John Hobcraft

Socio-economic factors in Infant and child mortality: A cross-national comparison

Using results from the World Fertility Survey (WFS) for 28 countries, socioeconomic differences in neonatal, postneonatal, and child mortality were examined. To maintain some degree of comparability and to make presentation of the results feasible, focus was on 5 variables which are available for each survey. It can be argued that each of the 5 socioeconomic variables considered here--mothers education, mothers work status since marriage, current or most recent husband of mothers occupation and education, and current type of place of residence of mother--affects infant and child mortality, although often as surrogates for other variables which were usually not directly available. For over 24 countries, the neonatal mortality rate varied from 84 in Nepal to 15 in Malaysia. In Nepal the rate for children of the skilled and unskilled was high (124) but where the husband had received 7 or more years of education the rate of 54 was low. At the other extreme, rates in Malaysia varied from 5 when mothers had 7 or more years of education to 23 for offspring of the least educated husbands. The highest overall postneonatal rate of 89 was again found in Nepal and the lowest national rate in Trinidad and Tobago at 13. In 9 out of 24 countries the high values were over 3 times as great as the low values and the absolute difference exceeded 30/1000 in 13 countries. Differences on child mortality are substantial, reflecting the greater influence of socioeconomic factors on mortality in early childhood. Nationally, the values ranged from 186 in Senegal to a low of 8 in Trinidad and Tobago. In only Haiti, Guyana, and Pakistan did the ratio of the maximum to the minimum rates for sizeable groups fall below 2. At the other extreme, in 5 countries the ratio exceeded 10 and in a further 6 was above 4. Differences between the high and low groups within countries exceeded 30 in 18 out of 28 countries and were over 50 in 10 of these. In 9 countries the highest rates occurred among mothers with no education and in a further 6 among husbands with no education. Education of mother, followed by education of her husband and his occupation were generally the strongest explanatory variables. The work status of the mother was not likely to be an important explanatory variable in these analyses. Results of a multivariate analysis suggested intriguing differences in the relative roles of different socioeconomic variables. Mothers education seemed to play an important role in determining childrens chances of surviving in several Latin American and South East Asian countries. In no country did husbands level of education appear in all 3 models. The occupation of the husband was possibly the purest indicator of socioeconomic status, and this factor appeared in the models for all 3 segments of infant and child mortality. Mothers work status appeared least often.

Demographic Determinants of Infant and Early Child Mortality: A Comparative Analysis

In this paper we examine the relative importance of a number of demographic determinants of infant and early child mortality using information from 39 World Fertility Survey countries. We include sex of the child, age of the mother at the time of the birth, birth order, mothers educational level and a number of indicators of spacing of adjacent births among the correlates of chances of survival for children below the age of five years. Mortality of firstborn children and of those born to teenage mothers is shown to be higher than average; that of later children and those of older mothers was not much higher than average, once other factors are controlled. Effects of poor birth-spacing persist even after other factors have been controlled, and are similar where a sib was born during the two years preceding the birth of the child, regardless of the survival status of that sib; however, mortality was higher when that sib had died, due to increased familial risks of mortality. Rapid subsequent births also ra...

Age, Period, and Cohort Effects in Demography: A Review

This paper considers only the vital events of demographic measurement, the factors influencing the rate at which those events occur and then investigates the consequences of patterns of these events. It reviews the state of the art of age, period and cohort analysis for demographic dependent variables. Major examples of such analyses are given in both mortality and fertility studies. In the area of mortality the conventional approach to such analysis apears to be well suited to a wide range of applications yielding useful results. The reasons for this suitability are: early childhood experience is important in many major disease and death processes, so that cohorts are legitimately viewed as acquiring early on a certain fixed susceptibility; data sometimes stretch back far enough that stationary standards of age patterns can be developed empirically, and applied to later experience; and, logarithmic or logistic transformations linearize comparisons of age schedules or mortality so that standard statistical procedures are suitable. Applications of age, period, and cohort analysis are not always routine; external constraints are required, in the form of theoretically based and mathematically expressed age patterns of mortality, in order to distinguish effectively between period and cohort effects. A set of models of age patterns of mortality that are based on cohort as well as period experience could be constructed with useful applications. With fertility analysis the conventional approach is much less suitable. Once goal directed behavior is introduced, empirical examinations must be based on theories or assumptions about how such goals are formulated and pursued. Conventional analysis might suffice only if one is prepared to accept the assumption that all pertinent goals and strategies are formulated before the initiation of childbearing and remain unaffected by subsequent events. This assumption is untenable for modern developed populations and the forms of analysis appropriate to age period cohort investigations of fertility will have to develop along with theories of reproductive behavior.

Social disadvantage, genetic sensitivity, and children's telomere length

Significance This paper makes two contributions to research on the link between the social environment and health. Using data from a birth cohort study, we show that, among African American boys, those who grow up in highly disadvantaged environments have shorter telomeres (at age 9) than boys who grow up in highly advantaged environments. We also find that the association between the social environment and telomere length (TL) is moderated by genetic variation within the serotonin and dopamine pathways. Boys with the highest genetic sensitivity scores had the shortest TL when exposed to disadvantaged environments and the longest TL when exposed to advantaged environments. To our knowledge, this report is the first to document a gene–social environment interaction for TL, a biomarker of stress exposure. Disadvantaged social environments are associated with adverse health outcomes. This has been attributed, in part, to chronic stress. Telomere length (TL) has been used as a biomarker of chronic stress: TL is shorter in adults in a variety of contexts, including disadvantaged social standing and depression. We use data from 40, 9-y-old boys participating in the Fragile Families and Child Wellbeing Study to extend this observation to African American children. We report that exposure to disadvantaged environments is associated with reduced TL by age 9 y. We document significant associations between low income, low maternal education, unstable family structure, and harsh parenting and TL. These effects were moderated by genetic variants in serotonergic and dopaminergic pathways. Consistent with the differential susceptibility hypothesis, subjects with the highest genetic sensitivity scores had the shortest TL when exposed to disadvantaged social environments and the longest TL when exposed to advantaged environments.

Parental Divorce during Childhood: Age at First Intercourse, Partnership and Parenthood

It is well established that young people whose parents divorced or experienced marital breakdown during their childhood are likely to enter into first partnerships and into parenthood earlier than those whose parents remained married. In this paper using data from the British National Sexual Attitudes and Lifestyles Survey we examine how far the timing of first coitus plays a role in the genesis of this demographic behaviour for children of divorced parents. Other factors including the timing of menarche attitudes to sexual activity degree of parental strictness and religiosity were also examined. In general these factors had little explanatory power. The analysis showed that earlier sexual activity for men and women from disrupted families is an important proximate determinant of their earlier entry into partnership and parenthood compared with those brought up with both natural parents. (EXCERPT)

Parental divorce and subsequent disadvantage: A cross-cohort comparison

Although many studies have examined the link between parental divorce and subsequent wellbeing, some theories of the effects of divorce suggest that the negative associations should have declined over time. However, few studies have examined the extent to which the associations have remained stable over time. Using data from two British cohorts, we analyzed both shorter- and longer-term outcomes of children who experienced parental divorce and the extent to which the associations have changed over time. Estimating similar models for both cohorts, we found little evidence of any change in the size of the relationship as divorce became more commonplace.

Role of mother's genes and environment in postpartum depression

Most studies of human molecular genetics and social environment interactions on health have relied heavily on the classic diathesis-stress model that treats genetic variations and environments as being either “risky” or “protective.” The biological susceptibility model posits that some individuals have greater genetic reactivity to stress, leading to worse outcomes in poor environments, but better outcomes in rich environments. Using a nontruncated measure of a chronic environmental stressor—socioeconomic status—measured by education, and two polymorphisms (5-HTTLPR and STin2 VNTR) of the serotonin transporter gene (5-HTT), we find strong evidence that some women are genetically more reactive to the environment, resulting in a crossover of risks of postpartum depression for the most reactive groups. We discuss how our approach and findings provide a framework for understanding some of the confusion in the gene-environment interaction literature on stress, 5-HTT, and depression.

Every death counts: measurement of maternal mortality via a census

Methods for measuring maternal mortality at national and subnational levels in the developing world lag far behind the demand for estimates. We evaluated use of the national population census as a means of measuring maternal mortality by assessing data from five countries (Benin, Islamic Republic of Iran, Lao Peoples Democratic Republic, Madagascar, and Zimbabwe) which identified maternal deaths in their censuses. Standard demographic methods were used to evaluate the completeness of reporting of adult female deaths and births in the year prior to the census. The results from these exercises were used to adjust the data. In four countries, the numbers of adult female deaths needed to be increased and three countries required upward adjustment of the numbers of recent births. The number of maternal deaths was increased by the same factor as that used for adult female deaths on the assumption that the proportion of adult female deaths due to maternal causes was correct. Age patterns of the various maternal mortality indicators were plausible and consistent with external sources of data for other populations. Our data suggest that under favourable conditions a national census is a feasible and promising approach for the measurement of maternal mortality. Moreover, use of the census circumvents several of the weaknesses of methods currently in use. However, it should also be noted that careful evaluation of the data and adjustment, if necessary, are essential. The public health community is urged to encourage governments to learn from the experience of these five countries and to place maternal mortality estimation in the hands of statistical agencies.

Fertility in England and Wales: a fifty-year perspective.

This paper provides a detailed account of fertility levels and trends in England and Wales since 1938, with a briefer coverage of a much longer time-span. The paper is concerned both with the measurement of fertility and with understanding the observed fertility behaviour. We lament and correct the failure of demographers to apply measurement tools available since the 1950s to the analysis of fertility in England and Wales, with a particular emphasis on adjustment of period measures and period parity progression ratios and show how some of the grosser errors of analysis and interpretation might have been avoided by earlier use of these approaches. We also relate these estimates to more recent ones. Once a clearer account of trends has been established, the paper goes on to reinterpret and explain the baby boom and baby bust. The conclusion looks at future prospects for fertility.

Fertility exposure analysis: A new method for assessing the contribution of proximate determinants to fertility differentials*

Summary Several recent papers have dealt with the problem of assessing the impact of the proximate determinants on fertility. All these approaches rely on combining a series of separately estimated aggregate level indicators. This paper proposes an approach which uses individual-level data and thus permits regression analyses as well as analyses for sub-groups. In the course of development it became clear that there are several deficiencies and inconsistencies in the measurement and formation of indices proposed elsewhere, which are overcome. We illustrate our approach with data from the Dominican Republic. The approach used involves attributing exposure to one or more of several states, including pregnancy, lactational and non-lactational components of post-partum amenorrhoea, absence of sexual relations and contraception. Key elements are efficacies of contraception and components of post-partum infecundity and the treatment of overlaps through an explicit hierarchy. We treat both unconditional (or additive) and conditional analyses. Intriguing findings on the age-specific pattern of fertility control emerge. Major advantages of regression analysis, such as simultaneous treatment of several variables and estimation of sampling variation are stressed.