Assessment of circulating apoE4 levels from dried blood spot samples in a large survey setting.

INTRODUCTION: The apolipoprotein E (APOE) ε4 allele is associated with high risk for Alzheimer's disease. It is unclear whether individual levels of the circulating apoE4 protein in ε4 carriers confer additional risk. Measuring apoE4 protein levels from dried blood spots (DBS) has the potential to provide information on genetic status as well as circulating levels and to include these measures in large survey settings. METHODS: We developed a multiplex immunoassay to detect apoE4 protein levels in DBS from 15,974 participants, aged 50+ from Wave 6 of the Survey of Health, Ageing and Retirement in Europe (SHARE). RESULTS: The apoE4 protein signal was presented in two separable distributions. One distribution corresponded to carriers of at least one copy of the ε4 allele. Fieldwork cofounders affected protein levels but did not explain individual differences. DISCUSSION: Future research should investigate how genotype and apoE4 level interact with lifestyle and other variables to impact cognitive aging.

Saving Regret and Procrastination.

In countries, where a substantial proportion of retirement income rests on savings, there is much concern that a sizeable fraction of the population reaches retirement with insufficient financial resources. We define saving regret as the wish in hindsight to have saved more earlier in life. We measured saving regret and possible determinants in a survey of U.S. households in which respondents were aged 60-79. We find high levels of saving regret, affirmed by some 58%. Saving regret exhibits significant and plausible correlations with personal characteristics and wealth: Married, older, healthier and wealthier respondents are less likely to report saving regret, suggesting the measure's validity. We find only weak evidence for correlations between saving regret and measures of procrastination: persons with traits associated with procrastination express saving regret about as often as those without those traits.

Effects of spot size on biomarker levels of field-collected dried blood spots: A new algorithm for exact dried blood spot size measurement.

OBJECTIVES: The quality of blood values analyzed from survey-collected dried blood spot (DBS) samples is affected by fieldwork conditions, particularly spot size. We offer an image-based algorithm that accurately measures the area of field-collected DBS and we investigate the impact of spot size on the analyzed blood marker values. METHODS: SHARE, a pan-European study, collected 24 000 DBS samples in 12 countries in its sixth wave. Our new algorithm uses photographs of the DBS samples to calculate the number of pixels of the blood-covered area to measure the spot sizes accurately. We ran regression models to examine the association of spot size and seven DBS analytes. We then compared the application of our new spot-size measures to common spot-size estimation. RESULTS: Using automated spot-size measurement, we found that spot size has a significant effect on all markers. Smaller spots are associated with lower measured levels, except for HbA1c, for which we observe a negative effect. Our precisely measured spot sizes explain substantially more variance of DBS analytes compared to commonly used spot-size estimation. CONCLUSION: The new algorithm accurately measures the size of field-collected DBS in an automated way. This methodology can be applied to surveys even with very large numbers of observations. The measured spot sizes improve the accuracy of conversion formulae that translate blood marker values derived from DBS into venous blood values. The significance of the spot-size effects on biomarkers in DBS should also incentivize the improvement of fieldwork training and monitoring.

Dried blood spot collection, sample quality, and fieldwork conditions: Structural validations for conversion into standard values.

OBJECTIVES: SHARE, a pan-European panel study in 27 European countries and Israel, has collected dried blood spot (DBS) samples from approximately 27 000 respondents in 13 countries. We aim to obtain factors to convert analyte values between DBS and venous blood samples (VBS) taking account of adverse fieldwork conditions such as small spot size, high temperature and humidity, short drying time and long shipment times. METHODS: We obtained VBS and DBS from a set of 20 donors in a laboratory setting, and treated the DBS in a systematic and controlled fashion simulating SHARE fieldwork conditions. We used the 3420 outcomes to estimate from DBS analyte values the values that we would have obtained had it been feasible to collect and analyze the donors' venous blood samples. RESULTS: The influence of field conditions and sample quality on DBS analyte values is significant and differs among assays. Varying spot size is the main challenge and affects all markers except HbA1c. Smaller spots lead to overly high measured levels. A missing desiccant is detrimental for all markers except CRP and tHb. The temperature to which the samples are exposed plays a significant role for HDL and CysC, while too brief a drying time affects CRP and CysC. Lab-based adjustment formulae only accounting for the differences between re-liquefied DBS and venous blood do not address these fieldwork conditions. CONCLUSIONS: By simulating adverse fieldwork conditions in the lab, we were able to validate DBS collected under such conditions and established conversion formulae with high prediction accuracy.

Early Determinants of Work Disability in an International Perspective.

This study explores the interrelated roles of health and welfare state policies in the decision to take up disability insurance (DI) benefits due to work disability (WD), defined as the (partial) inability to engage in gainful employment as a result of physical or mental illness. We exploit the large international variation of health, self-reported WD, and the uptake of DI benefits in the United States and Europe using a harmonized data set with life history information assembled from SHARE, ELSA, and HRS. We find that the mismatch between WD and DI benefit receipt varies greatly across countries. Objective health explains a substantial share of the within-country variation in DI, but this is not the case for the variation across countries. Rather, most of the variation between countries and the mismatches are explained by differences in DI policies.

Reliability, measurement error and minimum detectable change in mobility measures: a cohort study of community-dwelling adults aged 50 years and over in Ireland.

OBJECTIVE: To estimate the effects of repeat assessments, rater and time of day on mobility measures and to estimate their variation between and within participants in a population-based sample of Irish adults aged ≥50 years. DESIGN: Test-retest study in a population representative sample. SETTING: Academic health assessment centre of The Irish Longitudinal Study on Ageing (TILDA). PARTICIPANTS: 128 community-dwelling adults from the Survey for Health, Ageing and Retirement in Europe (SHARE) Ireland study who agreed to take part in the SHARE-Ireland/TILDA collaboration. INTERVENTIONS: Not applicable. OUTCOME MEASURES: Participants performed timed up-and-go (TUG), repeated chair stands (RCS) and walking speed tests administered by one of two raters. Repeat assessments were conducted 1-4 months later. Participants were randomised with respect to a change in time (morning, afternoon) and whether the rater was changed between assessments. Within and between-participant variance for each measure was estimated using mixed-effects models. Intraclass correlation (ICC), SE of measurement and minimum detectable change (MDC) were reported. RESULTS: Average performance did not vary between baseline and repeat assessments in any test, except RCS. The rater significantly affected performance on all tests except one, but time of day did not. Reliability varied from ICC=0.66 (RCS) to ICC=0.88 (usual gait speed). MDC was 2.08 s for TUG, 4.52 s for RCS and ranged from 19.49 to 34.73 cm/s for walking speed tests. There was no evidence for lower reliability of gait parameters with increasing time between assessments. CONCLUSIONS: Reliability varied for each test when measurements are obtained over 1-4 months with most variation due to rater effects. Usual and motor dual task gait speed demonstrated highest reliability.

Mothering alone: cross-national comparisons of later-life disability and health among women who were single mothers.

BACKGROUND: Single motherhood is associated with poorer health, but whether this association varies between countries is not known. We examine associations between single motherhood and poor later-life health in the USA, England and 13 European countries. METHODS: Data came from 25 125 women aged 50+ who participated in the US Health and Retirement Study, the English Longitudinal Study of Ageing and Survey of Health, Ageing and Retirement in Europe. We tested whether single motherhood at ages 16-49 was associated with increased risk of limitations with activities of daily living (ADL), instrumental ADL and fair/poor self-rated health in later life. RESULTS: 33% of American mothers had experienced single motherhood before age 50, versus 22% in England, 38% in Scandinavia, 22% in Western Europe and 10% in Southern Europe. Single mothers had higher risk of poorer health and disability in later life than married mothers, but associations varied between countries. For example, risk ratios for ADL limitations were 1.51 (95% CI 1.29 to 1.98) in England, 1.50 (1.10 to 2.05) in Scandinavia and 1.27 (1.17 to 1.40) in the USA, versus 1.09 (0.80 to 1.47) in Western Europe, 1.13 (0.80 to 1.60) in Southern Europe and 0.93 (0.66 to 1.31) in Eastern Europe. Women who were single mothers before age 20, for 8+ years, or resulting from divorce or non-marital childbearing, were at particular risk. CONCLUSIONS: Single motherhood during early-adulthood or mid-adulthood is associated with poorer health in later life. Risks were greatest in England, the USA and Scandinavia. Selection and causation mechanisms might both explain between-country variation.

Labor-Force Participation, Policies & Practices in an Aging America: Adaptation Essential for a Healthy & Resilient Population.

Population aging in the United States poses challenges to societal institutions while simultaneously creating opportunities to build a more resilient, successful, and cohesive society. Work organization and labor-force participation are central to both the opportunities and challenges posed by our aging society. We argue that expectations about old age have not sufficiently adapted to the reality of aging today. Our institutions need more adaptation in order to successfully face the consequences of demographic change. Although this adaptation needs to focus especially on work patterns among the "younger elderly," our society has to change its general attitudes toward work organization and labor-force participation, which will have implications for education and health care. We also show that work's beneficial effects on well-being in older ages are often neglected, while the idea that older workers displace younger workers is a misconception emerging from the "lump of labor" fallacy. We conclude, therefore, that working at older ages can lead to better quality of life for older people and to a more productive and resilient society overall.

The Consortium on Health and Ageing: Network of Cohorts in Europe and the United States (CHANCES) project--design, population and data harmonization of a large-scale, international study.

There is a public health demand to prevent health conditions which lead to increased morbidity and mortality among the rapidly-increasing elderly population. Data for the incidence of such conditions exist in cohort studies worldwide, which, however, differ in various aspects. The Consortium on Health and Ageing: Network of Cohorts in Europe and the United States (CHANCES) project aims at harmonizing data from existing major longitudinal studies for the elderly whilst focussing on cardiovascular diseases, diabetes mellitus, cancer, fractures and cognitive impairment in order to estimate their prevalence, incidence and cause-specific mortality, and identify lifestyle, socioeconomic, and genetic determinants and biomarkers for the incidence of and mortality from these conditions. A survey instrument assessing ageing-related conditions of the elderly will be also developed. Fourteen cohort studies participate in CHANCES with 683,228 elderly (and 150,210 deaths), from 23 European and three non-European countries. So far, 287 variables on health conditions and a variety of exposures, including biomarkers and genetic data have been harmonized. Different research hypotheses are investigated with meta-analyses. The results which will be produced can help international organizations, governments and policy-makers to better understand the broader implications and consequences of ageing and thus make informed decisions.

Data Resource Profile: the Survey of Health, Ageing and Retirement in Europe (SHARE).

SHARE is a unique panel database of micro data on health, socio-economic status and social and family networks covering most of the European Union and Israel. To date, SHARE has collected three panel waves (2004, 2006, 2010) of current living circumstances and retrospective life histories (2008, SHARELIFE); 6 additional waves are planned until 2024. The more than 150 000 interviews give a broad picture of life after the age of 50 years, measuring physical and mental health, economic and non-economic activities, income and wealth, transfers of time and money within and outside the family as well as life satisfaction and well-being. The data are available to the scientific community free of charge at www.share-project.org after registration. SHARE is harmonized with the US Health and Retirement Study (HRS) and the English Longitudinal Study of Ageing (ELSA) and has become a role model for several ageing surveys worldwide. SHARE's scientific power is based on its panel design that grasps the dynamic character of the ageing process, its multidisciplinary approach that delivers the full picture of individual and societal ageing, and its cross-nationally ex-ante harmonized design that permits international comparisons of health, economic and social outcomes in Europe and the USA.

SHARELIFE-One century of life histories in Europe.

Welfare state interventions shape our life courses in almost all of their multiply linked domains. In this introduction, we sketch how cross-nationally comparative retrospective data can be fruitfully employed to better understand these links and the long-run effects of the welfare state at the same time. We briefly introduce SHARE, the Survey of Health, Ageing and Retirement in Europe, and SHARELIFE, which collected 30,000 life histories of SHARE respondents from 14 European countries, providing a unique data infrastructure for interdisciplinary research on the various influences of contextual structures on the lives of Europeans during the last century until today. The eight studies in this special issue show that the multidisciplinary cross national approach of SHARELIFE allows a much more detailed understanding of life histories in Europe than was possible before.

The Role of Institutions and Health in European Patterns of Work and Retirement.

This paper uses the Survey of Health, Ageing and Retirement in Europe (SHARE) to investigate the role of pension and social security institutions in shaping the European patterns of work and retirement. The key novelty of our paper is a careful account of the health status of the respondents. We provide new evidence on the extent of health-adjusted "unused capacity" in the labour force, on the institutional determinants of the pathways to retirement, and on the relationship between actual health status and disability-benefit recipiency. We find that institutional differences between countries explain much of the cross-national differences in work and retirement, while differences in health and demographics play only a minor role.

Quality of work, well-being, and intended early retirement of older employees: baseline results from the SHARE Study.

BACKGROUND: Given the challenge of a high proportion of older employees who retire early from work we analyse associations of indicators of a poor psychosocial quality of work with intended premature departure from work in a large sample of older male and female employees in 10 European countries. METHODS: Baseline data from the 'Survey of Health, Ageing and Retirement in Europe' (SHARE) were obtained from 3523 men and 3318 women in 10 European countries. Data on intended early retirement, four measures of well-being (self-rated health, depressive symptoms, general symptom load, and quality of life), and quality of work (effort-reward imbalance; low control at work) were obtained from structured interviews and questionnaires. Country-specific and total samples are analysed, using logistic regression analysis. RESULTS: Poor quality of work is significantly associated with intended early retirement. After adjustment for well-being odds ratios (OR) of effort-reward imbalance [OR 1.72 (1.43-2.08)] and low control at work [OR 1.51 (1.27-1.80)] on intended early retirement are observed. Poor quality of work and reduced well-being are independently associated with the intention to retire from work. CONCLUSION: The consistent association of a poor psychosocial quality of work with intended early retirement among older employees across all European countries under study calls for improved investments into better quality of work, in particular increased control and an appropriate balance between efforts spent and rewards received at work.

A new comprehensive and international view on ageing: introducing the 'Survey of Health, Ageing and Retirement in Europe'.

This paper introduces the 'Survey of Health, Ageing and Retirement in Europe' (SHARE) to researchers on ageing. SHARE provides an infrastructure to help researchers better understand the individual and population ageing process: where we are, where we are heading to, and how we can influence the quality of life as we age, both as individuals and as societies. The baseline wave in 2004 provides data on the life circumstances of some 27,000 persons aged 50 and over in 11 European countries, ranging from Scandinavia across Western and Central Europe to the Mediterranean. SHARE has made great efforts to deliver truly comparable data, so we can reliably study how differences in cultures, living conditions and policy approaches shape the life of Europeans just before and after retirement. The paper first describes the SHARE data. In order to demonstrate its value, it then presents highlights from the three main research areas covered by SHARE, namely economics, sociology, and health.