In sub-Saharan Africa, socioeconomic factors such as place of residence, mother’s educational level, or household wealth, are strongly associated with risk factors of under-five mortality (U5M) such as health behavior or exposure to diseases and injuries. The aim of the study was to assess the relative contribution of four known socioeconomic factors to the variability in U5M in sub-Saharan countries. The study was based on birth histories from the Demographic and Health Surveys conducted in 32 sub-Saharan countries in 2010–2016. The relative contribution of sex of the child, place of residence, mother’s educational level, and household wealth to the variability in U5M was assessed using a regression-based decomposition of a Gini-type index. The Gini index – measuring the variability in U5M related to the four socioeconomic factors – varied from 0.006 (95%CI: 0.001–0.010) in Liberia 2013 to 0.034 (95%CI: 0.029–0.039) in Côte d’Ivoire 2011/12. The main contributors to the Gini index (with a relative contribution higher than 25%) were different across countries: mother’s educational level in 13 countries, sex of the child in 12 countries, household wealth in 11 countries, and place of residence in 8 countries (in some countries, more than one main contributor was identified). Factors related to socioeconomic status exert varied effects on the variability in U5M in sub-Saharan African countries. The findings provide evidence in support of prioritizing intersectoral interventions aiming at improving child survival in all subgroups of a population.

From 1990 to 2016, the mortality of children younger than 5 years decreased by more than half, and there are plentiful data regarding mortality in this age group through which we can track global progress in reducing the under-5 mortality rate. By contrast, little is known on how the mortality risk among older children (5-9 years) and young adolescents (10-14 years) has changed in this time. We aimed to estimate levels and trends in mortality of children aged 5-14 years in 195 countries from 1990 to 2016. In this analysis of empirical data, we expanded the United Nations Inter-agency Group for Child Mortality Estimation database containing data on children younger than 5 years with 5530 data points regarding children aged 5-14 years. Mortality rates from 1990 to 2016 were obtained from nationally representative birth histories, data on household deaths reported in population censuses, and nationwide systems of civil registration and vital statistics. These data were used in a Bayesian B-spline bias-reduction model to generate smoothed trends with 90% uncertainty intervals, to determine the probability of a child aged 5 years dying before reaching age 15 years. Globally, the probability of a child dying between the ages 5 years and 15 years was 7·5 deaths (90% uncertainty interval 7·2-8·3) per 1000 children in 2016, which was less than a fifth of the risk of dying between birth and age 5 years, which was 41 deaths (39-44) per 1000 children. The mortality risk in children aged 5-14 years decreased by 51% (46-54) between 1990 and 2016, despite not being specifically targeted by health interventions. The annual number of deaths in this age group decreased from 1·7 million (1·7 million-1·8 million) to 1 million (0·9 million-1·1 million) in 1990-2016. In 1990-2000, mortality rates in children aged 5-14 years decreased faster than among children aged 0-4 years. However, since 2000, mortality rates in children younger than 5 years have decreased faster than mortality rates in children aged 5-14 years. The annual rate of reduction in mortality among children younger than 5 years has been 4·0% (3·6-4·3) since 2000, versus 2·7% (2·3-3·0) in children aged 5-14 years. Older children and young adolescents in sub-Saharan Africa are disproportionately more likely to die than those in other regions; 55% (51-58) of deaths of children of this age occur in sub-Saharan Africa, despite having only 21% of the global population of children aged 5-14 years. In 2016, 98% (98-99) of all deaths of children aged 5-14 years occurred in low-income and middle-income countries, and seven countries alone accounted for more than half of the total number of deaths of these children. Increased efforts are required to accelerate reductions in mortality among older children and to ensure that they benefit from health policies and interventions as much as younger children. UN Children's Fund, Bill & Melinda Gates Foundation, United States Agency for International Development.

The global health community is devoting considerable attention to adolescents and young people, but risk of death in this population is poorly measured. We aimed to reconstruct global, regional, and national mortality trends for youths aged 15-24 years between 1990 and 2019. In this systematic analysis, we used all publicly available data on mortality in the age group 15-24 years for 195 countries, as compiled by the UN Inter-agency Group for Child Mortality Estimation. We used nationally representative vital registration data, estimated the completeness of death registration, and extracted mortality rates from surveys with sibling histories, household deaths reported in censuses, and sample registration systems. We used a Bayesian B-spline bias-reduction model to generate trends in 10q15, the probability that an adolescent aged 15 years would die before reaching age 25 years. This model treats observations of the 10q15 probability as the product of the actual risk of death and an error multiplier that varies depending on the data source. The main outcome that we assessed was the levels of and trends in youth mortality and the global and regional mortality rates from 1990 to 2019. Globally, the probability of an individual dying between age 15 years and 24 years was 11·2 deaths (90% uncertainty interval [UI] 10·7-12·5) per 1000 youths aged 15 in 2019, which is about 2·5 times less than infant mortality (28·2 deaths [27·2-30·0] by age 1 year per 1000 live births) but is higher than the risk of dying from age 1 to 5 (9·7 deaths [9·1-11·1] per 1000 children aged 1 year). The probability of dying between age 15 years and 24 years declined by 1·4% per year (90% UI 1·1-1·8) between 1990 and 2019, from 17·1 deaths (16·5-18·9) per 1000 in 1990; by contrast with this total decrease of 34% (27-41), under-5 mortality declined by 59% (56-61) in this period. The annual number of deaths declined from 1·7 million (90% UI 1·7-1·9) in 1990 to 1·4 million (1·3-1·5) in 2019. In sub-Saharan Africa, the number of deaths increased by 20·8% from 1990 to 2019. Although 18·3% of the population aged 15-24 years were living in sub-Saharan Africa in 2019, the region accounted for 37·9% (90% UI 34·8-41·9) of all worldwide deaths in youth. It is urgent to accelerate progress in reducing youth mortality. Efforts are particularly needed in sub-Saharan Africa, where the burden of mortality is increasingly concentrated. In the future, a growing number of countries will see youth mortality exceeding under-5 mortality if current trends continue. UN Children's Fund, Bill & Melinda Gates Foundation, United States Agency for International Development.

This paper provides an overview of trends in mortality in children aged under 5 and adults between the ages of 15 and 60 in sub-Saharan Africa, using data on the survival of the children and siblings collected in Demographic and Health Surveys. If conspicuous stalls in the 1990s are disregarded, child mortality levels have generally declined and converged over the last 30–40 years. In contrast, adult mortality in many East and Southern African countries has increased markedly, echoing earlier increases in the incidence of HIV. In recent years, adult mortality levels have begun to decline once again in East Africa, in some instances before the large-scale expansion of antiretroviral therapy programmes. More surprising is the lack of sustained improvements in adult survival in some countries that have not experienced severe HIV epidemics. Because trends in child and adult mortality do not always evolve in tandem, we argue that model-based estimates, inferred by matching indices of child survival onto standard mortality schedules, can be very misleading.

Because of incomplete registration of deaths in most countries in sub-Saharan Africa, data on the survival of close relatives constitute the cornerstone of estimates of adult mortality. Since 1990, sibling histories have been widely collected in Demographic and Health Surveys and are increasingly being relied upon to estimate both general and maternal mortality. Until recently, the use of sibling histories was thought to lead to underestimates of mortality, but a more optimistic view in the literature emerged with the development by Gakidou and King (Demography 43:569–585, 2006) of corrections for selection biases. Based on microsimulations, this article shows that Gakidou and King’s weighting scheme has been incorrectly applied to survey data, leading to overestimates of mortality, especially for males. The evidence for an association between mortality and sibship size in adulthood is reviewed. Female mortality appears to decline slightly with the number of surviving sisters, although this could be an artifact of severe recall errors in larger sibships or familial clustering of deaths. Under most circumstances, corrections for selection biases should have only a modest effect on sibling estimates.

In countries with limited vital registration, adult mortality is frequently estimated using siblings' survival histories (SSHs) collected during Demographic and Health Surveys (DHS). These data are affected by reporting errors. We developed a new SSH questionnaire, the siblings' survival calendar (SSC). It incorporates supplementary interviewing techniques to limit omissions of siblings and uses an event history calendar to improve reports of dates and ages. We hypothesized that the SSC would improve the quality of adult mortality data. We conducted a retrospective validation study among the population of the Niakhar Health and Demographic Surveillance System in Senegal. We randomly assigned men and women aged 15–59 y to an interview with either the DHS questionnaire or the SSC. We compared SSHs collected in each group to prospective data on adult mortality collected in Niakhar. The SSC reduced respondents' tendency to round reports of dates and ages to the nearest multiple of five or ten (“heaping”). The SSC also had higher sensitivity in recording adult female deaths: among respondents whose sister(s) had died at an adult age in the past 15 y, 89.6% reported an adult female death during SSC interviews versus 75.6% in DHS interviews (p = 0.027). The specificity of the SSC was similar to that of the DHS questionnaire, i.e., it did not increase the number of false reports of deaths. However, the SSC did not improve the reporting of adult deaths among the brothers of respondents. Study limitations include sample selectivity, limited external validity, and multiple testing. The SSC has the potential to collect more accurate SSHs than the questionnaire used in DHS. Further research is needed to assess the effects of the SSC on estimates of adult mortality rates. Additional validation studies should be conducted in different social and epidemiological settings. Controlled-Trials.com ISRCTN06849961 Please see later in the article for the Editors' Summary Governments and international health agencies need accurate information on births and deaths in populations to help them plan health care policies and monitor the effectiveness of public health programs. The most common way of collecting information on vital statistics in an area or country is through civil registration, an administrative system used by governments to record vital events that occur in their populations. In low-to-middle-income countries that have limited resources to devote to such a system, unconventional techniques are often used to estimate mortality levels and trends. One such method is siblings' survival histories collected while conducting a health or other type of public survey. Those surveyed are asked to list all their maternal siblings by birth order and report survival status and current age (for living siblings) or age at death (for deceased siblings). Use of siblings' survival histories leaves the accuracy of the mortality record vulnerable to reporting errors and selection bias. Selection bias is a statistical prejudice that is introduced by the choice of the individuals or groups taking part in the analysis. Reporting errors occur when an individual fails to report a sibling's death, misreports the age of a sibling, or does not recall the exact date when a sibling died. This study was conducted to estimate whether modifying a standard siblings' survival history questionnaire could improve the accuracy of data obtained. The researchers conducted a study in Niakhar, Senegal, using a modified siblings' survival history questionnaire to incorporate some innovative techniques for assisting memory recall, such as recall cues, to help prevent omissions. The researchers also introduced an event history calendar format to help with more accurate reporting of dates. This modified questionnaire is called the siblings' survival calendar. The researchers randomly assigned men and women registered by the Niakhar Health and Demographic Surveillance System, aged 15–59 years old, to an interview with the basic questionnaire or the modified siblings' survival calendar. The modifications included emphasizing the importance of accurate recall before the participant started and asking respondents to list their maternal siblings in the order that they came to the mind instead of birth order. Also, the researchers used supplementary interviewing techniques designed to stimulate the recall of potentially omitted siblings and also used an event history calendar approach for collecting data on ages at, and dates of, vital events that had affected the siblings of a respondent. The researchers compared the results from the two survey instruments and precise data on adult mortality collected by continuous demographic surveillance in a small area of Senegal. They found that the calendar survey improved the sensitivity of survey data in recording adult female deaths. In addition, the modified questionnaire significantly reduced age and date heaping (the tendency of respondents to round off dates) observed with the basic questionnaire. The modified questionnaire took six minutes longer to complete on average than the basic questionnaire. These findings suggest that a new approach (the siblings' survival calendar) that uses simple interview tools to improve estimates of mortality in resource-limited countries is feasible and may improve the quality of the data from siblings' survival histories, particularly in reporting female deaths. Although the study was limited by sample selectivity, limited external validity, and multiple testing, the findings suggest that this new approach has the potential to allow the collection of more accurate data from siblings' survival histories than that collected from the current questionnaire. The next step is to validate these findings in other settings. Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001652.