Care Need, Caregiver Availability, and Care Receipt: Variations Across Countries and Over Time in Three Middle-Income Countries.

BACKGROUND: Dementia is expected to increase more rapidly in low- and middle-income countries (LMIC) than in high-income countries (HIC) in the coming decades. Nevertheless, research on dementia care remains limited for LMIC. This study aims to fill this gap by investigating care needs and care receipt in three LMIC: China, Mexico, and India. METHODS: Using harmonized data from the Gateway to Global Aging Data in China, Mexico, and India and focusing on individuals aged 65 and older with cognitive impairment (N = 15,118), we estimated the proportions of care needs related to difficulties with activities of daily living (ADL) and instrumental activities of daily living (IADL), and care receipt. We then used logistic regressions to examine the association between caregiver availability and informal care receipt. RESULTS: We observed relatively similar patterns in care need measures across countries and over time. In contrast, the association between caregiver availability and informal care receipt showed some cross-country variations. Generally, living with family members was associated with a higher probability of receiving informal care in China and India. However, for Mexico, this association was only evident for men. Additionally, we found that the magnitude of the association between caregiver availability and informal care receipt varied with the care recipient's gender. CONCLUSIONS: While living with family members was generally associated with a higher likelihood of receiving informal care in China, Mexico, and India, there are differences in the association between caregiver availability and informal care receipt across countries and over time.

Life history data from the gateway to global ageing data platform: resources for studying life courses across Europe.

Research from a range of disciplines highlights the need to adopt a life course perspective that considers earlier life courses to explain outcomes in later life (e.g. later life health, cognitive ageing or retirement behaviour). This includes a more comprehensive assessment of earlier life courses over time and of how they are shaped by societal and political contexts. But quantitative data with detailed information on life courses that allow to address these questions are rare. Or, in case the data are available, the data are rather difficult to handle and appears to be underused. This contribution introduces the harmonized life history data from the gateway to global ageing data platform from two European Surveys, SHARE and ELSA, with data from 30 European countries. Besides providing some details on the collection of life history data in the two surveys, we also describe the way how raw data were rearranged in a user-friendly state sequence format and additionally give some examples based on the resulting data. This illustrates the potential of collected life history data from SHARE and ELSA, clearly going beyond the description of single aspects of the life course. By providing harmonized data of two prominent studies on ageing in Europe in a user-friendly format, the gateway to global ageing data platform provides a unique data source that is easily accessible for research, and permits to study life course and their links to later life in a cross-national perspective.

A longitudinal study shows stress proliferation effects from early childhood adversity and recent stress on risk for depressive symptoms among older adults.

Objectives: We evaluated whether the effects of recent stressful life events (SLEs) and early childhood adversities (ECAs) on depressive symptoms are consistent between men and women and across older age, and whether there was evidence for the following: stress sensitization, whereby the psychological impact of SLEs is greater for individuals with ECAs compared with those without; or stress proliferation effect, whereby those with ECAs are more likely to report more SLEs than those without ECAs to effect depressive symptoms.Method: ECAs, SLEs in the past two years, and current depressive symptoms through a modified CES-D were obtained from 11,873 individuals participating in a population representative study of older adults, yielding 82,764 observations. Mixed-effects regression models on depressive symptoms were constructed to control for multiple observations per participant and evaluate within-person effects over time, thereby reducing bias from reverse causation.Results: Results suggest a stress proliferation effect and do not support stress sensitization. ECAs contribute to vulnerability for depressive symptoms, with a dosage effect for each additional ECA. Recent SLEs result in greater depressive symptom risk, with stable effects over age and dosage effects for each additional SLE that were smaller than the effects of ECAs among men, but not women. Belonging to an ethnic minority group, having less education, and less household income at baseline were associated with greater depressive symptom risk.Conclusions: Findings suggest the importance of addressing early childhood adversity and sociodemographic factors, among at-risk older adults to mitigate life-course stress proliferative processes and thereby reduce disparate risk for depression in older age.

Gateway to Global Aging Data: Resources for Cross-National Comparisons of Family, Social Environment, and Healthy Aging.

OBJECTIVES: The Gateway to Global Aging Data (Gateway; g2aging.org) is a data and information platform developed to facilitate cross-country analyses on aging, especially those using the international family of Health and Retirement studies. We provide a brief introduction to the Gateway to Global Aging Data, discussing its potential for cross-national comparisons of family, social environment, and healthy aging. METHODS: We summarize the survey metadata, study characteristics, and harmonized data available from the Gateway, describing the population represented in each study. We portray cohort characteristics and key measures of health and social environment from 37 countries in North America, Europe, and Asia using harmonized data. RESULTS: Significant cross-country heterogeneity was observed in many measures of family, social environment, and healthy aging indicators. For example, there was a threefold difference in coresidence with children, ranging from 14% in Sweden to over 46% in Spain and Korea in 2014. From 2002 to 2014, the difference between informal care receipt in individuals of low and high wealth decreased by 6% in the United States and remained unchanged in England. The percentage of individuals aged 50-59 living alone in 2012 varied 15-fold, from a low of 2% in China to a high of 30% in Mexico. DISCUSSION: By partnering with nationally representative studies around the globe, the Gateway to Global Aging Data facilitates comparative research on aging through the provision of easy-to-use harmonized data files and other valuable tools.

Disability prevalence in midlife (aged 55-65 years): Cross-Country comparisons of gender differences and time trends.

BACKGROUND: Prior literature on disability has centered on disability prevalence among older adults ages 65 and older, providing only limited insight to potential gender differences in disability prevalence in mid-life. Midlife is, however, a critical time to be examined, as it is typically the time in the life course when large inequalities in physical health first emerge. METHODS: Using the Harmonized data files provided by the Gateway to Global Aging Data, we estimate disability prevalence of nationally representative adults ages 55-65 from 23 countries (N = 79,465). We examine gender differences in two disability indicators, limitations in instrumental activities of daily living (IADLs) and activities of daily living (ADLs) in two time periods, 2004/05 and 2014/15. RESULTS: There are substantial cross-country variations in IADL and ADL disability prevalence in midlife. Within countries, we find that women have higher IADL prevalence than men in only one out of five countries. Similarly, for ADL prevalence, women have higher ADL prevalence than men in only one out of ten countries. Further, comparing disability prevalence in two time periods, we observe different country-specific time trends. CONCLUSIONS: In the majority of mid and high-income countries, there is no significant gender difference in IADL and ADL prevalence, but there are few countries where women show higher prevalence of disability than men in mid-life. This finding calls for future research into what contributes to cross-country variations.

Disability Incidence Rates for Men and Women in 23 Countries: Evidence on Health Effects of Gender Inequality.

BACKGROUND: Inequality in gender varies across social contexts, which may influence the health of both men and women. Based on theories of gender as a social system, we examine whether systematic gender inequality at the macro-level influences health of men and women. METHOD: Using harmonized panel data from the Gateway to Global Aging Data in 23 high- and middle-income countries (N = 168 873), we estimate disability prevalence and incidence for men and women ages 55-89 (2000-2016). Within each country or geographic region, we also investigate gender differences in age gradients of the probability of disability onset. We, then, pool data from all countries and test the hypothesis that gender inequality increases the probability of disability onset. RESULTS: We found substantial cross-country variation in disability incidence rates, and this variation is greater for women than for men. Among ages 65-69, disability incidence rates ranged from 0.4 to 5.0 for men and from 0.5 to 9.4 for women. Our within-country analysis showed significant gender differences in age gradients of the probability of disability onset in the United States, Korea, Southern Europe, Mexico, and China, but not in Northern, Central, and Eastern Europe, England, and Israel. Testing hypothesized effects of gender inequality, we find that gender inequality is significantly associated with the probability of disability onset for women, but not for men. CONCLUSIONS: Macro-level societal gender inequality is significantly associated with the probability of disability onset for women. Reducing and eliminating gender inequality is crucial to achieving good health for women.

Frailty Index associates with GRIN2B in two representative samples from the United States and the United Kingdom.

The concept of frailty has been used in the clinical and research field for more than two decades. It is usually described as a clinical state of heightened vulnerability to poor resolution of homeostasis after a stressor event, which thereby increases the risk of adverse outcomes, including falls, delirium, disability and mortality. Here we report the results of the first genome-wide association scan and comparative gene ontology analyses where we aimed to identify genes and pathways associated with the deficit model of frailty. We used a discovery-replication design with two independent, nationally representative samples of older adults. The square-root transformed Frailty Index (FI) was the outcome variable, and age and sex were included as covariates. We report one hit exceeding genome-wide significance: the rs6765037 A allele was significantly associated with a decrease in the square-root transformed FI score in the Discovery sample (beta = -0.01958, p = 2.14E-08), without confirmation in the Replication sample. We also report a nominal replication: the rs7134291 A allele was significantly associated with a decrease in the square-root transformed FI score (Discovery sample: beta = -0.01021, p = 1.85E-06, Replication sample: beta = -0.005013, p = 0.03433). These hits represent the KBTBD12 and the GRIN2B genes, respectively. Comparative gene ontology analysis identified the pathways 'Neuropathic pain signalling in dorsal horn neurons' and the 'GPCR-Mediated Nutrient Sensing in Enteroendocrine Cells', exceeding the p = 0.01 significance in both samples, although this result does not survive correction for multiple testing. Considering the crucial role of GRIN2B in brain development, synaptic plasticity and cognition, this gene appears to be a potential candidate to play a role in frailty. In conclusion, we conducted genome-wide association scan and pathway analyses and have identified genes and pathways with potential roles in frailty. However, frailty is a complex condition. Therefore, further research is required to confirm our results and more thoroughly identify relevant biological mechanisms.

Genome-wide scan of depressive symptomatology in two representative cohorts in the United States and the United Kingdom.

Unlike the diagnosed Major Depressive Disorder, depressive symptomatology in the general population has received less attention in genome-wide association scan (GWAS) studies. Here we report a GWAS study on depressive symptomatology using a discovery-replication design and the following approaches: To improve the robustness of the phenotypic measure, we used longitudinal data and calculated mean scores for at least 3 observations for each individual. To maximize replicability, we used nearly identical genotyping platforms and identically constructed phenotypic measures in both the Discovery and Replication samples. We report one genome-wide significant hit; rs58682566 in the EPG5 gene was associated (p = 3.25E-08) with the mean of the depression symptom in the Discovery sample, without confirmation in the Replication sample. We also report 4 hits exceeding the genome-wide suggestive significance level with nominal replications. Rs11774887, rs4147527 and rs1379328, close to the SAMD12 gene, were associated with the mean depression symptom score (P-values in Discovery sample: 4.58E-06, 7.65E-06 and 7.66E-06; Replication sample: 0.049, 0.029 and 0.030, respectively). Rs13250896, located in an intergenic region, was associated with the mean score of the three somatic items of the depression symptoms score (p = 3.31E-07 and 0.042 for the Discovery and Replication samples). These results were not supported by evidence in the literature. We conclude that despite the strengths of our approach, using robust phenotypic measures and samples that maximize replicability potential, this study does not provide compelling evidence of a single genetic variant's significant role in depressive symptomatology.

Cross-Country Comparisons of Disability and Morbidity: Evidence from the Gateway to Global Aging Data.

Background: International comparisons of disease prevalence have been useful in understanding what proportion of disease might be preventable and in informing potential policy interventions in different cultural and economic contexts. Using newly available, harmonized data from 20 countries, we compare disability and morbidity of older adults between the ages of 55 and 74. Methods: The Gateway to Global Aging Data, a data and information portal, provides access to easy-to-use individual-level longitudinal data from 10 surveys covering over 30 countries. Exploiting harmonized measures available from the Gateway, we descriptively examine how disability and morbidity differ across countries. Results: Significant cross-country differences are observed for several health indicators. Comparing countries with the highest and lowest prevalence rates, we observe that hypertension rates vary twofold and stroke rates vary threefold, while disability and arthritis rates vary more than fivefold. Among women, higher gross domestic product and life expectancy are related to lower diabetes, heart disease, and better functioning. Among men, national indicators of economic conditions are not significantly associated with reported disease prevalence. Conclusions: We document substantial heterogeneity in disability and morbidity across countries, separately for men and women and after controlling for population age composition and education. Rich data from various surveys across the world offers remarkable opportunities for cross-country analyses, calling for further investigation of what drives observed differences. The Gateway to Global Aging Data provides easy-to-use harmonized data files and tools to facilitate this type of research.

Effects of Recent Stress and Variation in the Serotonin Transporter Polymorphism (5-HTTLPR) on Depressive Symptoms: A Repeated-Measures Study of Adults Age 50 and Older.

Depending on genetic sensitivity to it, stress may affect depressive symptomatology differentially. Applying the stress-diathesis hypothesis to older adults, we postulate: (1) recent stress will associate with increased depressive symptom levels and (2) this effect will be greater for individuals with at least one short allele of the serotonin transporter gene promoter region (5-HTTLPR). Further, we employ a design that addresses specific limitations of many prior studies that have examined the 5-HTTLPR × SLE relation, by: (a) using a within-person repeated-measures design to address fluctuations that occur within individuals over time, increase power for detecting G × E, and address GE correlation; (b) studying reports of exogenous stressful events (those unlikely to be caused by depression) to help rule out reverse causation and negativity bias, and in order to assess stressors that are more etiologically relevant to depressive symptomatology in older adults. The sample is drawn from the Health and Retirement Study, a U.S. population-based study of older individuals (N = 28,248; mean age = 67.5; 57.3 % female; 80.7 % Non-Hispanic White, 14.9 % Hispanic/Latino, 4.5 % African American; genetic subsample = 12,332), from whom measures of depressive symptoms and exogenous stressors were collected biannually (1994-2010). Variation in the 5-HTTLPR was characterized via haplotype, using two single nucleotide polymorphisms (SNPs). Ordered logit models were constructed to predict levels of depressive symptoms from 5-HTTLPR and stressors, comparing results of the most commonly applied statistical approaches (i.e., comparing allelic and genotypic models, and continuous and categorical predictors) used in the literature. All models were stratified by race/ethnicity. Overall, results show a main effect of recent stress for all ethnic groups, and mixed results for the variation in 5-HTTLPR × stress interaction, contingent upon statistical model used. Findings suggest there may be a differential effect of stressors and 5-HTTLPR on depressive symptoms by ethnicity, but further research is needed, particularly when using a haplotype to characterize variation in 5-HTTLPR in population-based sample with a diverse ethnic composition.

A polygenic risk score associated with measures of depressive symptoms among older adults.

It has been suggested that depression is a polygenic trait, arising from the influences of multiple loci with small individual effects. The aim of this study is to generate a polygenic risk score (PRS) to examine the association between genetic variation and depressive symptoms. Our analytic sample included N = 10,091 participants aged 50 and older from the Health and Retirement Study (HRS). Depressive symptoms were measured by Center for Epidemiological Studies-Depression scale (CESD) scores assessed on up to nine occasions across 18 years. We conducted a genome-wide association analysis for a discovery set (n = 7,000) and used the top 11 single-nucleotide polymorphisms, all with p < 10(-5) to generate a weighted PRS for our replication sample (n = 3,091). Results showed that the PRS was significantly associated with mean CESD score in the replication sample (ß = .08, p = .002). The R(2) change for the inclusion of the PRS was .003. Using a multinomial logistic regression model, we also examined the association between genetic risk and chronicity of high (4+) CESD scores. We found that a one-standard-deviation increase in PRS was associated with a 36 percent increase in the odds of having chronically high CESD scores relative to never having had high CESD scores. Our findings are consistent with depression being a polygenic trait and suggest that the cumulative influence of multiple variants increases an individual's susceptibility for chronically experiencing high levels of depressive symptoms.