Examining the Relationship between Life Expectancy,Reproduction, and Educational Attainment

Life history theory aims to explain the relationship between life events, recognizing that the fertility and growth schedules of organisms are dependent on environmental conditions and an organism’s ability to extract resources from its environment. Using models from life history theory, we predict life expectancy to be positively correlated with educational investments and negatively correlated with adolescent reproduction and total fertility rates. Analyses of UN data from 193 countries support these predictions and demonstrate that, although variation is evident across world regions, strong interactions exist among life expectancy, reproductive investments, and educational attainment, and these relationships occur independently of economic pressures and disease burdens. The interactions are strongest, however, in countries with a life expectancy of ≥60 years as these countries tend to have stable economies and a limited HIV/AIDS burden. These findings suggest that policies aimed at influencing education and reproductive decisions should consider environmental characteristics that drive people’s expectations about their longevity.     

Life history variables and risk-taking propensity

We examined the effects of life-history variables on risk-taking propensity, measured by subjective likelihoods of engaging in risky behaviors in five evolutionarily valid domains of risk, including between-group competition, within-group competition, environmental challenge, mating and resource allocation, and fertility and reproduction. The effects of life-history variables on risk-taking propensity were domain specific, except for the expected sex difference, where men predicted greater risk-taking than women in all domains. Males also perceived less inherent risk in actions than females across the five domains. Although the age range in the sample was limited, older respondents showed lower risk propensity in both between- and within-group competition. Parenthood reduced risk-taking propensity in within- and between-group competitions. Higher reproductive goal setting (desiring more offspring) was associated with lower risk-taking propensity. This effect was strongest in the risk domains of mating and reproduction. Having more siblings reduced risk-taking propensity (contrary to our initial prediction) in the domains of environmental challenge, reproduction, and between-group competition. Later-born children showed a higher propensity to engage in environmental and mating risks. Last, shorter subjective life expectancy was associated with increased willingness to take mating and reproductive risks. These results suggest that life-history variables regulate human risk-taking propensity in specific risk domains.     

Life expectancy,economic inequality,homicide, and reproductive timing in Chicago neighbourhoods.

In comparisons among Chicago neighbourhoods, homicide rates in 1988-93 varied more than 100-fold, while male life expectancy at birth ranged from 54 to 77 years, even with effects of homicide mortality removed. This "cause deleted" life expectancy was highly correlated with homicide rates; a measure of economic inequality added significant additional prediction, whereas median household income did not. Deaths from internal causes (diseases) show similar age patterns, despite different absolute levels, in the best and worst neighbourhoods, whereas deaths from external causes (homicide, accident, suicide) do not. As life expectancy declines across neighbourhoods, women reproduce earlier; by age 30, however, neighbourhood no longer affects age specific fertility. These results support the hypothesis that life expectancy itself may be a psychologically salient determinant of risk taking and the timing of life transitions.     

Jealousy in a small-scale,natural fertility population: the roles of paternity,investment and love in jealous response

Evolutionary scientists have predicted a universal sex difference in response to different forms of infidelity, with men expected to be more upset than women by a sexual infidelity when both a sexual transgression and an emotional transgression occur. Although this finding has proven to be robust, the vast majority of studies have occurred in industrialized countries and student populations. Here I present the first test of the jealousy hypothesis among a small-scale, natural fertility population, the Himba of Namibia. In this population, the majority of both men and women report greater distress over a sexual infidelity, with men reaching an almost unanimous consensus (96%). Despite the skew for both men and women, there is a significant sex difference in the direction predicted by the evolutionary hypothesis, providing further support for this view. The increased risks of both pregnancy and paternity loss that occur in this natural fertility population may help to explain why these results differ from previously studied populations. More broadly, these data suggest that both the type and the intensity of jealousy expressed may be facultative responses and that further investigation of correlates related to life history trade-offs, forms of investment, and the sexual division of labor can help us to understand the inter-cultural variation in jealous response.     

Mass HIV Treatment and Sex Disparities in Life Expectancy: Demographic Surveillance in Rural South Africa

Background

Women have better patient outcomes in HIV care and treatment than men in sub-Saharan Africa. We assessed—at the population level—whether and to what extent mass HIV treatment is associated with changes in sex disparities in adult life expectancy, a summary metric of survival capturing mortality across the full cascade of HIV care. We also determined sex-specific trends in HIV mortality and the distribution of HIV-related deaths in men and women prior to and at each stage of the clinical cascade.

Methods and Findings

Data were collected on all deaths occurring from 2001 to 2011 in a large population-based surveillance cohort (52,964 women and 45,688 men, ages 15 y and older) in rural KwaZulu-Natal, South Africa. Cause of death was ascertained by verbal autopsy (93% response rate). Demographic data were linked at the individual level to clinical records from the public sector HIV treatment and care program that serves the region. Annual rates of HIV-related mortality were assessed for men and women separately, and female-to-male rate ratios were estimated in exponential hazard models. Sex-specific trends in adult life expectancy and HIV-cause-deleted adult life expectancy were calculated. The proportions of HIV deaths that accrued to men and women at different stages in the HIV cascade of care were estimated annually.Following the beginning of HIV treatment scale-up in 2004, HIV mortality declined among both men and women. Female adult life expectancy increased from 51.3 y (95% CI 49.7, 52.8) in 2003 to 64.5 y (95% CI 62.7, 66.4) in 2011, a gain of 13.2 y. Male adult life expectancy increased from 46.9 y (95% CI 45.6, 48.2) in 2003 to 55.9 y (95% CI 54.3, 57.5) in 2011, a gain of 9.0 y. The gap between female and male adult life expectancy doubled, from 4.4 y in 2003 to 8.6 y in 2011, a difference of 4.3 y (95% CI 0.9, 7.6). For women, HIV mortality declined from 1.60 deaths per 100 person-years (95% CI 1.46, 1.75) in 2003 to 0.56 per 100 person-years (95% CI 0.48, 0.65) in 2011. For men, HIV-related mortality declined from 1.71 per 100 person-years (95% CI 1.55, 1.88) to 0.76 per 100 person-years (95% CI 0.67, 0.87) in the same period. The female-to-male rate ratio for HIV mortality declined from 0.93 (95% CI 0.82–1.07) in 2003 to 0.73 (95% CI 0.60–0.89) in 2011, a statistically significant decline (p = 0.046). In 2011, 57% and 41% of HIV-related deaths occurred among men and women, respectively, who had never sought care for HIV in spite of the widespread availability of free HIV treatment. The results presented here come from a poor rural setting in southern Africa with high HIV prevalence and high HIV treatment coverage; broader generalizability is unknown. Additionally, factors other than HIV treatment scale-up may have influenced population mortality trends.

Conclusions

Mass HIV treatment has been accompanied by faster declines in HIV mortality among women than men and a growing female–male disparity in adult life expectancy at the population level. In 2011, over half of male HIV deaths occurred in men who had never sought clinical HIV care. Interventions to increase HIV testing and linkage to care among men are urgently needed.     

Fertility intentions: are the undecided more like those who want more or want no more children?

In fertility surveys often women (and sometimes men) are asked their fertility desires, i.e. whether they want a/nother birth or not. Some respond that they are undecided. This study examines whether these persons are more like those who say they want more births or like those who say they want no more births. Data on married men and women in 29 Demographic and Health Surveys with sample sizes ranging from 300 to 3000 are used. A logistic regression equation is estimated within each country for those with known desires and then used to classify each person who was undecided. In all sub-Saharan African countries (n=20) and for both sexes, 50% or more of the undecided persons are classified as wanting more children (with one exception of wives in Kenya). By contrast in all five Latin American countries for both sexes less than 50% of the undecided were classified in the 'want more' group (with an exception of husbands in the Dominican Republic). Generally, the undecided tend to be classified the same as the majority among those in the survey with stated desires.     

Life Expectancy and Death by Diseases of the Circulatory System in Patients with Bipolar Disorder or Schizophrenia in the Nordic Countries

Objective

Excess mortality from diseases and medical conditions (natural death) in persons with psychiatric disorders has been extensively reported. Even in the Nordic countries with well-developed welfare systems, register based studies find evidence of an excess mortality. In recent years, cardiac mortality and death by diseases of the circulatory system has seen a decline in all the Nordic countries, but a recent paper indicates that women and men in Denmark, Finland, and Sweden, who had been hospitalised for a psychotic disorder, had a two to three-fold increased risk of dying from a cardiovascular disease. The aim of this study was to compare the mortality by diseases of the circulatory system among patients with bipolar disorder or schizophrenia in the three Nordic countries Denmark, Sweden, and Finland. Furthermore, the aim was to examine and compare life expectancy among these patients. Cause specific Standardized Mortality Rates (SMRs) were calculated for each specific subgroup of mortality. Life expectancy was calculated using Wiesler’s method.

Results

The SMR for bipolar disorder for diseases of the circulatory system was approximately 2 in all countries and both sexes. SMR was slightly higher for people with schizophrenia for both genders and in all countries, except for men in Denmark. Overall life expectancy was much lower among persons with bipolar disorder or schizophrenia, with life expectancy being from 11 to 20 years shorter.

Conclusion

Our data show that persons in the Nordic countries with schizophrenia or bipolar disorder have a substantially reduced life expectancy. An evaluation of the reasons for these increased mortality rates should be prioritized when planning healthcare in the coming years.     

Biological and behavioral determinants of fertility in Tierra del Fuego

The reproductive history of 182 women in postreproductive life or near menopause from the Chilean part of Tierra del Fuego was traced back by means of familial interviews. These postmenopausal women represent the population since almost the beginning of the settlement, and their reproductive years were spent on the island. Path analysis was applied to analyze fertility determinants of these women and to propose a complex model of interconnections among factors. The reproductive history of these women is characterized by a long fertile span, a short childbearing period, and low fertility. Age at menarche is relatively late, and the age of the women at first birth is mainly determined by their late age at marriage. The use of contraception is related to both spacing and stopping behaviors. The late age of women at marriage, the rhythm of conception, and practices of contraception are proposed as the main determinants of fertility in Tierra del Fuego.     

Life expectancy,maximum longevity and lifetime reproductive success in female Thornicroft's giraffe in Zambia

Gestation and longevity scale with body mass across taxa, yet within size dimorphic taxa, males tend to have reduced lifespans compared with females. Testing life history models, and accounting for sex differences in longevity, requires obtaining accurate longitudinal data from wild populations. We provide the first report describing key life history parameters from a long‐term study of giraffes in Africa. We followed a population of Thornicroft's giraffe (Giraffa camelopardalis thornicrofti) in Zambia for over 40 years. Maximum longevity among females was approximately 28 years, with lifespan accounting for 81% of the variance in lifetime reproductive success. Average adult female life expectancy was no different than average adult male life expectancy. However, the breeding lifespan of males was about half that of females, while maximum lifespan of males was 75% that of females. Our findings support the suggestion that sex differences in maximum lifespan arise from stronger selection for lengthy lives in females than in males. Among females, longer lives are associated with greater reproductive output.     

The factors influencing transactional sex among young men and women in 12 sub-Saharan African countries

Transactional sex may put young women and young men in sub-Saharan Africa at increased risk of contracting sexually transmitted infections (STIs), including HIV/AIDS. This behavior may also put young women at higher risk of pregnancy and childbearing. Policymakers and program managers need to know what factors put youth at increased risk. We investigated this issue using logistic regression analyses of data from male and female modules of Demographic and Health Surveys from 12 sub-Saharan African countries. We found that young men and young women are at greater risk of engaging in transactional sex than are older people. Unmarried young women and young men were significantly more likely to engage in transactional sex than married youth. Based on these results, our conclusions were that programs geared toward reducing the incidence of transactional sex or protecting men and women already in transactional sexual relationships should be aimed at both young women and young men. Due to our finding that unmarried young women and young men are more vulnerable to experiencing transactional sex, programs to prevent transactional sex should be specifically directed to this subgroup of young people.     

Threshold Levels of Infant and Under-Five Mortality for Crossover between Life Expectancies at Ages Zero,One and Five in India: A Decomposition Analysis

Objectives

Under the prevailing conditions of imbalanced life table and historic gender discrimination in India, our study examines crossover between life expectancies at ages zero, one and five years for India and quantifies the relative share of infant and under-five mortality towards this crossover.

Methods

We estimate threshold levels of infant and under-five mortality required for crossover using age specific death rates during 1981–2009 for 16 Indian states by sex (comprising of India’s 90% population in 2011). Kitagawa decomposition equations were used to analyse relative share of infant and under-five mortality towards crossover.

Findings

India experienced crossover between life expectancies at ages zero and five in 2004 for menand in 2009 for women; eleven and nine Indian states have experienced this crossover for men and women, respectively. Men usually experienced crossover four years earlier than the women. Improvements in mortality below ages five have mostly contributed towards this crossover. Life expectancy at age one exceeds that at age zero for both men and women in India except for Kerala (the only state to experience this crossover in 2000 for men and 1999 for women).

Conclusions

For India, using life expectancy at age zero and under-five mortality rate together may be more meaningful to measure overall health of its people until the crossover. Delayed crossover for women, despite higher life expectancy at birth than for men reiterates that Indian women are still disadvantaged and hence use of life expectancies at ages zero, one and five become important for India. Greater programmatic efforts to control leading causes of death during the first month and 1–59 months in high child mortality areas can help India to attain this crossover early.     

Worldwide variation in life-span sexual dimorphism and sex-specific environmental mortality rates

In all human populations mean life span of women generally exceeds that of men, but the extent of this sexual dimorphism varies across different regions of the world. Our purpose here is to study, using global demographic and environmental data, the general tendency of this variation and local deviations from it. We used data on male and female life history traits and environmental conditions for 227 countries and autonomous territories; for each country or territory the life-span dimorphism was defined as the difference between mean life spans of women and men. The general tendency is an increase of life-span dimorphism with increasing average male-female life span; this tendency can be explained using a demographic model based on the Makeham-Gompertz equation. Roughly, the life-span dimorphism increases with the average life span because of an increase in the duration of expressing sex- and age-dependent mortality described by the second (exponential) term of the Makeham-Gompertz equation. Thus we investigated the differences in male and female environmental mortality described by the first term of the Makeham-Gompertz equation fitted to the data. The general pattern that resulted was an increase in male mortality at the highest and lowest latitudes. One plausible explanation is that specific factors tied to extreme latitudes influence males more strongly than females. In particular, alcohol consumption increases with increasing latitude and, on the contrary, infection pressures increase with decreasing latitude. This finding agrees with other observations, such as an increase in male mortality excess in Europe and Christian countries and an increase in female mortality excess in Asia and Muslim countries. An increase in the excess of female mortality may also be due to increased maternal mortality caused by an increase in fertility. However, this relation is not linear: In regions with the highest fertility (e.g., in Africa) the excess of female mortality is smaller than in regions with relatively lower fertility (e.g., in Asia). A possible explanation of this phenomenon is an evolutionary adaptation of women to the pressures of extremely high fertility by means of some reduction of their maternal mortality.     

Life expectancy at birth for people with serious mental illness and other major disorders from a secondary mental health care case register in London

Objective

Despite improving healthcare, the gap in mortality between people with serious mental illness (SMI) and general population persists, especially for younger age groups. The electronic database from a large and comprehensive secondary mental healthcare provider in London was utilized to assess the impact of SMI diagnoses on life expectancy at birth.

Method

People who were diagnosed with SMI (schizophrenia, schizoaffective disorder, bipolar disorder), substance use disorder, and depressive episode/disorder before the end of 2009 and under active review by the South London and Maudsley NHS Foundation Trust (SLAM) in southeast London during 2007–09 comprised the sample, retrieved by the SLAM Case Register Interactive Search (CRIS) system. We estimated life expectancy at birth for people with SMI and each diagnosis, from national mortality returns between 2007–09, using a life table method.

Results

A total of 31,719 eligible people, aged 15 years or older, with SMI were analyzed. Among them, 1,370 died during 2007–09. Compared to national figures, all disorders were associated with substantially lower life expectancy: 8.0 to 14.6 life years lost for men and 9.8 to 17.5 life years lost for women. Highest reductions were found for men with schizophrenia (14.6 years lost) and women with schizoaffective disorders (17.5 years lost).

Conclusion

The impact of serious mental illness on life expectancy is marked and generally higher than similarly calculated impacts of well-recognised adverse exposures such as smoking, diabetes and obesity. Strategies to identify and prevent causes of premature death are urgently required.     

The evolution of the family planning programme and its role in influencing fertility change in Kenya

Kenya was one of the first sub-Saharan countries to enter the fertility transition, and analysts have suggested various explanations for this. This paper examines the growth in contraceptive availability in Kenya by looking at the Kenya family planning programme and its association with the fertility transition. This is of critical programmatic importance because the fertility transition is not yet underway in many sub-Saharan countries. Policymakers will find the information from this study helpful in evaluating the efficacy of current programmes and replicating the Kenyan programme in areas where fertility decline has not yet occurred. For researchers, the study attempts to highlight some of the major factors driving Kenya's fertility decline, apart from the conventional arguments about social and economic development.     

A divergent pattern of the sex difference in life expectancy: Sweden and Japan, early 1970s-late 1990s

For most of the 20th century the sex gap in life expectancy in the industrialized countries has widened in favor of women. By the early 1980s a reversal in the long-term pattern of this differential had occurred in some countries, where it reached a maximum and thereafter followed a declining trend. Of particular interest to the present investigation is the anomalous experience of Japan, where unlike other high-income countries the female advantage in life expectancy has been expanding. We contrast the case of Japan with that of Sweden, where, like many other high-income nations, the sex differential in longevity has been narrowing in recent years. We observe that in Sweden, until the early 1980s, the sex gap in life expectancy (female-male) exceeded that of Japan; but this situation reversed in subsequent periods, when the Swedish differential narrowed and that of Japan widened. A decomposition analysis indicates that these divergent patterns since 1980 have resulted mainly from larger than expected reductions in male mortality in Sweden due to heart disease and from accidents and violence, lung cancer and "other" cancers. In Japan, death rates for men and women from heart disease--which is a leading cause of death--have tended to decline more or less at the same pace since the early 1980s; and with regard to lung cancer, and "other" neoplasms, male death rates in Japan have been rising while those of women have either declined or risen more slowly. Moreover, during the 1990s, male and female suicide rates rose in Japan, but the rates for men went up faster. Altogether, the net effect of these divergent mortality trends for men and women in Japan underlie much of the observed widening of its sex differential in longevity in recent years.     

Life Expectancies of South African Adults Starting Antiretroviral Treatment: Collaborative Analysis of Cohort Studies

Background

Few estimates exist of the life expectancy of HIV-positive adults receiving antiretroviral treatment (ART) in low- and middle-income countries. We aimed to estimate the life expectancy of patients starting ART in South Africa and compare it with that of HIV-negative adults.

Methods and Findings

Data were collected from six South African ART cohorts. Analysis was restricted to 37,740 HIV-positive adults starting ART for the first time. Estimates of mortality were obtained by linking patient records to the national population register. Relative survival models were used to estimate the excess mortality attributable to HIV by age, for different baseline CD4 categories and different durations. Non-HIV mortality was estimated using a South African demographic model. The average life expectancy of men starting ART varied between 27.6 y (95% CI: 25.2–30.2) at age 20 y and 10.1 y (95% CI: 9.3–10.8) at age 60 y, while estimates for women at the same ages were substantially higher, at 36.8 y (95% CI: 34.0–39.7) and 14.4 y (95% CI: 13.3–15.3), respectively. The life expectancy of a 20-y-old woman was 43.1 y (95% CI: 40.1–46.0) if her baseline CD4 count was ≥200 cells/µl, compared to 29.5 y (95% CI: 26.2–33.0) if her baseline CD4 count was <50 cells/µl. Life expectancies of patients with baseline CD4 counts ≥200 cells/µl were between 70% and 86% of those in HIV-negative adults of the same age and sex, and life expectancies were increased by 15%–20% in patients who had survived 2 y after starting ART. However, the analysis was limited by a lack of mortality data at longer durations.

Conclusions

South African HIV-positive adults can have a near-normal life expectancy, provided that they start ART before their CD4 count drops below 200 cells/µl. These findings demonstrate that the near-normal life expectancies of HIV-positive individuals receiving ART in high-income countries can apply to low- and middle-income countries as well. Please see later in the article for the Editors'' Summary     

Narrowing sex differentials in life expectancy in the industrialized world: Early 1970's to early 1990's

Abstract

Between the early 1970's and 1990's, twelve industrialized nations experienced for the first time a narrowing of their sex differences in life expectancy at age zero. In another set of countries, the differential has not yet reached a stage of convergence, although in some of these nations the female advantage appears to be increasing at a slower pace than ever before. We discuss the demographic and epidemiologic conditions for this new and largely unanticipated trend, as well as its applied and theoretical implications in the context of the following questions: (1) Is the observed change a function of males’ faster pace of gains in life expectancy since the early 1970s? (2) What is the relationship between country differences in socioeconomic development (as measured by GNP) and the degree of convergence in the sex gap in average length of life? (3) What is the degree of association between temporal change in age‐sex specific death rates and change in the sex gap in life expectancy over the twenty‐year interval between the early 1970s and early 1990s? Our results indicate that where some convergence has taken place, in relation to women, men have experienced more rapid gains in survival; the higher a nation's level of social and economic development, the greater the amount of convergence in male and female life expectancies. The most pronounced age‐specific association with the changing sex gap in longevity is that of ages 25–59, where the greater reductions in male mortality, as compared to that for females, contributed to a significant portion of the observed convergence in life expectancy across industrialized nations.     

Regional variation in the age-specific natural fertility curve

This paper examines the question of whether there are consistent regional variations in the level and shape of the age-specific natural fertility curve using data for 45 less-developed countries drawn from a recent US Census Bureau compilation. The 45 countries were grouped into 4 regional categories: sub-Saharan Africa; Middle East and North Africa; South and Southeast Asia; and Latin America. In general there do not appear to be variations. A consistent age pattern of natural fertility emerges, once the rates have been normalized and an adjustment made for age at 1st exposure to the risk of pregnancy. The results strongly support Coale's original natural fertility paradigm. The differences in the absolute fertility rates among the 4 regions correspond to the differences in proportion of females aged 15 and over who are currently married. The differences among 3 of the regions are relatively small whereas sub-Saharan Africa's proportion currently married is significantly higher.     

Healthy aging: the Swiss experience

The quantitative importance of ageing both in developed or in developing countries raised the subtle question of the quality of life of the ageing person. Precise definitions of life expectancy, healthy life expectancy and quality of life are presented. Then, presentation of the results of two cross-sectional studies performed with the same methodology at a 15-year time interval in French-speaking Switzerland illustrates compression of morbidity theory, with increased longevity, increased good perception of health and increased quality of life. Moreover, quantitative data concerning the longevity impact of hospital geriatric care are presented from Geneva. The 4-year survival rate of over 85 year old women, discharged from the hospital for acute care, reached 48%. Explanations of these outstanding medical progresses on longevity and socio-economical challenges of extreme ageing are discussed in the world context.     

Cross-country relationships between life expectancy,intertemporal choice and age at first birth

Humans, like other animals, typically discount the value of delayed rewards relative to those available in the present. From an evolutionary perspective, prioritising immediate rewards is a predictable response to high local mortality rates, as is an acceleration of reproductive scheduling. In a sample of 46 countries, we explored the cross-country relationships between average life expectancy, intertemporal choice, and women's age at first birth. We find that, across countries, lower life expectancy is associated with both a smaller percentage of people willing to wait for a larger but delayed reward, as well as a younger age at first birth. These results, which hold when controlling for region and economic pressure (GDP-per capita), dovetail with findings at the individual level to suggest that life expectancy is an important ecological predictor of both intertemporal and reproductive decision-making.