Estimation of mortality from orphanhood in adulthood

This paper extends earlier research into methods for estimating adult mortality from information on the recent incidence of orphanhood. It presents a series of regression coefficients for estimating female and male mortality from synthetic cohort data on the subsequent orphanhood of those who had a living mother or father at exact age 20. Such information can be obtained either where questions about parental survival have been asked in two inquiries or by asking retrospectively about dates of orphanhood in a single survey. Although the method is somewhat sensitive to errors in the reporting of ages and dates, it is a promising source of up-to-date estimates of adult mortality that are free from bias due to the underreporting of the orphanhood of young children ("the adoption effect").     

Estimation of average mortality under censoring and truncation

In demography mortality is usually reported through averages over time intervals. If average mortality is estimated from censored or truncated data, then direct methods of estimation may create biases that depend on the censoring or truncation distribution. Such discretization errors may be avoided by estimating survival curves first in continuous time, and then discretizing the estimators. We illustrate the different methods on data of the form obtained from family reconstitution.     

Estimation of adult mortality using forward and backward projections

Summary In this paper it is shown that, contrary to our intuitive understanding of the nature of population projection, the estimation of adult intercensal mortality leads to different results depending on whether forward or backward projection of the population is used. From this result a simple procedure is developed that yields estimates of the completeness of adult mortality registration. Finally, the nature and performance of a variety of methods that have recently been developed to estimate adult mortality in the absence of accurate data are compared.     

Maternal,prenatal and traditional practice factors associated with perinatal mortality in Yemen

Background

Perinatal mortality remains a major international problem responsible for nearly six million stillbirths and neonatal deaths.

Social,behavioral, and biological factors,and sex differences in mortality

Few studies have examined whether sex differences in mortality are associated with different distributions of risk factors or result from the unique relationships between risk factors and mortality for men and women. We extend previous research by systematically testing a variety of factors, including health behaviors, social ties, socioeconomic status, and biological indicators of health. We employ the National Health and Nutritional Examination Survey III Linked Mortality File and use Cox proportional hazards models to examine sex differences in adult mortality in the United States. Our findings document that social and behavioral characteristics are key factors related to the sex gap in mortality. Once we control for women’s lower levels of marriage, poverty, and exercise, the sex gap in mortality widens; and once we control for women’s greater propensity to visit with friends and relatives, attend religious services, and abstain from smoking, the sex gap in mortality narrows. Biological factors—including indicators of inflammation and cardiovascular risk—also inform sex differences in mortality. Nevertheless, persistent sex differences in mortality remain: compared with women, men have 30% to 83% higher risks of death over the follow-up period, depending on the covariates included in the model. Although the prevalence ofriskfactors differs by sex, the impact of those riskfactors on mortality is similar for men and women.     

Estimates of mortality from infant mortality rates

Estimates of mortality rates and expectation of life at birth, using infant mortality rates, are examined on the basis of 150 life tables for both sexes. Least squares linear estimates are given as well as estimates of their variances. Model life table calculations, as proposed by the U.N. Population Branch, are then compared with these unbiased minimum variance estimates and shown to overestimate the expectation of life by more than two years on the average, and to be at most 68% efficient. Though better estimates are provided in this paper, their variance is still so large as to cast doubt on the practical usefulness of anv estimates based exclusively on infant mortality rates.     

Estimation of a structural model of the determinants of neonatal mortality in Hungary, 1984-88 and 1994-98

We developed and evaluated a structural model of the determinants of neonatal mortality in Hungary that embodies the causal mechanisms by which its proximate and indirect determinants--socio-economic, behavioural, and biological--are related. The statistical model used distinguishes between endogenous and exogenous variables and allows the causal effect of each to be correctly estimated. Unobserved variables are integrated into the model, which was tested using Hungarian data for the periods 1984-88 and 1994-98. The principal findings are as follows: weight at birth and duration of gestation are the most important of the (direct) causal determinants of neonatal mortality. Mother's age has an indirect and detrimental effect: when mothers are older than 30 years of age, the risk of lower birth weight or multiple births and, in consequence, neonatal mortality is increased. Father's age has no direct or indirect causal effect on neonatal mortality.     

Estimating infant and childhood mortality under conditions of changing mortality

Summary It is well known that estimates of infant mortality obtained using Brass's technique are very accurate. Biases are introduced, however, when one or more of the assumptions on which it relies are violated. Departures from the assumption of constant fertility may be handled by using a variant of the technique which depends on information on the age distribution of surviving children, rather than on indexes of the fertility function. Violations of the assumption of constant mortality - an increasingly common situation in most developing societies - produce upward biases in the estimates. The amount of bias is a function of the speed of mortality decline, the characteristics of the fertility pattern and, finally, of the age of the mother. This paper presents a simple technique which corrects these biases, and in addition, generates estimates of the parameters of the mortality trend. It differs from others in that it uses a cohort definition of mortality decline and relies on knowledge of the age structure of surviving children rather than on indexes of the fertility pattern.     

An evaluation of brass mortality estimates under conditions of declining mortality

An evaluation of the Brass childhood mortality estimates under conditions of declining mortality shows them to overestimate current mortality. Error increases as the rate of mortality decline increases, as the childhood age up to which cumulative mortality is being estimated increases, and as age at onset of childbearing decreases. We use the results to develop a method for correcting the Brass estimates for the effects of quasistability. The method requires an estimate of the rate of mortality decline within the population in addition to information on the pattern of childbearing in the population.     

Population studies of mortality

Population Studies has become the principal outlet for demographic research on mortality. Many of the advances in the measurement of mortality in data-poor countries were reported in its pages. It has also published most of the influential articles which attempted to make a broad-scale assessment of the sources of mortality change. These include special attention to developments in England and Wales and Sri Lanka. Capitalizing on the widespread availability of demographic surveys, articles in the 1980s featured careful analyses of the demographic correlates of child mortality. Such studies have passed the point of diminishing returns, and declines in child mortality have focused increased attention on conditions among adults. Unfortunately, demography has not developed the means for measuring and analysing adult mortality in underdeveloped countries that are equivalent in their power to methods for studying child mortality.     

Reconsidering mortality compression and deceleration: an alternative model of mortality rates

In this research we develop a model of mortality rates that parameterizes mortality deceleration and compression, permits hypothesis tests for change in these parameters over time, and allows for formal gender comparisons. Our model fits mortality data well across all adult ages 20-105 for 1968-1992 U.S. white data, and the results offer some confirmation of findings of mortality research using conventional methods. We find that the age at which mortality deceleration begins is increasing over time, that decompression of mortality is occurring, and that these trends vary substantially across genders, although male and female mortality patterns appear to be converging to some extent.     

Infantile mortality rates

In this note a suggestion for calculating a more refined rate of infant mortality is put forward, which does not necessitate the tabulation of infant deaths by month of birth and death.     

Segmented generation mortality

For a clear understanding of the inherent changes in mortality with advance in age, it is necessary to observe the experience of generations rather than the cross-section of period experience. In fact, the latter may produce a misleading picture as can be illustrated in the case of tuberculosis. Period experience pointed to a rise in tuberculosis death rates with advance in age, whereas generation experience indicates a decline with aging, The present paper proposes the study of mortality changes of all generations existing at one period to a subsequent period. Some characteristics and trends in the changes in generation mortality of white males and white females since 1900 are discussed. It is pointed out, in particular, that since World War II white males have been experiencing a rapidly increasing rise in generation mortality with the approach of midlife. A comparison of generation mortality changes from 1950 to 1960 among countries of traditionally low mortality shows that only males in the other English-speaking countries may be undergoing the same experience as white males in the United States upon the approach of midlife. It is not evident in the Scandinavian countries and the Netherlands and in the other countries. The reason for these differences is not apparent.     

Religious attendance and mortality: Implications for the black-white mortality crossover

This study investigates the relationships among religious attendance, mortality, and the black-white mortality crossover. We build on prior research by examining the link between attendance and mortality while testing whether religious involvement captures an important source of population heterogeneity that contributes to a crossover Using data from the Established Populations for Epidemiologic Studies of the Elderly, we find a strong negative association between attendance and mortality. Our results also show evidence of a racial crossover in mortality rates for both men and women. When religious attendance is modeled in terms of differential frailty, clear gender differences emerge. For women, the effect of attendance is race- and age-dependent, modifying the age at crossover by 10 years. For men, however; the effect of attendance is not related to race and does not alter the crossover pattern. When other health risks are modeled in terms of differential frailty, wefind neither race nor age-related effects. Overall, the results highlight the importance of considering religious attendance when examining racial and gender differences in age-specific mortality rates.     

Mixed estimation of old-age mortality

"Section 2 will first extend the method of mixed estimation to maximum likelihood estimation in general. Then, we will review generalized linear models with logistic and Poisson regressions as examples. In Section 3 we discuss different approaches for formulating the auxiliary information in practice. Section 4 first reviews the method of Coale and Kisker, provides empirical estimates for it, and then proceeds with the mixed estimation variant. In Section 5 we apply the methods to the estimation of mortality at ages 80+ in Finland in 1980-1993. We will first consider the evidence for mortality crossover between males and females....Then we will estimate life expectancies at age 100." (EXCERPT)     

Evolution of fertility and mortality

Historical and current fertility trends in both Quebec and Canada as a whole are surveyed. While fertility among French Canadians was higher than that in neighboring provinces until the mid-20th century, in 1968 Quebec's crude birthrate was the lowest in Canada, and in 1972 it was 13.8 vs. 15.9 (the national birthrate). This reversal is explained in terms of the demographic transition theory, the declining influence of organized religion, and new opportunities for social mobility for minority groups. The birthrate throughout Canada is also declining. Although recent cohort studies are incomplete because women have not yet finished their reproductive years, it appears that completed family size will be lower than at any time in Canadian history. The period total fertility rate indicates an average family size of 1.8 children in 1976, but it is unclear whether this represents an actual reduction in family size or the postponement of childbearing. The sharpest fertility decline has been among women aged 35-49, but peak fertility rates have shifted from the 20-24 age group to those aged 25-29. Fertility is negatively related to education, and the lowest fertility is found among the intermediate income groups. Since the 1969 lifting of the ban on contraceptive sales and advertising, family planning activities have been stepped up. Also removed was the total ban on abortion. In 1975 there were 14.9 therapeutic abortions per 100 live births, but it has been charged that abortion standards are being applied inequitably from hospital to hospital.     

The momentum of mortality change

Mortality change is not usually assigned much importance as a source of population growth when future population trends are discussed. Yet it can make a significant contribution to population momentum. In populations that have experienced mortality change, cohort survivorship will continue varying for some time even if period mortality rates become constant. This continuing change in cohort survivorship can create a significant degree of mortality-induced population change, a process we call the 'momentum of mortality change'. The momentum of mortality change can be estimated by taking the ratio of e0 (the period life expectancy at birth) to CAL (the cross-sectional average length of life) for a given year. In industrialized nations, the momentum of mortality change can attenuate the negative effect on population growth of declining fertility or sustained below-replacement fertility. In India, where population momentum has a value of 1.436, the momentum of mortality change is the greatest contributor to its value.     

The momentum of mortality change

Mortality change is not usually assigned much importance as a source of population growth when future population trends are discussed. Yet it can make a significant contribution to population momentum. In populations that have experienced mortality change, cohort survivorship will continue varying for some time even if period mortality rates become constant. This continuing change in cohort survivorship can create a significant degree of mortality-induced population change, a process we call the ‘momentum of mortality change’. The momentum of mortality change can be estimated by taking the ratio of e ₀ (the period life expectancy at birth) to CAL (the cross-sectional average length of life) for a given year. In industrialized nations, the momentum of mortality change can attenuate the negative effect on population growth of declining fertility or sustained below-replacement fertility. In India, where population momentum has a value of 1.436, the momentum of mortality change is the greatest contributor to its value.