Variation in cognitive functioning as a refined approach to comparing aging across countries

Educational Attainment and Later-Life Cognitive Function in High- and Middle-Income Countries: Evidence From the Harmonized Cognitive Assessment Protocol

OBJECTIVES

Identifying social policies that can promote cognitive health is crucial for reducing the global burden of dementia. We evaluated the importance of educational attainment for later-life cognitive function in various social and geographic settings.

METHODS

Using harmonized data for individuals aged ≥65 years from the United States Health and Retirement Study (HRS) and its international partner studies in England, Mexico, China, and India, and each study's respective Harmonized Cognitive Assessment Protocol (HCAP), we conducted a cross-national comparative study to examine the role of educational attainment in later-life cognitive function across countries (n = 14,980, 2016-2019). We used multivariable-adjusted regression to estimate associations between educational attainment and harmonized global cognitive function scores.

RESULTS

In Mexico, China, and India, the general cognitive function scores on average are approximately one standard deviation of the HRS-HCAP cognitive function score distribution lower compared to the United States and England, paralleling patterns of educational attainment across countries. In all countries, higher educational attainment was associated with progressively higher later-life cognitive function scores. Population-level differences in educational attainment explained about 50%-90% of the observed differences in cognitive function scores across countries.

DISCUSSION

The relationship between education and later-life cognitive function across social and geographic contexts underscores the crucial role of education to promote cognitive health and reduce dementia risk. Continual improvement of educational attainment in low- and middle-income settings may yield a significant pay-off in later-life cognitive health.

Sex differences in cognitive decline among middle-aged and older adults: a cohort study in Europe

OBJECTIVES

Previous studies on sex differences in cognitive decline provide inconsistent findings, with many European countries being underrepresented. We determined the association between sex and cognitive decline in a sample of Europeans and explored differences across birth cohorts and regions.

METHODS

Participants 50+ years old enrolled in the Survey of Health, Ageing and Retirement in Europe had their cognition measured by tests of immediate recall, delayed recall and verbal fluency biennially up to 17 years of follow-up (median 6, interquartile range 3-9 years). We used linear mixed-effects models to assess the relationship between sex and the rate of cognitive decline, adjusting for sociodemographic and health-related characteristics.

RESULTS

Of 66,670 participants (mean baseline age 63.5 ± standard deviation 9.4), 55% were female. Males and females had similar rates of decline in the whole sample in immediate recall (beta for interaction sex × time B = 0.002, 95% CI -0.001 to 0.006), delayed recall (B = 0.000, 95% CI -0.004 to 0.004), and verbal fluency (B = 0.008, 95% CI -0.005 to 0.020). Females born before World War II had a faster rate of decline in immediate recall and delayed recall compared to males, while females born during or after World War II had a slower rate of decline in immediate recall. Females in Central and Eastern Europe had a slower rate of cognitive decline in delayed recall compared to males.

DISCUSSION

Our study does not provide strong evidence of sex differences in cognitive decline among older Europeans. However, we identified heterogeneity across birth cohorts and regions.

Speed of aging of populations by socioeconomics subgroups in China: A cross-sectional study of cognitive performance

Objectives

Although there is an association between socioeconomic factors and cognition, there are shortcomings in terms of examining the age of onset of decline between people with varying social backgrounds. This study aims to present the disparities in cognitive performance among older adults by simultaneously integrating health status, social characteristics, and age into an understandable metric.

Study design

This study is cross-sectional.

Methods

A sample of 3422 adults aged at least 60 was utilised from the 2015 wave of the China Health and Nutrition Survey to analyse the trajectories of cognitive ageing through the Characteristics approach. This approach generates an age-differential schedule whereby, as a hypothetical example, the cognition level Z of an individual aged 60 who has not completed schooling is demonstrated at age 66 by someone who has completed secondary schooling.

Results

There was an increasing advantage with cognitive performance as the level of education completed increased; men aged 61.9 with a primary level of schooling and those aged 67.8 with postsecondary qualifications exhibit the same cognition performance as those aged 60 with no completed schooling. The observation also suggested that cognition advantages diminish through age. In terms of income, the age-differential schedule follows a similar pattern. albeit lower outcomes, to that of education differentials.

Conclusion

When comparing education and income levels and their respective impacts on cognitive functioning, the former has been noted to have a larger effect. Education's effect has continuity in that it can influence opportunities until later ages.

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.

Determining impairment in the Swedish, Polish and German ECAS: the importance of adjusting for age and education

Objective: Age and years of education are strong predictors of cognitive performance in several versions of the Edinburgh Cognitive and Behavioral ALS Screen (ECAS) and cutoffs for the Swedish and Polish versions are not established yet. Here we evaluated the performance of healthy subjects on the national versions of the Swedish and Polish ECAS and compared cognitive performance on three European translations of the ECAS. Methods: The ECAS performances of healthy subjects from Sweden (n = 111), Poland (n = 124) and Germany (n = 86) were compared. Based on the test results on the national versions of ECAS, age- and education-adjusted cutoffs were compared for the German, Swedish and Polish versions, respectively. Results: Age and years of education correlated with performance in the ECAS. Swedish subjects under the age of 60 years and Swedish subjects with low education level scored significantly higher in memory than the respective German and Polish subgroups. German and Polish subjects over 60 years of age performed significantly better in language than the respective Swedish subgroup. The Polish cohort in total had lower executive scores compared to the Swedish cohort, and lower than the German subjects in the higher education subgroup. Conclusions: The results highlight the importance of establishing age- and education-adjusted ECAS cutoffs not only in general, but also for seemingly similar populations of different origins. The results should be taken into account when comparing cognition data across patient populations including in drug trials where an ECAS test result is being used as an inclusion criterium or outcome measure.

Socioeconomic Disparities in Cognitive Functioning Trajectories Among Older Filipinos: Applying the Characteristics Approach

Health functioning declines with age, but there are disparities in its progression with regard to socioeconomic status, particularly education attainment, income, and wealth. This paper focused on the use of the characteristics approach to present the trajectories of cognitive performance among older adults with different education and wealth levels in the Philippines. Using an analytical sample of 5209 adults aged at least 60 years, extracted from the first wave of the 2018 Longitudinal Study on Ageing and Health in the Philippines, it was observed that having higher levels of education delayed lower cognitive performance, whereby men had further gains than women. Greater wealth and income were also shown to slow diminishing cognitive performance, and women gained more in this regard. Viewing health only from an age perspective is limiting; and the results show that the older population is heterogeneous and social gradients exhibit disparities in health performance at later ages.

Comparing the cognitive functioning of middle-aged and older foreign-origin population in Estonia to host and origin populations

Background

In migration and health research, the healthy migrant effect has been a common finding, but it usually pertains to specific contexts only. Existing findings are inconsistent and inconclusive regarding the cognitive functioning of the (aging) foreign-origin population relative to the populations of their host and sending countries. Moreover, this comparison is an understudied design setting.

Objective

We analyze the outcomes and associations of cognitive functioning outcomes of the non-institutionalized middle-aged and older population, comparing the Russian-origin population in Estonia with Estonians in Estonia and Russians in Russia in a cross-sectional design. We aim to estimate the (long-term) effects of migration on cognitive functioning in later life, contextualizing the findings in previous research on the healthy migrant effect.

Data and methods

We use data from face-to-face interviews conducted within the SHARE Estonia (2010-2011) and SAGE Russia (2007-2010) surveys. Respondents aged 50+ living in urban areas were grouped by self-identified ethnicity, including 2,365 Estonians, 1,373 Russians in Estonia, and 2,339 Russians in Russia (total N = 6,077). Cognitive functioning was measured using a 25-percentile cut-off threshold for the results of two cognition outcomes - immediate recall and verbal fluency - and the odds of impairment were estimated using binary logistic regression.

Results

Russian men and women living in Estonia have significantly higher odds of impairment in immediate recall than Estonian men and women, though they do not differ from Russians in Russia in the final adjusted models. The differences between all groups are non-significant if age at migration is considered. There are no significant differences between the groups in verbal fluency.

Conclusion

Contrary to the commonly found healthy migrant effect, the middle-aged and older foreign-origin population in Estonia fares initially worse than the native population in the immediate recall outcome, but does not differ from their sending country population, possibly due to Russia's higher mortality rate and therefore the selective survival of healthier people. Different results depending on the cognitive functioning outcome suggest that migration may affect temporary memory more than crystallized knowledge. However, there are no differences between the groups if defined based on age at migration, which suggests that the age profile differences explain most of the groups' differences in cognitive functioning.

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).

The measurement of structural ageing – an axiomatic approach

The structural ageing of the population is one of the key global trends of the 21st Century. In this paper, we outline four axioms that, along with easy interpretability, we believe should underpin a theoretically valid measure of structural ageing: (1) population size invariance; (2) strong dominance; (3) weak dominance; and (4) age sensitivity. We then present a class of structural ageing indices that satisfy the axioms and are easily interpretable, with root-mean-squared-age (RMSA) as our preferred measure within the class. Using historical and cross-national data from the World Population Prospects, state-level data from the US Census Bureau, and local-authority-level data from New Zealand, we demonstrate that our preferred measure is correlated with conventional measures of structural ageing. Nevertheless, in each case there are large disparities in ranking for some countries, states, or local authorities between the different measures. These ranking disparities could be highly consequential for the allocation of resources, particularly between states or local areas within countries. Our proposed class of measures may help to avoid these disparities due to their axiomatically-consistent nature. Finally, we present considerations for future extensions of this important work, including the development of equivalent measures based on prospective age.

Explaining World-Wide Variation in Navigation Ability from Millions of People: Citizen Science Project Sea Hero Quest

Navigation ability varies widely across humans. Prior studies have reported that being younger and a male has an advantage for navigation ability. However, these studies have generally involved small numbers of participants from a handful of western countries. Here, we review findings from our project Sea Hero Quest, which used a video game for mobile and tablet devices to test 3.9 million people on their navigation ability, sampling across every nation-state and from 18 to 99 years of age. Results revealed that the task has good ecological validity and across all countries sufficiently sampled (N = 63), age is linked to a near-linear decline in navigation ability from the early 20s. All countries showed a male advantage, but this varied considerably and could be partly predicted by gender inequality. We found that those who reported growing up in a city were on average worse at navigating than those who grew up outside cities and that navigation performance helped identify those at greater genetic risk of Alzheimer's disease. We discuss the advantages and challenges of using a mobile app to study cognition and the future avenues for understanding individual differences in navigation ability arising from this research.

Disease burden of ageing, sex and regional disparities and health resources allocation: a longitudinal analysis of 31 provinces in Mainland China

OBJECTIVES

To measure the disease burden of ageing based on age-related diseases (ARDs), the sex and regional disparities and the impact of health resources allocation on the burden in China.

DESIGN

A national comparative study based on Global Burden of Diseases Study estimates and China's routine official statistics.

SETTING AND PARTICIPANTS

Thirty-one provinces of Mainland China were included for analysis in the study. No individuals were involved.

METHODS

We first identified the ARDs and calculated the disability-adjusted life years (DALYs) of ARDs in 2016. We assessed the ARD burden disparities by province and sex and calculated the provincial ARD burden-adjusted age. We assessed historical changes between 1990 and 2016. Fixed effects regression models were adopted to evaluate the impact of health expenditures and health workforce indicators on the ARD burden in 2010-2016.

RESULTS

In 2016, China's total burden of ARDs was 15 703.7 DALYs (95% uncertainty intervals: 12 628.5, 18 406.2) per 100 000 population. Non-communicable diseases accounted for 91.9% of the burden. There were significant regional disparities. The leading five youngest provinces were Beijing, Guangdong, Shanghai, Zhejiang and Fujian, located on the east coast of China with an ARD burden-adjusted age below 40 years. After standardising the age structure, western provinces, including Tibet, Qinghai, Guizhou and Xinjiang, had the highest burden of ARDs. Males were disproportionately affected by ARDs. China's overall age-standardised ARD burden has decreased since 1990, and females and eastern provinces experienced the largest decline. Regression results showed that the urban-rural gap in health workforce density was positively associated with the ARD burdens.

CONCLUSION

Chronological age alone does not provide a strong enough basis for appropriate ageing resource planning or policymaking. In China, concerted efforts should be made to reduce the ARDs burden and its disparities. Health resources should be deliberately allocated to western provinces facing the greatest health challenges due to future ageing.

Applications of new measures of population ageing using quantity and quality of remaining life years to India and selected states

In the latter part of the third stage, India is in demographic transition with declining fertility and mortality. This marked decline in death rates is driven by improvements in health conditions due to medical progress and better living conditions. The conventional measures of ageing do not account for the significant improvements in health and life expectancy, thus leading to a tendency to overestimate the impact of population ageing when these indicators are used. The old-age threshold in the conventional measures of ageing depends on chronological age. The present study estimated the multi-dimensional old-age thresholds (MOAT) based on the remaining life expectancy (RLE), self-rated health, activities of daily living (ADL), handgrip strength, and cognition in India and selected states. The standard population was derived for each dimension for 50 and over in states using the WHO Study on Global AGEing and Adult Health data. Keeping the dimensional characteristics as of the standard population, the estimated MOAT for India was 67 years where Maharashtra stands at the top (68.6), followed by, West Bengal (66.5) and Karnataka (66). A 64 year old woman was similar to 68.8 year old man, and a 66 year old rural person was equivalent to 68 year old urban person. The study suggests implications of MOATs on reducing the burden of ageing and increment in retirement age.

Prevalence and correlates of vision impairment and its association with cognitive impairment among older adults in India: a cross-sectional study

OBJECTIVE

This study aimed to investigate the predictors of vision impairment in old age and how impaired vision is associated with cognitive impairment among the ageing population.

DESIGN

A cross-sectional study was conducted using a large country-representative survey data.

SETTING AND PARTICIPANTS

This study used data from the 'Building a Knowledge Base on Population Ageing in India' survey, conducted in 2011. Participants included 9541 older adults aged 60 years and above.

PRIMARY AND SECONDARY OUTCOME MEASURES

The outcome variables were vision impairment and cognitive impairment. Descriptive statistics along with bivariate analysis were presented. Additionally, multivariable binary logistic regression analysis was performed to fulfil the objectives.

RESULTS

A proportion of 59.1% of the respondents had vision impairment. Nearly 60% of the participants had cognitive impairment. Those who had vision impairment were 11% more likely to have cognitive impairment compared to their counterparts (OR: 1.11, 95% CI: 1.01 to 1.23). low psychological health (OR: 1.55; 95% CI: 1.36 to 1.77), low activities of daily living (OR: 1.80; 95% CI: 1.43 to 2.27), low instrumental activities of daily living (OR: 1.26; 95% CI: 1.14 to 1.40), poor self-rated health (OR: 1.28; 95% CI: 1.15 to 1.41) and chronic morbidity (OR: 1.27; 95% CI: 1.14 to 1.41) were found to be risk factors for cognitive impairment among older adults.

CONCLUSIONS

Additional efforts in terms of advocacy, availability, affordability and accessibility especially in a country with big illiteracy issue are mandatory to increase the reach of eye-care services and reduce the prevalence of avoidable visual impairment and vision losses that lead to cognitive deficits among the older population.

The health-adjusted dependency ratio as a new global measure of the burden of ageing: a population-based study

BACKGROUND

The old-age dependency ratio (OADR), which is the ratio of older people (aged ≥65 years) to working age people (aged 20-64 years), is the most common way to assess and compare the burden of population ageing in different countries. However, the relationship between chronological age and dependency varies widely across countries. We therefore present the health-adjusted dependency ratio (HADR), a new measure of ageing burden based on the ageing-related health of the adult population.

METHODS

In this population-based study we used health data for diseases and injuries for 2017 from the Global Burden of Disease project and population data for 2017 from the UN's Population Division to identify the number of adults (aged >20 years) in each country who have the same or higher ageing-related disease burden as the global average 65-year-old. We then calculated the HADR as the ratio of adults who were less healthy than the average 65-year-old (dependent population) to those in better health (supporting population) and compared the HADR with the OADR for 188 countries. We also used cross-sectional, bivariate regression analysis to investigate whether the HADR is a more powerful predictor of changes in per capita health-care expenditure than the OADR as a measure of predictive validity.

FINDINGS

Many demographically younger populations have an earlier onset of ageing-related disease, and many demographically older populations have a later onset. For instance, Pakistan has an OADR of 0·09 and an HADR of 0·19, and France has an OADR of 0·35 and an HADR of 0·13. Relative to the OADR, the HADR suggests that Asia, western Europe, and North America have a lower ageing burden, whereas central Asia, southern Asia, and Africa have a greater burden. While Japan and countries in western Europe have the highest OADR, Russia, Papua New Guinea, and countries in southeast Europe have the highest HADR. Relative to the OADR, the HADR suggests that there is much less variation in the burden of ageing across countries than has previously been assumed. HADR was also more closely associated with growth in health spending than the OADR. A 0·1 increase in the HADR was associated with a 2·9 percentage points larger growth rate in per capita spending (p=0·0001), and a 0·1-point increase in the OADR was associated with a 1·8 percentage point larger growth rate.

INTERPRETATION

The OADR probably overestimates the burden of population ageing in many demographically older countries and underestimates the ageing burden in many demographically younger countries, which implies that the challenges associated with ageing are more universal than previously thought, and that the world cannot easily be divided in a young and an old groups of nations.

FUNDING

None.

The role of school education in time-dependent changes of cognitive abilities in cohorts from midlife to old age

OBJECTIVES

It is examined whether older adults' cognitive ability in terms of delayed recall and verbal fluency is improving over time, whether this occurs over all educational levels and both sexes, and whether these changes are due to increasing proportions of individuals with higher education.

METHODS

Analyses are based on the German samples of the Survey on Health, Ageing and Retirement in Europe (waves 2004 and 2013).

RESULTS

Achievement levels increased over time and in all age groups. Improvements over educational levels occurred in parallel, differences between educational levels in the earlier survey were later reproduced at higher levels. Increasing proportions of individuals with higher education did not explain improvements of cognitive ability. No sex differences emerged.

CONCLUSION

Improved cognitive abilities could not be explained by upward shifts of educational levels. Improvements in higher age groups may foster improved health status and prolonged self-determined life in the older population.

Examining the impact of socioeconomic status, demographic characteristics, lifestyle and other risk factors on adults' cognitive functioning in developing countries: an analysis of five selected WHO SAGE Wave 1 Countries

Background

Though extensive studies have been conducted on assessing the predictors of cognitive functioning among older adults in small community-based samples, very few studies have focused on understanding the impact of socioeconomic status (SES), demographic characteristics and other risk factors such as lifestyle and chronic diseases on the cognitive functioning among adults of all ages in a nationally representative population-based sample across low- and middle-income countries. This study, therefore, seeks to evaluate the impact of SES, demographic characteristics and risk factors on the cognitive functioning of adults across all ages in five selected developing countries.

Methods

Data from 12,430 observations obtained from the WHO Study on Global AGEing and Adult Health (SAGE) Wave 1; consisting of 2,486 observations each for China, Ghana, India, the Russian Federation, and South Africa, were used for the study. A meta-regression and a five-step hierarchical linear regression were used to analyze the data, with cognitive functioning as the dependent variable. Independent variables used in this study include SES; assessed by household income and education, demographic characteristics, other risk factors such as lifestyle, self-reported memory difficulty and chronic diseases.

Results

This study found that SES and lifestyle significantly predicted cognitive functioning in all the five selected countries as obtained by the pooled results of the meta-regression analysis. The hierarchical linear regression results also revealed that demographic characteristics such as age, type of residency, and self-reported memory difficulty significantly impact cognitive functioning in China, Ghana, Russia, and South Africa.

Conclusion

The findings in this study provide new insights for policymakers, caregivers, parents, and individuals, especially those in developing countries, to implement policies and actions targeted at improving SES and eliminating risk factors associated with cognitive decline, as these measures could help improve the cognitive functioning among their populations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12939-022-01622-7.

You Say Tomato, I Say Radish: Can Brief Cognitive Assessments in the U.S. Health Retirement Study Be Harmonized With Its International Partner Studies?

OBJECTIVES

To characterize the extent to which brief cognitive assessments administered in the population-representative U.S. Health and Retirement Study (HRS) and its International Partner Studies can be considered to be measuring a single, unidimensional latent cognitive function construct.

METHODS

Cognitive function assessments were administered in face-to-face interviews in 12 studies in 26 countries (N = 155,690), including the U.S. HRS and selected International Partner Studies. We used the time point of the first cognitive assessment for each study to minimize differential practice effects across studies and documented cognitive test item coverage across studies. Using confirmatory factor analysis models, we estimated single-factor general cognitive function models and bifactor models representing memory-specific and nonmemory-specific cognitive domains for each study. We evaluated model fits and factor loadings across studies.

RESULTS

Despite relatively sparse and inconsistent cognitive item coverage across studies, all studies had some cognitive test items in common with other studies. In all studies, the bifactor models with a memory-specific domain fit better than single-factor general cognitive function models. The data fit the models at reasonable thresholds for single-factor models in 6 of the 12 studies and for the bifactor models in all 12 of the 12 studies.

DISCUSSION

The cognitive assessments in the U.S. HRS and its International Partner Studies reflect comparable underlying cognitive constructs. We discuss the assumptions underlying our methods, present alternatives, and future directions for cross-national harmonization of cognitive aging data.

Ten German versions of Rey's auditory verbal learning test: Age and sex effects in 4,000 adults of the Rhineland Study

INTRODUCTION

Detecting early pathological cognitive decline is critical for dementia and aging-related research and clinical diagnostics. Rey's Auditory Verbal Learning Test (AVLT) is commonly used to measure episodic verbal memory. The test requires participants to learn a list of 15 words over several trials. Since multiple testing is often required to detect cognitive decline, but repeating the same test can bias results, we developed 10 German AVLT word lists.

METHOD

We randomly assigned the lists to 4,000 participants (aged 30-94 years) from a population-based cohort to test their comparability, as well as aging effects and sex differences.

RESULTS

Nine lists were highly comparable, with only one being slightly more difficult. Recall performance decreased on average by 0.6-1.1 words per trial per decade of age. Perseveration errors decreased with increasing age. Women remembered on average between 0.8 and 1.5 words per trial more than men, regardless of age. Women also outperformed men in the sum of Trials 1-5, learning over trials, retroactive inhibition, and false-positive and interference errors. Proactive inhibition remained stable across age and was unaffected by sex.

CONCLUSION

This German AVLT version presents comparable lists including detailed age and sex references and therefore allows test repetition excluding training effects. These versions are a valuable resource for research and clinical application.

Grandchild Caregiving and Cognitive Health Among Grandparents in Rural South Africa

Objectives: We investigate how caregiving for grandchildren is associated with cognitive function among rural South Africans, and whether the association differs by gender. We further investigate whether measures of physical activity or social engagement mediate this association. Methods: Data were from interviews with 3668 Black, South African grandparents in the "Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa" study, conducted between 2014 and 2015. Results: We find that caregiving grandparents have better cognitive function than non-caregiving grandparents, and this association does not differ by grandparent gender. Although grandchild caregiving is associated with physical activity and social engagement measures, and some of these measures are associated with cognitive function, we do not find conclusive evidence of mediation. Discussion: Providing care for grandchildren may stimulate cognitive function for both grandmothers and grandfathers. Neither physical activity nor social engagement explains the association between caregiving and cognitive function.

Cohort and Period Effects as Explanations for Declining Dementia Trends and Cognitive Aging

Studies have reported that the age-adjusted incidence of cognitive impairment and dementia may have decreased over the past two decades. Aging is the predominant risk factor for Alzheimer's disease and related dementias and for neurocognitive decline. However, aging cannot explain changes in overall age-adjusted incidence of dementia. The objective of this position paper was to describe the potential for cohort and period effects in cognitive decline and incidence of dementia. Cohort effects have long been reported in demographic literature, but starting in the early 1980s, researchers began reporting cohort trends in cognitive function. At the same time, period effects have emerged in economic factors and stressors in early and midlife that may result in reduced cognitive dysfunction. Recognizing that aging individuals today were once children and adolescents, and that research has clearly noted that childhood cognitive performance is a primary determinant of old-age cognitive performance, this is the first study that proposes the need to connect known cohort effects in childhood cognition with differences in late-life functioning.

Feeling about living arrangements and associated health outcomes among older adults in India: a cross-sectional study

INTRODUCTION

Advancement in the field of gerontology has been concerned with the well-being of older adults in a family setup that is associated with caregiving and support. While family life and well-being are defined by emotion, caregiving, and support activities, dissatisfaction/discontent with living arrangements is a public health concern, which is increasing with a rise in the proportion of the older population in the country. The study examines the association of dissatisfaction with living arrangements with health outcomes among older men and women in India.

METHODS

The present research used data from the 'Building a Knowledge Base on Population Aging in India'. The effective sample size for the analysis was 9181 older adults. Descriptive statistics and bivariate analysis were performed to present the preliminary estimates. For finding the association between various health outcomes over explanatory variables, binary logistic regression model was used separately for men and women.

RESULTS

About 22.8% of men and 30.8% of women who were living alone were dissatisfied with their present living arrangement. It was revealed that both men and women who were dissatisfied with their present living arrangements had significantly higher odds of experiencing poor self-rated health [OR:4.45, 3.25 ~ 6.09 and OR:3.32, 2.54 ~ 4.34], low psychological health [OR: 2.15, 1.61 ~ 2.86 and OR: 1.99, 1.57 ~ 2.53], low subjective well-being [OR: 3.37, 2.54 ~ 4.45 and OR: 3.03, 2.36 ~ 3.38], low ADL [OR: 1.77, 1.2 ~ 2.62 and OR: 1.59, 1.17 ~ 2.18, low IADL] [OR: 1.32, 1.03 ~ 1.69 and OR: 1.57, 1.24 ~ 1.98] and low cognitive ability [OR: 1.26, 0.98 ~ 1.61 and OR:1.44, 1.13 ~ 1.82] in comparison to their counterpart from men and women respectively.

CONCLUSION

It is found that dissatisfaction with the living arrangement of older men and women is negatively associated with major health outcomes. Hence, appropriate policies and programs must be developed to promote increased family care and support and an improved residential environment that would create a feeling of comfort and happiness among older individuals.

Increasingly capable at the ripe old age? Cognitive abilities from 2004 to 2013 in Germany, Spain, and Sweden

Background

Life expectancy is increasing in most high-income countries, but gains in life years are maximized if spent in good health and if cognitive abilities are maintained until old age. Age-related decline of cognitive abilities does nevertheless occur, but the pace of decline is decisive. This was the starting point for our study that aims to examine cohort effects of cognitive aging in women and men in Germany, Spain and Sweden by analyzing changes from 2004 to 2013 by estimating cohort effects within age groups starting from the age of 50 years.

Methods

A cohort study was conducted that was based on data of the surveys 2004 (N = 6,081) and 2013 (N = 8,650) from the Survey of Health, Ageing and Retirement in Europe (SHARE). The analyses were based on data of female and male respondents aged 50 years and older. Age-specific means of verbal fluency and delayed recall from the German, Spanish and Swedish samples were the cognitive domains considered in the study.

Results

In both domains of cognitive ability the achievements in the later surveys were higher than in the earlier ones. This was found in all countries, abut achievement levels increased markedly in the German and the Spanish samples, while the scores of the Swedish samples were not significantly different.

While the highest scores were found for Sweden, Germany ranked in the middle and the lowest scores were found in the Spanish samples. Over time, the scores of the German samples approached those of Sweden.

Conclusions

From the first to the second survey, improvements of older adults’ cognitive abilities were found for all countries considered. This may indicate improvements of the underlying educational systems, but also increasingly stimulating general living conditions.

Association of life course socioeconomic status and adult height with cognitive functioning of older adults in India and China

BACKGROUND

Cognitive functioning is an important measure of intrinsic capacity. In this study, we examine the association of life course socioeconomic status (SES) and height with cognitive functioning among older adults (50+) in India and China. The age pattern of cognitive functioning with measures of life course socioeconomic status has also been examined.

METHODS

Cross-sectional comparative analysis was conducted using the WHO's Study on global AGEing and adult health (SAGE) data for India and China. Multilevel mixed-effect linear regression analysis was used to examine the association of life course socioeconomic status and adult height with cognitive functioning.

RESULTS

In both India and China, parental education as a measure of childhood socioeconomic status was positively associated with cognitive functioning. The association between adult socioeconomic status and cognitive functioning was positive and significant. Height was significantly and positively associated with improved cognitive functioning of older adults in India and China. Furthermore, the age-related decline in cognitive functioning score was higher among older adults whose parents had no schooling, particularly in China. The cognitive functioning score with age was much lower among less-educated older adults than those with higher levels of education in China. Wealthier older adults in India had higher cognitive functioning in middle ages, however, wealth differences narrowed with age.

CONCLUSIONS

The results of this study suggest a significant association of lifetime socioeconomic status and cumulative net nutrition on later-life cognitive functioning in middle-income settings.

Association of self-perceived income sufficiency with cognitive impairment among older adults: a population-based study in India

BACKGROUND

Greater cognitive performance has been shown to be associated with better mental and physical health and lower mortality. The present study contributes to the existing literature on the linkages of self-perceived income sufficiency and cognitive impairment. Study also provides additional insights on other socioeconomic and health-related variables that are associated with cognitive impairment in older ages.

METHODS

Data for this study is derived from the 'Building Knowledge Base on Population Ageing in India'. The final sample size for the analysis after removing missing cases was 9176 older adults. Descriptive along with bivariate analyses were presented to show the plausible associations of cognitive impairment with potential risk factors using the chi-square test. Also, binary logistic regression analysis was performed to provide the relationship between cognitive impairment and risk factors. The software used was STATA 14.

RESULTS

About 43% of older adults reported that they had no source of income and 7.2% had income but not sufficient to fulfil their basic needs. Older adults with income but partially sufficient to fulfil their basic needs had 39% significantly higher likelihood to suffer from cognitive impairment than older adults who had sufficient income [OR: 1.39; OR: 1.21-1.59]. Likelihood of cognitive impairment was low among older adults with asset ownership than older adults with no asset ownership [OR: 0.83; CI: 0.72-0.95]. Again, older adults who work by compulsion (73.3%) or felt mental or physical stress due to work (57.6%) had highest percentage of cognitive impairment. Moreover, older adults with poor self-rated health, low instrumental activities of daily living, low activities of daily living, low subjective well-being and low psychological health were at increased risk for cognitive impairment.

CONCLUSION

The study highlights the pressing need for care and support and especially financial incentives in the old age to preserve cognitive health. Further, while planning geriatric health care for older adults in India, priority must be given to financially backward, with no asset ownership, with poor health status, older-older, widowed, and illiterate older individuals, as they are more vulnerable to cognitive impairment.

Socioeconomic inequality in psychological distress among older adults in India: a decomposition analysis

BACKGROUND

Older people coming from a lower wealth gradient are more vulnerable to have stressful life events further adding more risk for common mental health disorders and psychological distress situations. The present study explores the associations between socioeconomic and health-related variables and psychological distress among older adults in India and the contribution of such factors to the inequalities in psychological distress.

METHODS

A cross-sectional survey of 9181 older adults conducted as 'Building a Knowledge Base on Population Ageing in India' was assessed. Logistic regression and decomposition models were used to analyze the data. Psychological distress was measured from General Health Questionnaire (GHQ-12). The value of Cronbach's alpha was 0.90. It was having a scale of 0 to 12 on the basis of experiencing stressful symptoms and was re-coded as 0 (representing 6+ stressful symptoms) and 1 (representing 5 and fewer symptoms).

RESULTS

Older adults from the poored, suffering from multi-morbidity, disabled, with low activities of daily living and low instrumental activities of daily living and poor cognitive ability were suffering from high psychological distress in India. Further, factors such as religion, caste, education, living arrangements, and self-worth in the family were major contributors to the concentration of psychological distress in older adults from poor households (concentration index: - 0.23).

CONCLUSION

The study suggests that among older people, there is a wide disparity of experiencing psychological distress across different socio-economic groups with significant factors being responsible for inequality in psychological distress. There is a need to build a "win-win" circumstance across sectors, including a broad spectrum of health, social and economic benefits to the vulnerable older population.

Can changes in education alter future population ageing in Asia and Europe?

While population ageing is rising, the educational composition of the elderly remains rather heterogeneous. This study assesses the educational differences in future population ageing in Asia and Europe, and how future population ageing in Asia and Europe would change if the educational composition of its populations changed. A comparative population ageing measure (the Comparative Prospective Old-Age Threshold [CPOAT]) was used, which recalculates old-age thresholds after accounting for differences in life expectancy, and the likelihood of adults surviving to higher ages. Combined data from projected age- and sex-specific life-tables (from the United Nations) and projected age- and sex-specific survival ratios by different levels of education (from the Wittgenstein Centre for Demography and Global Human Capital) were used to construct projected life-tables (2015-2020, …, 2045-2050) by educational level and sex for different regions of Asia and Europe. Based on these life-tables, future comparative prospective old-age thresholds by educational level and sex were calculated. It was found that in both Asia and Europe, and among both men and women, the projected old-age thresholds are higher for higher educated people than for less-educated people. While Europe has a larger projected share of elderly in the population than Asia, Europe's older population is better educated. In alternative future scenarios in which populations hypothetically have higher levels of education, the projected shares of elderly in the population decrease across all regions of Asia and Europe, but more so in Asia. The results highlight the effectiveness of investing in education as a policy response to the challenges associated with population ageing in Asia and Europe. Such investments are more effective in the Asian regions, where the educational infrastructure is less developed.

Incidence of Cognitive Impairment during Aging in Rural South Africa: Evidence from HAALSI, 2014 to 2019

INTRODUCTION

Despite rapid population aging, there are currently limited data on the incidence of aging-related cognitive impairment in sub-Saharan Africa. We aimed to determine the incidence of cognitive impairment and its distribution across key demographic, social, and health-related factors among older adults in rural South Africa.

METHODS

Data were from in-person interviews with 3,856 adults aged ≥40 who were free from cognitive impairment at baseline in the population-representative cohort, "Health and Aging in Africa: a Longitudinal Study of an INDEPTH Community in South Africa" (HAALSI), in Agincourt sub-district, Mpumalanga province, South Africa (2014-19). Cognitive impairment was defined as scoring <1.5 standard deviations below the mean of the baseline distribution of orientation and episodic memory scores. Incidence rates and rate ratios for cognitive impairment were estimated according to key demographic, social, and health-related factors, adjusted for age, sex/gender, and country of birth.

RESULTS

The incidence of cognitive impairment was 25.7/1,000 person-years (PY; 95% confidence interval [CI]: 23.0-28.8), weighted for mortality (12%) and attrition (6%) over the 3.5-year mean follow-up (range: 1.5-4.8 years). Incidence increased with age, from 8.9/1,000 PY (95% CI: 5.2-16.8) among those aged 40-44 to 93.5/1,000 PY (95% CI: 75.9-116.3) among those aged 80+, and age-specific risks were similar by sex/gender. Incidence was strongly associated with formal education and literacy, as well as marital status, household assets, employment, and alcohol consumption but not with history of smoking, hypertension, stroke, angina, heart attack, diabetes, or prevalent HIV.

CONCLUSIONS

This study presents some of the first incidence rate estimates for aging-related cognitive impairment in rural South Africa. Social disparities in incident cognitive impairment rates were apparent in patterns similar to those observed in many high-income countries.

Disparity in Educational Attainment Partially Explains Cognitive Gender Differences in Older Rural South Africans

OBJECTIVES

Direction and magnitude of gender differences in late-life cognitive function are inextricably tied to sociocultural context. Our study evaluates education and literacy as primary drivers of gender equality in cognitive performance among middle-aged and older adults in rural South Africa.

METHOD

Data were collected on 1,938 participants aged 40-79 from Agincourt, South Africa. Cognitive function was measured via the Oxford Cognitive Screen-Plus, a tablet-based assessment with low literacy demands. Four cognitive domains were derived through confirmatory factor analysis: episodic memory, executive function, visual spatial, and language. Structural equation models tested domain-specific gender effects, incrementally controlling for demographic, education, health, and socioeconomic variables.

RESULTS

In the model adjusting only for demographic factors, men outperformed women on executive function and visual-spatial domains. Adding education and literacy to the model revealed a robust female advantage in episodic memory, and reduced the magnitude of male advantage in executive function and visual and spatial by 47% and 42%, respectively. Health and socioeconomic factors did not alter patterns of gender associations in subsequent models.

DISCUSSION

In this older South African cohort, gender inequality in cognitive performance was partially attributable to educational differences. Understanding biopsychosocial mechanisms that promote cognitive resilience in older women is critically important given the predominantly female composition of aging populations worldwide.

Relationship between chewing tobacco, smoking, consuming alcohol and cognitive impairment among older adults in India: a cross-sectional study

BACKGROUND

Physical aging increases the sensitivity to the effects of substance use, elevating the risk for cognitive impairment among older adults. Since studies on the association of substance use with cognitive ability in later years are scant in India, we aimed to explore the factors associated with cognitive impairment especially, alcohol consumption, smoking, and chewing tobacco later in life.

METHODS

The present research used nationally representative data from Building a Knowledge Base on Population Aging in India (BKPAI) that was conducted in 2011, across seven states of India (N=9,453). Sample distribution along with percentage distribution was calculated for cognitive impairment over explanatory variables. For finding the association between cognitive impairment over explanatory variables, binary logistic regression models were estimated.

RESULTS

About 16.5 percent of older adults in rural areas consumed smoked tobacco compared to 11.7 percent in urban areas. Nearly, 23.7 percent of rural older adults consumed smokeless tobacco in comparison to 16 percent in urban areas. Alcohol consumption was high among rural residents (7.9%) than urban counterparts (6.7%). The prevalence of cognitive impairment was 62.8% and 58% among older adults from rural and urban areas respectively. Older adults who smoked tobacco had a 24 percent significantly higher likelihood to have cognitive impairment with reference to older adults who did not smoke [OR: 1.24, CI: 1.02-1.49]. Moreover, older adults who consumed alcohol had a 30 percent significantly higher likelihood to have cognitive impairment [OR: 1.02, 1.65]. It was also found that older adults who had smoked along with consuming alcohol were at risk of worse cognitive outcomes than those who neither smoke nor drink alcohol [OR: 1.56, CI: 1.21-2.00] or consumed either of them unlike consuming smokeless tobacco only.

CONCLUSION

The encouragement of older people to stop smoking and smokeless tobacco use could be considered as part of a strategy to reduce the incidence of cognitive impairment. Further, appropriate measures should be taken for the detection of early stages of cognitive decline in older individuals and efforts should be made to improve the availability and quality of care for dementing older adults.

Live longer, retire later? Developments of healthy life expectancies and working life expectancies between age 50–59 and age 60–69 in Europe

Europe’s population is ageing. Statutory retirement ages are commonly raised to account for continuous increases in life expectancy. In order to estimate the potential to increase statutory and consequently effective retirement ages further, in this study, we investigate the relationship between partial working life expectancy (WLE) and three health expectancies that represent health aspects important for work ability and employability between ages 50 and 59 as well as 60 and 69 for women and men in Europe. We also explore the association between these four indicators and the highest level of educational attainment. We apply Sullivan’s method to estimate WLE and three selected measures that capture general, physical, and cognitive health status of older adults for 26 European countries since 2004. Over time, WLEs increased significantly in the younger age group for women and in the older age group for both sexes. The expected number of years in good physical health have continuously been higher than any of the other three indicators, while the expected number of years in good cognitive health have shown a noticeable increase over time. The investigation of the relationship between education and each life expectancy confirms the well-established positive correlation between education and economic activity as well as good health. Our results indicate potential to extend working lives beyond current levels. However, significant differences in the expected number of years in good health between persons with different levels of education require policies that account for this heterogeneity.

The long-term effect of intra-European migration on cognitive abilities in later life

The study raises the question about the long-term effect of intra-European migration on cognitive abilities in later life. In contrast to previous research that compares migrants to natives of the destination country, this study uses stayers in the European origin countries as reference group for migrants who moved to another European country earlier in life and are now growing old abroad. Selection into migration is addressed methodologically by applying an instrumental variable approach. Using the Global Bilateral Migration Database to generate the country- and time-specific share of emigrants as instrument for migration, the results indicate that intra-European migration turns out to have a negative long-term effect on the level of cognitive abilities.

Social contact, social support, and cognitive health in a population-based study of middle-aged and older men and women in rural South Africa

BACKGROUND

Several theories seek to explain how social connections and cognitive function are interconnected in older age. These include that social interaction protects against cognitive decline, that cognitive decline leads to shedding of social connections and that cognitive decline leads to increased instrumental support. We investigated how patterns of social contact, social support and cognitive health in rural South Africa fit with these three theories.

METHOD

We used data from the baseline of "Health and Aging in Africa: a Longitudinal Study of an INDEPTH community in South Africa" (HAALSI), a population-based study of 5059 individuals aged ≥ 40 years. We evaluated how a range of egocentric social connectedness measures varied by respondents' cognitive function.

RESULTS

We found that respondents with lower cognitive function had smaller, denser social networks that were more local and more kin-based than their peers. Lower cognitive function was associated with receipt of less social support generally, but this difference was stronger for emotional and informational support than for financial and physical support. Impairment was associated with greater differences among those aged 40-59 and those with any (versus no) educational attainment.

CONCLUSIONS

The patterns we found suggest that cognitively impaired older adults in this setting rely on their core social networks for support, and that theories relating to social connectedness and cognitive function developed in higher-income and higher-education settings may also apply in lower-resource settings elsewhere.

Using grip strength to compute physical health-adjusted old age dependency ratios

The standard approach for comparing the potential challenges of population aging across countries based on conventional old-age dependency ratios (OADR) does not account for cross-population differences in health, functional capacity or disability, despite their importance for labor force participation and dependency more broadly. We investigate how OADRs observed across selected low-, middle-, and high-income countries change if population differences in physical health measured by hand-grip strength are accounted for. Specifically, we propose and calculate an adjusted measure of the OADR based on hand-grip strength, which serves as an objective indicator of muscle function and has been shown to predict future morbidity, disability and mortality. We show that adjusting the OADR for differences in hand-grip strength results in substantial changes in country rankings by OADR compared to a ranking based on the conventional OADR definition. Accounting for cross-population differences in hand-grip strength, the estimated OADRs for low- and middle-income countries tend to increase compared to the conventional OADR approach based on age only, whereas the estimated OADRs in high-income countries decline substantially relative to the standard approach. Since hand-grip strength is an important prerequisite for maintaining functional capacity and productivity and preventing disability -especially in economies in low-income settings- our grip-strength-adjusted OADRs clearly show that population aging is not just a challenge in high-income countries but also an important concern for economies in the developing world.

Association of Low to Moderate Alcohol Drinking With Cognitive Functions From Middle to Older Age Among US Adults

IMPORTANCE

Studies examining the association of low to moderate drinking with various cognitive functions have yielded mixed findings.

OBJECTIVE

To investigate whether associations exist between low to moderate alcohol drinking and cognitive function trajectories or rates of change in cognitive function from middle age to older age among US adults.

DESIGN, SETTING, AND PARTICIPANTS

A prospective cohort study of participants drawn from the Health and Retirement Study (HRS), a nationally representative sample of US adults, with mean (SD) follow-up of 9.1 (3.1) years. In total, 19 887 participants who had their cognitive functions measured in the HRS starting in 1996 through 2008 and who had participated in at least 3 biennial surveys were included. The data analysis was conducted from June to November 2019.

EXPOSURES

Alcohol consumption and aging.

MAIN OUTCOMES AND MEASURES

Trajectories and annual rates of change for the cognitive domains of mental status, word recall, and vocabulary and for the total cognitive score, which was the sum of the mental status and word recall scores. Participants were clustered into 2 cognitive function trajectories for each cognition measure assessed based on their scores at baseline and through at least 3 biennial surveys: a consistently low trajectory (representing low cognitive scores throughout the study period) and a consistently high trajectory (representing high cognitive scores throughout the study period).

RESULTS

The mean (SD) age of 19 887 participants was 61.8 (10.2) years, and the majority of the HRS participants were women (11 943 [60.1%]) and of white race/ethnicity (16 950 [85.2%]). Low to moderate drinking (<8 drinks per week for women and <15 drinks per week for men) was significantly associated with a consistently high cognitive function trajectory and a lower rate of cognitive decline. Compared with never drinkers, low to moderate drinkers were less likely to have a consistently low trajectory for total cognitive function (odds ratio [OR], 0.66; 95% CI, 0.59-0.74), mental status (OR, 0.71; 95% CI, 0.63-0.81), word recall (OR, 0.74; 95% CI, 0.69-0.80), and vocabulary (OR, 0.64; 95% CI, 0.56-0.74) (all P < .001). In addition, low to moderate drinking was associated with decreased annual rates of total cognitive function decline (β coefficient, 0.04; 95% CI, 0.02-0.07; P = .002), mental status (β coefficient, 0.02; 95% CI, 0.01-0.03; P = .002), word recall (β coefficient, 0.02; 95% CI, 0.01-0.04; P = .01), and vocabulary (β coefficient, 0.01; 95% CI, 0.00-0.03; P = .08). A significant racial/ethnic difference was observed for trajectories of mental status (P = .02 for interaction), in which low to moderate drinking was associated with lower odds of having a consistently low trajectory for white participants (OR, 0.65; 95% CI, 0.56-0.75) but not for black participants (OR, 1.02; 95% CI, 0.74-1.39). Finally, the dosage of alcohol consumed had a U-shaped association with all cognitive function domains for all participants, with an optimal dose of 10 to 14 drinks per week.

CONCLUSIONS AND RELEVANCE

These findings suggested that low to moderate alcohol drinking was associated with better global cognition scores, and these associations appeared stronger for white participants than for black participants. Studies examining the mechanisms underlying the association between alcohol drinking and cognition in middle-aged or older adults are needed.

Dependency ratios in healthy ageing

Although people are living longer, there is no discernible pattern about the quality of life in an increasing lifespan. This restricts our capacity to predict and prepare for the consequences of population ageing. Accordingly, we propose a population ageing indicator that combines demographic and disability prevalence data through a characteristics approach and explore different scenarios to account for uncertainty in life quality projections. Our results, available for 186 countries, show that countries that rank older under conventional chronological ageing measures may rank younger under our qualitative measure. Additionally, we find substantial differences in our projections depending on different health assumptions, demonstrating the risk of using ageing indicators that make implicit assumptions about health characteristics.

Aspects of healthcare efficiency in the framework of ensuring the longevity of the population and socio-demographic security of the region

The article considers modern demographic trends, in the conditions of medical care cost increasing and aging of the population. The expediency of studying aspects of health care efficiency is justified. The relationship and mutual influence of changes in the country’s economy and changes in the health care system are revealed. The problems of preserving the health of the population are considered comprehensively, taking into account the influence of environmental factors, behavioral factors and attitudes to human health, the effectiveness of public policy implementation and the effectiveness of the health system. An integrative model for evaluating the effectiveness of regional health care is proposed based on an integrated approach aimed at improving the population health and ensuring social and demographic security of the region. The integrative model is adapted on the example of the Sverdlovsk region. In dynamics for 2008-2018, improved medical and demographic indicators and high effects were achieved as a result of comprehensive measures to neutralize factors that have a negative impact on the health of the population, promotion and implementation of healthy lifestyle, strengthening state support for the industry, and the successful functioning of regional health care.

A multi-dimensional perspective on the gender gap in health among older adults in India and China: application of a new ageing measure

A continuous rise of female life expectancy above that of males among older adults in India and China may give the impression that the relative gender gap in health in these countries is decreasing. However, given the systemic gender bias against older females in these countries across multiple dimensions of health, a fuller understanding of the gender gap in health calls for a multi-dimensional perspective. We estimate a multi-dimensional old-age threshold (MOAT) that specifies different old-age thresholds for female and male populations which accommodates multiple dimensions related to physical, intellectual and general health. We use the MOAT to evaluate the multi-dimensional gender gap in India and China by differencing the MOAT for females with that of males. Females in both countries have a lower MOAT than their male counterparts, indicating an earlier advent of ‘old age’ for females. The multi-dimensional estimates of the gender gap are also higher than the estimates based on only one dimension of health. A considerable level of variation is also observed in the gender gap across provinces. The study illustrates the need to understand the gender gap in health in India and China from a multi-dimensional perspective and provides an innovative way to quantify such a gap. Province-specific as well as health dimension-specific interventions are vital in reducing the gender gap among older adults in these countries.

Religion and Health Among Hispanics: Exploring Variations by Age

The purpose of this study is to see whether there are age differences in the relationship between church-based social ties and Epstein-Barr virus (EBV) antibodies among Hispanics (250) and non-Hispanic Whites (N = 602). The data indicate that emotional support that is received from fellow church members is associated with lower EBV values among Hispanics of all ages, but not among Whites of all ages. In contrast, emotional support that is received outside religious institutions failed to provide similar protective effects for Hispanics. No age differences emerged from the data.

Cognitive Performance Among Older Persons in Japan and the United States

OBJECTIVE

To compare cognitive performance among Japanese and American persons, aged 68 years and older, using two nationally representative studies and to examine whether differences can be explained by differences in the distribution of risk factors or in their association with cognitive performance.

DESIGN

Nationally representative studies with harmonized collection of data on cognitive functioning.

SETTING

Nihon University Japanese Longitudinal Study of Aging and the US Health and Retirement Study.

PARTICIPANTS

A total of 1953 Japanese adults and 2959 US adults, aged 68 years or older.

MEASUREMENTS

Episodic memory and arithmetic working memory are measured using immediate and delayed word recall and serial 7s.

RESULTS

Americans have higher scores on episodic memory than Japanese people (0.72 points on a 20-point scale); however, when education is controlled, American and Japanese people did not differ. Level of working memory was higher in Japan (0.36 on a 5-point scale) than in the United States, and the effect of education on working memory was stronger among Americans than Japanese people. There are no differences over the age of 85 years.

CONCLUSION

Even with large differences in educational attainment and a strong effect of education on cognitive functioning, the overall differences in cognitive functioning between the United States and Japan are modest. Differences in health appear to have little effect on national differences in cognition. J Am Geriatr Soc 68:354-361, 2020.

Differences in cognitive performance and cognitive decline across European regions: a population-based prospective cohort study

BACKGROUND

A large variation in cognitive performance exists between European regions. However, it is unclear how older Europeans differ in the rate of cognitive decline.

METHODS

We analysed data from 22 181 individuals (54% women; median age 71) who participated in the Survey on Health, Ageing and Retirement in Europe. Cognition was measured using tests on verbal fluency, immediate and delayed recall. We used linear regression and linear mixed effects regression to examine regional differences in the level of cognitive performance and the rate of cognitive decline.

RESULTS

Scandinavians had the highest baseline cognitive scores (mean standardized overall cognitive score 0.3), followed by Western Europeans (mean 0.2), Central and Eastern Europeans (mean 0.1) and individuals from Mediterranean countries (mean -0.4). These differences persisted even after adjustment for sociodemographic and clinical characteristics. The annual cognitive decline in Scandinavia (0.59%) was approximately two times greater than in Western Europe (0.28%), Central and Eastern Europe (0.25%) and Mediterranean countries (0.23%).

DISCUSSION

There are substantial differences in cognitive performance as well as rates of cognitive decline among the elderly throughout European regions. This might be explained by differing levels of cognitive reserve.

Measuring population ageing: an analysis of the Global Burden of Disease Study 2017

BACKGROUND

Traditional metrics for population health ageing tend not to differentiate between extending life expectancy and adding healthy years. A population ageing metric that reflects both longevity and health status, incorporates a comprehensive range of diseases, and allows for comparisons across countries and time is required to understand the progression of ageing and to inform policies.

METHODS

Using the Global Burden of Diseases, Injuries, and Risk Factors Study 2017, we developed a metric that reflects age-related morbidity and mortality at the population level. First, we identified a set of age-related diseases, defined as diseases with incidence rates among the adult population increasing quadratically with age, and measured their age-related burden, defined as the sum of disability-adjusted life-years (DALYs) of these diseases among adults. Second, we estimated age-standardised age-related health burden across 195 countries between 1990 and 2017. Using global average 65-year-olds as the reference population, we calculated the equivalent age in terms of age-related disease burden for all countries. Third, we analysed how the changes in age-related burden during the study period relate to different factors with a decomposition analysis. Finally, we describe how countries with similar levels of overall age-related burden experience different onsets of ageing. We represent the uncertainty of our estimates by calculating uncertainty intervals (UI) from 1000 draw-level estimates for each disease, country, year, and age.

FINDINGS

92 diseases were identified as age related, accounting for 51·3% (95% UI 48·5-53·9) of all global burden among adults in 2017. Across the Socio-demographic Index (SDI), the rate of age-related burden ranged from 137·8 DALYs (128·9-148·3) per 1000 adults in high SDI countries to 265·9 DALYs (251·0-280·1) in low SDI countries. The equivalent age to average 65-year-olds globally spanned from 76·1 years (75·6-76·7) in Japan to 45·6 years (42·6-48·2) in Papua New Guinea. Age-standardised age-related disease rates have decreased over time across all SDI levels and regions between 1990 and 2017, mainly due to decreases in age-related case fatality and disease severity. Even among countries with similar age-standardised death rates, large differences in the onset and patterns of accumulating age-related burden exist.

INTERPRETATION

The new metric facilitates the shift from thinking not just about chronological age but the health status and disease severity of ageing populations. Our findings could provide inputs into policymaking by identifying key drivers of variation in the ageing burden and resources required for addressing the burden.

FUNDING

National Institute on Aging of the National Institutes of Health.

Comparison of Population Aging in Europe and Asia Using a Time-Consistent and Comparative Aging Measure

Objective: We compare population aging in Europe and Asia using a measure that is both consistent over time and appropriate for cross-country comparison. Method: Sanderson and Scherbov proposed to estimate the old-age threshold by the age at which the remaining life expectancy (RLE) equals 15 years. We propose an adjustment of this measure, taking into account cross-national differences in the exceptionality of reaching that age. Results: Our old-age threshold was lower than 65 years in 2012 in Central Asia, Southern Asia, Southeastern Asia, and many Eastern European countries. These populations also experienced a higher share of elderly compared with the RLE15 method. Our method revealed more geographical diversity in the shares of elderly. Both methods exhibited similar time trends for the old-age thresholds and the shares of elderly. Discussion: Our prospective and comparative measure reveals higher population aging estimates in most Asian and Eastern European countries and more diversity in aging.