The case for monitoring life-span inequality

From convergence to divergence: Lifespan variation in US states, 1959-2017

BACKGROUND

Large disparities in life expectancy exist across US states and the gaps have been widening in recent decades. Less is known about the lifespan variability - a measure that can provide important insights into mortality inequalities both between and within states.

METHOD

Using yearly lifetables from the United States Mortality Database, we explore geographic and temporal patterns in lifespan variation (unconditional and conditional on survival to age 10, 35 and 65) across US states between 1959 and 2017. We also examine the contribution of state differences in life expectancy to overall lifespan variation using standard decomposition techniques.

RESULTS

Despite overall convergence in lifespan variation across states over the last six decades, in more recent years there has been notable divergence. Gender-specific analyses show that lifespan variation was generally greater among males than among females; but this pattern reverses for mortality past age 65. Much of the state disparities in lifespan variation, unconditional and conditional on survival to age 10 and 35, were due to mortality differences under the age 65. Decomposition analysis shows that while within-state variability remains the primary driver of overall lifespan variation, the contribution of cross-state differences in life expectancy is growing.

CONCLUSIONS

Variation in longevity is greater within US States than between them, yet cross-states disparities in mortality are increasing. This likely reflects the long-term consequences of rising social, economic, and political stratification for health inequalities both within and across states.

The Cross-sectional Average Inequality in Lifespan (CAL†): A Lifespan Variation Measure That Reflects the Mortality Histories of Cohorts

Lifespan variation is a key metric of mortality that describes both individual uncertainty about the length of life and heterogeneity in population health. We propose a novel and timely lifespan variation measure, which we call the cross-sectional average inequality in lifespan, or CAL†. This new index provides an alternative perspective on the analysis of lifespan inequality by combining the mortality histories of all cohorts present in a cross-sectional approach. We demonstrate how differences in the CAL† measure can be decomposed between populations by age and cohort to explore the compression or expansion of mortality in a cohort perspective. We apply these new methods using data from 10 low-mortality countries or regions from 1879 to 2013. CAL† reveals greater uncertainty in the timing of death than the period life table-based indices of variation indicate. Also, country rankings of lifespan inequality vary considerably between period and cross-sectional measures. These differences raise intriguing questions as to which temporal dimension is the most relevant to individuals when considering the uncertainty in the timing of death in planning their life courses.

Trends in health equity in mortality in the United States, 1969-2019

RATIONALE

Health equity is a significant concern of public health, yet a comprehensive assessment of health equity in the United States over time is lacking. While one might presume that overall health will improve with rising living standards, no such presumption is warranted for health equity, which may decline even as average health improves.

OBJECTIVES

To assess trends in national and state-level health equity in mortality for people up to age 25, ages 25-64 and aged 65 and older.

METHODS

A health equity metric was calculated as the weighted mean life expectancy relative to a benchmark level, defined as the life expectancy of the most socially-privileged subpopulation (white, non-Latinx males with a college education or higher).We analyzed 114,558,346 death records from the National Center for Health Statistics, from January 1, 1969 to December 31, 2019 to estimate health equity annually at the national and state-level. Using ICD-9/ICD-10 classification codes, inequities in health were decomposed by major causes of death.

RESULTS

From 1969 to 2019, health equity in the United States improved (+0.36 points annually [95% CI 0.31-0.41]), albeit at a slower rate over the last two decades (+0.08 points annually [95% CI 0.03-0.14] from 2000 to 2019, compared to +0.57 points annually from 1969 to 2000 [95% CI 0.50-0.65]). Health equity among those under 25 improved substantially (+0.82 points annually [95% CI 0.75-0.89]) but remained flat for adults 25-64 (-0.01 points annually [95% CI -0.03-0.003]) For those over 65, health equity displayed a downward trend (-0.08 points annually [95% CI -0.09 to -0.07]). Gains in equity from reduced unintentional injuries and homicides have been largely offset by rising mortality attributable to drug overdoses.

CONCLUSIONS

The US is failing to advance health equity, especially for adults. Keeping policy-makers accountable to a summary measure of health equity may help coordinate efforts at improving population health.

What Can We Learn from the Functional Clustering of Mortality Data? An Application to the Human Mortality Database

This study analyzed whether there are different patterns of mortality decline among low-mortality countries by identifying the role played by all the mortality components. We implemented a cluster analysis using a functional data analysis (FDA) approach, which allowed us to consider age-specific mortality rather than summary measures, as it analyses curves rather than scalar data. Combined with a functional principal component analysis, it can identify what part of the curves is responsible for assigning one country to a specific cluster. FDA clustering was applied to the data from 32 countries in the Human Mortality Database from 1960 to 2018 to provide a comprehensive understanding of their patterns of mortality. The results show that the evolution of developed countries followed the same pattern of stages (with different timings): (1) a reduction of infant mortality, (2) an increase of premature mortality and (3) a shift and compression of deaths. Some countries were following this scheme and recovering the gap with precursors; others did not show signs of recovery. Eastern European countries were still at Stage (2), and it was not clear if and when they will enter Stage 3. All the country differences related to the different timings with which countries underwent the stages, as identified by the clusters.

Growing Income-Based Inequalities in Old-Age Life Expectancy in Sweden, 2006-2015

Sweden is known for high life expectancy and economic egalitarianism, yet in recent decades it has lost ground in both respects. This study tracked income inequality in old-age life expectancy and life span variation in Sweden between 2006 and 2015, and examined whether patterns varied across levels of neighborhood deprivation. Income inequality in remaining life expectancy at ages 65, 75, and 85 increased. The gap in life expectancy at age 65 grew by more than a year between the lowest and the highest income quartiles, for both men (from 3.4 years in 2006 to 4.5 years in 2015) and women (from 2.3 to 3.4 years). This widening income gap in old-age life expectancy was driven by different rates of mortality improvement: individuals with higher incomes increased their life expectancy at a faster rate than did those with lower incomes. Women with the lowest incomes experienced no improvement in old-age life expectancy. Furthermore, life span variation increased in the lowest income quartile, while it decreased slightly among those in the highest quartile. Income was found to be a stronger determinant of old-age life expectancy than neighborhood deprivation.

The impact of income definitions on mortality inequalities

Income is a strong predictor of adult mortality. Measuring income is not as simple as it may sound. It can be conceptualized at the individual or the household level, with the former better reflecting an individual's earning ability, and the latter better capturing living standards. Furthermore, respondents are often grouped into income categories based on their positions in the income distribution, and this operationalization can be done on the basis of age-specific or total population income distributions. In this study, we look at how four combinations of different conceptualizations (individual vs. household) and operationalizations (age-specific vs. total population) of income can affect mortality inequality estimates. Using Finnish registry data, we constructed period life tables for ages 25+ from 1996 to 2017 by gender and for four income definitions. The results indicated that the slope index of inequality for life expectancy varied by 1.1-5.7 years between income definitions, with larger differences observed for women than for men. The overall age patterns of relative index of inequality for mortality rates yielded by the four definitions were similar, but the levels differed. The period trends across income definitions were consistent for men, but not for women. We conclude that researchers should pay particular attention to the choice of the income definitions when analyzing the association between income and mortality, and when comparing the magnitude of inequality across studies and over time.

What can lifespan variation reveal that life expectancy hides? Comparison of five high-income countries

OBJECTIVES

In most countries, life expectancy at birth (e0) has improved for many decades. Recently, however, progress has stalled in the UK and Canada, and reversed in the USA. Lifespan variation, a complementary measure of mortality, increased a few years before the reversal in the USA. To assess whether this measure offers additional meaningful insights, we examine what happened in four other high-income countries with differing life expectancy trends.

DESIGN

We calculated life disparity (a specific measure of lifespan variation) in five countries -- USA, UK, France, Japan and Canada -- using sex- and age specific mortality rates from the Human Mortality Database from 1975 to 2017 for ages 0--100 years. We then examined trends in age-specific mortality to identify the age groups contributing to these changes.

SETTING

USA, UK, France, Japan and Canada.

PARTICIPANTS

aggregate population data of the above nations.

MAIN OUTCOME MEASURES

Life expectancy at birth, life disparity and age-specific mortality.

RESULTS

The stalls and falls in life expectancy, for both males and females, seen in the UK, USA and Canada coincided with rising life disparity. These changes may be driven by worsening mortality in middle-age (such as at age 40). France and Japan, in contrast, continue on previous trajectories.

CONCLUSIONS

Life disparity is an additional summary measure of population health providing information beyond that signalled by life expectancy at birth alone.

Estimating the burden of the COVID-19 pandemic on mortality, life expectancy and lifespan inequality in England and Wales: a population-level analysis

BACKGROUND

Deaths directly linked to COVID-19 infection may be misclassified, and the pandemic may have indirectly affected other causes of death. To overcome these measurement challenges, we estimate the impact of the COVID-19 pandemic on mortality, life expectancy and lifespan inequality from week 10 of 2020, when the first COVID-19 death was registered, to week 47 ending 20 November 2020 in England and Wales through an analysis of excess mortality.

METHODS

We estimated age and sex-specific excess mortality risk and deaths above a baseline adjusted for seasonality with a systematic comparison of four different models using data from the Office for National Statistics. We additionally provide estimates of life expectancy at birth and lifespan inequality defined as the SD in age at death.

RESULTS

There have been 57 419 (95% prediction interval: 54 197, 60 752) excess deaths in the first 47 weeks of 2020, 55% of which occurred in men. Excess deaths increased sharply with age and men experienced elevated risks of death in all age groups. Life expectancy at birth dropped 0.9 and 1.2 years for women and men relative to the 2019 levels, respectively. Lifespan inequality also fell over the same period by 5 months for both sexes.

CONCLUSION

Quantifying excess deaths and their impact on life expectancy at birth provide a more comprehensive picture of the burden of COVID-19 on mortality. Whether mortality will return to-or even fall below-the baseline level remains to be seen as the pandemic continues to unfold and diverse interventions are put in place.

Estimating the burden of the COVID-19 pandemic on mortality, life expectancy and lifespan inequality in England and Wales: a population-level analysis

BACKGROUND

Deaths directly linked to COVID-19 infection may be misclassified, and the pandemic may have indirectly affected other causes of death. To overcome these measurement challenges, we estimate the impact of the COVID-19 pandemic on mortality, life expectancy and lifespan inequality from week 10 of 2020, when the first COVID-19 death was registered, to week 47 ending 20 November 2020 in England and Wales through an analysis of excess mortality.

METHODS

We estimated age and sex-specific excess mortality risk and deaths above a baseline adjusted for seasonality with a systematic comparison of four different models using data from the Office for National Statistics. We additionally provide estimates of life expectancy at birth and lifespan inequality defined as the SD in age at death.

RESULTS

There have been 57 419 (95% prediction interval: 54 197, 60 752) excess deaths in the first 47 weeks of 2020, 55% of which occurred in men. Excess deaths increased sharply with age and men experienced elevated risks of death in all age groups. Life expectancy at birth dropped 0.9 and 1.2 years for women and men relative to the 2019 levels, respectively. Lifespan inequality also fell over the same period by 5 months for both sexes.

CONCLUSION

Quantifying excess deaths and their impact on life expectancy at birth provide a more comprehensive picture of the burden of COVID-19 on mortality. Whether mortality will return to-or even fall below-the baseline level remains to be seen as the pandemic continues to unfold and diverse interventions are put in place.

Changes in life expectancy and lifespan variability by income quartiles in four Nordic countries: a study based on nationwide register data

OBJECTIVES

Levels, trends or changes in socioeconomic mortality differentials are typically described in terms of means, for example, life expectancies, but studies have suggested that there also are systematic social disparities in the dispersion around those means, in other words there are inequalities in lifespan variation. This study investigates changes in income inequalities in mean and distributional measures of mortality in Denmark, Finland, Norway, and Sweden over two decades.

DESIGN

Nationwide register-based study.

SETTING

The Danish, Finnish, Norwegian and Swedish populations aged 30 years or over in 1997 and 2017.

MAIN OUTCOME MEASURES

Income-specific changes in life expectancy, lifespan variation and the contribution of 'early' and 'late' deaths to increasing life expectancy.

RESULTS

Increases in life expectancy has taken place in all four countries, but there are systematic differences across income groups. In general, the largest gains in life expectancy were observed in Denmark, and the smallest increase among low-income women in Sweden and Norway. Overall, life expectancy increased and lifespan variation decreased with increasing income level. These differences grew larger over time. In all countries, a marked postponement of early deaths led to a compression of mortality in the top three income quartiles for both genders. This did not occur for the lowest income quartile.

CONCLUSION

Increasing life expectancy is typically accompanied by postponement of early deaths and reduction of lifespan inequality in the higher-income groups. However, Nordic welfare societies are challenged by the fact that postponing premature deaths among people in the lowest-income groups is not taking place.

Diversification in causes of death in low-mortality countries: emerging patterns and implications

INTRODUCTION

An important role of public health organisations is to monitor indicators of variation, so as to disclose underlying inequality in health improvement. In industrialised societies, more individuals than ever are reaching older ages and have become more homogeneous in their age at death. This has led to a decrease in lifespan variation, with substantial implications for the reduction of health inequalities. We focus on a new form of variation to shed further light on our understanding of population health and ageing: variation in causes of death.

METHODS

Data from the WHO Mortality Database and the Human Mortality Database are used to estimate cause-of-death distributions and life tables in 15 low-mortality countries. Cause-of-death variation, using 19 groups of causes, is quantified using entropy measures and analysed from 1994 to 2017.

RESULTS

The last two decades have seen increasing diversity in causes of death in low-mortality countries. There have been important reductions in the share of deaths from diseases of the circulatory system, while the share of a range of other causes, such as diseases of the genitourinary system, mental and behavioural disorders, and diseases of the nervous system, has been increasing, leading to a more complex cause-of-death distribution.

CONCLUSIONS

The diversification in causes of death witnessed in recent decades is most likely a result of the increase in life expectancy, together with better diagnoses and awareness of certain diseases. Such emerging patterns bring additional challenges to healthcare systems, such as the need to research, monitor and treat a wider range of diseases. It also raises new questions concerning the distribution of health resources.

The long lives of primates and the 'invariant rate of ageing' hypothesis

Is it possible to slow the rate of ageing, or do biological constraints limit its plasticity? We test the 'invariant rate of ageing' hypothesis, which posits that the rate of ageing is relatively fixed within species, with a collection of 39 human and nonhuman primate datasets across seven genera. We first recapitulate, in nonhuman primates, the highly regular relationship between life expectancy and lifespan equality seen in humans. We next demonstrate that variation in the rate of ageing within genera is orders of magnitude smaller than variation in pre-adult and age-independent mortality. Finally, we demonstrate that changes in the rate of ageing, but not other mortality parameters, produce striking, species-atypical changes in mortality patterns. Our results support the invariant rate of ageing hypothesis, implying biological constraints on how much the human rate of ageing can be slowed.

Declining regional disparities in mortality in the context of persisting large inequalities in economic conditions: the case of Germany

BACKGROUND

Subnational regional mortality inequalities are large and appear to be mostly increasing within industrialized countries, although comparative studies across high-income countries are scarce. Germany is an important country to examine because it continues to experience considerable economic disparities between its federal states, in part resulting from its former division.

METHODS

We analyse state-level mortality in Germany utilizing data from a newly constructed regional database based on the methodology of the Human Mortality Database. We compare time trends (1991-2015) in the German state-level standard deviation in life expectancy to that of other large, wealthy countries and examine the association between mortality and economic inequalities at the regional level. Finally, using contour-decomposition methods, we investigate the degree to which age patterns of mortality are converging across German federal states.

RESULTS

Regional inequalities in life expectancy in Germany are comparatively low internationally, particularly among women, despite high state-level inequalities in economic conditions. These low regional mortality inequalities emerged 5-10 years after reunification. Mortality is converging over most ages between the longest- and shortest-living German state populations and across the former East-West political border, with the exception of an emerging East-West divergence in mortality among working-aged men.

CONCLUSIONS

The German example shows that large regional economic inequalities are not necessarily paralleled with large regional mortality disparities. Future research should investigate the factors that fostered the emergence of this unusual pattern in Germany.

Demographic perspectives on the rise of longevity

This article reviews some key strands of demographic research on past trends in human longevity and explores possible future trends in life expectancy at birth. Demographic data on age-specific mortality are used to estimate life expectancy, and validated data on exceptional life spans are used to study the maximum length of life. In the countries doing best each year, life expectancy started to increase around 1840 at a pace of almost 2.5 y per decade. This trend has continued until the present. Contrary to classical evolutionary theories of senescence and contrary to the predictions of many experts, the frontier of survival is advancing to higher ages. Furthermore, individual life spans are becoming more equal, reducing inequalities, with octogenarians and nonagenarians accounting for most deaths in countries with the highest life expectancy. If the current pace of progress in life expectancy continues, most children born this millennium will celebrate their 100th birthday. Considerable uncertainty, however, clouds forecasts: Life expectancy and maximum life span might increase very little if at all, or longevity might rise much faster than in the past. Substantial progress has been made over the past three decades in deepening understanding of how long humans have lived and how long they might live. The social, economic, health, cultural, and political consequences of further increases in longevity are so significant that the development of more powerful methods of forecasting is a priority.

A Mixture-Function Mortality Model: Illustration of the Evolution of Premature Mortality

Premature mortality is often a neglected component of overall deaths, and the most difficult to identify. However, it is important to estimate its prevalence. Following Pearson's theory about mortality components, a definition of premature deaths and a parametric model to study its transformations are introduced. The model is a mixture of three distributions: a Half Normal for the first part of the death curve and two Skew Normals to fit the remaining pieces. One advantage of the model is the possibility of obtaining an explicit equation to compute life expectancy at birth and to break it down into mortality components. We estimated the mixture model for Sweden, France, East Germany and Czech Republic. In addition, to the well-known reduction in infant deaths, and compression and shifting trend of adult mortality, we were able to study the trend of the central part of the distribution of deaths in detail. In general, a right shift of the modal age at death for young adults is observed; in some cases, it is also accompanied by an increase in the number of deaths at these ages: in particular for France, in the last twenty years, premature mortality increases.

Black-white disparities during an epidemic: Life expectancy and lifespan disparity in the US, 1980-2000

Covid-19 has demonstrated again that epidemics can affect minorities more than the population in general. We consider one of the last major epidemics in the United States: HIV/AIDS from ca. 1980-2000. We calculate life expectancy and lifespan disparity (a measure of variance in age at death) for thirty US states, finding noticeable differences both between states and between the black and white communities. Lifespan disparity allows us to examine distributional effects, and, using decomposition methods, we find that for six states lifespan disparity for blacks increased between 1980 and 1990, while life expectancy increased less than for whites. We find that we can attribute most of this to the impact of HIV/AIDS.

Variability Matters

Much of science, including public health research, focuses on means (averages). The purpose of the present paper is to reinforce the idea that variability matters just as well. At the hand of four examples, we highlight four classes of situations where the conclusion drawn on the basis of the mean alone is qualitatively altered when variability is also considered. We suggest that some of the more serendipitous results have their origin in variability.

The ratio of expansion to compression: A new measure of lifespan disparity

Numerous studies have shown that high life expectancy is closely related to low life disparity. Unlike life expectancy, which can be increased by mortality decline at any age, life disparity can either increase or decrease in response to mortality decline. Disparity can thus be decomposed into two opposite components, called compression and expansion, depending on the effect of mortality decline on the age distribution of mortality. Without specifying the two components, various conventional measures of disparity may provide misleading information relating to how life chances in society can be equalized. Based on the relevant properties of changes in disparity, we develop a new measure of disparity—the ratio of expansion to compression—that can account for the relative importance of the two components. This simple measure not only provides a clear view of the evolution of disparity, but also permits changes in disparity related to mortality decline to be interpreted in a consistent manner similar to life expectancy. Simulations and an empirical analysis demonstrated the advantages of this new measure over conventional measures of disparity.

Assessing the contribution of alcohol-specific causes to socio-economic inequalities in mortality in England and Wales 2001-16

BACKGROUND AND AIMS

When measuring inequalities in health, public health and addiction research has tended to focus on differences in average life-span between socio-economic groups. This does not account for the extent to which age of death varies between individuals within socio-economic groups or whether this variation differs between groups. This study assesses (1) socio-economic inequalities in both average life-span and variation in age at death, (2) the extent to which these inequalities can be attributed to alcohol-specific causes (i.e. those attributable only to alcohol) and (3) how this contribution has changed over time.

DESIGN

Cause-deleted life table analysis of national mortality records.

SETTING

England and Wales, 2001-16.

CASES

All-cause and alcohol-specific deaths for all adults aged 18+, stratified by sex, age and quintiles of the index of multiple deprivation (IMD).

MEASUREMENTS

Life expectancy at age 18 yearss and standard deviation in age at death within IMD quintiles and the contribution of alcohol to overall differences in both measures between the highest and lowest IMD quintiles by comparing observed and cause-deleted inequality 'gaps'.

FINDINGS

In 2016, alcohol-specific causes reduced life expectancy for men and women by 0.26 and 0.14 years, respectively, and increased the standard deviation in age at death. These causes also increased the inequality gap in life expectancy by 0.33 years for men and 0.17 years for women, and variation in age at death by 0.14 years and 0.13 years, respectively. For both measures, the contribution of alcohol to mortality inequalities rose after 2001 and subsequently fell back. For women, alcohol accounted for 3.6% of inequality in age at death and 6.0% of life-span uncertainty, suggesting that using only the former may underestimate alcohol-induced inequalities. There was no comparable difference for men.

CONCLUSIONS

Deaths from alcohol-specific causes increase inequalities in both life expectancy and variation in age of death between socio-economic groups. Using both measures can provide a fuller picture of overall inequalities in health.

Genetic differences and longevity-related phenotypes influence lifespan and lifespan variation in a sex-specific manner in mice

Epidemiological studies of human longevity found two interesting features, robust advantage of female lifespan and consistent reduction of lifespan variation. To help understand the genetic aspects of these phenomena, the current study examined sex differences and variation of longevity using previously published mouse data sets including data on lifespan, age of puberty, and circulating insulin-like growth factor 1 (IGF1) levels in 31 inbred strains, data from colonies of nuclear-receptor-interacting protein 1 (Nrip1) knockout mice, and a congenic strain, B6.C3H-Igf1. Looking at the overall data for all inbred strains, the results show no significant difference in lifespan and lifespan variation between sexes; however, considerable differences were found among and within strains. Across strains, lifespan variations of female and male mice are significantly correlated. Strikingly, between sexes, IGF1 levels correlate with the lifespan variation and maximum lifespan in different directions. Female mice with low IGF1 levels have higher variation and extended maximum lifespan. The opposite is detected in males. Compared to domesticated inbred strains, wild-derived inbred strains have elevated lifespan variation due to increased early deaths in both sexes and extended maximum lifespan in female mice. Intriguingly, the sex differences in survival curves of inbred strains negatively associated with age of female puberty, which is significantly accelerated in domesticated inbred strains compared to wild-derived strains. In conclusion, this study suggests that genetic factors are involved in the regulation of sexual disparities in lifespan and lifespan variation, and dissecting the mouse genome may provide novel insight into the underlying genetic mechanisms.

Relationships between best-practice and greatest possible life expectancies

This paper investigated the relationships between the best-practice and the greatest possible life expectancies by means of gaps, lags and decomposition analyses, from 1950-1955 up to 2095-2100. The data were gathered from the United Nations' World Population Prospects (2017), containing abridged period life tables, for both sexes combined, for 201 countries or areas, which allowed the identification of low-mortality regions that are sometimes omitted in previous studies. It was observed that both best-practice and greatest possible life expectancies rose and are expected to continue to rise linearly in a very similar way. Moreover, the average gap between the best-practice and the greatest possible life expectancies was of about 1.14 years and the average lag was 7.59 years. Finally, it was found that major contributions to the gap are typically due to age groups beyond 65 years.

Rethinking morbidity compression

Studies of morbidity compression routinely report the average number of years spent in an unhealthy state but do not report variation in age at morbidity onset. Variation was highlighted by Fries (1980) as crucial for identifying disease postponement. Using incidence of first hospitalization after age 60, as one working example, we estimate variation in morbidity onset over a 27-year period in Denmark. Annual estimates of first hospitalization and the population at risk for 1987 to 2014 were identified using population-based registers. Sex-specific life tables were constructed, and the average age, the threshold age, and the coefficient of variation in age at first hospitalization were calculated. On average, first admissions lasting two or more days shifted towards older ages between 1987 and 2014. The average age at hospitalization increased from 67.8 years (95% CI 67.7-67.9) to 69.5 years (95% CI 69.4-69.6) in men, and 69.1 (95% CI 69.1-69.2) to 70.5 years (95% CI 70.4-70.6) in women. Variation in age at first admission increased slightly as the coefficient of variation increased from 9.1 (95% CI 9.0-9.1) to 9.9% (95% CI 9.8-10.0) among men, and from 10.3% (95% CI 10.2-10.4) to 10.6% (95% CI 10.5-10.6) among women. Our results suggest populations are ageing with better health today than in the past, but experience increasing diversity in healthy ageing. Pensions, social care, and health services will have to adapt to increasingly heterogeneous ageing populations, a phenomenon that average measures of morbidity do not capture.

The impact of violence on Venezuelan life expectancy and lifespan inequality

BACKGROUND

Venezuela is one of the most violent countries in the world. According to the United Nations, homicide rates in the country increased from 32.9 to 61.9 per 100 000 people between 2000 and 2014. This upsurge coincided with a slowdown in life expectancy improvements. We estimate mortality trends and quantify the impact of violence-related deaths and other causes of death on life expectancy and lifespan inequality in Venezuela.

METHODS

Life tables were computed with corrected age-specific mortality rates from 1996 to 2013. From these, changes in life expectancy and lifespan inequality were decomposed by age and cause of death using a continuous-change model. Lifespan inequality, or variation in age at death, is measured by the standard deviation of the age-at-death distribution.

RESULTS

From 1996 to 2013 in Venezuela, female life expectancy rose 3.57 [95% confidence interval (CI): 3.08-4.09] years [from 75.79 (75.98-76.10) to 79.36 (78.97-79.68)], and lifespan inequality fell 1.03 (-2.96 to 1.26) years [from 18.44 (18.01-19.00) to 17.41 (17.30-18.27)]. Male life expectancy increased 1.64 (1.09-2.25) years [from 69.36 (68.89-59.70) to 71.00 (70.53-71.39)], but lifespan inequality increased 0.95 (-0.80 to 2.89) years [from 20.70 (20.24-21.08) to 21.65 (21.34-22.12)]. If violence-related death rates had not risen over this period, male life expectancy would have increased an additional 1.55 years, and lifespan inequality would have declined slightly (-0.31 years).

CONCLUSIONS

As increases in violence-related deaths among young men (ages 15-39) have slowed gains in male life expectancy and increased lifespan inequality, Venezuelan males face more uncertainty about their age at death. There is an urgent need for more accurate mortality estimates in Venezuela.

Child volunteers in a women's paramilitary organization in World War II have accelerated reproductive schedules

Understanding how conditions experienced during development affect reproductive timing is of considerable cross-disciplinary interest. Life-history theory predicts that organisms will accelerate reproduction when future survival is unsure. In humans, this can be triggered by early exposure to mortality. Previous studies, however, have been inconclusive due to several confounds that are also likely to affect reproduction. Here we take advantage of a natural experiment in which a population is temporarily divided by war to analyze how exposure to mortality affects reproduction. Using records of Finnish women in World War II, we find that young girls serving in a paramilitary organization wait less time to reproduce, have shorter inter-birth intervals, and have more children than their non-serving peers or sisters. These results support the hypothesis that exposure to elevated mortality rates during development can result in accelerated reproductive schedules and adds to our understanding of how participation in warfare affects women.

Life history theory predicts that females will adjust reproductive timing in response to environmental challenges. Here the authors show that young girls exposed to higher mortality rates during war give birth earlier and more often than their peers who were not exposed to these conditions.

Dynamics of life expectancy and life span equality

As people live longer, ages at death are becoming more similar. This dual advance over the last two centuries, a central aim of public health policies, is a major achievement of modern civilization. Some recent exceptions to the joint rise of life expectancy and life span equality, however, make it difficult to determine the underlying causes of this relationship. Here, we develop a unifying framework to study life expectancy and life span equality over time, relying on concepts about the pace and shape of aging. We study the dynamic relationship between life expectancy and life span equality with reliable data from the Human Mortality Database for 49 countries and regions with emphasis on the long time series from Sweden. Our results demonstrate that both changes in life expectancy and life span equality are weighted totals of rates of progress in reducing mortality. This finding holds for three different measures of the variability of life spans. The weights evolve over time and indicate the ages at which reductions in mortality increase life expectancy and life span equality: the more progress at the youngest ages, the tighter the relationship. The link between life expectancy and life span equality is especially strong when life expectancy is less than 70 y. In recent decades, life expectancy and life span equality have occasionally moved in opposite directions due to larger improvements in mortality at older ages or a slowdown in declines in midlife mortality. Saving lives at ages below life expectancy is the key to increasing both life expectancy and life span equality.

Greater mortality variability in the United States in comparison with peer countries

BACKGROUND

Over the past several decades, US mortality declines have lagged behind other high-income countries. However, scant attention has been devoted to how US mortality variability compares with other countries.

OBJECTIVE

We examine trends in mortality and mortality variability in the US and 16 peer countries from 1980 through 2016.

METHODS

We employ the Human Mortality Database and demographic techniques - with a focus on patterns in the interquartile (IQR), interdecile (IDR), and intercentile (ICR) ranges of survivorship - to better understand US mortality and mortality variability trends in comparative perspective.

RESULTS

Compared to other high-income countries, the US: (1) mortality ranking has slipped for nearly all age groups; (2) is losing its old age mortality advantage; (3) has seen growth in relative age-specific mortality gaps from infancy through midlife; and (4) exhibits greater concentrations of deaths from infancy through adulthood, resulting in much greater mortality variability.

CONCLUSIONS

We contribute to calls for renewed attention to the relatively low and lagging US life expectancy. The ICR draws particular attention to the comparatively high US early and midlife mortality.

CONTRIBUTION

We find comparatively high variability in US mortality. Further reductions in early and midlife mortality could diminish variability, reduce years of potential life lost, and increase life expectancy. Consistent with previous research, we encourage policymakers to focus on reducing the unacceptably high early and midlife mortality in the US. And we urge researchers to more frequently monitor and track mortality variation in conjunction with mortality rates and life expectancy estimates.

Social inequalities in multimorbidity, frailty, disability, and transitions to mortality: a 24-year follow-up of the Whitehall II cohort study

BACKGROUND

Social inequalities in mortality persist in high-income countries with universal health care, and the mechanisms by which these inequalities are generated remain unclear. We aimed to examine whether social inequalities were present before or after the onset of adverse health conditions (multimorbidity, frailty, and disability).

METHODS

Our analysis was based on data from the ongoing Whitehall II cohort study, which enrolled British civil servants aged 35-55 years in 1985-88. Participants were assessed for three indicators of socioeconomic status (education, occupational position, and literacy) at age 50 years. Participants underwent clinical examinations (in 2002-04, 2007-09, 2012-13, and 2015-16) for assessment of frailty (two or more of low physical activity, slow walking speed, poor grip strength, weight loss, and exhaustion) and disability (two or more difficulties in bathing, dressing, going to the toilet, transferring, feeding, and walking). In addition, electronic health records were used to assess the incidence of multimorbidity (two or more of diabetes, coronary heart disease, stroke, chronic obstructive pulmonary disease, depression, arthritis, cancer, dementia, and Parkinson's disease) and mortality. In analyses adjusted for sociodemographic factors, we used multistate models to examine social inequalities in transitions from healthy state to adverse health conditions and subsequently to mortality.

FINDINGS

Of 10 308 individuals in the Whitehall II study cohort, 6425 had relevant data available at 50 years and to the end of follow-up on Aug 31, 2017, and were included in our analysis. Participants were followed up for a median of 23·6 years (IQR 19·6-28·9). 1694 (26·4%) of 6425 participants developed multimorbidity, 1733 (27·0%) became frail, 692 (10·8%) had a disability, and 611 (9·5%) died. Multimorbidity (hazard ratio [HR] 4·12 [95% CI 3·41-4·98]), frailty (HR 2·38 [95% CI 1·93-2·93]), and disability (HR 1·73 [95% CI 1·34-2·22]) were associated with increased risk of mortality; these associations were not modified by socioeconomic status. In multistate models, occupation was the socioeconomic status indicator that was most strongly associated with inequalities in the transition from healthy state to multimorbidity (HR 1·54 [95% CI 1·37-1·73]), to frailty (HR 2·08 [95% CI 1·85-2·33]), and to disability (HR 1·44 [95% CI 1·18-1·74]). Socioeconomic status indicators did not affect transitions to mortality in those with multimorbidity, frailty, or disability.

INTERPRETATION

Socioeconomic status affects the risk of multimorbidity, frailty, and disability, but does not affect the risk of mortality after the onset of these adverse health conditions. Therefore, primary prevention is key to reducing social inequalities in mortality. Of the three adverse health conditions, multimorbidity had the strongest association with mortality, making it a central target for improving population health.

FUNDING

UK Medical Research Council; National Institute on Aging, National Institutes of Health; British Heart Foundation.

Twin consequences of rising U.S. death rates among young adults: Lower life expectancy and greater lifespan variability

The current study is an original investigation of the U.S. mortality pattern from 2000 to 2017. Previous research has shown that the unusual post-2014 decline in life expectancy is related to the increase in death rates for ages 25-44, mostly due to rising prevalence in drug poisoning and suicide deaths. Our investigation reveals that such increase in younger-age mortality has had an impact not only on life expectancy (or mean age at death), but also, and to a larger extent, on lifespan variability (the dispersion around the mean age at death). Even though lifespan variability is a key component of mortality change, as well as a measure of human well-being, with social, economic, and psychological implications, it has received much less attention than life expectancy has.

Multivariate analysis of biopsychosocial determinants of professional activity among patients after kidney or liver transplantation in Poland

OBJECTIVE

The aim of the present study was to assess the employment rate among kidney and liver transplant recipients in Poland and identify the predictors of employment.

SETTINGS

The study was based on a self-prepared questionnaire containing five parts: demographic data and professional, medical, physical and psychological factors. This is a multicentre study involving four hospitals in Poland.

PARTICIPANTS

The investigated group consisted of 285 individuals (92 women and 185 men; 8 no sex given) aged between 18 and 45 years who underwent kidney or liver transplantation 1-5 years prior. Because of missing data, 279 questionnaires were considered regarding employment status after transplantation and 277 when sex differences were considered.

RESULTS

A total of 120 patients (43%) worked full-time, 42 (15%) part-time and 117 (42%) remained unemployed, with a higher employment rate post-transplantation among men than women (60% vs 55%, p=0.04). More women performed white collar work (74% vs 41%, p=0.0003) and had to modify their working position than men (22% vs 7%, p=0.0118). Factors determining employment after transplantation included higher level of education (OR=27.08; p=0.0096), employment 1 year prior to transplantation (OR=11.05; p<0.001) and good psychological adaptation (OR=4.23; p<0.001). Men working the year before transplantation had higher education (OR=9.66; p=0.0356). Among men, more kidney recipients worked compared with liver recipients (OR=3.567; p=0.0417). Among women, age determined employment status (OR=0.89; p=0.0234).

CONCLUSION

Higher education is the most important predictor of employment after transplantation. Therefore, rehabilitation programmes including vocational activity should be directed to increase the level of education, both pretransplantation and post-transplantation if possible.

Period and cohort-specific trends in life expectancy at different ages: Analysis of survival in high-income countries

The number of older adults is increasing in high-income countries as survival chances continue to improve. We investigate changes in survival at older ages in high-income countries and show that although survival chances have improved, these improvements are concentrated at the top of the survival distribution where there is a small share of the population. Among females who survive to age 85 in the most recently birth cohort (1925), for example, about half die within 8 years while those in the top 25% of the survival distribution live at least 50% longer (12 years or more). Importantly, these results indicate that having some individuals reach exceptionally old age does not imply that the majority of the population is living longer. In addition, estimates of lifespan inequality at older ages suggests that years of life lost because of death have increased in recent times and among recently born cohorts leading to an increase uncertainty in the age at death at older ages. Thus, slow survival improvements at ages 65+ suggest that most of the population is unlikely to reach long life expectancies in the near future, which may lead to lower than expected fraction of adults reaching older ages.

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There has been an increasing number of older adults in high-income countries as survival chances continue to improve.

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We document large survival inequalities over time and across birth cohorts particularly at older ages.

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The age at death in the top 10% of the distribution increased faster than in the bottom 25% over time and across cohorts.

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Slow survival improvements at older ages suggest most people are not reaching life expectancy of 100 years in the near future.

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Survival inequalities highlight persistent disparities by socioeconomic status and health behaviors across the life course.

Anti-aging interventions affect lifespan variability in sex, strain, diet and drug dependent fashion

Decreased forkhead box O1 (FoxO1) activity induces hyperlipidemia and increased PPARγ, leading to hyperlipidemia in association with endoplasmic reticulum (ER) stress. In the liver, aging and comorbidities such as hyperlipidemia and diabetes significantly influence a wide variety of steatosis, but the underlying mechanisms are complex and remain elusive.

To establish the modulatory role of FoxO1 and the functional consequences of its altered interaction with PPARγ in the present study, we utilized a cell culture system, aged rats and diabetic db/db mice.

We found that, under ER stress, FoxO1 induces PPARγ-mediated lipid accumulation in aged rat livers. Our data showed that the FoxO1-induced hepatic lipid accumulation was negatively regulated by Akt signaling. PPARγ, a key lipogenesis transcription factor, was increased in aged liver, resulting in lipid accumulation via hepatic ER stress under hyperglycemic conditions. We further demonstrated that loss of FoxO1 causes a decline in PPARγ expression and reduces lipid accumulation. In addition, the interaction between FoxO1 and PPARγ was shown to induce hepatic steatosis in aging and db/db mice.

We provide evidence that, in aged rats, FoxO1 interaction with PPARγ promotes hepatic steatosis, due to hyperglycemia-induced ER stress, which causes an impairment in Akt signaling, such in aging-related diabetes.

Latin American convergence and divergence towards the mortality profiles of developed countries

It is uncertain whether Latin America and Caribbean (LAC) countries are approaching a single mortality regime. Over the last three decades, LAC has experienced major public health interventions and the highest number of homicides in the world. However, these interventions and homicide rates are not evenly shared across countries. This study documents trends in life expectancy and lifespan variability for 20 LAC countries, 2000-14. By extending a previous method, we decompose differences in lifespan variability between LAC and a developed world benchmark into cause-specific effects. For both sexes, dispersion of amenable diseases through the age span makes the largest contribution to the gap between LAC and the benchmark. Additionally, for males, the concentration of homicides, accidents, and suicides in mid-life further impedes mortality convergence. Great disparity exists in the region: while some countries are rapidly approaching the developed regime, others remain far behind and suffer a clear disadvantage in population health.

The increasing lifespan variation gradient by area-level deprivation: A decomposition analysis of Scotland 1981-2011

Life expectancy inequalities are an established indicator of health inequalities. More recent attention has been given to lifespan variation, which measures the amount of heterogeneity in age at death across all individuals in a population. International studies have documented diverging socioeconomic trends in lifespan variation using individual level measures of income, education and occupation. Despite using different socioeconomic indicators and different indices of lifespan variation, studies reached the same conclusion: the most deprived experience the lowest life expectancy and highest lifespan variation, a double burden of mortality inequality. A finding of even greater concern is that relative differences in lifespan variation between socioeconomic group were growing at a faster rate than life expectancy differences. The magnitude of lifespan variation inequalities by area-level deprivation has received limited attention. Area-level measures of deprivation are actively used by governments for allocating resources to tackle health inequalities. Establishing if the same lifespan variation inequalities emerge for area-level deprivation will help to better inform governments about which dimension of mortality inequality should be targeted. We measure lifespan variation trends (1981-2011) stratified by an area-level measure of socioeconomic deprivation that is applicable to the entire population of Scotland, the country with the highest level of variation and one of the longest, sustained stagnating trends in Western Europe. We measure the gradient in variation using the slope and relative indices of inequality. The deprivation, age and cause specific components driving the increasing gradient are identified by decomposing the change in the slope index between 1981 and 2011. Our results support the finding that the most advantaged are dying within an ever narrower age range while the most deprived are facing greater and increasing uncertainty. The least deprived group show an increasing advantage, over the national average, in terms of deaths from circulatory disease and external causes.