cut score of 22/23 yielding optimal classification accuracy.
MMSE; African American; ethnicity; dementia; cognition
The effect of race on cognitive test performance in the evaluation of Alzheimer’s disease (AD) remains controversial. One factor that may contribute substantially to differences in cognitive test performance in diverse populations is education. The current study examined the extent to which quality of education, even after controlling for formal years of education, accounts for differences in cognitive performance between African Americans and White Non-Hispanics (WNHs). The retrospective cohort included 244 patients diagnosed with AD who self-identified as African Americans (n=51) or WNHs (n=193). The Wechsler Test of Adult Reading (WTAR) was used as an estimate of quality of education. In an analysis that controlled for traditional demographics, including age, sex, and years of formal education, African Americans scored significantly lower than WNHs on the Mini-Mental State Examination, as well as on neuropsychological tests of memory, attention, and language. However, after also adjusting for reading level, all previously observed differences were significantly attenuated. The attenuating effect remained even after controlling for disease severity, indicating that reading scores are not confounded by severity of dementia. These findings suggest that quality, and not just quantity, of education needs to be taken into account when assessing cognitive performance in African Americans with AD.
A strong inverse relationship of functional limitation and socioeconomic status has been established in western ageing society. Functional limitation can be related to chronic diseases, disuse, cognitive decline, and ageing. Among chronic diseases in the Thai population, cerebrovascular diseases, diabetes, and arthritis are common. These factors are known to contribute to disability and poor quality of life in the elder population. Neuropsychiatric problems, cognitive decline, dementia, and cultural issues in elderly people also can alter the quality of life of the elderly.
The Dementia and Disability Project in Thai Elderly (DDP) aims at comprehensively assessing community dwelling Thai elderly to understand the relationship between disability and motor function, neuropsychiatric symptoms, cognitive function, and chronic diseases. The DDP is the first study to look at the prevalence and etiology of dementia and of mild cognitive impairment (MCI) in Thai elders and to explore the relationship of cognition, disability, small vessel diseases and cortical degeneration with neuroimaging in Thai elderly people. 1998 Thai elders were screened in 2004–2006 and diagnosed as having MCI or dementia. 223 elders with MCI or dementia and cognitively normal elderly had brain magnetic resonance imaging (MRI) or at baseline. 319 elders from the 3 groups had blood tests to investigate the risks and possible etiologies of dementia including genotyping at baseline.
The mean age of elders in this study is 69.51(SD=6.71, min=60, max=95) years. 689(34.9%) are men and 1284(65.1%) are women. Mean body weight was 58.36(SD=11.20) kgs. The regression model reveals that performance on gait and balance and serum triglyceride predicts activity of daily living performance (adjusted r2 = 0.280, f=2.644, p=0.003). The majority of abnormal gait in Thai elders was lower level gait disturbance. Only 1.5% (29/1952) had highest level gait disorders. 39.5% of 1964 subjects were free of chronic diseases. Treatment gap (indicating those who have untreated or inadequate treatment) of diabetes mellitus and hypertension in Thai elders in this study was 37% and 55.5% respectively. 62.6% of Thai elders have ApoE3E3 allele. Prevalence of positive ApoE4 gene in this study is 22.85%. 38.6% of Thai elders who had MRI brain study have moderate to severe white matter lesions.
The large and comprehensive set of measurements in DDP allows a wide-ranging explanation of the functional and clinical features to be investigated in relation to white matter lesions or cortical atrophy of the brain in Thai elderly population. An almost 2 year follow up was made available to those with MCI and dementia and some of the cognitively normal elderly. The longitudinal design will provide great understanding of the possible contributors to disability in the elderly and to the progression of cognitive decline in Thai elders.
Mild cognitive impairment; Dementia; Alzheimer disease; Disability; White matter lesions; Thailand
The objective of this study was to investigate how a measure of educational and occupational attainment, a component of cognitive reserve, modifies the relationship between biomarkers of pathology and cognition in Alzheimer's disease. The biomarkers evaluated quantified neurodegeneration via atrophy on magnetic resonance images, neuronal injury via cerebral spinal fluid t-tau, brain amyloid-β load via cerebral spinal fluid amyloid-β1–42 and vascular disease via white matter hyperintensities on T2/proton density magnetic resonance images. We included 109 cognitively normal subjects, 192 amnestic patients with mild cognitive impairment and 98 patients with Alzheimer's disease, from the Alzheimer's Disease Neuroimaging Initiative study, who had undergone baseline lumbar puncture and magnetic resonance imaging. We combined patients with mild cognitive impairment and Alzheimer's disease in a group labelled ‘cognitively impaired’ subjects. Structural Abnormality Index scores, which reflect the degree of Alzheimer's disease-like anatomic features on magnetic resonance images, were computed for each subject. We assessed Alzheimer's Disease Assessment Scale (cognitive behaviour section) and mini-mental state examination scores as measures of general cognition and Auditory–Verbal Learning Test delayed recall, Boston naming and Trails B scores as measures of specific domains in both groups of subjects. The number of errors on the American National Adult Reading Test was used as a measure of environmental enrichment provided by educational and occupational attainment, a component of cognitive reserve. We found that in cognitively normal subjects, none of the biomarkers correlated with the measures of cognition, whereas American National Adult Reading Test scores were significantly correlated with Boston naming and mini-mental state examination results. In cognitively impaired subjects, the American National Adult Reading Test and all biomarkers of neuronal pathology and amyloid load were independently correlated with all cognitive measures. Exceptions to this general conclusion were absence of correlation between cerebral spinal fluid amyloid-β1–42 and Boston naming and Trails B. In contrast, white matter hyperintensities were only correlated with Boston naming and Trails B results in the cognitively impaired. When all subjects were included in a flexible ordinal regression model that allowed for non-linear effects and interactions, we found that the American National Adult Reading Test had an independent additive association such that better performance was associated with better cognitive performance across the biomarker distribution. Our main conclusions included: (i) that in cognitively normal subjects, the variability in cognitive performance is explained partly by the American National Adult Reading Test and not by biomarkers of Alzheimer's disease pathology; (ii) in cognitively impaired subjects, the American National Adult Reading Test, biomarkers of neuronal pathology (structural magnetic resonance imaging and cerebral spinal fluid t-tau) and amyloid load (cerebral spinal fluid amyloid-β1–42) all independently explain variability in general cognitive performance; and (iii) that the association between cognition and the American National Adult Reading Test was found to be additive rather than to interact with biomarkers of Alzheimer's disease pathology.
Alzheimer's disease; mild cognitive impairment; CSF biomarkers; MRI; cognitive reserve
Neuropsychological tests, including tests of language ability, are frequently used to differentiate normal from pathological cognitive aging. However, language can be particularly difficult to assess in a standardized manner in cross-cultural studies and in patients from different educational and cultural backgrounds. This study examined the effects of age, gender, education and race on performance of two language tests, the animal fluency task (AFT) and the Indiana University Token Test (IUTT). We report population-based normative data on these tests from two combined ethnically divergent, cognitively normal, representative population samples of older adults.
Participants aged ≥65 years from the Monongahela-Youghiogheny Healthy Aging Team (MYHAT) and from the Indianapolis Study of Health and Aging (ISHA) were selected based on (1) a Clinical Dementia Rating (CDR) score of 0; (2) non-missing baseline language test data; and (3) race self-reported as African American or white. The combined sample (n=1885) was 28.1 % African American. Multivariate ordinal logistic regression was used to model the effects of demographic characteristics on test scores.
On both language tests, better performance was significantly associated with higher education, younger age, and white race. On the IUTT, better performance was also associated with female gender. We found no significant interactions between age and sex, and between race and education.
Age and education are more potent variables than are race and gender influencing performance on these language tests. Demographically-stratified normative tables for these measures can be used to guide test interpretation and aid clinical diagnosis of impaired cognition.
neuropsychological tests; norms; cognitive aging; verbal fluency; token test
Previous research has shown that reading ability is a stronger predictor of cognitive functioning than years of education, particularly for African Americans. The current study was designed to determine whether the relative influence of literacy and education on cognitive abilities varies as a function of race or socioeconomic status (SES). We examined the unique influence of education and reading scores on a range of cognitive tests in low and high SES African Americans and Whites. Literacy significantly predicted scores on all but one cognitive measure in both African American groups and in low SES Whites, while education was not significantly associated with any cognitive measure. In contrast, both education and reading scores predicted performance on many cognitive measures in high SES Whites. These findings provide further evidence that reading ability better predicts cognitive functioning than years of education and suggest that disadvantages associated with racial minority status and low SES affect the relative influence of literacy and years of education on cognition.
reading; income; demographics; ethnicity; neuropsychological testing; cognition
Psychometric definitions of mild cognitive impairment (MCI) typically use cut-off levels set at 1.5 standard deviations below age- and education-adjusted norms, assuming that the education adjustment accounts for premorbid abilities. However, non-cognitive factors impact educational attainment, potentially leading to incorrect categorization as MCI. We examined whether using an adjustment based on reading performance (Wide Range Achievement Test [WRAT] Reading) improved MCI diagnostic accuracy.
935 Framingham Offspring (mean age 72 ± 5) underwent tests of Memory, Executive Function, Abstraction, Language, and Visuospatial Function as part of a neuropsychological test battery. Domain-specific test scores were regressed onto age and WRAT score, or education, to define MCI. Survival analyses were used to relate baseline MCI to incident dementia.
The two MCI definitions differed most for the lowest and highest education groups. The WRAT definition was more strongly associated with incident dementia for all five tests. MCI-level Abstraction performance was associated with incident dementia using the WRAT definition (HR = 3.20, p = .033), but not the education definition (HR = 1.19, p = .814).
The WRAT should be considered along with the standard measure of years of education, as it may be a better surrogate marker of premorbid abilities.
Mild cognitive impairment; premorbid abilities; neuropsychological assessment; Alzheimer's disease; longitudinal
The present study examined differences in cognitive performance of African American and European American older adults on cognitive and intellectual measures, and the extent to which literacy status or reading level was useful in explaining these group differences. African American elders performed more poorly than European American elders on twelve of thirteen cognitive tests administered, p < .05. After controlling for reading level achievement, differences in performance became non-significant for five of these twelve tests. Nonetheless, some differences persisted, suggesting that other potential mediators of race differences remain to be explored in future research.
Fluent reading is characterized by speed and accuracy in the decoding and comprehension of connected text. Although a variety of measures are available for the assessment of reading skills most tests do not evaluate rate of text recognition as reflected in fluent reading. Here we evaluate FastaReada, a customized computer-generated task that was developed to address some of the limitations of currently available measures of reading skills. FastaReada provides a rapid assessment of reading fluency quantified as words read per minute for connected, meaningful text. To test the criterion validity of FastaReada, 124 mainstream school children with typical sensory, mental and motor development were assessed. Performance on FastaReada was correlated with the established Neale Analysis of Reading Ability (NARA) measures of text reading accuracy, rate and comprehension, and common single word measures of pseudoword (non-word) reading, phonetic decoding, phonological awareness (PA) and mode of word decoding (i.e., visual or eidetic versus auditory or phonetic). The results demonstrated strong positive correlations between FastaReada performance and NARA reading rate (r = 0.75), accuracy (r = 0.83) and comprehension (r = 0.63) scores providing evidence for criterion-related validity. Additional evidence for criterion validity was demonstrated through strong positive correlations between FastaReada and both single word eidetic (r = 0.81) and phonetic decoding skills (r = 0.68). The results also demonstrated FastaReada to be a stronger predictor of eidetic decoding than the NARA rate measure, with FastaReada predicting 14.4% of the variance compared to 2.6% predicted by NARA rate. FastaReada was therefore deemed to be a valid tool for educators, clinicians, and research related assessment of reading accuracy and rate. As expected, analysis with hierarchical regressions also highlighted the closer relationship of fluent reading to rapid visual word recognition than to phonological-based skills. Eidetic decoding was the strongest predictor of FastaReada performance (16.8%) followed by phonetic decoding skill (1.7%). PA did not make a unique contribution after eidetic decoding and phonetic decoding skills were accounted for.
FastaReada; reading fluency; reading development; assessment; automaticity; visual word recognition; phonological awareness
There is an urgent need to more accurately diagnose HIV-associated neurocognitive disorder (HAND) in Africa. Rapid screening tests for HIV-associated dementia are of limited utility due to variable sensitivity and specificity. The use of selected neuropsychological tests is more appropriate, but norms for HIV seronegative people are not readily available for sub-Saharan African populations. We sought to derive normative scores for two commonly used neuropsychological tests that generate four test scores -- namely the Trail-Making Test (Parts A and B) and the Digit Span Test [Forward (DSF) and Backward (DSB)]. To assess memory and recall, we used the memory item of the International HIV Dementia Scale (IHDS).
One hundred and ten HIV seronegative participants were assessed at McCord Hospital, Durban, South Africa between March 3rd and October 31st, 2008. We excluded people with major depressive disorder, substance use abuse and dependence and head injuries (with or without loss of consciousness). All the participants in this study were African and predominantly female with an average age of 28.5 years and 10 years of education. Age and gender influenced neuropsychological functioning, with older people performing worse. The effect of gender was not uniform across all the tests.
These two neuropsychological tests can be administered with the IHDS in busy antiretroviral clinics. Their performance can be measured against these norms to more accurately diagnose the spectrum and progression of HAND.
Older African Americans tend to perform poorly in comparison with older Whites on episodic memory tests. Observed group differences may reflect some combination of biological differences, measurement bias, and other confounding factors that differ across groups. Cognitive reserve refers to the hypothesis that factors, such as years of education, cognitive activity, and socioeconomic status, promote brain resilience in the face of pathological threats to brain integrity in late life. Educational quality, measured by reading test performance, has been postulated as an important aspect of cognitive reserve. Previous studies have not concurrently evaluated test bias and other explanations for observed differences between older African Americans and Whites. We combined data from two studies to address this question. We analyzed data from 273 African American and 720 White older adults. We assessed DIF using an item response theory/ordinal logistic regression approach. DIF and factors associated with cognitive reserve did not explain the relationship between race, and age- and sex-adjusted episodic memory test performance. However, reading level did explain this relationship. The results reinforce the importance of considering education quality, as measured by reading level, when assessing cognition among diverse older adults.
Mental recall; Ethnic groups; Psychometrics; Cognition; Education; Health status disparities
We compared the prevalence of disability among older American Indians and Alaska Natives (AI/ANs) with that among their African American and White peers, then examined sociodemographic characteristics associated with disability among AI/ANs.
Design and Methods
We analyzed the 5% 2000 Census Public Use Microdata Sample. We assessed disability by functional limitation, mobility disability, and self-care disability for four age groups (55–64, 65–74, 75–84, and 85 years or older).
For all age strata, AI/ANs reported the highest rates of functional limitation and African Americans the highest level of mobility disability. In the 55-to-64 age group, AI/ANs experienced the highest prevalence of self-care disability, and among those aged 65 years or older, African Americans reported the highest prevalence. Compared to Whites, the adjusted odds ratios for functional limitation, mobility disability, and self-care disability were significantly elevated in AI/ANs (1.62, 1.33, and 1.56, respectively) and African Americans (1.27, 1.54, and 1.56, respectively). For AI/ANs, being of increased age, being female, having lower educational attainment and household income, not being married or in the labor force, and residing in a metropolitan area were associated with disabilities.
This study contributes to researchers’ limited knowledge regarding disability among older AI/ANs. The lack of available empirical data poses obstacles to understanding the antecedents and consequences of disability for AI/ANs. More information on the nature and extent of disabilities among AI/AN elders would enhance the ability of advocates to document their needs and raise public awareness. Likewise, policy makers could enact prevention strategies and make comprehensive rehabilitative and long-term care services available to this population.
American Indians and Alaska Natives; Older adults; Disability; US Census
Knowledge of the relationship between depressive symptoms and cognition in older adults has primarily come from studies of clinically depressed, functionally impaired or cognitively impaired individuals, and in predominately White samples. Limited minority representation in depression research exposes the need to examine these associations in more ethnic/racially diverse populations. We sought to examine the relationship between depressive symptoms and cognition in a sample of non-demented older African Americans recruited from surrounding U.S. cities of New York, Greensboro, Miami, and Nashville (N = 944). Depressive symptoms were evaluated with the Geriatric Depression Scale (GDS). Cognition was evaluated with a comprehensive neuropsychological battery. Test scores were summarized into attention, executive function, memory, language, and processing speed composites. Controlling for age, education, reading level, and sex, African American older adults who endorsed more symptoms obtained significantly lower scores on measures of memory, language, processing speed, and executive functioning. Further investigation of the causal pathway underlying this association, as well as potential mediators of the relationship between depressive symptoms and cognitive test performance among older African Americans, such as cardiovascular and cerebrovascular disease, may offer potential avenues for intervention.
Aging; Ethnic groups; Depression; Executive function; Memory; Language
This study examined the ability of computerized maze test performance to predict the road test performance of cognitively impaired and normal older drivers. The authors examined 133 older drivers, including 65 with probable Alzheimer disease, 23 with possible Alzheimer disease, and 45 control subjects without cognitive impairment. Subjects completed 5 computerized maze tasks employing a touch screen and pointer as well as a battery of standard neuropsychological tests. Parameters measured for mazes included errors, planning time, drawing time, and total time. Within 2 weeks, subjects were examined by a professional driving instructor on a standardized road test modeled after the Washington University Road Test. Road test total score was significantly correlated with total time across the 5 mazes. This maze score was significant for both Alzheimer disease subjects and control subjects. One maze in particular, requiring less than 2 minutes to complete, was highly correlated with driving performance. For the standard neuropsychological tests, highest correlations were seen with Trail Making A (TrailsA) and the Hopkins Verbal Learning Tests Trial 1 (HVLT1). Multiple regression models for road test score using stepwise subtraction of maze and neuropsychological test variables revealed significant independent contributions for total maze time, HVLT1, and TrailsA for the entire group; total maze time and HVLT1 for Alzheimer disease subjects; and TrailsA for normal subjects. As a visual analog of driving, a brief computerized test of maze navigation time compares well to standard neuropsychological tests of psychomotor speed, scanning, attention, and working memory as a predictor of driving performance by persons with early Alzheimer disease and normal elders. Measurement of maze task performance appears to be useful in the assessment of older drivers at risk for hazardous driving.
driving; dementia; mild cognitive impairment; maze; computerized assessment
Glucose and insulin are important moderators of cognitive function. African Americans have poorer glycemic control across the glycemic spectrum and are at increased risk for type 2 diabetes and poor cognitive health. It is unclear which glucoregulatory markers predict cognitive function in this at-risk population. The purpose of this study was to examine the association between cognitive function and common markers of glucoregulation in non-diabetic African Americans elders.
Thirty-four, community-dwelling African Americans, aged 50-75 years completed cognitive testing and blood collection as part of a health screening assessment. Cognitive outcomes were composite scores derived from neuropsychological tests of executive function and verbal memory. Linear regression was used to examine relationships between cognitive composite scores and fasting blood levels of glucose, insulin, and hemoglobin A1C, with adjustments for age, education, body mass index, and antihypertensive medication use.
Fasting plasma glucose was negatively associated with executive function (β=−0.41, p=0.03). There was a trend of an association between fasting plasma glucose and verbal memory (β=−0.34, p=0.06). Fasting insulin and hemoglobin A1c were not associated with cognitive function.
High non-diabetic fasting glucose levels were associated with poorer executive function and verbal memory. These results provide preliminary support for proactive glucose control in older African Americans even before glycemic criteria for type 2 diabetes are met. Our findings suggests that high-normal FPG levels may represent an early red-flag to signify increased risk of cognitive impairment or decline.
Glucose; Type 2 diabetes; Memory; Executive function; African Americans
The Minho Integrative Neuroscience Database (MIND)-Ageing project aims to identify predictors of healthy cognitive ageing, including socio-demographic factors. In this exploratory analysis we sought to establish baseline cohorts for longitudinal assessment of age-related changes in cognition.
The population sample (472 individuals) was strictly a convenient one, but similar to the Portuguese population in the age profile. Participants older than 55 years of age were included if they did not present defined disabling pathologies or dementia. A standardized clinical interview was conducted to assess medical history and a battery of neuropsychological tests was administered to characterize global cognition (Mini Mental State Examination), memory and executive functions (Selective Reminding Test; Stroop Color and Word Test; and Block Design subtest of the Wechsler Adult Intelligence Scale). Cross-sectional analysis of the neuropsychological performance with individual characteristics such as age, gender, educational level and setting (retirement home, senior university, day care center or community), allowed the establishment of baseline clusters for subsequent longitudinal studies.
Based on different socio-demographic characteristics, four main clusters that group distinctive patterns of cognitive performance were identified. The type of institution where the elders were sampled from, together with the level of formal education, were the major hierarchal factors for individual distribution in the four clusters. Of notice, education seems to delay the cognitive decline that is associated with age in all clusters.
Social-inclusion/engagement and education seem to have a protective effect on mental ageing, although this effect may not be effective in the eldest elders.