Cohort Life Tables Research Articles

Exploring urban–rural inequities in older adults life expectancy: a case study in Zhejiang, China for health equity

This study investigates the inequities in life expectancy among individuals aged 65 and above in urban and rural areas of Zhejiang Province, China, with a primary focus on promoting health equity among the older adults population. The objective is to analyze the trends and factors contributing to the urban–rural gap in life expectancy and to propose strategies for reducing this disparity. Data from the 2010 and 2020 statistical records and census data were analyzed using cohort life tables and gray correlation analysis. Results indicate an overall increase in life expectancy among the older adults, with a more pronounced improvement in rural areas, thereby narrowing the urban–rural gap from 1.53 years in 2010 to 1 year in 2020. Income inequality emerges as the primary factor influencing life expectancy, followed by educational attainment, with variations across different age groups and gender. This underscores the importance of tailored interventions that consider the specific needs of older adults individuals in diverse geographical areas and age brackets to extend life expectancy and promote health equity. By tackling these unfair differences, health equity can be ensured and the overall well-being of the older population in both urban and rural areas can be improved.

How do subjective mortality beliefs affect the value of social security and the optimal claiming ages?

AbstractHouseholds that postpone claiming Social Security benefits are, in effect, making additional purchases of the Social Security annuity and acquiring valuable longevity insurance. This paper investigates the impact of plausible variations of subjective mortality beliefs on the value of delayed claiming and the optimal claiming ages of retired workers. Using the Health and Retirement Study data, we show that older individuals could, on average, predict their life expectancy correctly; however, the average variance of age of death calculated from subjective mortality tables is 6.2%–14.4% lower than that from cohort life tables. Using numerical optimization techniques, we further show that, theoretically, older households place a lower value on delaying claiming when they have greater confidence in their ability to forecast their age of death. But the magnitude of this effect is not large enough to change their optimal claiming ages, unless they hold extreme subjective mortality beliefs. As a result, we conclude that subjective mortality beliefs alone cannot explain the prevalence of early claiming behaviors.

Using life expectancy as a risk assessment metric: The case of respirable crystalline silica

The change in age-related mortality patterns is an important characteristic of the population that can be used as a metric of risk by comparing exposed and non-exposed populations.In this paper, the mortality parameters were predicted for populations exposed to crystalline silica, a proven lung carcinogen.Seven hazard functions were tested for a dose–response relationship between lung cancer and characteristics of exposure. Life tables were calculated, along with parameters of the Gompertz-Makeham model for the force of mortality.It was demonstrated, in particular, that exposure to crystalline silica in the range from 0.03 to 0.3 mg/m3 for 40 years starting at age 20 causes a predicted drop in average life expectancy in the range of from 0.15 to 1.38 years.It was demonstrated that the lost life expectancy linearly correlates with relative risk (R = 0.995, R2 = 0.989, p< 0.00001). The probability of the life expectancy increasing while relative risk decreases was as low as 0.01.It was found that exponential parameter α of the Gompertz-Makeham equation increases with crystalline silica exposure, while the two linear parameters A and R (which are negatively correlated between each other) increase or decrease with exposure depending on the duration and onset age. Modal age of death in the cohort decreases with cumulative exposure with R = -0.977, R2 = 0.954, p < 0.0001.Based on several different approaches, it was suggested that the threshold of cumulative crystalline silica exposure concentration causing statistically significant change in the cohort life tables can be found in the range from 1.81 to 2.50 mg/m3-years. The change of average age of death in exposed male population does not exceed 1% below cumulative exposure of 3.5 mg/m3-years, and does not exceed 5% at cumulative exposure less than 9.8 mg/m3-years. It shows that no significant acceleration of death rate with age is happening even at the high levels of exposure to crystalline silica.The study demonstrated the value and advantages of the use of life expectancy and other lifetable characteristics as a tool for quantitative risk assessment.

State-level variation in the cumulative prevalence of child welfare system contact, 2015–2019

BackgroundPrior estimates of the cumulative risks of child welfare system contact illustrate the prominence of this system in the lives of children in the United States (U.S.). However, these estimates report national data on a system administered at the state and local levels and are unable to detail potential simultaneous geographic and racial/ethnic variation in the prevalence of these events. MethodsUsing 2015–2019 data from the National Child Abuse and Neglect Data System and Adoption and Foster Care Analysis and Reporting System, we use synthetic cohort life tables to estimate cumulative state- and race/ethnicity-specific risks by age 18 of experiencing: (1) a child protective services investigation, (2) confirmed maltreatment, (3) foster care placement, and (4) termination of parental rights for children in the U.S. ResultsIn the U.S., state-level investigation risks ranged from 14% to 63%, confirmed maltreatment risks from 3% to 27%, foster care placement risks from 2% to 18%, and risks of parental rights termination from 0% to 8%. Racial/ethnic disparities in these risks varied greatly across states, with larger disparities at higher levels of involvement. Whereas Black children had higher risks of all events than white children in nearly all states, Asian children had consistently lower risks. Finally, ratios comparing risks of child welfare events show these prevalences did not move in parallel, across states or racial/ethnic groups. ContributionThis study provides new estimates of spatial and racial/ethnic variation in children’s lifetime risks of maltreatment investigation, confirmed maltreatment, foster care placement, and termination of parental rights in the U.S., as well as relative risks of these events.

Childhood Prevalence of Involvement with the Child Protection System in Quebec: A Longitudinal Study

The goal of this study, the first of its kind in Canada, was to estimate the child lifetime prevalence of child protection involvement in Quebec. Using administrative and population data spanning 17 years, we performed a survival analysis of initial incidents of child protection reports, confirmed reports, confirmation of a child's security or development being compromised, and placement outside the home for one day or more. We found that before reaching the age of 18 years, over 18% of children were reported to child protection at least once, one in every ten children (10.1%) in the province had a report that led to the finding of their security or development being compromised, and over 5% were placed outside the home. We found that neglect was a primary concern in close to half (47.6%) of cases. By using a full population dataset, we obtained a more accurate prevalence estimate than studies using synthetic cohort life tables. These findings only captured initial incidents of involvement with child protection, meaning this study does not show the extent of recurrent involvement for some children. The findings reflect prior results showing that neglect is common in initial child protection involvement but less pervasive than has been shown in incidence studies, suggesting that recurrent child protection involvement is more driven by neglect than initial incidents are.

The Cumulative Prevalence of Congregate Care Placement for U.S. Children by Race/Ethnicity, 2019.

Congregate care placement is among the most consequential forms of foster care placement that youth can experience, as it means a removal from both the family of origin and a family setting more broadly. Unfortunately, little research has estimated how common this intervention is. In this article, we use data from the Adoption and Foster Care Analysis Reporting System (AFCARS) and synthetic cohort life tables to show what proportion of children ever placed in foster care will ever be placed in congregate care, what proportion of children in the entire population will ever be placed in congregate care, and how these proportions vary by state of residence and race/ethnicity. Our results support four main conclusions. First, roughly 15% of all children ever placed in foster care will experience congregate care placement. Second, among children who will ever be placed in foster care, the risk of congregate care placement peaks at age 16. Third, congregate care placement is highly stratified by race/ethnicity. Finally, there are vast geographic differences in both congregate care placement and ethno-racial disparities therein. Taken together, these findings enhance our understanding of the demography of the child welfare system with implications for research, policy, and practice.

Distribution of Expected Time of Old-Age Pension Receipt in Czechia

This paper presents a calculation of the estimated value of the time of old age pension receipt for individual birth cohorts of Czech males and females born in the period 1900-2020. It is assumed that people start to receive the pension at the moment of reaching retirement age and receive it until death. Starting with the birth cohort of 1966, two variants of retirement age determination are assumed: (a) a fixed retirement age threshold equal to 65 years for both males and females; and (b) a flexible retirement age (equal for males and females) defined in such a way that the average time of pension receipt would be equal to one quarter of the total expected total life span of people reaching senior age. The average lengths of pension receipt as well as the structure of adult persons from each birth cohort according to five-year time intervals of pension receipt (including the proportion of adult persons not surviving until retirement age) in the future are presented. Cohort life tables were used for calculations.

Biological parameters of stem borer Stromatium barbatum reared on grapevine wood logs under laboratory conditions

Stem borer Stromatium barbatum has recently emerged as a serious pest problem of grapevines in India. Hidden biology and lack of effective chemical control of stem borer warranted finding out weak links in its life cycle which aids in formulating effective management strategies. Being a monovoltine pest with annual life cycle, the systematic studies on developmental biology and stage specific mortality of stem borer in grapes are limited. In present study, a cohort life table was constructed for S. barbatum by rearing it on grapevine wood logs in the laboratory at 27 ± 1 ℃ temperature and 65 ± 5% RH. The life cycle of S. barbatum was tracked from egg hatching through larval and pupal stages till adult emergence and observations were recorded on stage specific developmental durations and mortality of immature stages, and longevity and fecundity of adult stages. The results revealed that the mean durations of egg, larvae and pupae were 6.60 ± 0.28 days, 296.10 ± 1.06 days and 19.70 ± 1.17 days, respectively. The adults after emerging from pupae could survive up to 36.40 ± 0.81 days. The egg hatching and adult emergence from pupae were 42.51% and 83.02%, respectively. S. barbatum population attained a net reproductive rate of 64.96 females/female/generation and a gross reproductive rate of 72.93 females/female/generation in her mean oviposition period of 9.80 ± 0.13 days. The data indicated that, S. barbatum population potentially might increase with an intrinsic rate (rm) of 0.087 females/female/day and a finite rate $$(\lambda )$$ of 1.09 females/ female/ day with a doubling time of 9.98 days and a mean generation time of 324.30 days. The mortality was relatively higher during the egg and larval stages, which was then gradually decreased for rest of the life span when S. babatum was reared on grapevine wood logs under laboratory conditions. Generation mortality for S. barbatum was 90.72%. The present study has generated detailed information on critical life events such as days to egg hatch, adult longevity and fecundity, time required for adults to oviposit after mating, and age-stage specific mortality. This could facilitate formulation and implementation of effective management strategies for S. barbatum in grape vineyards.

Measurement of Longevity Risk of Life Annuity Based on C-ROSS Framework

This paper constructs a model to measure longevity risk and explains the reasons for restricting the supply of annuity products in life insurance companies. According to the Lee–Carter Model and the VaR-based stochastic simulation, it can be found that the risk margin of the first type of longevity risk for ignoring the improvement of mortality rate is about 7%, and the risk margin of the second type of longevity risk for underestimating mortality improvement is about 7%. Therefore, the insurer needs to use cohort life table pricing premium and gradually prepares longevity risk capital during the insurance period.

Estimating and explaining ethnic disparities in the cumulative risk of paternal incarceration in Denmark

Background: Paternal incarceration is a well-known risk factor for poor child outcomes. Although existing research documents the prevalence of paternal incarceration and racial/ethnic disparities in this risk, research in this area is still sorely limited in two ways. First, the range of groups for which we know the cumulative risk of paternal incarceration is still quite narrow. Second, no research has decomposed disparities in the risk of paternal incarceration into analytically distinct components. Objective: To estimate and explain ethnic disparities in paternal incarceration risk in Denmark. Methods: We use Danish administrative data and two core demographic techniques. First, we use birth cohort life tables to estimate country of origin-specific paternal incarceration risks for native Danes, Western descendants of immigrants, and ten groups of non-Western descendants of immigrants. Second, we conduct Blinder-Oaxaca decompositions to see how three factors – paternal employment, education, and previous criminal justice contact – shape these risks. Results: We find that descendants of immigrants are much more likely to experience paternal incarceration than native Danes, but that there is substantial heterogeneity across country of origin. Additionally, we find that for most countries the observed disparities in paternal incarceration risk can be almost entirely explained by group differences in paternal employment, education, and previous criminal justice contact. Contribution: By using two core demographic techniques we provide insight into how future research on paternal incarceration and other risk factors for poor child well-being could better estimate and explain the risk of experiencing these events.

Sex differentials in under five mortality in India in last two decades: Evidence from pooled NFHS data

Abstract Under Five Mortality Rate (U5MR) of a nation is widely accepted and a long-standing indicator of their children. In 2017, the sex-specific under-five mortality rate was 39 per 1,000 live births for male and 40 per 1,000 live births for females. India U5MR decrease from 124 per 1000 live birth in 1990 to 39 per 1000 live birth in 2017. According to NFHS, U5MR was 109 in 1992–93, 95 in 1998–99, 74 in 2005–06 and 50 in 2015–16. Sex differential in U5MR 6, 7, 11 and −8. Is there any sex differential in u5mr and relation between socioeconomic and u5mr. The dataset for this study comes from the three round of NFHS (National Family Health Survey) conducted during 1992–1993, 1997–1998 and 2015–2016. NFHS-1 and NFHS-2 used as append data. Synthetic cohort life table approach and multiple linear regression (fixed effect) model use. Sex differential in U5MR is increasing till 2005–06, after 2006, it is decreases. Sex differential in U5MR decrease most of the southern part, Literate, urban, Hindu, SC/ST and in non-SC/ST over time 1995–2015. Proportion of explained variation to overall unexplained variation in the model mainly explain by female U5MR at NSS level.

Changes in life histories of cladocerans (Cladocera) from the rotifer-mediated allelochemicals

ABSTRACT We hypothesised that at higher densities herbivorous rotifers through their allelochemicals affect the survival and reproduction of cladocerans. To test this, we separately cultured three rotifers (Brachionus calyciflorus, Brachionus havanaensis, and Plationus patulus) and three cladocerans (Ceriodaphnia dubia, Daphnia pulex, and Moina macrocopa). Chlorella vulgaris was used as food and reconstituted moderately hard water was used as medium. The conditioned-medium (CM) obtained from each of rotifer species was used to conduct cohort life table tests of cladocerans. SDS PAGE electrophoresis revealed the molecular weights of proteins present in the rotifer conditioned medium were 55–63 kDa. Compared to C. dubia and D. pulex, Moina was more resistant to rotifer-mediated chemicals. Gross reproductive rate of C. dubia was significantly stimulated by the rotifer-CM. However, gross and net reproductive rates of D. pulex were strongly reduced (72–85%) due to P. patulus-CM but not from the other two rotifer species. The rate of population increase of M. macrocopa was significantly reduced by the rotifer CM. Overall, about 46% (adverse effect: 24%; stimulatory impact: 22%) of the life history variables in controls significantly differed from rotifer-CM treatments, thus proving our hypothesis that rotifer-mediated allelochemicals had some effect on the cladoceran life history variables.

Cumulative Prevalence of Confirmed Maltreatment and Foster Care Placement for US Children by Race/Ethnicity, 2011-2016.

Objectives. To estimate the cumulative prevalence of confirmed child maltreatment and foster care placement for US children and changes in prevalence between 2011 and 2016.Methods. We used synthetic cohort life tables and data from the Adoption and Foster Care Analysis and Reporting System and the National Child Abuse and Neglect Data System and population counts from the Centers for Disease Control and Prevention.Results. US children's cumulative prevalence of confirmed maltreatment remained stable between 2011 and 2016 at about 11.7% (95% confidence interval [CI] = 11.6%, 11.7%) of the population and increased by roughly 11% for foster care placement from 4.8% (95% CI = 4.8%, 4.8%) to 5.3% (95% CI = 5.3%, 5.4%). American Indian/Alaska Native children experienced the largest change, an 18.0% increase in confirmed maltreatment risk from 13.4% (95% CI = 13.1%, 13.6%) to 15.8% (95% CI = 15.6%, 16.1%) and a 21% increase in foster care placement risk from 9.4% (95% CI = 9.2%, 9.6%) to 11.4% (95% CI = 11.2%, 11.6%).Conclusions. Confirmed child maltreatment and foster care placement continued to be experienced at high rates in the United States in 2012 through 2016, with especially high risks for American Indian/Alaska Native children. Rates of foster care have increased, whereas rates of confirmed maltreatment have remained stable.

Mortality shifts and mortality compression in period and cohort life tables

Background: When age-specific mortality falls, period life tables give a distorted view of the life expectancy (LE) and the degree of mortality compression in birth cohorts. Objective: To derive mathematical expressions for the link between LEs and compression in period life tables on the one hand and corresponding variables in birth cohorts on the other hand. Methods: We analyse the age at death distribution (AADD) computed from the life table’s d(x)-column. We derive general expressions for the moments of this distribution in a series of annual period life tables, written as functions of the moments in the AADD of cohorts. Results: We use data for Norwegian men and women to illustrate simple versions of the new expressions. The LE increases twice as fast across cohorts compared to what period life tables suggest under this model. Compression in Norwegian mortality, expressed in terms of decreasing variance of the AADDs, is approximately 40% slower in period than in cohort mortality. Conclusions: We show how one can analyse the amount of distortion in period LEs compared to cohort LEs. In addition, we show how period compression is determined by cohort compression, together with both period and cohort LEs. Contribution: We derive new expressions that link the period AADD to the cohort AADD. Under a simple linear model, we show why compression in the period AADD often goes together with increases in the period LE.

Beyond the proportional frailty model: Bayesian estimation of individual heterogeneity on mortality parameters.

Today, we know that demographic rates can be greatly influenced by differences among individuals in their capacity to survive and reproduce. These intrinsic differences, commonly known as individual heterogeneity, can rarely be measured and are thus treated as latent variables when modeling mortality. Finite mixture models and mixed effects models have been proposed as alternative approaches for inference on individual heterogeneity in mortality. However, in general models assume that individual heterogeneity influences mortality proportionally, which limits the possibility to test hypotheses on the effect of individual heterogeneity on other aspects of mortality such as ageing rates. Here, we propose a Bayesian model that builds upon the mixture models previously developed, but that facilitates making inferences on the effect of individual heterogeneity on mortality parameters other than the baseline mortality. As an illustration, we apply this framework to the Gompertz-Makeham mortality model, commonly used in human and wildlife studies, by assuming that the Gompertz rate parameter is affected by individual heterogeneity. We provide results of a simulation study where we show that the model appropriately retrieves the parameters used for simulation, even for low variances in the heterogeneous parameter. We then apply the model to a dataset on captive chimpanzees and on a cohort life table of 1751 Swedish men, and show how model selection against a null model (i.e., without heterogeneity) can be carriedout.

The Cumulative Prevalence of Termination of Parental Rights for U.S. Children, 2000-2016.

Recent research has used synthetic cohort life tables to show that having a Child Protective Services investigation, experiencing confirmed maltreatment, and being placed in foster care are more common for American children than would be expected based on daily or annual rates for these events. In this article, we extend this literature by using synthetic cohort life tables and data from the Adoption and Foster Care Analysis and Reporting System to generate the first cumulative prevalence estimates of termination of parental rights. The results provide support for four conclusions. First, according to the 2016 estimate, 1 in 100 U.S. children will experience the termination of parental rights by age 18. Second, the risk of experiencing this event is highest in the first few years of life. Third, risks are highest for Native American and African American children. Nearly 3.0% of Native American children and around 1.5% of African American children will ever experience this event. Finally, there is dramatic variation across states in the risk of experiencing this event and in racial/ethnic inequality in this risk. Taken together, these findings suggest that parental rights termination, which involves the permanent loss of access to children for parents, is far more common than often thought.

Sex ratios and life tables: Historical demography of the age at which women outnumber men in seven countries, 1850–2016

The male/female sex ratio (SR) and its age-specific patterns vary considerably across time and place. The SR generally begins male-biased at birth and becomes female-biased later in life, but this relationship should respond to historical trends and events. Temporal trends in SRs remain largely unstudied and formal demographic relationships are not well defined. We (1) define SRs in a life table framework, (2) estimate the age at which the number of males and females achieves parity—the sex ratio crossover (SRX)—using basic life table methods, and (3) explore historical and international patterns in these trends. Using publicly-available data from the Human Mortality Database, we construct SR and SRX measures from period and cohort life tables. Analyses explore temporal patterns for seven countries in different global regions since 1850. Overall temporal trends show the SRX advancing to older ages. The SRX also appears to respond to historical events such as wars and epidemics. The measure is simple to construct from life table data, and provides additional insight into the historical context of gender dynamics.

Neighborhood inequality in the prevalence of reported and substantiated child maltreatment.

Prior research documents spatial concentration in the incidence of child maltreatment reported to and confirmed by Child Protective Services (CPS), but without estimates of the prevalence of such reports, the extent of CPS contact in different communities is unknown. To estimate the prevalence of CPS reports during early childhood and substantiated investigations during childhood for children living in different types of neighborhoods. Children who experienced CPS reports and substantiated investigations in Connecticut. This study uses synthetic cohort life tables to estimate the cumulative risk of CPS reports before age five and substantiated CPS investigations before age 18, by neighborhood poverty rate and neighborhood racial composition. The analysis reveals substantial stratification in the prevalence of CPS contact by the demographic characteristics of children's residential neighborhoods. For example, while 7% of children in low-poverty neighborhoods (under 10% poor) experience a substantiated CPS investigation at some point during childhood at 2014 and 2015 rates, this risk more than doubles to 17% for their peers in moderate-poverty neighborhoods (10-20% poor) and more than triples to 26% for their peers in high-poverty neighborhoods (over 20% poor). Similar trends emerge when examining CPS reports in early childhood as well as when comparing neighborhoods with different proportions of White residents. CPS reports and substantiated investigations are a widespread and disproportionately experienced life event for children in poor neighborhoods and children in non-White neighborhoods.

Effects of cladoceran-conditioned medium on the demography of brachionid rotifers (Rotifera: Brachionidae)

Rotifers and cladocerans compete for resources in freshwater ecosystems. Cladocerans, due to their large size, are competitively superior to rotifers. Cladocerans also release secondary metabolites into the medium which may be allelopathic to rotifers. However, in many eutrophic water bodies, rotifers are competitively dominant to cladocerans. We therefore hypothesize that allelochemicals released by competing species of Cladocera have weak or no adverse effects on rotifers. To test this, we conducted cohort life table demography experiments of the three rotifers Brachionus calyciflorus, Brachionus havanaensis, and Plationus patulus with cladoceran-conditioned medium (CM) derived from Moina macrocopa, Ceriodaphnia dubia, and Daphnia pulex. All six zooplankton species were isolated at the same time from a shallow eutrophic water body in Central Mexico. We found that the following demographic variables of B. calyciflorus cultured in CM did not differ from controls: life expectancy at birth, gross and net reproductive rates, generation time and the rate of population increase. We further showed that B. havanaensis was most sensitive to the cladoceran-mediated chemicals and that M. macrocopa-CM caused varied demographic responses in rotifers. We conclude that cladoceran-conditioned medium had weak allelopathic effects on rotifers unlike the negative experience from direct physical contact with Cladocera.

Manual and Automated Procedures for Compiling a Very Large Sample of Centenarian Pedigrees

A large portion of the baby boomer population will live beyond the age of 90 years, and entitlement programs and various insurance products have thus become interested in longevity risk. Beyond cohort life table predictions, actuaries have little to go on in determining which individuals or portions of populations are at increased risk of living to 90 or 100 or even older. We and others have noted strong familial risk for living beyond the oldest one percentile of survival, and we developed an algorithm that uses information about relatives’ longevity to compute the chance of an individual surviving to extreme old age. An important step of this work is to compile large samples of pedigrees with and without long-lived family members. Here we describe our process of hand curation of centenarian pedigrees and software that we have developed for the automated construction of such pedigrees using internet-based resources that can support the manual process.