Reporting Errors in Siblings’ Survival Histories and Their Impact on Adult Mortality Estimates: Results From a Record Linkage Study in Senegal

Estimates of adult mortality in countries with limited vital registration (e.g., sub-Saharan Africa) are often derived from information about the survival of a respondent’s siblings. We evaluated the completeness and accuracy of such data through a record linkage study conducted in Bandafassi, located in southeastern Senegal. We linked at the individual level retrospective siblings’ survival histories (SSH) reported by female respondents (n = 268) to prospective mortality data and genealogies collected through a health and demographic surveillance system (HDSS). Respondents often reported inaccurate lists of siblings. Additions to these lists were uncommon, but omissions were frequent: respondents omitted 3.8 % of their live sisters, 9.1 % of their deceased sisters, and 16.6 % of their sisters who had migrated out of the DSS area. Respondents underestimated the age at death of the siblings they reported during the interview, particularly among siblings who had died at older ages (≥45 years). Restricting SSH data to person-years and events having occurred during a recent reference period reduced list errors but not age and date errors. Overall, SSH data led to a 20 % underestimate of ₄₅ q ₁₅ relative to HDSS data. Our study suggests new quality improvement strategies for SSH data and demonstrates the potential use of HDSS data for the validation of “unconventional” demographic techniques.     

On the Survival of Centenarians and the Span of Life

It has been argued in the literature that the observed mortality crossover among older black Americans relative to the white population is a result of ‘differential early mortality which selects the least robust persons from the disadvantaged population at relatively earlier ages so that, at advanced ages, the disadvantaged population has proportionately more robust persons’ (Kenneth G. Manton). The authors examine the plausibility of the observed black mortality crossover and the heterogeneity argument supporting its existence. In addition to citing evidence from the literature, they use life tables from various countries known to have good mortality data to explore the relation between mortality in childhood and at younger adult ages and mortality in old age for cohorts and periods. Analysis suggests that the association between childhood and old-age mortality for cohorts is positive, implying that observed mortality crossovers are produced by deficient data rather than population heterogeneity.     

Bayesian population reconstruction of female populations for less developed and more developed countries

We show that Bayesian population reconstruction, a recent method for estimating past populations by age, works for data of widely varying quality. Bayesian reconstruction simultaneously estimates age-specific population counts, fertility rates, mortality rates, and net international migration flows from fragmentary data, while formally accounting for measurement error. As inputs, Bayesian reconstruction uses initial bias-reduced estimates of standard demographic variables. We reconstruct the female populations of three countries: Laos, a country with little vital registration data where population estimation depends largely on surveys; Sri Lanka, a country with some vital registration data; and New Zealand, a country with a highly developed statistical system and good quality vital registration data. In addition, we extend the method to countries without censuses at regular intervals. We also use it to assess the consistency of results between model life tables and available census data, and hence to compare different model life table systems.     

Comparison of Four Methods for Estimating Complete Life Tables from Abridged Life Tables Using Mortality Data Supplied to EUROCARE-3

ABSTRACT

To estimate mortality due to cancer, it is necessary to have mortality data by year of age in the population of cancer patients. When such data are not available, estimating one-year (complete) life tables from five-year (abridged) life tables is necessary. Four such methods—Elandt–Johnson, Kostaki, Brass logit, and Akima spline methods—are compared with respect to 782 empirical complete life tables pertaining to 19 European regions or countries, from 1954 to 2000. Abridged life tables are first derived from the empirical ones, then used to produce one-year-life tables by each of the four methods. These reconstituted complete life tables are then compared with the empirical complete life tables. Among the four methods, the Elandt–Johnson demographic method produces the best reconstitutions at adult ages, specifically those ages at which observed cancer survival needs to be corrected.     

Voting status life tables for the United States, 1968–1980

Using current and retrospective voting data from the November Current Population Surveys of Presidential election years, this study modifies and applies demographic accounting and increment-decrement life table methods to construct voting status life tables for three recent election periods. The paper shows how to combine a continuously occurring process (mortality) with a process that is active only at discrete times (voting transitions) within a multistate life table. Empirical results pertain to the number of Presidential elections an individual is expected to vote in at ages 0 and 18, the typical life course pattern of transitions between voting and not voting statuses, sex and race differentials, changes across the three election periods, and cohort effects.     

Parental survival data: Some results of the application of Ledermann's model life tables

Summary Ledermann's one- and two-parameter model life tables are used in order to summarize and compare adult mortality estimates derived from parental survival data, and also to link parental survival with child survival data. The Ledermann models provide an alternative to the logit model used by Brass and Hill. Examination of life tables derived from actual child and adult mortality estimates reveals that although the two types of models yield similar overall levels of mortality, they show marked differences in the estimated patterns by sex and age. It has not been possible to disentangle completely how much of this divergence is due to the models themselves and how much to inadequacies in the data available. Finally, we question whether it is always wise to establish a full life table from child and adult mortality estimates when these are based on data which refer to different periods of exposure to the risk of dying, without allowance for possible distortions resulting from mortality change.     

Polygyny and child survival in Nigeria: Age-dependent effects

Mortality risks under age five are estimated using data from the 1990 Nigerian Demographic and Health Survey for children in monogamous and polygynous families. Integrating existing theories on polygyny’s relationship with infant and child mortality and some demographic concepts, the study shows that polygyny has different effects on infant and child mortality at different ages. The results indicate that polygyny does not have a significant effect on neonatal mortality (age less than one month). In contrast to the results of previous research, polygyny is significantly associated with lower child mortality during the post-neonatal period (1–11 months), but not during childhood (12–59 months). The study found socio-economic factors to be important confounders of the relationship between polygyny and mortality during the neonatal and post-neonatal periods. The protective effect of polygyny during the post-neonatal period suggests the need to further investigate circumstances that may favour post-neonatal child survival in polygynous families including availability of childcare.     

近50年来世界人口期望寿命的演变轨迹

进入21世纪以来,全球人口已经突破60亿,但是人口增长速度明显减慢。许多国家已经完成了人口转变,其总和生育率在更替水平以下。与此同时,人口健康状况得到明显改善,死亡水平显著降低,期望寿命在不断提高。本文利用联合国人口司发布的192个国家人口死亡信息,系统分析了世界人口平均期望寿命在过去50年里的演变态势、区域差异以及演变模式。结果显示世界人口期望寿命经历了半个多世纪的持续增长,有50%以上的人口或国家平均期望寿命达到了70岁。演变轨迹呈多样化的发展模式,区域发展不平衡。欠发达地区总体上较发达地区增幅大,人口比重上升幅度也很显著。人均期望寿命增幅最大的是亚洲国家,非洲国家与世界不同步,而且区域内差异较大。     

Effects of Childhood Mortality and Morbidity on the Fertility Transition in sub‐Saharan Africa

Child mortality rates have fallen substantially in developing countries since 1960. The expected fertility decline has followed only weakly in sub‐Saharan Africa compared to other recent and historic demographic transitions. Disease and anthropometric data suggest that morbidity remains prevalent in Africa despite child survival improvements. The uniquely high infectious disease burden among children in Africa reduces population health and diminishes the returns to human capital investment, thwarting the quantity–quality tradeoff for children that typically accompanies the mortality transition. Individual‐level data from the Demographic and Health Surveys are used to show that persistent morbidity has weakened the positive relationship between child mortality and total fertility rates throughout the region, slowing Africa's demographic transition.     

Revised regional model life tables at very low levels of mortality

This paper presents and discusses new model life tables at very low mortality, which make use of age-specific death rates from the 1960s, 1970s, and 1980s. These life tables fit recorded death rates in very low mortality populations better than do the existing ones at expectations of life of 77.5 and 80 years. The old tables incorporate too-high mortality at the higher ages and in infancy and they incorporate regional differences that no longer exist. The new tables "close out" the mortality schedules above age 80 more realistically. The convergence of age patterns of mortality at very high life expectancies in populations that used to conform to different families is in itself of demographic interest. Some convergence may perhaps be expected. Sullivan (1973) found that, in Taiwan, the comparison of mortality at ages 1-5 to mortality at 5-35 in the late 1950s showed higher mortality at the younger ages relative to the ensuing 30-year age interval than was found in any of the models, including the South model, which has the highest relative mortality from ages 1-5 among the 4 regional patterns. Then, in the late 1960s, the relation of mortality at 1-5 to mortality at 5-35 in Taiwan fell to a position intermediate between the West and South tables. Sullivan found in data on mortality by cause of death a large reduction in mortality from diarrhea and enteritis, no doubt as a result of environmental sanitation. Mortality from these causes is concentrated among young children, and reduction in deaths from these causes would naturally diminish the excess mortality in this age interval. The East pattern, characterized by very high mortality in infancy (but not from 1-5), may be the result of the prevalence of early weaning or avoidance of breast feeding altogether in the populations characterized by this pattern. As health conditions have improved, evidenced by the overall design of mortality, these special factors are diminished or erased. Model life tables at these very low mortality levels have different uses from most applications of model life tables at higher mortality. The use of model tables to estimate accurate schedules of mortality when the basic data are incomplete or inaccurate is less relevant in this range of mortality levels.     

On the scale of global demographic convergence, 1950-2000

The second half of the twentieth century saw global demographic change of unprecedented magnitude, with pronounced falls in both mortality and fertility in many developing countries. This article assesses the extent to which these changes have led to the convergence of demographic patterns around the world. It considers not just the levels of fertility and mortality in each country at different points in time, but also the size of each population. It also disaggregates China and India into their constituent provinces and states in order to provide estimates for units more typical of the size of the populations of other countries. The note presents proportions of the world's population according to the levels of life expectancy and total fertility they experienced in the early 1950s, the late 1970s, and around 2000. The graphs and tables thus produced give a convenient and novel way to view the scale and nature of demographic convergence over the last 50 years.     

Some macroeconomic aspects of global population aging

Across the demographic transition, declining mortality followed by declining fertility produces decades of rising support ratios as child dependency falls. These improving support ratios raise per capita consumption, other things equal, but eventually deteriorate as the population ages. Population aging and the forces leading to it can produce not only frightening declines in support ratios but also very substantial increases in productivity and per capita income by raising investment in physical and human capital. Longer life, lower fertility, and population aging all raise the demand for wealth needed to provide for old-age consumption. This leads to increased capital per worker even as aggregate saving rates fall. However, capital per worker may not rise if the increased demand for wealth is satisfied by increased familial or public pension transfers to the elderly. Thus, institutions and policies matter for the consequences of population aging. The accumulation of human capital also varies across the transition. Lower fertility and mortality are associated with higher human capital investment per child, also raising labor productivity. Together, the positive changes due to human and physical capital accumulation will likely outweigh the problems of declining support ratios. We draw on estimates and analyses from the National Transfer Accounts project to illustrate and quantify these points.     

Population statistics] as of July 1, 1999

Reported in tabular form are population statistics published by the Institute for Population and Social Research, Mahidol University, in Thailand, as of July 1, 1999. The three objectives of the table were 1) to present the most recent estimates of relevant population numbers and vital rates twice a year, 2) to provide the most accurate demographic estimates possible through the use of standard techniques of demographic analysis, and 3) to disseminate the demographic data to Thailand, and international researchers and planners. The table shows statistics on the following elements: total population; population by sex; population in urban and rural areas; population by region; population by age group; crude birth and death rates; natural growth rate; infant mortality rate; life expectancies at birth and at 60 years and over; total fertility rate; contraceptive prevalence rate; and median age. A new basis for age estimates is also presented.     

Estimating the Effect of Smoking on Slowdowns in Mortality Declines in Developed Countries

Declines in mortality rates for females at older ages in some developed countries, including the United States, have slowed in recent decades even as decreases have steadily continued in some other countries. This study presents a modified version of the indirect Peto-Lopez method, which uses lung cancer mortality rates as a proxy for smoking exposure, to analyze this trend. The modified method estimates smoking-attributable mortality for more-specific age groups than does the Peto-Lopez method. An adjustment factor is also introduced to account for low mortality in the indirect method’s study population. These modifications are shown to be useful specifically in the estimation of deaths attributable to smoking for females at older ages, and in the estimation of smoking-attributable mortality more generally. In a comparison made between the United States and France with the modified method, smoking is found to be responsible for approximately one-half the difference in life expectancy for females at age 65.     

Contribution of mortality decline to longer working life: The case of indonesian males 1980–1995

The length of working life of Indonesian males has been estimated for 1980 and 1995. Data on age specific labour force participation rates are obtained from the 1980 census and the 1995 intercensal population survey. Data on agespecific mortality have been adopted from appropriate model life tables based on indirect estimates of child mortality in the absence of any direct information about mortality. The contribution of declining mortality to the lengthening of working life has been greater than the contribution of higher labour force participation rates. Reductions in mortality at ages before entry into the labour force have increased the potential for added and improved education and training needed for the work force, which is also a contribution of reduced mortality to human capital development. The findings have implications for policy and future employment plans.     

Obituary

The demographic consequences of the First World War in Britain have never been fully assessed partly on account of the lack of reliable mortality data on soldiers and civilians in the years 1914–18. In this paper, the extent of British military losses is determined and estimates of their age structure are given on the basis of the mortality experience in 1913–17 of the approximately five million men whose lives were insured by the Prudential Assurance Company. An examination of male mortality at ages 16–49 of this primarily working-class population shows both the age-incidence of war-related deaths and an improvement in life expectation for men too old for active service or combat. This latter phenomenon is related to a rising standard of living for the working class during the 1914–18 war.     

Bayesian Estimation of Age-Specific Mortality and Life Expectancy for Small Areas With Defective Vital Records

High sampling variability complicates estimation of demographic rates in small areas. In addition, many countries have imperfect vital registration systems, with coverage quality that varies significantly between regions. We develop a Bayesian regression model for small-area mortality schedules that simultaneously addresses the problems of small local samples and underreporting of deaths. We combine a relational model for mortality schedules with probabilistic prior information on death registration coverage derived from demographic estimation techniques, such as Death Distribution Methods, and from field audits by public health experts. We test the model on small-area data from Brazil. Incorporating external estimates of vital registration coverage though priors improves small-area mortality estimates by accounting for underregistration and automatically producing measures of uncertainty. Bayesian estimates show that when mortality levels in small areas are compared, noise often dominates signal. Differences in local point estimates of life expectancy are often small relative to uncertainty, even for relatively large areas in a populous country like Brazil.     

Life Potential as a Basic Demographic Indicator

This paper proposes an indicator that integrates life expectancy with the demographic structure of the population for a given society. By doing this, we have a simple indicator of mortality and aging combined, which could be very useful for developed societies. As is widely known, life expectancy at birth is independent of the demographic structure of the population, and therefore is adequate for measuring overall mortality. However, it neglects to take into account the fact that as life expectancy increases society ages, and so looking at life expectancy alone can produce an overly optimistic view of the development process, especially if we pay attention to future sustainability. Aging can in fact affect quality of life and sustainability in the long run. The indicators for aging are usually very crude, such as providing information on the share of the population who are 65 and over. We propose a simple indicator that integrates life expectancy at different ages, not only at birth, with the demographic structure of the population at a given point in time. The indicator has an intuitive interpretation in terms of the life potential, or biological capital, of society; and given that it is a weighted average, its changes can be easily decomposed into reductions in mortality (gains in life expectancy) and aging for different age intervals.     

Population statistics] as of July 1, 1998

This article presents estimates of relevant population numbers and vital rates in Thailand as of July 1, 1998. Utilizing the standard demographic techniques of analysis, the estimates provided are assured to be the most accurate demographic estimates possible. Total population was estimated at 61,143,000. Estimates by sex, locales, region, and by age group are included. In addition, the crude birth rate per 1000 population was estimated at 18.7; the crude death rate per 1000 population was 6.5. For the natural growth rate the estimate was at 1.2%, and the infant mortality rate was 25.0 per 1000 live births. In terms of life expectancy at birth, the estimate for males was 69.9 years, while for females it was 74.9 years. Additional years in life expectancy at age 60 were 20.3 years for males and 23.9 years for females. The total fertility rate per woman is 1.98, and contraceptive prevalence is 72.2%. The demographic data will be disseminated to Thai and international population researchers and planners.     

Diverging Trends in Female Old‐Age Mortality: The United States and the Netherlands versus France and Japan

In the most advanced countries, child mortality and adult mortality under age 65 years have fallen so low that further improvement in life expectancy relies almost completely on the decline of mortality at older ages. This phenomenon is particularly pronounced among women, who are far ahead of men in survival rates. Thus, to project the future of life expectancy, this study focuses on trends in female life expectancy at ages 65 and older. Four countries are selected for this analysis: the United States, Netherlands, France, and Japan. It is particularly interesting to understand why American and Dutch trends in female old‐age mortality have been diverging from those in France and Japan for two decades. It is shown here that most of the divergence derives from the fact that decline in cardiovascular mortality is more and more offset by increases in other causes of death in the United States and the Netherlands, while the other two countries are more successful in reducing mortality from all causes at increasingly older ages. This latter phenomenon could represent a new stage of the health transition.