The Aging, Demographics, and Memory Study: Study Design and Methods

A longitudinal study of the mediator role of physical activity in the bidirectional relationships of cognitive function and specific dimensions of depressive symptoms

BACKGROUND

The bidirectional relationship between cognitive function and depressive symptoms has been extensively reported. However, the potential mechanisms are still not clear. We aim to longitudinally investigate whether physical activity mediates the bidirectional relationships between cognitive function and specific dimensions of depressive symptoms.

METHODS

Data from 6,787 individuals aged ≥50 of 2014/15 (T1), 2016/17 (T2), and 2018/19 (T3) waves of the English Longitudinal Study of Ageing (ELSA). Cognitive function was assessed by domains of memory, orientation in time, and executive function. Physical activity was measured with the intensity and frequency of participation. Specific dimensions of depressive symptoms were assessed by the 8-item Center for Epidemiologic Studies Depression Scale, distinguishing between cognitive-affective and somatic symptoms. Cross-lagged panel models were used to investigate the mediating role of physical activity in the bidirectional relationships between cognitive function and two dimensions of depressive symptoms.

RESULTS

Poorer cognitive function was indirectly associated with worse cognitive-affective symptoms (indirect effect = -0.002, 95%CI: -0.004, -0.001) through lower physical activity levels. Poorer cognitive function was also indirectly associated with worse somatic symptoms (indirect effect = -0.003, 95%CI: -0.006, -0.002) through lower physical activity levels, and the reverse mediation was observed as well (indirect effect = -0.002, 95%CI: -0.004, -0.001).

LIMITATIONS

There is no distinction between potential within-person and between-person effects.

CONCLUSIONS

Collaborative interventions of physical activity are beneficial in protecting cognitive function and mental health in older adults.

Testing of significant changes in big-five personality factors over time in the presence and absence of memory impairment and life-related stress

This study tests whether memory impairment and perceived increases in stress due to life changes independently contribute to similar personality changes, such as increased neuroticism and decreased conscientiousness. Longitudinal data from 12,912 participants aged 50+ from the Health and Retirement Study (2006-2020) were analyzed using Latent Growth Curve Models (LGCMs). Six LGCMs were simultaneously estimated to examine how changes in personality across three data points spanning 8 years are predicted by both the classification of memory impairment (MI) statuses assessed via the Telephone Interview for Cognitive Status and estimated increases in life stress. Decreases were observed in all Big Five personality factors (B =  - 0.240/- 0.510, SE = 0.085/0.089) over the 8-year period. No significant differences in personality changes were found between MI cases and non-MI cases. Increased life stress was significantly associated with a rise in neuroticism (B = 0.587, SE = 0.094) and reductions in conscientiousness, extraversion, agreeableness, and openness (B ranges from - 0.223 to - 0.497). The findings emphasize adaptive/developmental shifts in personality in response to life stress rather than neuropathological ones related to memory impairment. Clinical assessment of personality changes in mid-to-late life should first consider psychological maladaptation to situational threats and challenges.

Cognitive Trajectories in Older Adults Diagnosed With Hematologic Malignant Neoplasms

Importance

More people are surviving long-term after diagnosis with hematologic malignant neoplasm (HMN), yet there are limited data on cancer-related cognitive impairment in people with HMN. Better understanding cognitive outcomes after HMN in older adults is important for patient counseling and management.

Objective

To model cognitive trajectories and rates of cognitive decline before and after HMN diagnosis in older adults compared with a matched noncancer cohort.

Design, Setting, and Participants

In this population-based cohort study, older adults from the Health and Retirement Study (HRS) diagnosed with HMN between 1998 and 2016 after age 65 years were matched 1:3 to participants without cancer from the same HRS wave using propensity scores incorporating variables relevant to cognition. Cognitive trajectories were modeled with piecewise linear splines, and rates of cognitive decline before, during, and after diagnosis were compared in the 2 groups. Data were analyzed from April 2022 to April 2024.

Exposures

HMN diagnosis by Medicare diagnosis codes.

Main Outcomes and Measures

Cognitive function was assessed by the Langa-Weir cognitive summary score from 1992 to 2020. Sociodemographic and health-related variables relevant to cognition were incorporated into propensity scores.

Results

At baseline, there were 668 participants in the HMN cohort (mean [SD] age, 76.8 [7.6] years; 343 [51.3%] male; 72 [10.8%] Black, 33 [4.9%] Hispanic, and 585 [87.6%] White) and 1994 participants in the control cohort (mean [SD] age, 76.5 [7.3] years; 1020 [51.2%] male; 226 [11.3%] Black, 91 [4.6%] Hispanic, and 1726 [86.6%] White). The HMN cohort consisted predominantly of more indolent diagnoses, and only 96 patients (14.4%) received chemotherapy. Before and in the 2 years around the time of diagnosis, the HMN and control cohorts had similar rates of cognitive decline. At 1 year postdiagnosis and beyond, the rate of cognitive decline was slower in the HMN cohort (-0.18; 95% CI, -0.23 to -0.14) than in the control group (-0.24; 95% CI, -0.26 to -0.23) (P = .02), but this difference was no longer significant after accounting for the competing risk of death (HMN group, -0.27; 95% CI, -0.34 to -0.19; control group, -0.30; 95% CI, -0.33 to -0.27; P = .48).

Conclusions and Relevance

In this cohort study of older adults, the HMN and matched noncancer control cohorts had similar rates of cognitive decline before, during, and after diagnosis after accounting for the competing risk of death.

Foreclosure, memory decline, and dementia probability: A longitudinal cohort study

INTRODUCTION

Housing insecurity is rising among older adults; health researchers know little about how this may impact their cognitive health. We investigated links between foreclosure and older adults' memory and probability of dementia.

METHODS

Using the Health and Retirement Study (2008 to 2018), we fit mixed models comparing the memory and dementia probability scores of 249 older adults who experienced foreclosure (treated) with 15,645 who did not. Baseline covariates included sociodemographics, health, and cognition. Models were stratified by age group.

RESULTS

Foreclosure was associated with faster memory decline among middle-aged (50 to 64) older adults (-0.007 standard deviations/year, 95% confidence interval: -0.13, -0.001). Compared to average memory decline among middle-aged older adults who were stably housed, foreclosure equated to 3.7 additional years of aging over 10 years. Among those 65+, differences between those who were and were not foreclosed upon were short-lived and less clear, potentially driven by depletion-of-susceptibles bias.

DISCUSSION

Foreclosure may endanger older adults' memory.

HIGHLIGHTS

Housing instability is a key determinant of cognitive aging. We examined foreclosure and levels and changes in memory and dementia probability scores in the US older adult population. Foreclosure was associated with faster memory decline among middle-aged (50 to 64) older adults, equivalent to 3.7 additional years of cognitive aging over 10 years. Foreclosure yielded sharp memory declines and increases in dementia probability among older adults 65 and above. Foreclosure imposes a greater risk for older adults' cognitive decline.

Personality and Transition From Mild Cognitive Impairment to Normal Cognition vs Dementia

OBJECTIVES

Mild cognitive impairment (MCI) is a critical stage preceding incident dementia, but not all individuals with MCI progress to dementia and some revert to normal cognition. This study examined whether personality is associated with the probability of transition from MCI to normal cognition or dementia.

DESIGN

Longitudinal observational study.

SETTING AND PARTICIPANTS

Older adults with MCI from the Health and Retirement Study (N = 1608, 56% female, mean age = 72.29, SD = 9.91). Personality traits; cognitive status; and demographic (age, sex, education, race, and ethnicity), clinical (diabetes, hypertension), behavioral (smoking, physical activity), psychological (depressive symptoms), and genetic (apolipoprotein E ε4) covariates were obtained in 2006/2008. Follow-up data on cognitive status were collected every 2 years up to the 2020 wave.

METHODS

Cox regression analyses tested the association between personality and reversion from MCI to normal cognition and progression to dementia, controlling for demographic, clinical, behavioral, psychological, and genetic covariates.

RESULTS

Controlling for demographic factors, lower neuroticism and higher openness and conscientiousness were associated with a higher likelihood of reversion from MCI to normal cognition and a lower risk of progression to dementia over time. Higher agreeableness was related to a lower risk of progression to dementia. Clinical, behavioral, psychological, and genetic factors partially accounted for these associations. There was little evidence that demographic, genetic factors, or baseline cognition moderated these associations.

CONCLUSIONS AND IMPLICATIONS

Personality traits can help identify individuals who are more likely to revert from MCI and not progress to dementia. These findings suggest that even during mild impairment, personality may modulate dementia risk and thus inform targeted interventions.

High-risk medication use among older adults with cognitive impairment living alone in the United States

BACKGROUND

More than one-fourth of older adults with cognitive impairment (CI) live alone; these individuals often lack support for medication management and face a high risk of adverse drug events. We characterized the frequency and types of high-risk medications used by older adults with CI living alone and, for context, compared patterns with those in older adults with CI living with others.

METHODS

This was a cross-sectional study of National Health and Aging Trends Study (NHATS) data and Medicare claims (2015-2017). We ascertained cognitive status from NHATS and medication use with Part D claims. We compared high-risk medication use (those with adverse cognitive effects or low tolerance for misuse) among older adults with CI living alone versus living with others using logistic regression models adjusted for demographic/clinical factors.

RESULTS

The unweighted sample included 1569 older adults with CI, of whom 491 (weighted national estimate, 31%) were living alone. In the living-alone group, the mean age was 79.9 years and 66% were female, 64% reported managing medications on their own without difficulty, 14% reported managing medications on their own with difficulty, and 18% received total support with medication management. Older adults with CI living alone used a median of 5 medications (IQR, 3-8), 16% took ≥10 medications, and 46% took ≥1 high-risk medication (anticholinergic/sedating: 24%; opioid: 13%; anticoagulant: 10%; sulfonylurea: 10%; insulin: 9%). Compared with those living with others, the use of high-risk medications was similar (p > 0.05 for unadjusted/adjusted comparisons). Those living alone were more likely both to take at least one high-risk medication and not receive help with medication management: 34% in those living alone versus 23% living with others (p < 0.05 for unadjusted/adjusted comparisons).

CONCLUSIONS

Older adults with CI living alone use many medications; nearly half use high-risk medications. Our findings can inform medication optimization interventions supporting this vulnerable population.

Medication Management Difficulty, Medication Nonadherence, and Risk of Hospitalization Among Cognitively Impaired Older Americans: A Nationally Representative Study

Effective disease management in older adults relies on medication adherence to prevent adverse outcomes like hospitalization, particularly among those with cognitive impairment. In this study, we examined the impact of cognitive impairment on medication management, adherence, and hospitalization risk across levels of cognitive function. Analyzing data from 28,558 community-dwelling older adults, we found that those with dementia had the most difficulty managing medications (13.12%), followed by cognitive impairment without dementia (5.80%), and intact cognition (1.96%). Only persons with dementia showed a significant association between medication management difficulty and hospitalization risk (Odds Ratio [OR] = 1.71; 95% Confidence Intervals: 1.08, 2.70; p = .02). Cost-related medication nonadherence was associated with hospitalization risk solely among those with intact cognition (OR = 1.25; 95% CI: 1.07, 1.45; p = .004). Dementia was associated with higher odds of medication management difficulty and subsequently hospitalization risk, underscoring the need for resources to support medication use for this population.

Association of Caregiving Receipt With Mental Health Utilization in a National Cohort of Older Adults

OBJECTIVE

There exist significant age disparities in mental health (MH) utilization, such that older adults, including older veterans, are much less likely to use MH services. In-home caregivers represent a novel, yet understudied, pathway to increase appropriate utilization. We sought to examine the association between receiving caregiving assistance and MH utilization and test moderation effects of cognitive status and depression severity in a sample of older veterans.

METHODS

Cross-sectional, mixed effects logistic regression with moderation analyses was used with a unique data resource combining survey data from the 2000-2012 U.S. Health and Retirement Study with Veterans Affairs (VA) healthcare administrative records. The analytic sample included N=1,957 Community-dwelling veterans (mean age 68.2 [9.7]), primarily male (96.5%) and non-Hispanic white (77.0%). Measures included MH utilization extracted from VA records or self-report; CESD-8 for depressive symptoms; and the Langa-Weir cognitive status classification using the modified TICS.

RESULTS

After accounting for demographics, spousal caregiver availability, health factors, and socioeconomic status, caregiving receipt was associated with two-fold odds of MH utilization, compared to receiving no assistance (8,839 person-year observations; OR = 2.02; 95% CI 1.54-2.65) and remained similar following VA policy changes to enhance MH access. Exploratory analyses revealed that categories of cognition and depressive symptoms may moderate the association.

CONCLUSION

Receipt of any in-home caregiving is associated with increased likelihood of MH use by older adults. Caregivers may represent an underutilized resource to reduce age-related mental health access disparities.

Longitudinal study of cognitive decline among women with and without urinary incontinence

BACKGROUND

Cross-sectional and short-term cohort studies have demonstrated an association between urinary incontinence and dementia, as well as lower performance on cognitive testing. The Health and Retirement Study, a longitudinal study of community-dwelling older adults, offers an opportunity to assess the temporal association between these conditions because it included an assessment of incontinence symptoms and biennial assessments of cognitive function.

OBJECTIVE

This study aimed to evaluate if urinary incontinence before the age of 70 years had an effect on changes in cognitive function among women participating in the Health and Retirement Study.

STUDY DESIGN

This secondary analysis included data from female respondents in the Health and Retirement Study aged 58 to 67 years with ≥2 cognitive assessments. Urinary incontinence was defined as any involuntary loss of any urine in the preceding 12 months. A control group without incontinence was reweighted for better comparability using coarsened exact matching for age and comorbidities. Validated methods, including neuropsychological test data, estimated a memory score and dementia probability for each participant biennially. Coprimary outcomes were the changes in memory score and dementia probability. Linear regression models were used to estimate the association of urinary incontinence with change in memory score and dementia probability, adjusting for baseline demographics and comorbidities. A subgroup analysis was performed to assess the effects of urinary incontinence frequency on these outcomes. The infrequent subgroup reported <15 days of leakage per month and the frequent subgroup reported ≥15 days of leakage per month.

RESULTS

Among eligible female respondents, 40.6% reported urinary incontinence between the ages of 58 and 69 years. Baseline memory scores and dementia probability were similar between those with urinary incontinence (n=1706) and controls (n=2507). Memory score declined significantly in both cohorts, indicating poorer memory over time (-0.222 among those with incontinence [95% confidence interval, -0.245 to -0.199] vs -0.207 in controls [95% confidence interval, -0.227 to -0.188]). The decline of memory score was not statistically significantly different between cases and controls (mean difference, -0.015; 95% confidence interval, -0.045 to 0.015). Dementia probability increased significantly in both groups, indicating a greater probability of developing dementia by 0.018 among those with incontinence (95% confidence interval, 0.015-0.020) and by 0.020 among controls (95% confidence interval, 0.017-0.022). The change in dementia probability was not significantly different between groups (mean difference, -0.002; 95% confidence interval, -0.006 to 0.002). Frequent urinary incontinence was reported in 105 of 1706 (6%) of those with urinary incontinence. Memory score declined and dementia probability increased with time (P<.001) in frequent and infrequent urinary incontinence subgroups. There was no dose-response relationship.

CONCLUSION

Measures of cognitive performance declined during approximately 10 years of observation. The changes in performance were not associated with the presence of urinary incontinence in the participants' younger years.

Impact of Care-Recipient Relationship Type on Quality of Life in Community-Dwelling Older Adults With Dementia Over Time

INTRODUCTION

Maintaining quality of life (QoL) has been identified as the primary goal of care services for person living with dementia (PLWD).

METHODS

A secondary analysis was conducted on five rounds of the National Health and Aging Trends Study (NHATS) over 4 years. A generalized estimating equation (GEE) was used to examine the prediction of relationship type on older adults' QoL through four domains: mental health, general health, functional limitations, and pain.

RESULTS

older adults cared for by an adult-child or multiple caregivers predicted increased risk for functional limitations after adjustment for their socio-demographic and dementia status (IRR = 1.53, CI [1.26, 1.86]; IRR = 1.36, CI [1.14, 1.61], respectively). The interaction between the relationship type and education was significant. Older adults with a high school education or below, who were cared for by an adult child, had a significantly higher risk of increasing functional limitations over 4 years compared to those cared for by a spouse/partner (contrast = .50, P = .01, 95% CI [.07, .93]; contrast=.52, P = .03, 95% CI [.03, 1.02]; respectively). Similarly, older adults with a high school education, who were cared for by multiple caregivers, also experienced a significantly higher risk of increasing functional limitations than those cared for by a spouse/partner (contrast = .44, P = .03, 95% CI [.02, .85]).

CONCLUSION

Our findings provide evidence of the significant contribution of relationship type on PLWD's QoL changes over time. They also help to prioritize resource allocation while addressing PLWD's demands by socio-demographics such as education level.

Dementia severity at incident diagnosis in a population representative sample of older Americans

INTRODUCTION

We provide the first analysis of distribution of dementia severity at incident diagnosis for a population representative sample of older Americans.

METHODS

Using data from the Aging, Demographics, and Memory Study (ADAMS), the Health Retirement Study (HRS), and traditional Medicare claims, we estimated the Clinical Dementia Rating Scale for ADAMS respondents and applied parameter estimates to predict dementia severity for HRS respondents with claims-based incident dementia diagnosis.

RESULTS

Seventy percent of older adults received a dementia diagnosis of mild cognitive impairment or mild dementia (early stages). Fewer individuals were diagnosed at early stages in years 2000 to 2008 (65%) compared to years 2009 to 2016 (76%). About 72% of non-Hispanic white persons were diagnosed at early stages, compared to 63% non-Hispanic black and 59% Hispanic persons. More males than females were diagnosed at early stages (75% vs 67%).

DISCUSSION

These data linkages allow population surveillance of early and equitable dementia detection in the older US population to assess clinical and policy levers to improve detection.

Highlights

For the US population 70 and older, 30% were diagnosed with dementia at a moderate or severe stage.Fewer were diagnosed at early stages in years 2000 to 2008 compared to 2009 to 2016 (65% vs 76%).A total of 72% of white persons were diagnosed at early stages, compared to 63% black and 59% Hispanic persons.More males than females were diagnosed at early stages (75% vs 67%).High wealth and education level were associated with diagnosis at early stages disease.

APOE epsilon variants and composite risk of dementia, disability, and death in the health and retirement study

BACKGROUND

Clinical trials in older adults are increasingly focused on functional outcomes, and the composite outcome of dementia, disability, and death is gaining pivotal importance. Genetic variation, particularly the APOE epsilon(ε) variants, may modify responses to new treatments. Although APOE ε4 is known to influence these outcomes separately, the magnitude of its effect on this composite outcome remains unknown. We tested the hypothesis that APOE ε4 increases, whereas APOE ε2 decreases, the risk of a composite outcome of dementia, disability, and death.

METHODS

We evaluated clinical and genomic data from the Health and Retirement Study collected from 1992 to 2020. We used variants rs429358 and rs7412 to determine APOE genotypes, modeled dominantly (carriers/noncarriers). We conducted survival analysis, using multivariable Cox proportional hazards models with a composite endpoint of dementia, disability, and death. Our primary analysis evaluated participants with genetic data and no previous dementia or disability. In secondary analyses, we focused on persons aged > = 75 years without heart disease or stroke, a subpopulation increasingly important in clinical trials of older adults.

RESULTS

We included 14,527 participants in the primary analysis. Over a median of 18 (Interquartile Range [IQR] 12-24) years, 6711 (46%) participants developed the composite outcome. In Cox analyses, APOE ε4 associated with higher risk (HR:1.15, 95%CI:1.09-1.22) of the composite outcome, whereas APOE ε2 associated with lower risk (HR:0.92, 95%CI:0.86-0.99). In the secondary analysis, we included 3174 participants. Over a median of 7 (IQR 4-11) years, 1326 participants (42%) developed the composite outcome. In Cox analyses, APOE ε4 associated with higher risk (HR:1.25, 95%CI:1.10-1.41) of the composite outcome, whereas APOE ε2 associated with lower risk (HR:0.84, 95%CI:0.71-0.98).

CONCLUSIONS

APOE ε variants are linked to the risk of dementia, disability, and death in older adults. By examining these variants in clinical trials, we can better elucidate how they might alter the effectiveness of tested interventions. Importantly, this genetic information could help identify participants who may have greater absolute benefit from such interventions.

Bidirectional relationship between epigenetic age and brain health events

Chronological age offers an imperfect estimate of the molecular changes that occur with aging. Epigenetic age, which is derived from DNA methylation data, provides a more nuanced representation of aging-related biological processes. This study examines the bidirectional relationship between epigenetic age and the occurrence of brain health events (stroke, dementia, and late-life depression). Using data from the Health and Retirement Study, we analyzed blood samples from over 4,000 participants to determine how epigenetic age relates to past and future brain health events. Study participants with a prior brain health event prior to blood collection were 4% epigenetically older (beta 0.04, SE 0.01), suggesting that these conditions are associated with faster aging than that captured by chronological age. Furthermore, a one standard deviation increase in epigenetic age was associated with 70% higher odds of experiencing a brain health event in the next four years after blood collection (OR 1.70, 95%CI 1.16-2.50), indicating that epigenetic age is not just a consequence but also a predictor of poor brain health. Both results were replicated through Mendelian Randomization analyses, supporting their causal nature. Our findings support the utilization of epigenetic age as a useful biomarker to evaluate the role of interventions aimed at preventing and promoting recovery after a brain health event.

Enhancing predictive validity of motoric cognitive risk syndrome for incident dementia and all-cause mortality with handgrip strength: insights from a prospective cohort study

Background

This study aimed to assess whether integrating handgrip strength (HGS) into the concept of motoric cognitive risk (MCR) would enhance its predictive validity for incident dementia and all-cause mortality.

Methods

A cohort of 5, 899 adults from the Health and Retirement Study underwent assessments of gait speed, subjective cognitive complaints, and HGS were involved. Over a 10-year follow-up, biennial cognitive tests and mortality data were collected. Cox proportional hazard analyses assessed the predictive power of MCR alone and MCR plus HGS for incident dementia and all-cause mortality.

Results

Patients with MCR and impaired HGS (MCR-HGS) showed the highest adjusted hazard ratios (AHR) for dementia (2.33; 95% CI, 1.49-3.65) and mortality (1.52; 95% CI, 1.07-2.17). Even patients with MCR and normal HGS (MCR-non-HGS) experienced a 1.77-fold increased risk of incident dementia; however, this association was not significant when adjusted for socioeconomic status, lifestyle factors, and medical conditions. Nevertheless, all MCR groups demonstrated increased risks of all-cause mortality. The inclusion of HGS in the MCR models significantly improved predictive discrimination for both incident dementia and all-cause mortality, as indicated by improvements in the C-statistic, integrated discrimination improvement (IDI) and net reclassification indices (NRI).

Conclusion

Our study underscores the incremental predictive value of adding HGS to the MCR concept for estimating risks of adverse health outcomes among older adults. A modified MCR, incorporating HGS, could serve as an effective screening tool during national health examinations for identifying individuals at risk of dementia and mortality.

Keeping Us Young? Grandchild Caregiving and Older Adults' Cognitive Functioning

Objective

This study investigates longitudinal associations between providing care to grandchildren and cognitive functioning. It also examines heterogeneity in these relationships.

Background

Grandchild caregiving may support older adults' cognitive functioning by providing social engagement and emotional meaning. However, studies caution that time- intensive or custodial grandchild caregiving can take a toll on grandparents. The cognitive health implications of grandchild caregiving may thus depend on contexts including time spent providing care and living arrangements. They may also vary across sociodemographic groups and have greater effects on older adults who are more vulnerable to cognitive decline.

Method

Data came from the 1998-2016 waves of the Health and Retirement Study (HRS) and represented over 11,000 U.S. adults age 50+. Using linear growth curve and dynamic panel models, the analysis explored relationships between level of grandchild care and cognitive functioning over time and across sociodemographic, family, work and health characteristics.

Results

Those providing 100-199, 200-499 or 500+ hours of care to grandchildren had better cognitive functioning than non-caregivers regardless of whether they lived with grandchildren. Positive links between grandchild caregiving and cognition were stronger for lower income, non-working, and unpartnered adults and grew with age and functional limitations.

Conclusion

These findings suggest that providing care to minor grandchildren may help support cognitive functioning as adults age. They also support the hypothesis that more vulnerable or isolated groups of older adults may benefit the most from grandchild caregiving.

Long-term cognitive outcome after elective hip or knee total joint arthroplasty: A population-based observational study

BACKGROUND

One year after elective hip or knee total joint arthroplasty (TJA), >30% of older adults meet criteria for postoperative neurocognitive disorder. However, this is not contextualized with long-term cognitive outcomes in comparable surgical and nonsurgical controls. We analyzed population-based data to compare long-term cognitive outcomes in older adults after TJA, other surgeries, and with and without arthritis pain.

METHODS

This was a retrospective observational analysis of United States older adults in the Health and Retirement Study (HRS) who underwent elective TJA, or elective surgery without expected functional benefits (e.g., cholecystectomy; inguinal herniorrhaphy), between 1998 and 2018 at aged 65 or older. TJA recipients were also age- and sex-matched to nonsurgical controls who reported moderate-severe arthritic pain or denied pain, so that comparison groups included surgical and nonsurgical (pain-suffering and pain-free) controls. We modeled biennially-assessed memory performance, a measure of direct and proxy cognitive assessments, before and after surgery, normalized to the rate of memory decline ("cognitive aging") in controls to express effect size estimates as excess, or fewer, months of memory decline. We used linear mixed effects models adjusted for preoperative health and demographic factors, including frailty, flexibly capturing time before/after surgery (knots at -4, 0, 8 years; discontinuity at surgery).

RESULTS

There were 1947 TJA recipients (average age 74; 63% women; 1358 knee, 589 hip) and 1631 surgical controls (average age 76; 38% women). Memory decline 3 years after TJA was similar to surgical controls (5.2 [95% confidence interval, CI -1.2 to 11.5] months less memory decline in the TJA group, p = 0.11) and nonsurgical controls. At 5 years, TJA recipients experienced 5.0 [95% CI -0.9 to 10.9] months less memory decline than arthritic pain nonsurgical controls.

CONCLUSION

There is no systematic accelerated memory decline at 3 years after TJA compared with surgical or nonsurgical controls.

General cognitive ability in high school, attained education, occupational complexity, and dementia risk

INTRODUCTION

We address the extent to which adolescent cognition predicts dementia risk in later life, mediated by educational attainment and occupational complexity.

METHODS

Using data from Project Talent Aging Study (PTAS), we fitted two structural equation models to test whether adolescent cognition predicts cognitive impairment (CI) and Ascertain Dementia 8 (AD8) status simultaneously (NCognitive Assessment = 2477) and AD8 alone (NQuestionnaire = 6491) 60 years later, mediated by education and occupational complexity. Co-twin control analysis examined 82 discordant pairs for CI/AD8.

RESULTS

Education partially mediated the effect of adolescent cognition on CI in the cognitive assessment aample and AD8 in the questionnaire sample (Ps < 0.001). Within twin pairs, differences in adolescent cognition were small, but intrapair differences in education predicted CI status.

DISCUSSION

Adolescent cognition predicted dementia risk 60 years later, partially mediated through education. Educational attainment, but not occupational complexity, contributes to CI risk beyond its role as a mediator of adolescent cognition, further supported by the co-twin analyses.

HIGHLIGHTS

Project Talent Aging Study follows enrollees from high school for nearly 60 years. General cognitive ability in high school predicts later-life cognitive impairment. Low education is a risk partially due to its association with cognitive ability.

Analysis of agreement between measures of subjective cognitive impairment and probable dementia in the National Health and Aging Trends Study

BACKGROUND

Subjective cognitive impairment (SCI) measures in population-based surveys offer potential for dementia surveillance, yet their validation against established dementia measures is lacking.

METHODS

We assessed agreement between SCI and a validated probable dementia algorithm in a random one-third sample (n = 1936) of participants in the 2012 National Health and Aging Trends Study (NHATS).

RESULTS

SCI was more prevalent than probable dementia (12.2% vs 8.4%). Agreement between measures was 90.0% and of substantial strength. Misclassification rates were higher among older and less-educated subgroups due to higher prevalence of false-positive misclassification but did not vary by sex or race and ethnicity.

DISCUSSION

SCI sensitivity (63.4%) and specificity (92.5%) against dementia were comparable with similar metrics for the NHATS probable dementia measure against the "gold-standard" Aging, Demographics, and Memory Study-based dementia criteria, implying that population-based surveys may afford cost-effective opportunities for dementia surveillance to assess risk and inform policy.

HIGHLIGHTS

The prevalence of subjective cognitive impairment (SCI) is generally higher than that of a validated measure of probable dementia, particularly within the youngest age group, females, Whites, and persons with a college or higher degree. Percent agreement between SCI and a validated measure of probable dementia was 90.0% and of substantial strength (prevalence- and bias-adjusted kappa, 0.80). Agreement rates were higher in older and less-educated subgroups, driven by the higher prevalence of false-positive disagreement, but did not vary significantly by sex or race and ethnicity. SCI's overall sensitivity and specificity were 63.4% and 92.5%, respectively, against a validated measure of probable dementia, suggesting utility as a low-cost option for dementia surveillance. Heterogeneity in agreement quality across subpopulations warrants caution in its use for subgroup analyses.

Performance of probable dementia classification in a European multi-country survey

Feasibility constraints limit availability of validated cognitive assessments in observational studies. Algorithm-based identification of 'probable dementia' is thus needed, but no algorithm developed so far has been applied in the European context. The present study sought to explore the usefulness of the Langa-Weir (LW) algorithm to detect 'probable dementia' while accounting for country-level variation in prevalence and potential underreporting of dementia. Data from 56 622 respondents of the Survey of Health, Ageing and Retirement in Europe (SHARE, 2017) aged 60 years and older with non-missing data were analyzed. Performance of LW was compared to a logistic regression, random forest and XGBoost classifier. Population-level 'probable dementia' prevalence was compared to estimates based on data from the Organisation for Economic Co-operation and Development. As such, application of the prevalence-specific LW algorithm, based on recall and limitations in instrumental activities of daily living, reduced underreporting from 61.0 (95% CI, 53.3-68.7%) to 30.4% (95% CI, 19.3-41.4%), outperforming tested machine learning algorithms. Performance in other domains of health and cognitive function was similar for participants classified 'probable dementia' and those self-reporting physician-diagnosis of dementia. Dementia classification algorithms can be adapted to cross-national cohort surveys such as SHARE and help reduce underreporting of dementia with a minimal predictor set.

Prevalence of cognitive impairment in home health physical therapy

BACKGROUND

The prevalence of cognitive impairment in home health physical therapy (HHPT) is unknown. We sought to identify the prevalence of cognitive impairment, including cognitive impairment no dementia (CIND) and dementia, among older adults who used HHPT, and if cognitive impairment prevalence was higher among those with HHPT-relevant characteristics.

METHODS

For our cross-sectional analysis, we identified 963 fee-for-service Medicare beneficiaries with HHPT claims (>85 years old: 28.8%, women: 63.7%, non-Hispanic White: 82.1%) in the 2014 and 2016 waves of the Health and Retirement Study (HRS) and used a validated algorithm to categorize cognitive status as normal, CIND, or dementia. We estimated the population prevalence and calculated age, gender, race/ethnicity adjusted odds ratio (aOR) of CIND and dementia for characteristics relevant to HHPT service delivery including depression, walking difficulty, fall history, incontinence, moderate-vigorous physical activity (MVPA) ≤1x/week, and community-initiated HHPT using multinomial logistic regression.

RESULTS

The population prevalence of cognitive impairment was 46.4% (CIND: 27.3%, dementia: 19.1%). The prevalence of cognitive impairment was greater among those with depression (46.7% vs. 39.5%), difficulty walking across the room (58.9% vs. 41.8%), fall history (49.1% vs. 42.9%), MVPA ≤1x/week (50.0% vs. 38.0%), and community-initiated HHPT (55.2% vs. 40.2%). Compared to normal cognitive status, the odds of cognitive impairment were greater for those with MVPA≤1x/week (CIND: aOR = 1.57 [95% CI: 1.05-2.33], dementia: aOR = 2.55 [95% CI: 1.54-4.22]), depression (dementia: aOR = 1.99 [95% CI: 1.19-3.30]), difficulty walking across the room (dementia: aOR = 2.54 [95% CI: 1.40-4.60]), fall history (dementia: aOR = 1.85 [95% CI: 1.20-2.83]), and community-initiated HHPT (dementia: aOR = 1.72 (95% CI: 1.13-2.61]).

CONCLUSION

There is a high prevalence of CIND and dementia in HHPT, and no characteristics had a low prevalence of cognitive impairment. Physical therapists should be ready to identify cognitive impairment and adapt home health service delivery for this vulnerable population of older adults.

Factors associated with reduced sleep among spouses and caregivers of older adults with varying levels of cognitive decline

BACKGROUND

Caregivers of persons with cognitive decline (PWCD) are at increased risk of poor sleep quantity and quality. It is unclear whether this is due to factors in the caregiver versus in the PWCD.

METHODS

This secondary data analysis using Aging, Demographics, and Memory Study data from the Health Retirement Study examined factors contributing to reduced sleep/rest among spouses and caregivers of older adults with varying levels of cognitive decline (cognitively normal (CN), cognitive impairment but not dementia (CIND), or dementia).

RESULTS

In our preliminary analysis, among N = 218 spouses (not necessarily caregivers) (mean age (SD) = 73.77 (7.30); 70.64% female) of older adults with varying levels of cognitive decline, regression revealed that frequency of sleep complaints was lowest among spouses with CN partners, second highest with CIND partners, and highest with dementia-partners, X2  = 26.810, P = 0.002.

PRIMARY AIM

among n = 136 caregivers of PWCD (mean age (SD) = 59.27 (13.97); 74.26% female; 22.79% spouses), we analyzed whether caregiver reduced sleep/rest was predicted by PWCD factors (i.e., frequent nighttime waking, dementia severity) and/or caregiver factors (i.e., depression symptoms, caregiver role overload). Regression revealed that caregiver depression symptoms (d = 0.62) and role overload (d = 0.88), but not PWCD factors, were associated with reduced caregiver sleep/rest after adjusting for demographic factors, caregiving frequency, and shared-dwelling status (overall model: X2  = 31.876, P = 0.002). Exploratory analyses revealed that a caregiver was 7.901 times more likely (95% CI: 0.99-63.15) to endorse experiencing reduced sleep/rest if back-up care was not available (P = 0.023).

CONCLUSION

Findings highlight that the frequency of reported sleep problems among spouses increases in a stepwise fashion when partners have dementia versus CIND versus CN. The results also emphasise that caregiver mental health and burden are strongly associated with caregiver sleep disturbances and thus may be targets of intervention for caregiver sleep problems.

An outcome-wide analysis of the effects of diagnostic labeling of Alzheimer's disease and related dementias on social relationships

INTRODUCTION

This study examines how receiving a dementia diagnosis influences social relationships by race and ethnicity.

METHODS

Using data from the Health and Retirement Study (10 waves; 7,159 observations) of adults 70 years and older predicted to have dementia using Gianattasio-Power scores (91% accuracy), this study assessed changes in social support, engagement, and networks after a dementia diagnosis. We utilized quasi-experimental methods to estimate treatment effects and subgroup analyses by race/ethnicity.

RESULTS

A diagnostic label significantly increased the likelihood of gaining social support but reduced social engagement and one measure of social networks. With some exceptions, the results were similar by race and ethnicity.

DISCUSSION

Results suggest that among older adults with assumed dementia, being diagnosed by a doctor may influence social relationships in both support-seeking and socially withdrawn ways. This suggests that discussing services and supports at the time of diagnosis is important for healthcare professionals.

Cognitive impairment and partnership status in the United States, 1998-2016, by sex, race/ethnicity, and education

Cognitively impaired adults without a partner are highly disadvantaged, as partners constitute an important source of caregiving and emotional support. With the application of innovative multistate models to the Health and Retirement Study, this paper is the first to estimate joint expectancies of cognitive and partnership status at age 50 by sex, race/ethnicity, and education in the United States. We find that women live a decade longer unpartnered than men. Women are also disadvantaged as they experience three more years as both cognitively impaired and unpartnered than men. Black women live over twice as long as cognitively impaired and unpartnered compared with White women. Lower-educated men and women live around three and five years longer, respectively, as cognitively impaired and unpartnered than more highly educated men and women. This study addresses a novel facet of partnership and cognitive status dynamics and examines their variations by key socio-demographic factors.

Cost of care for Alzheimer's disease and related dementias in the United States: 2016 to 2060

Medical and long-term care for Alzheimer's disease and related dementias (ADRDs) can impose a large economic burden on individuals and societies. We estimated the per capita cost of ADRDs care in the in the United States in 2016 and projected future aggregate care costs during 2020-2060. Based on a previously published methodology, we used U.S. Health and Retirement Survey (2010-2016) longitudinal data to estimate formal and informal care costs. In 2016, the estimated per patient cost of formal care was $28,078 (95% confidence interval [CI]: $25,893-$30,433), and informal care cost valued in terms of replacement cost and forgone wages was $36,667 ($34,025-$39,473) and $15,792 ($12,980-$18,713), respectively. Aggregate formal care cost and formal plus informal care cost using replacement cost and forgone wage methods were $196 billion (95% uncertainty range [UR]: $179-$213 billion), $450 billion ($424-$478 billion), and $305 billion ($278-$333 billion), respectively, in 2020. These were projected to increase to $1.4 trillion ($837 billion-$2.2 trillion), $3.3 trillion ($1.9-$5.1 trillion), and $2.2 trillion ($1.3-$3.5 trillion), respectively, in 2060.

Geographic Relocation in Response to Parents' Health Shocks: Who Moves and How Close?

Objective

This article examines how parent-child geographic proximity changes around the onset of parental health shocks in the United States. Differences in the likelihood of moving closer across social groups are also investigated.

Background

Adult children often care for older parents with health problems, but this requires relatively close proximity. As families are becoming smaller and many adult children live away from their parents, it is unclear how responsive families will be to older adults' health problems.

Method

We estimate a series of fixed effects and event study models on data from the Health and Retirement Study (2004-2018) to assess changes in parent-child proximity after parents' first onset of cognitive impairment and functional limitations.

Results

We find robust evidence that parents and children tend to stay close or move closer to each other in response to parent's health declines. Moves occur immediately and in subsequent waves after the onset of health shocks. Reductions in parent-child distance are consistently larger among mother-daughter dyads, dyads without spouses or multiple children, and non-Hispanic white families.

Conclusion

The geographic availability of adult children to provide care is responsive to parents' needs. After the onset of a serious health condition, most older adults have a spouse or child living close enough to provide care. Parents' and children's lives are dynamically linked, and either or both may relocate to facilitate care.

Investigating the prevalence of cognitive impairment and dementia in the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA): the Harmonised Cognitive Assessment Protocol (HCAP) cross-sectional substudy

INTRODUCTION

The Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA) study is the largest study of ageing in Northern Ireland (NI). The Harmonised Cognitive Assessment Protocol (HCAP) is a substudy of NICOLA designed to assess cognitive impairment and dementia in individuals aged 65 and over. The NICOLA-HCAP substudy is funded by the National Institute on Aging as part of a network for enhancing cross-national research within a worldwide group of population-based, longitudinal studies of ageing, all of which are centred around the US-based Health and Retirement Study.

METHODS AND ANALYSIS

The NICOLA-HCAP study will draw on the main NICOLA cohort (of 8283 participants) and randomly sample 1000 participants aged 65 and over to take part in the substudy. Participants will complete a series of cognitive tests (n=19) via a computer-assisted personal interview administered in their home (or alternatively within the research centre) and will be asked to nominate a family member or friend to complete an additional interview of validated instruments to provide information on respondent's prior and current cognitive and physical functioning and whether the individual requires help with daily activities. The objectives of the study are: to investigate the prevalence of dementia and cognitive impairment in NICOLA; harmonise scoring of the NICOLA-HCAP data to the HCAP studies conducted in Ireland, the USA and England; to explore the validity of dementia estimates; and investigate the risk factors for dementia and cognitive impairment.

ETHICS AND DISSEMINATION

The study received ethical approval from the Faculty of Medicine, Health and Life Sciences Research Ethics Committee, Queen's University Belfast. We will provide data from the Northern Irish HCAP to the research community via data repositories such as the Dementias Platform UK and Gateway to Global Aging to complement existing public data resources and support epidemiological research by others. Findings will also be disseminated through peer-reviewed publications and at international conferences.

Modeling Risk Factors for Intraindividual Variability: A Mixed-Effects Beta-Binomial Model Applied to Cognitive Function in Older People in the English Longitudinal Study of Ageing

Cognitive functioning in older age profoundly impacts quality of life and health. While most research on cognition in older age has focused on mean levels, intraindividual variability (IIV) around this may have risk factors and outcomes independent of the mean value. Investigating risk factors associated with IIV has typically involved deriving a summary statistic for each person from residual error around a fitted mean. However, this ignores uncertainty in the estimates, prohibits exploring associations with time-varying factors, and is biased by floor/ceiling effects. To address this, we propose a mixed-effects location scale beta-binomial model for estimating average probability and IIV in a word recall test in the English Longitudinal Study of Ageing. After adjusting for mean performance, an analysis of 9,873 individuals across 7 (mean = 3.4) waves (2002-2015) found IIV to be greater at older ages, with lower education, in females, with more difficulties in activities of daily living, in later birth cohorts, and when interviewers recorded issues potentially affecting test performance. Our study introduces a novel method for identifying groups with greater IIV in bounded discrete outcomes. Our findings have implications for daily functioning and care, and further work is needed to identify the impact for future health outcomes.

Cognitive decline among older adults with depressive symptoms before and during the COVID-19 pandemic

BACKGROUND

Whether the COVID-19 pandemic would induce accelerated cognitive decline in individuals with depressive symptoms is undetermined.

OBJECTIVE

To investigate the impact of the COVID-19 pandemic on cognitive function among older adults with depressive symptoms.

METHODS

Data were from the Health and Retirement Study. The interval between wave 13 and wave 14 was defined as the prepandemic period, and the interval between wave 14 and wave 15 was defined as the pandemic period. Linear mixed models and modified Poisson regression models were employed to compare the differences in cognitive decline and incident dementia between participants with and without depressive symptoms before and during the pandemic.

RESULTS

A total of 9304 participants were included. During the prepandemic period, no significant difference was observed in changes in cognitive scores between participants with and without depressive symptoms. During the pandemic period, an accelerated decline in cognitive scores was found between the two groups (global cognition: -0.25, 95 % CI: -0.41 to -0.08, P = 0.004; memory: -0.16, 95 % CI: -0.31 to -0.02, P = 0.030; executive function: -0.08, 95 % CI: -0.15 to -0.02, P = 0.014). Participants with depressive symptoms had a higher risk of developing dementia during the pandemic (RR: 1.48, 95 % CI: 1.17 to 1.88, P < 0.001).

LIMITATIONS

Causal relationship cannot be concluded due to the observational study design.

CONCLUSIONS

Older adults with depressive symptoms suffered more severe cognitive deterioration and had a higher risk of incident dementia during the pandemic, underscoring the need to provide cognitive monitoring and interventions for those with depressive symptoms during the COVID-19 pandemic.

Factor structure of the Harmonized Cognitive Assessment Protocol neuropsychological battery in the Health and Retirement Study

OBJECTIVE

The Harmonized Cognitive Assessment Protocol (HCAP) describes an assessment battery and a family of population-representative studies measuring neuropsychological performance. We describe the factorial structure of the HCAP battery in the US Health and Retirement Study (HRS).

METHOD

The HCAP battery was compiled from existing measures by a cross-disciplinary and international panel of researchers. The HCAP battery was used in the 2016 wave of the HRS. We used factor analysis methods to assess and refine a theoretically driven single and multiple domain factor structure for tests included in the HCAP battery among 3,347 participants with evaluable performance data.

RESULTS

For the eight domains of cognitive functioning identified (orientation, memory [immediate, delayed, and recognition], set shifting, attention/speed, language/fluency, and visuospatial), all single factor models fit reasonably well, although four of these domains had either 2 or 3 indicators where fit must be perfect and is not informative. Multidimensional models suggested the eight-domain model was overly complex. A five-domain model (orientation, memory delayed and recognition, executive functioning, language/fluency, visuospatial) was identified as a reasonable model for summarizing performance in this sample (standardized root mean square residual = 0.05, root mean square error of approximation = 0.05, confirmatory fit index = 0.94).

CONCLUSIONS

The HCAP battery conforms adequately to a multidimensional structure of neuropsychological performance. The derived measurement models can be used to operationalize notions of neurocognitive impairment, and as a starting point for prioritizing pre-statistical harmonization and evaluating configural invariance in cross-national research.

The Prevalence of Cognitive Impairment Among Medicare Beneficiaries Who Use Outpatient Physical Therapy

OBJECTIVE

The objective of this study was to estimate the prevalence of cognitive impairment (including cognitive impairment no dementia [CIND] and dementia) among Medicare fee-for-service beneficiaries who used outpatient physical therapy and to estimate the prevalence of cognitive impairment by measures that are relevant to rehabilitation practice.

METHODS

This cross-sectional analysis included 730 Medicare fee-for-service beneficiaries in the 2016 wave of the Health and Retirement Study with claims for outpatient physical therapy. Cognitive status, our primary variable of interest, was categorized as normal, CIND, or dementia using a validated approach, and population prevalence of cognitive impairment (CIND and dementia) was estimated by sociodemographic variables and Charlson comorbidity index score. Age-, gender- (man/woman), race-/ethnicity-adjusted population prevalence of CIND and dementia were also calculated for walking difficulty severity, presence of significant pain, self-reported fall history, moderate-vigorous physical activity (MVPA) ≤1×/week, and sleep disturbance frequency using multinomial logistic regression.

RESULTS

Among Medicare beneficiaries with outpatient physical therapist claims, the prevalence of any cognitive impairment was 20.3% (CIND:15.2%, dementia:5.1%). Cognitive impairment was more prevalent among those who were older, Black, had lower education attainment, or higher Charlson comorbidity index scores. The adjusted population prevalence of cognitive impairment among those who reported difficulty walking across the room was 29.8%, difficulty walking 1 block was 25.9%, difficulty walking several blocks was 20.8%, and no difficulty walking was 16.3%. Additionally, prevalence of cognitive impairment among those with MVPA ≤1×/week was 27.1% and MVPA >1×/week was 14.1%. Cognitive impairment prevalence did not vary by significant pain, self-reported fall history, or sleep disturbance.

CONCLUSION

One in 5 older adults who use outpatient physical therapist services have cognitive impairment. Furthermore, cognitive impairment is more common in older physical therapist patients who report worse physical function and less physical activity.

IMPACT

Physical therapists should consider cognitive screening for vulnerable older adults to inform tailoring of clinical practice toward a patient's ability to remember and process rehabilitation recommendations.

Perceived discrimination and nativity status: risk of cognitive impairment among Latin American older adults

OBJECTIVES

We examined the association between perceived discrimination and the risk of cognitive impairment with no dementia (CIND) and Alzheimer's disease and related dementias (ADRD) while considering the potential effects of nativity status.

DESIGN

A prospective analysis of discrimination and nativity status with dementia and cognitive impairment was conducted among Latinx adults aged 51 years and older who participated in the Health and Retirement Study.

SETTING

A national representative sample.

PARTICIPANTS

A sample of 1,175 Latinx adults aged 51 years and older.

MEASUREMENTS

Demographics, cognitive functioning, perceived discrimination, and nativity status (US-born vs. non-US born) were assessed. Traditional survival analysis methods (Fine and gray models) were used to account for the semi-competing risk of death with up to 10 years of follow-up.

RESULTS

According to our results, neither everyday discrimination nor nativity status on their own had a statistically significant association with CIND/ADRD; however, non-US-born Latinx adults who reported no discrimination had a 42% lower risk of CIND/ADRD (SHR = 0.58 [0.41, 0.83], p = .003) than US-born adults.

CONCLUSIONS

These results highlight the need for healthcare providers to assess for discrimination and provide support and resources for those experiencing discrimination. It also highlights the need for better policies that address discrimination and reduce health disparities.

Health care utilization and costs in the years preceding dementia identification

INTRODUCTION

There is evidence that health care utilization increases after incident dementia, particularly after dementia diagnosis and toward the end of life; however, less is known about utilization in the years before dementia identification.

METHODS

In this retrospective cohort study we obtained data on n = 5547 beneficiaries from the Health and Retirement Study (HRS)-Medicare linked sample (n = 1241 with and n = 4306 without dementia) to compare longitudinal trends in health care costs and utilization in the 6 years preceding dementia identification relative to a confounder-balanced reference group without dementia.

RESULTS

We found that persons with dementia had a greater prevalence of outpatient emergency department (ED), inpatient hospital, skilled nursing, and home health use, and total health care costs in the years preceding dementia identification compared to their similar counterparts without dementia across a comparable timespan in later life.

CONCLUSIONS

This study provides evidence to suggest greater healthcare burden may exist well before clinical manifestation and identification of dementia.

HIGHLIGHTS

Several studies have documented the tremendous healthcare-related costs of living with dementia, particularly toward the end of life. Dementia is a progressive neurodegenerative disease, which, for some, includes a prolonged pre-clinical phase. However, health services research to date has seldom considered the time before incident dementia. This study documents that health care utilization and costs are significantly elevated in the years before incident dementia relative to a demographically-similar comparison group without dementia.

Mechanisms of Change in Cognitive Function Domains Among Older Adults in Cognitive Deterioration and Improvement Groups: Evidence From Phenotypic Network Structure

OBJECTIVE

To investigate how cognitive function domains change in phenotypic networks in cognitive deterioration and improvement groups.

DESIGN

Secondary data analysis.

SETTING AND PARTICIPANTS

Respondents in the Aging, Demographics, and Memory Study (ADAMS) who were 70 years or older at the time of the data collection in 2000 or 2002.

METHODS

This study used data from the ADAMS in Wave A and Wave B. We assessed 12 cognitive function domains. Latent profile transition analysis (LPTA) and the cross-lagged panel network model were used to the dynamic interactions of the 12 cognitive function domains over time in both the deterioration and improvement groups.

RESULTS

A total of 252 participants were included in the final analysis. LPTA identified 5 subgroups and categorized all samples into 3 main categories: improvement group (n = 61), deterioration group (n = 54), and no change group (n = 137). "D9: psychomotor processing" showed the largest value of out-strength in the deterioration group (r = 0.941) and improvement group (r = 0.969). The strongest direct positive effect in the deterioration group was "C9: psychomotor processing" -> "C8: attention" [β = 0.39 (0.00, 1.13)]. In the improvement group, the strongest direct positive effect was "C9 = psychomotor processing" -> "C7 = visual memory" [β = 0.69 (0.07, 1.30)].

CONCLUSION AND IMPLICATIONS

Psychomotor processing affected other cognitive domains, and it played a crucial role in changes of cognitive function. The paths of psychomotor processing to attention and visual memory were found to be major factors in cognitive deterioration and improvement. Targeting psychomotor processing may lead to the development of more effective and precise interventions.

Association between BMI trajectories in late-middle age and subsequent dementia risk in older age: a 26-year population-based cohort study

BACKGROUND

The association between body mass index (BMI) and dementia risk differs depending on follow-up time and age at BMI measurement. The relationship between BMI trajectories in late-middle age (50-65 years old) and the risk of dementia in older age (> 65 years old) has not been revealed.

METHODS

In the present study, participants from the Health and Retirement Study were included. BMI trajectories were constructed by combining BMI trend and variation information. The association between BMI trajectories at the age of 50-65 years and dementia risk after the age of 65 years was investigated. Participants with European ancestry and information on polygenic scores for cognitive performance were pooled to examine whether genetic predisposition could modify the association.

RESULTS

A total of 10,847 participants were included in the main analyses. A declining BMI trend and high variation in late-middle age were associated with the highest subsequent dementia risk in older age compared with an ascending BMI trend and low variation (RR = 1.76, 95% CI = 1.45-2.13). Specifically, in stratified analyses on BMI trajectories and dementia risk based on each individual's mean BMI, the strongest association between a declining BMI trend with high variation and elevated dementia risk was observed in normal BMI group (RR = 2.66, 95% CI = 1.72-4.1). Similar associations were found when participants were stratified by their genetic performance for cognition function without interaction.

CONCLUSIONS

A declining BMI trend and high variation in late-middle age were associated with a higher risk of dementia. Early monitoring of these individuals is needed to prevent dementia in older individuals.

Assessing cognitive function in longitudinal studies of ageing worldwide: some practical considerations

Over 55 million people live with dementia worldwide. With 40% of modifiable risk factors estimated to contribute to dementia, the potential for prevention is high, and preventive measures, at an early stage of cognitive decline, are likely to positively influence future dementia trends. Countries need reliable health data and adequate measurement tools to quantify, monitor and track early changes in cognitive capacity in the general population. Many cognitive tests exist; however, there is no consensus to date about which instruments should be employed, and important variations in measurement have been observed. In this narrative review, we present a number of cognitive tests that have been used in nationally representative population-based longitudinal studies of ageing. Longitudinal panel studies of ageing represent critical platforms towards capturing the process of cognitive ageing and understanding associated risk and protective factors. We highlight optimal measures for use at a population level and for cross-country comparisons, taking into consideration instrument reliability, validity, duration, ease of administration, costs, literacy and numeracy requirements, adaptability to sensory and fine motor impairments and portability to different cultural and linguistic milieux. Drawing upon the strengths and limitations of each of these tests, and the experience gained and lessons learnt from conducting a nationally representative study of ageing, we indicate a comprehensive battery of tests for the assessment of cognitive capacity, designed to facilitate its standardised operationalisation worldwide.

Telehealth Use Among Older Adults With Sensory, Cognitive, and Physical Impairments: A Substitute or Supplement to Traditional Care?

OBJECTIVES

Telehealth use flourished during the COVID-19 pandemic, as older patients faced obstacles to seeking in-person care. Heavy reliance on telehealth may continue postpandemic, due to increased Medicare investments in its use. However, it is unclear if older adults with disabilities face obstacles to effective telehealth use. We evaluate (a) how sensory, physical, and cognitive impairments affect older adults' use of telehealth only, traditional in-person care only, neither, or both (i.e., combined care); and (b) whether these patterns differ on the basis of socioeconomic and social resources that may facilitate telehealth use.

METHOD

Data are from the Self-Administered Questionnaire in the 2020 wave of the Health and Retirement Study (n = 4,453). We estimated multinomial logistic regression models to evaluate associations between impairments and health care service use and tested 2-way interaction terms to evaluate moderation effects.

RESULTS

Persons without impairments were most likely to use combined care, considered the optimal form of care. Persons with vision or cognitive impairment were more likely to use telehealth or traditional care only, whereas persons with 3 or more physical limitations were least likely to use telehealth alone, relative to combined care. Patterns did not differ significantly on the basis of any of the potential moderators.

DISCUSSION

We discuss implications for health care policy and practice, in light of reimbursement changes proposed by the Centers for Medicare and Medicaid Services for telehealth services. These proposals include the elimination of voice-only services which may be particularly beneficial to vision-impaired older adults.

Cognitive impairment indicator for the neuropsychological test batteries in the Canadian Longitudinal Study on Aging: definition and evidence for validity

BACKGROUND

Prevalence of overall cognitive impairment based on each participant's performance across a neuropsychological battery is challenging; consequently, we define and validate a dichotomous cognitive impairment/no cognitive indicator (CII) using a neuropsychological battery administered in a population-based study. This CII approximates the clinical practice of interpretation across a neuropsychological battery and can be applied to any neuropsychological dataset.

METHODS

Using data from participants aged 45-85 in the Canadian Longitudinal Study on Aging receiving a telephone-administered neuropsychological battery (Tracking, N = 21,241) or a longer in-person battery (Comprehensive, N = 30,097), impairment was determined for each neuropsychological test based on comparison with normative data. We adjusted for the joint probability of abnormally low scores on multiple neuropsychological tests using baserates of low scores demonstrated in the normative samples and created a dichotomous CII (i.e., cognitive impairment vs no cognitive impairment). Convergent and discriminant validity of the CII were assessed with logistic regression analyses.

RESULTS

Using the CII, the prevalence of cognitive impairment was 4.3% in the Tracking and 5.0% in the Comprehensive cohorts. The CII demonstrated strong convergent and discriminant validity.

CONCLUSIONS

The approach for the CII is a feasible method to identify participants who demonstrate cognitive impairment on a battery of tests. These methods can be applied in other epidemiological studies that use neuropsychological batteries.

Racial, Ethnic, Nativity, and Educational Disparities in Cognitive Impairment and Activity Limitations in the United States, 1998-2016

Despite extensive research on cognitive impairment and limitations in basic activities of daily living, no study has investigated the burden of their co-occurrence (co-impairment). Using the Health and Retirement Study data and incidence-based multistate models, we study the population burden of co-impairment using three key indicators: mean age at onset, lifetime risk, and health expectancy. We examine patterns by gender, race, ethnicity, nativity, education, and their interactions for U.S. residents aged 50-100. Furthermore, we analyze what fractions of racial, ethnic, and nativity disparities in co-impairment are attributable to inequalities in educational attainment. Results reveal that an estimated 56% of women and 41% of men aged 50 will experience co-impairment in their remaining life expectancy. Men experience an earlier onset of co-impairment than women (74 vs. 77 years), and women live longer in co-impairment than men (3.4 vs. 1.9 years). Individuals who are Black, Latinx, and lower educated, especially those experiencing intersecting disadvantages, have substantially higher lifetime risk of co-impairment, earlier co-impairment onset, and longer life in co-impairment than their counterparts. Up to 75% of racial, ethnic, and nativity disparity is attributable to inequality in educational attainment. This study provides novel insights into the burden of co-impairment and offers evidence of dramatic disparities in the older U.S. population.

The Association of Cognitive Status and Post-Operative Opioid Prescribing in Older Adults

Objective

To examine the differences in opioid prescribing by cognitive status following common elective surgical procedures among Medicare beneficiaries.

Background

Older individuals commonly experience changes in cognition with age. Although opioid prescribing is common after surgery, differences in opioid prescribing after surgery by cognitive status are poorly understood.

Methods

We conducted a retrospective analysis of patients ≥65 years participating in the Health and Retirement Study (HRS) linked with Medicare claims data who underwent surgeries between January 2007 and November 2016 and had cognitive assessments before the index operation. Cognitive status was defined as normal cognition, mild cognitive impairment (MCI), or dementia. Outcomes assessed were initial perioperative opioid fill rates, refill rates, and high-risk prescriptions fill rates. The total amount of opioids filled during the 30-day postdischarge period was also assessed. Adjusted rates were estimated for patient factors using the Cochran-Armitage test for trend.

Results

Among the 1874 patients included in the analysis, 68% had normal cognition, 21.3% had MCI, and 10.7% had dementia. Patients with normal cognition (58.1%) and MCI (54.5%) had higher initial preoperative fill rates than patients with dementia (33.5%) (P < 0.001). Overall, patients with dementia had similar opioid refill rates (21%) to patients with normal cognition (24.1%) and MCI (26.5%) (P = 0.322). Although prior opioid exposure did not differ by cognitive status (P = 0.171), among patients with high chronic preoperative use, those with dementia had lower adjusted prescription sizes filled within 30 days following discharge (281 OME) than patients with normal cognition (2147 OME) and MCI (774 OME) (P < 0.001; P = 0.009 respectively). Among opioid-naive patients, patients with dementia also filled smaller prescription sizes (97 OME) compared to patients with normal cognition (205 OME) and patients with MCI (173 OME) (P < 0.001 and P = 0.019, respectively).

Conclusions

Patients with dementia are less likely to receive postoperative prescriptions, less likely to refill prescriptions, and receive prescriptions of smaller sizes compared to patients with normal cognition or MCI. A cognitive assessment is an additional tool surgeons can use to determine a patient's individualized postoperative pain control plan.

Gender of Study Partners and Research Participants Associated With Differences in Study Partner Ratings of Cognition and Activity Level

OBJECTIVES

Studies of Alzheimer's disease typically include "study partners" (SPs) who report on participants' cognition and function. Prior studies show SP reports differ depending on the relationship between the SP and participant, that is, spouse or adult child. Adult children SPs are typically female. Could differing reports be due to gender? Knowing this may help explain variability in measurement.

METHODS

The Aging, Demographics, and Memory Study enrolled a subset of participants from the Health and Retirement Study. Each participant had an SP. Bivariate and multivariable regression models compared 718 SP-participant dyads.

RESULTS

In analyses of 4 groups defined by SP and participant gender, dyads composed of 2 women were less likely to identify as White (75.8%, 95% confidence interval [CI], 70.4-80.5) than dyads composed of 2 men (93.3%, 95% CI, 81.2-97.8). In analyses adjusted for the severity of cognitive and functional impairment, women SPs rated women participants as more active than they rated men, mean 2.15 (95% CI, 2.07-2.22) versus mean 2.30 (95% CI, 2.24-2.37), respectively, on a 4-point scale. Similarly, men SPs rated women participants as more active than they rated men, mean 2.1 (95% CI, 2.0-2.2) and mean 2.4 (95% CI, 2.3-2.5), respectively. In an analysis of cognitively unimpaired participants, women SPs rated participants' memory worse than men SPs did (p < .05).

DISCUSSION

SP and participant gender influence SPs' reports of another person's cognition and activity level. Our findings expand what is understood about how nondisease factors influence measures of disease severity.

CogDrisk, ANU-ADRI, CAIDE, and LIBRA Risk Scores for Estimating Dementia Risk

Importance

While the Australian National University-Alzheimer Disease Risk Index (ANU-ADRI), Cardiovascular Risk Factors, Aging, and Dementia (CAIDE), and Lifestyle for Brain Health (LIBRA) dementia risk tools have been widely used, a large body of new evidence has emerged since their publication. Recently, Cognitive Health and Dementia Risk Index (CogDrisk) and CogDrisk for Alzheimer disease (CogDrisk-AD) risk tools have been developed for the assessment of dementia and AD risk, respectively, using contemporary evidence; comparison of the relative performance of these risk tools is limited.

Objective

To evaluate the performance of CogDrisk, ANU-ADRI, CAIDE, LIBRA, and modified LIBRA (LIBRA with age and sex estimates from ANU-ADRI) in estimating dementia and AD risks (with CogDrisk-AD and ANU-ADRI).

Design, Setting, and Participants

This population-based cohort study obtained data from the Rush Memory and Aging Project (MAP), the Cardiovascular Health Study Cognition Study (CHS-CS), and the Health and Retirement Study-Aging, Demographics and Memory Study (HRS-ADAMS). Participants who were free of dementia at baseline were included. The factors were component variables in the risk tools that included self-reported baseline demographics, medical risk factors, and lifestyle habits. The study was conducted between November 2021 and March 2023, and statistical analysis was performed from January to June 2023.

Main outcomes and measures

Risk scores were calculated based on available factors in each of these cohorts. Area under the receiver operating characteristic curve (AUC) was calculated to measure the performance of each risk score. Multiple imputation was used to assess whether missing data may have affected estimates for dementia risk.

Results

Among the 6107 participants in 3 validation cohorts included for this study, 2184 participants without dementia at baseline were available from MAP (mean [SD] age, 80.0 [7.6] years; 1606 [73.5%] female), 548 participants without dementia at baseline were available from HRS-ADAMS (mean [SD] age, 79.5 [6.3] years; 288 [52.5%] female), and 3375 participants without dementia at baseline were available from CHS-CS (mean [SD] age, 74.8 [4.9] years; 1994 [59.1%] female). In all 3 cohorts, a similar AUC for dementia was obtained using CogDrisk, ANU-ADRI, and modified LIBRA (MAP cohort: CogDrisk AUC, 0.65 [95% CI, 0.61-0.69]; ANU-ADRI AUC, 0.65 [95% CI, 0.61-0.69]; modified LIBRA AUC, 0.65 [95% CI, 0.61-0.69]; HRS-ADAMS cohort: CogDrisk AUC, 0.75 [95% CI, 0.71-0.79]; ANU-ADRI AUC, 0.74 [95% CI, 0.70-0.78]; modified LIBRA AUC, 0.75 [95% CI, 0.71-0.79]; CHS-CS cohort: CogDrisk AUC, 0.70 [95% CI, 0.67-0.72]; ANU-ADRI AUC, 0.69 [95% CI, 0.66-0.72]; modified LIBRA AUC, 0.70 [95% CI, 0.68-0.73]). The CAIDE and LIBRA also provided similar but lower AUCs than the 3 aforementioned tools (eg, MAP cohort: CAIDE AUC, 0.50 [95% CI, 0.46-0.54]; LIBRA AUC, 0.53 [95% CI, 0.48-0.57]). The performance of CogDrisk-AD and ANU-ADRI in estimating AD risks was also similar.

Conclusions and relevance

CogDrisk and CogDrisk-AD performed similarly to ANU-ADRI in estimating dementia and AD risks. These results suggest that CogDrisk and CogDrisk-AD, with a greater range of modifiable risk factors compared with other risk tools in this study, may be more informative for risk reduction.

Estimating Transition Probabilities Across the Alzheimer's Disease Continuum Using a Nationally Representative Real-World Database in the United States

INTRODUCTION

Clinical Alzheimer's disease (AD) begins with mild cognitive impairment (MCI) and progresses to mild, moderate, or severe dementia, constituting a disease continuum that eventually leads to death. This study aimed to estimate the probabilities of transitions across those disease states.

METHODS

We developed a mixed-effects multi-state Markov model to estimate the transition probabilities, adjusted for 5 baseline covariates, using the Health and Retirement Study (HRS) database. HRS surveys older adults in the United States bi-annually. Alzheimer states were defined using the modified Telephone Interview of Cognitive Status (TICS-m).

RESULTS

A total of 11,292 AD patients were analyzed. Patients were 70.8 ± 9.0 years old, 54.9% female, and with 12.0 ± 3.3 years of education. Within 1 year from the initial state, the model estimated a higher probability of transition to the next AD state in earlier disease: 12.8% from MCI to mild AD and 5.0% from mild to moderate AD, but < 1% from moderate to severe AD. After 10 years, the probability of transition to the next state was markedly higher for all states, but still higher in earlier disease: 29.8% from MCI to mild AD, 23.5% from mild to moderate AD, and 5.7% from moderate to severe AD. Across all AD states, the probability of transition to death was < 5% after 1 year and > 15% after 10 years. Older age, fewer years of education, unemployment, and nursing home stay were associated with a higher risk of disease progression (p < 0.01).

CONCLUSIONS

This analysis shows that the risk of progression is greater in earlier AD states, increases over time, and is higher in patients who are older, with fewer years of education, unemployed, or in a nursing home at baseline. The estimated transition probabilities can provide guidance for future disease management and clinical trial design optimization, and can be used to refine existing cost-effectiveness frameworks.

Decision Making for Patients With Severe Dementia Versus Normal Cognition Near the End of Life

Background and Objectives

The clinical progression of severe dementia frequently leads to situations where surrogate decision makers must quickly make choices about potentially burdensome treatments that offer limited clinical benefit. We examined whether the number of decision makers and their access to advance directives were related to treatment choice for patients with severe dementia in comparison to those with normal cognition.

Research Design and Methods

We retrospectively linked survey responses about end-of-life treatment decisions to Medicare claims for Health and Retirement Study respondents dying between 2002 and 2015 whose next-of-kin reported a need for surrogate decision making. We estimated multivariable logistic regression models to study measures of aggressive care in the last 6 months of life; in-hospital death, burdensome transfers, and burdensome treatments.

Results

Compared to patients who were cognitively normal near the end of life (n = 1 198), patients with severe dementia (n = 722) were less likely to experience burdensome treatments (18% [95% confidence interval {CI} 14-21] vs 32% [95% CI 29-35]), burdensome transfers (20% [95% CI 17-24] vs 30% [95% CI 27-33]), and in-hospital death (24% [95% CI 20-28] vs 30% [95% CI 26-33]) when surrogates were involved. Rates of burdensome treatments, transfers, or in-hospital death for decedents with severe dementia did not vary with single versus multiple decision makers or when decision makers were informed by advance directives. However, among decedents with normal cognition, a single decision maker informed by an advance directive was associated with the lowest rates of burdensome treatments and in-hospital death.

Discussion and Implications

Surrogate decision makers made similar choices around end-of-life care for patients with severe dementia regardless of the number of decision makers and availability of advance directives. However, both advance directives and single decision makers were associated with less aggressive care for cognitively normal decedents.

Six-Year Cognitive Trajectory in Older Adults Following Major Surgery and Delirium

Importance

The study results suggest that delirium is the most common postoperative complication in older adults and is associated with poor outcomes, including long-term cognitive decline and incident dementia.

Objective

To examine the patterns and pace of cognitive decline up to 72 months (6 years) in a cohort of older adults following delirium.

Design, Setting, and Participants

This was a prospective, observational cohort study with long-term follow-up including 560 community-dwelling older adults (older than 70 years) in the ongoing Successful Aging after Elective Surgery study that began in 2010. The data were analyzed from 2021 to 2022.

Exposure

Development of incident delirium following major elective surgery.

Main Outcomes and Measures

Delirium was assessed daily during hospitalization using the Confusion Assessment Method, which was supplemented with medical record review. Cognitive performance using a comprehensive battery of neuropsychological tests was assessed preoperatively and across multiple points postoperatively to 72 months of follow-up. We evaluated longitudinal cognitive change using a composite measure of neuropsychological performance called the general cognitive performance (GCP), which is scaled so that 10 points on the GCP is equivalent to 1 population SD. Retest effects were adjusted using cognitive test results in a nonsurgical comparison group.

Results

The 560 participants (326 women [58%]; mean [SD] age, 76.7 [5.2] years) provided a total of 2637 person-years of follow-up. One hundred thirty-four participants (24%) developed postoperative delirium. Cognitive change following surgery was complex: we found evidence for differences in acute, post-short-term, intermediate, and longer-term change from the time of surgery that were associated with the development of postoperative delirium. Long-term cognitive change, which was adjusted for practice and recovery effects, occurred at a pace of about -1.0 GCP units (95% CI, -1.1 to -0.9) per year (about 0.10 population SD units per year). Participants with delirium showed significantly faster long-term cognitive change with an additional -0.4 GCP units (95% CI, -0.1 to -0.7) or -1.4 units per year (about 0.14 population SD units per year).

Conclusions and Relevance

This cohort study found that delirium was associated with a 40% acceleration in the slope of cognitive decline out to 72 months following elective surgery. Because this is an observational study, we cannot be sure whether delirium directly causes subsequent cognitive decline, or whether patients with preclinical brain disease are more likely to develop delirium. Future research is needed to understand the causal pathway between delirium and cognitive decline.

Development of a latent dementia index in the aging, demographics, and memory study: Validation and measurement invariance by sex

Latent variable models can create a latent dementia index (LDI) using cognitive and functional ability to approximate dementia likelihood. The LDI approach has been applied across diverse cohorts. It is unclear whether sex affects its measurement properties. We use Wave A (2001-2003) of the Aging, Demographics, and Memory Study (n = 856). Multiple group confirmatory factor analysis (CFA) was used to test measurement invariance (MI) using informant-reported functional ability and cognitive performance tasks, which we group into verbal, nonverbal, and memory. Partial scalar invariance was found, allowing for testing sex differences in LDI means (MDiff = 0.38). The LDI correlated with consensus panel dementia diagnosis, Mini-Mental State Examination (MMSE), and dementia risk factors (low education, advanced age, and apolipoprotein ε4 [APOE-ε4] status) for men and women. The LDI validly captures dementia likelihood to permit estimation of sex differences. LDI sex differences indicate higher dementia likelihood in women, potentially due to social, environmental, and biological factors.

CERAD (Consortium to Establish a Registry for Alzheimer's Disease) Neuropsychology Assessment Battery: 35 Years and Counting

BACKGROUND

In 1986, the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) was mandated to develop a brief neuropsychological assessment battery (CERAD-NAB) for AD, for uniform neuropsychological assessment, and information aggregation. Initially used across the National Institutes of Aging-funded Alzheimer's Disease Research Centers, it has become widely adopted wherever information is desired on cognitive status and change therein, particularly in older populations.

OBJECTIVE

Our purpose is to provide information on the multiple uses of the CERAD-NAB since its inception, and possible further developments.

METHODS

Since searching on "CERAD neuropsychological assessment battery" or similar terms missed important information, "CERAD" alone was entered into PubMed and SCOPUS, and CERAD-NAB use identified from the resulting studies. Use was sorted into major categories, e.g., psychometric information, norms, dementia/differential dementia diagnosis, epidemiology, intervention evaluation, genetics, etc., also translations, country of use, and alternative data gathering approaches.

RESULTS

CERAD-NAB is available in ∼20 languages. In addition to its initial purpose assessing AD severity, CERAD-NAB can identify mild cognitive impairment, facilitate differential dementia diagnosis, determine cognitive effects of naturally occurring and experimental interventions (e.g., air pollution, selenium in soil, exercise), has helped to clarify cognition/brain physiology-neuroanatomy, and assess cognitive status in dementia-risk conditions. Surveys of primary and tertiary care patients, and of population-based samples in multiple countries have provided information on prevalent and incident dementia, and cross-sectional and longitudinal norms for ages 35-100 years.

CONCLUSION

CERAD-NAB has fulfilled its original mandate, while its uses have expanded, keeping up with advances in the area of dementia.

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.