Midlife Vascular Factors and Prevalence of Mild Cognitive Impairment in Late-Life in Mexico

Development and Validation of a Predictive Model for Early Identification of Cognitive Impairment Risk in Community-Based Hypertensive Patients

Objective: To investigate the risk factors for the development of mild cognitive dysfunction in hypertensive patients in the community and to develop a risk prediction model. Method: The data used in this study were obtained from two sources: the China Health and Retirement Longitudinal Study (CHARLS) and the Chinese Longitudinal Healthy Longevity Survey (CLHLS). A total of 1121 participants from CHARLS were randomly allocated into a training set and a validation set, following a 70:30 ratio. Meanwhile, an additional 4016 participants from CLHLS were employed for external validation of the model. The patients in this study were divided into two groups: those with mild cognitive impairment and those without. General information, employment status, pension, health insurance, and presence of depressive symptoms were compared between the two groups. LASSO regression analysis was employed to identify the most predictive variables for the model, utilizing 14-fold cross-validation. The risk prediction model for cognitive impairment in hypertensive populations was developed using generalized linear models. The model's discriminatory power was evaluated through the area under the receiver operating characteristic (ROC) curve and calibration curves. Results: In the modeling group, eight variables such as gender, age, residence, education, alcohol use, depression, employment status, and health insurance were ultimately selected from an initial pool of 21 potential predictors to construct the risk prediction model. The area under the curve (AUC) values for the training, internal, and external validation sets were 0.777, 0.785, and 0.782, respectively. All exceeded the threshold of 0.7, suggesting that the model effectively predicts the incidence of mild cognitive dysfunction in community-based hypertensive patients. A risk prediction model was developed using a generalized linear model in conjunction with Lasso regression. The model's performance was evaluated using the area under the receiver operating characteristic (ROC) curve. Hosmer-Lemeshow test values yielded p = .346 and p = .626, both of which exceeded the 0.05 threshold. Calibration curves demonstrated a significant agreement between the nomogram model and observed outcomes, serving as an effective tool for evaluating the model's predictive performance. Discussion: The predictive model developed in this study serves as a promising and efficient tool for evaluating cognitive impairment in hypertensive patients, aiding community healthcare workers in identifying at-risk populations.

Brain health index as a predictor of possible vascular dementia in the Mexican health and aging study 2012-2015

To determine the burden of disease among subjects at risk of developing stroke or dementia, brain health indexes (BHI) tend to rely on anatomical features. Recent definitions emphasize the need of a broader perspective that encompasses cardiovascular risk factors (CVRFS) and lifestyle components which can be considered partial contributors to optimal brain health. In this study, we aimed to establish the association and risk detected by a Brain Health Index and the risk of possible vascular dementia (PVD) using data from the Mexican Health and Aging Study (MHAS) 2012-2015. The MHAS is a longitudinal study of adults aged ≥ 50 years. We analyzed the data obtained between 2012 and 2015. CVRFS included in the index were diabetes mellitus, hypertension, myocardial infarction, depression, obesity, physical inactivity, and smoking history. A PVD diagnosis was established when scores in the Cross-Cultural Cognitive Examination were below reference norms and limitations in ≥1 instrumental activities of daily living and a history of stroke were present. A multinomial regression model was developed to determine the association between BHI scores and PVD. In 2015, 75 PVD cases were identified. Mean age was 67.1 ±13.2 years, 35.8% were female, and the mean educational level was 5.8 ±5.5 years. In cases with a higher score in the BHI, the model revealed a hazards ratio of 1.63 (95% CI: 1.63-1.64, p< 0.001) for PVD. In this longitudinal study, with the use of a feasible multifactorial BHI in the Mexican population, a greater score was associated with a 1.63-fold risk of developing PVD during the 3-year follow-up, while the risk for stroke was 1.75. This index could potentially be used to predict the risk of PVD in adults with modifiable CVRFS.

Assessment of memory deficits in psychiatric disorders: A systematic literature review

Memory deficits are observed across psychiatric disorders ranging from the prodrome of psychosis to common mental disorders such as anxiety, depression, and dissociative disorders. Memory deficits among patients recovering from psychiatric disorders could be directly related to the primary illness or secondary to the adverse effect of a treatment such as Electroconvulsive Therapy (ECT). The trouble in the meaningful integration of working-memory and episodic memory is the most commonly affected domain that requires routine assessments. An update on the recent trends of methods of assessment of memory deficits is the first step towards understanding and correcting these deficits to target optimum recovery. A systematic literature search was conducted from October 2018 to October 2022 to review the recent methods of assessment of memory deficits in psychiatric disorders. The definition of 'Memory deficit' was operationalized as 'selective processes of memory, commonly required for activities of daily living, and affected among psychiatric disorders resulting in subjective distress and dysfunction'. We included 110 studies, most of them being conducted in western countries on patients with schizophrenia. Other disorders included dementia and mild cognitive impairment. Brief Assessment of Cognition in Schizophrenia, Cambridge Automated Neuropsychological Test Battery, California Verbal Learning Test, Trail Making Test Part A and B, Rey Auditory Verbal Learning Test, Wechsler Memory Scale, Wechsler Adults Intelligence Scale-IV were the most common neuropsychological assessments used. Mini-Mental State Examination and Montreal Cognitive Assessment were the most common bedside assessment tools used while Squire Subjective Memory Questionnaire was commonly used to measure ECT-related memory deficits. The review highlights the recent developments in the field of assessment of memory deficits in psychiatric disorders. Findings recommend and emphasize routine assessment of memory deficits among psychiatric disorders in developing countries especially severe mental illnesses. It remains interesting to see the role of standardized assessments in diagnostic systems given more than a decade of research on memory deficits in psychiatric disorders.

Prevalence of DSM-5 mild and major neurocognitive disorder in India: Results from the LASI-DAD

INTRODUCTION

India, with its rapidly aging population, faces an alarming burden of dementia. We implemented DSM-5 criteria in large-scale, nationally representative survey data in India to characterize the prevalence of mild and major Neurocognitive disorder.

METHODS

The Harmonized Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD) (N = 4,096) is a nationally representative cohort study in India using multistage area probability sampling methods. Using neuropsychological testing and informant reports, we defined DSM-5 mild and major neurocognitive disorder, reported its prevalence, and evaluated criterion and construct validity of the algorithm using clinician-adjudicated Clinical Dementia Ratings (CDR)®.

RESULTS

The prevalence of mild and major neurocognitive disorder, weighted to the population, is 17.6% and 7.2%. Demographic gradients with respect to age and education conform to hypothesized patterns. Among N = 2,390 participants with a clinician-adjudicated CDR, CDR ratings and DSM-5 classification agreed for N = 2,139 (89.5%) participants.

DISCUSSION

The prevalence of dementia in India is higher than previously recognized. These findings, coupled with a growing number of older adults in the coming decades in India, have important implications for society, public health, and families. We are aware of no previous Indian population-representative estimates of mild cognitive impairment, a group which will be increasingly important in coming years to identify for potential therapeutic treatment.

Harmonisation of later-life cognitive function across national contexts: results from the Harmonized Cognitive Assessment Protocols

BACKGROUND

The Harmonized Cognitive Assessment Protocol (HCAP) is an innovative instrument for cross-national comparisons of later-life cognitive function, yet its suitability across diverse populations is unknown. We aimed to harmonise general and domain-specific cognitive scores from HCAP studies across six countries, and evaluate reliability and criterion validity of the resulting harmonised scores.

METHODS

We statistically harmonised general and domain-specific cognitive function scores across publicly available HCAP partner studies in China, England, India, Mexico, South Africa, and the USA conducted between October, 2015 and January, 2020. Participants missing all cognitive test items in a given HCAP were excluded. We used an item banking approach that leveraged common cognitive test items across studies and tests that were unique to studies. We generated harmonised factor scores to represent a person's relative functioning on the latent factors of general cognitive function, memory, executive function, orientation, and language using confirmatory factor analysis. We evaluated the marginal reliability, or precision, of the factor scores using test information plots. Criterion validity of factor scores was assessed by regressing the scores on age, gender, and educational attainment in a multivariable analysis adjusted for these characteristics.

FINDINGS

We included 21 144 participants from the six HCAP studies of interest (11 480 women [54·3%] and 9664 [45·7%] men), with a median age of 69 years (IQR 64-76). Confirmatory factor analysis models of cognitive function in each country fit well: 31 (88·6%) of 35 models had adequate or good fit to the data (comparative fit index ≥0·90, root mean square error of approximation ≤0·08, and standardised root mean residual ≤0·08). Marginal reliability of the harmonised general cognitive function factor was high (>0·9) for 19 044 (90·1%) of 21 144 participant scores across the six countries. Marginal reliability of the harmonised factor was above 0·85 for 19 281 (91·2%) of 21 142 participant factor scores for memory, 7805 (41·0%) of 19 015 scores for executive function, 3446 (16·3%) of 21 103 scores for orientation, and 4329 (20·5%) of 21 113 scores for language. In each country, general cognitive function scores were lower with older age and higher with greater levels of educational attainment.

INTERPRETATION

We statistically harmonised cognitive function measures across six large population-based studies of cognitive ageing. These harmonised cognitive function scores empirically reflect comparable domains of cognitive function among older adults across the six countries, have high reliability, and are useful for population-based research. This work provides a foundation for international networks of researchers to make improved inferences and direct comparisons of cross-national associations of risk factors for cognitive outcomes in pooled analyses.

FUNDING

US National Institute on Aging.

The Mex-Cog cognitive assessment battery: discriminant analysis of the cognitive performance profile in older adults

OBJECTIVE

To analyze the cognitive profile of a clinical sample using the Mex-Cog cognitive battery and establish which cognitive measures and domains contribute most to group separation.

MATERIALS AND METHODS

A group of 145 older adults previously diagnosed with dementia (n= 47), mild cognitive impairment MCI (n= 47), or as cognitively normal (n= 51) were assessed with the Mex-Cog cognitive battery. Six linear discriminant analyses (LDA) were estimated to compare dementia vs. cognitively normal, MCI vs. cognitively normal, and MCI vs. dementia, using ten individual measures and six cognitive domains. We used a leave-one-out cross-validation procedure to evaluate the predictive capacity of LDA models.

RESULTS

Discriminant functions using individual measures and domains distinguished correctly 100% of dementia and cognitively normal groups showing a memory and executive function profile. The predictive group membership for MCI versus cognitively normal varied between 82 and 85%, with a cognitive profile associated with attention-executive function followed by memory. Group separation between MCI and dementia was between 80 and 87%, characterized by orientation, memory, and visuospatial abilities.

CONCLUSIONS

The Mex-Cog cognitive battery is useful for identifying cognitive impairment in older adults.

Memory and language cognitive data harmonization across the United States and Mexico

INTRODUCTION

We used cultural neuropsychology-informed procedures to derive and validate harmonized scores representing memory and language across population-based studies in the United States and Mexico.

METHODS

Data were from the Health and Retirement Study Harmonized Cognitive Assessment Protocol (HRS-HCAP) and the Mexican Health and Aging Study (MHAS) Ancillary Study on Cognitive Aging (Mex-Cog). We statistically co-calibrated memory and language domains and performed differential item functioning (DIF) analysis using a cultural neuropsychological approach. We examined relationships among harmonized scores, age, and education.

RESULTS

We included 3170 participants from the HRS-HCAP (Mage = 76.6 [standard deviation (SD): 7.5], 60% female) and 2042 participants from the Mex-Cog (Mage = 68.1 [SD: 9.0], 59% female). Five of seven memory items and one of twelve language items demonstrated DIF by study. Harmonized memory and language scores showed expected associations with age and education.

DISCUSSION

A cultural neuropsychological approach to harmonization facilitates the generation of harmonized measures of memory and language function in cross-national studies.

HIGHLIGHTS

We harmonized memory and language scores across studies in the United States and Mexico.A cultural neuropsychological approach to data harmonization was used.Harmonized scores showed minimal measurement differences between cohorts.Future work can use these harmonized scores for cross-national studies of Alzheimer's disease and related dementias.

Harmonization of Later-Life Cognitive Function Across National Contexts: Results from the Harmonized Cognitive Assessment Protocols (HCAPs)

Background

The Harmonized Cognitive Assessment Protocol (HCAP) is an innovative instrument for cross-national comparisons of later-life cognitive function, yet its suitability across diverse populations is unknown. We aimed to harmonize general and domain-specific cognitive scores from HCAPs across six countries, and evaluate precision and criterion validity of the resulting harmonized scores.

Methods

We statistically harmonized general and domain-specific cognitive function across the six publicly available HCAP partner studies in the United States, England, India, Mexico, China, and South Africa (N=21,141). We used an item banking approach that leveraged common cognitive test items across studies and tests that were unique to studies, as identified by a multidisciplinary expert panel. We generated harmonized factor scores for general and domain- specific cognitive function using serially estimated graded-response item response theory (IRT) models. We evaluated precision of the factor scores using test information plots and criterion validity using age, gender, and educational attainment.

Findings

IRT models of cognitive function in each country fit well. We compared measurement reliability of the harmonized general cognitive function factor across each cohort using test information plots; marginal reliability was high (r> 0·90) for 93% of respondents across six countries. In each country, general cognitive function scores were lower with older ages and higher with greater levels of educational attainment.

Interpretation

We statistically harmonized cognitive function measures across six large, population-based studies of cognitive aging in the US, England, India, Mexico, China, and South Africa. Precision of the estimated scores was excellent. This work provides a foundation for international networks of researchers to make stronger inferences and direct comparisons of cross-national associations of risk factors for cognitive outcomes.

Funding

National Institute on Aging (R01 AG070953, R01 AG030153, R01 AG051125, U01 AG058499; U24 AG065182; R01AG051158).

Measurement differences in the assessment of functional limitations for cognitive impairment classification across geographic locations

INTRODUCTION

The measurement of dementia in cross-national contexts relies on the assessment of functional limitations. We aimed to evaluate the performance of survey items on functional limitations across culturally diverse geographic settings.

METHODS

We used data from the Harmonized Cognitive Assessment Protocol Surveys (HCAP) in five countries (total N = 11,250) to quantify associations between items on functional limitations and cognitive impairment.

RESULTS

Many items performed better in the United States and England compared to South Africa, India, and Mexico. Items on the Community Screening Instrument for Dementia (CSID) had the least variability across countries (SD = 0.73 vs. 0.92 [Blessed] and 0.98 [Jorm IQCODE]), but also the weakest associations with cognitive impairment (median odds ratio [OR] = 2.23 vs. 3.01 [Blessed] and 2.75 [Jorm IQCODE]).

DISCUSSION

Differences in cultural norms for reporting functional limitations likely influences performance of items on functional limitations and may affect the interpretation of results from substantive studies.

HIGHLIGHTS

There was substantial cross-country variation in item performance. Items from the Community Screening Instrument for Dementia (CSID) had less cross-country variability but lower performance. There was more variability in performance of instrumental activities of daily living (IADL) compared to activities of daily living (ADL) items. Variability in cultural expectations of older adults should be taken into account. Results highlight the need for novel approaches to assessing functional limitations.

The aging brain: risk factors and interventions for long term brain health in women

PURPOSE OF REVIEW

Poor cognitive aging and dementia pose a significant public health burden, and women face unique risks compared to men. Recent research highlights the role of genetics, menopause, chronic disease, and lifestyle in risk and resilience in women's cognitive aging. This work suggests avenues for clinical action at midlife that may change the course of brain health in aging.

RECENT FINDINGS

Studies indicate women's risk for poor cognitive aging relates in part to hormone changes at menopause, a time when memory, brain structure and function, and Alzheimer's pathology may be observed in women and not men. Medical and lifestyle risks including diabetes, hypertension, and low physical activity also contribute to women's unique risks. At the same time, literature on resilience suggests women may benefit from lifestyle and chronic disease intervention, possibly more than men. Current studies emphasize the importance of interacting genetic and lifestyle risks, and effects of social determinants of health.

SUMMARY

Women have greater risk than men for poor cognitive aging; however, by treating the whole person, including genetics, lifestyle, and social environment, clinicians have an opportunity to support healthy cognitive aging in women and reduce the future public health burden of dementia.

A cultural neuropsychological approach to harmonization of cognitive data across culturally and linguistically diverse older adult populations

OBJECTIVE

To describe a cultural neuropsychological approach to prestatistical harmonization of cognitive data across the United States (U.S.) and Mexico with the Harmonized Cognitive Assessment Protocol (HCAP).

METHOD

We performed a comprehensive review of the administration, scoring, and coding procedures for each cognitive test item administered across the English and Spanish versions of the HCAP in the Health and Retirement Study (HRS) in the U.S. and the Ancillary Study on Cognitive Aging in Mexico (Mex-Cog). For items that were potentially equivalent across studies, we compared each cognitive test item for linguistic and cultural equivalence and classified items as confident or tentative linking items, based on the degree of confidence in their comparability across cohorts and language groups. We evaluated these classifications using differential item functioning techniques.

RESULTS

We evaluated 132 test items among 21 cognitive instruments in the HCAP across the HRS and Mex-Cog. We identified 72 confident linking items, 46 tentative linking items, and 14 items that were not comparable across cohorts. Measurement invariance analysis revealed that 64% of the confident linking items and 83% of the tentative linking items showed statistical evidence of measurement differences across cohorts.

CONCLUSIONS

Prestatistical harmonization of cognitive data, performed by a multidisciplinary and multilingual team including cultural neuropsychologists, can identify differences in cognitive construct measurement across languages and cultures that may not be identified by statistical procedures alone. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Neuropsychological Assessment of Older Adults in Nepal for Population-Based Dementia Ascertainment: Needs, Challenges, and Opportunities

The population of Nepal is rapidly aging, as in other low and middle-income countries, and the number of individuals living with Alzheimer's Disease and related dementias (ADRD) is expected to increase. However, information about the neuropsychological assessment of ADRD in Nepal is lacking. We first aimed to examine the needs, challenges, and opportunities associated with the neuropsychological assessment of older adults in Nepal for population-based ADRD ascertainment. Second, we introduce the Chitwan Valley Family Study-Study of Cognition and Aging in Nepal (CVFS-SCAN), which is poised to address these needs, and its collaboration with the Harmonized Cognitive Assessment Protocol (HCAP) international network. We reviewed the existing literature on the prevalence, risk factors, available neuropsychological assessment instruments, and sociocultural factors that may influence the neuropsychological assessment of older adults for ADRD ascertainment in Nepal. Our review revealed no existing population-based data on the prevalence of ADRD in Nepal. Very few studies have utilized formal cognitive assessment instruments for ADRD assessment, and there have been no comprehensive neuropsychological assessment instruments that have been validated for the assessment of ADRD in Nepal. We describe how the CVFS-SCAN study will address this need through careful adaptation of the HCAP instrument. We conclude that the development of culturally appropriate neuropsychological assessment instruments is urgently needed for the population-based assessment of ADRD in Nepal. The CVFS-SCAN is designed to address this need and will contribute to the growth of global and equitable neuropsychology and to the science of ADRD in low- and middle-income countries.

Differences in the measurement of cognition for the assessment of dementia across geographic contexts: Recommendations for cross-national research

INTRODUCTION

Most cognitive assessments have been developed in high-income countries but are used in diverse contexts. Differences in culture and context may affect the performance of cognitive items.

METHODS

We used the Harmonized Cognitive Assessment Protocol (HCAP) surveys in the United States, Mexico, India, England, and South Africa (combined N = 11,364) to quantify associations across countries between cognitive items and cognitive impairment status using age- and sex-adjusted logistic regression.

RESULTS

Associations were stronger in the United States (median odds ratio [OR] across items = 0.17) and England (median OR = 0.19), compared to South Africa (median OR = 0.23), India (median OR = 0.29), and Mexico (median OR = 0.28). Items assessing memory (e.g., delayed recall tasks) had the most consistent associations of the largest magnitudes across contexts.

DISCUSSION

Transporting cognitive items among countries and cultures warrants caution. Our results can guide the design of future instruments by identifying items that performed well either in individual contexts or across the range of contexts considered.

HIGHLIGHTS

Little quantitative evidence exists to guide the design of cognitive assessments in cross-national studies. The performance of cognitive items for the measurement of dementia varied across countries. Items with lower variation across countries (e.g., delayed word recall) should be used in future cross-national assessments. Across countries, there was variability in the performance of language assessments, with the exception of the animal naming task. Results can be used to design future cross-national or location-specific cognitive assessments.

Rural/urban dwelling across the life-course and late-life cognitive ability in Mexico

BACKGROUND

Urban advantages in older adults' cognitive function have been observed. Less is known about early-life urban dwelling and late-life cognition. We evaluate how rural/urban dwelling throughout life and rural to urban shifts in life relate with cognition in Mexico, a country experiencing aging and urbanization.

METHODS

Data came from the 2003 and 2012 Mexican Health and Aging Study (n = 12,238 adults age 50+). Early-life urban dwelling was self-reported. Late-life urban dwelling was based on population size of respondents' community of residence (community 2500+ people) at the time of survey. Cognitive function was measured across several cognitive tasks. We assess differences in baseline cognitive function and nine-year decline across groups using a latent change score model.

RESULTS

Cross-sectionally, compared to always rural dwellers, rural-urban transitions were associated with cognitive benefits, though individuals residing in urban areas continuously through life exhibited the highest levels of cognitive function (β = 0.89, 95% CI: 0.83, 0.96) even after adjusting for SES, health, and health behaviors (β = 0.28, 95% CI: 0.22, 0.35). Longitudinally, always urban dwellers exhibited slower decline than always rural dwellers when adjusting for baseline cognition (β = 0.11, 95% CI: 0.03, 0.18), though faster decline when baseline cognition was not adjusted (β = -0.11, 95% CI: -0.18, -0.04). No differences were observed for cognitive change across comparison groups after adjusting for potential mechanisms.

CONCLUSIONS

Early- and late-life urban dwelling may result in cognitive advantages for older Mexican adults. Clinicians should consider where individuals resided throughout life to better understand a patient's likelihood of experiencing poor cognitive outcomes.

The complex burden of determining prevalence rates of mild cognitive impairment: A systematic review

Mild cognitive impairment (MCI) is a syndrome characterized by a decline in cognitive performance greater than expected for an individual's age and education level, but that does not interfere much with daily life activities. Establishing the prevalence of MCI is very important for both clinical and research fields. In fact, in a certain percentage of cases, MCI represents a prodromal condition for the development of dementia. Accordingly, it is important to identify the characteristics of MCI that allow us to predict the development of dementia. Also, initial detection of cognitive decline can allow the early implementation of prevention programs aimed at counteracting or slowing it down. To this end, it is important to have a clear picture of the prevalence of MCI and, consequently, of the diagnostic criteria used. According to these issues, this systematic review aims to analyze MCI prevalence, exploring the methods for diagnosing MCI that determine its prevalence. The review process was conducted according to the PRISMA statement. Three thousand one hundred twenty-one international articles were screened, and sixty-six were retained. In these studies, which involved 157,035 subjects, the prevalence of MCI ranged from 1.2 to 87%. The review results showed a large heterogeneity among studies due to differences in the subjects' recruitment, the diagnostic criteria, the assessed cognitive domains, and other methodological aspects that account for a higher range of MCI prevalence. This large heterogeneity prevents drawing any firm conclusion about the prevalence of MCI.