Age at sexual debut is known to have implications for future sexual behaviours and health outcomes, including HIV infection, early pregnancy and maternal mortality, but may also influence educational outcomes. Longitudinal data on schooling and sexual behaviour from a demographic surveillance site in Karonga district, northern Malawi, were analysed for 3153 respondents between the ages of 12 and 25 years to examine the association between sexual debut and primary school dropout, and the role of prior school performance. Time to dropout was modelled using the Fine and Gray survival model to account for the competing event of primary school completion. To deal with the time-varying nature of age at sexual debut and school performance, models were fitted using landmark analyses. Sexual debut was found to be associated with a five-fold increase in rate of subsequent dropout for girls and a two-fold increase in dropout rate for boys (adjusted hazard ratio [aHR] of 5.27, CI 4.22–6.57, and 2.19, CI 1.77–2.7, respectively). For girls who were sexually active by age 16, only 16% ultimately completed primary schooling, compared with 70% aged 18 or older at sexual debut. Prior to sexual debut, girls had primary completion levels similar to those of boys. The association between sexual debut and school dropout could not be explained by prior poor school performance: the effect of sexual debut on dropout was as strong among those who were not behind in school as among those who were overage for their school grade. Girls who were sexually active were more likely to repeat a grade, with no effect being seen for boys. Pathways to dropout are complex and may differ for boys and girls. Interventions are needed to improve school progression so children complete primary school before sexual debut, and to improve sex education and contraception provision.

Official figures show that life expectancy in Costa Rica is longer than in the United States (US), in spite of the fact that per capita health expenditure is only one-tenth that of the US. To check whether this is for real and to explore some of its determinants, 900 Costa Ricans aged 60+ were followed from 1984 to 2001. Follow-up household visits were made, deaths were tracked in the national death registry, and survival status in the voting registry was double-checked. In addition, the survivors were contacted in 2002. Two-thirds of the panel had died by December 2001. Kaplan–Meier curves, life tables and Cox regression were used to analyse the panel’s survival. Mortality in the panel was slightly higher than the Costa Rican average and similar to that in the US, confirming the exceptional longevity of Costa Ricans. Survival was substantially lower among unmarried men and individuals with limited autonomy at the beginning of the study. The effect of socioeconomic status is weak. Insurance effects seem to be confounded by selection biases.

The composition of human milk during the first year of lactation was studied. The effect of age, parity and the length of inter-delivery interval on the composition is described. Of the three parameters, the length of inter-delivery intervals was the most important, while the other two were weakly correlated. (Summary in Arabic, p. 409.)

Four hundred and fourteen adoptees were located in a population of 28,879 males born within a 4-year period. For all of these males, two social class ratings were obtained, based upon their occupations at age 25–28 and 35–38. A single rating was obtained for their fathers, based upon occupation at the time of birth of the population males. In the case of adoptees, this rating was obtained for both the biological and the adoptive fathers. The adoptees had, at both ages, an average social class not deviating from that of the population at large. Their biological fathers were, however, below average paternal social class and their adoptive fathers were above it. Positive correlations for social class were found between the adoptees, at both ages, and their biological and adoptive fathers. The social class of adoptees is less well predicted by that of their biological and adoptive fathers, even when these are taken jointly, than the social class of sons in the population is predicted by that of their fathers. Evidence from both the group means and the correlations suggests that the adoptees at age 35–38 came to resemble their biological fathers in social class more than they had done at age 25–28.

Time spent on subsistence activities was compared between rural sedentes and urban migrants of the Huli population in Papua New Guinea. Person-day observation data were collected for rural sedentes (441) in the Tari basin and for urban migrants in Port Moresby (175). The time spent on subsistence activities by males was longer in the urban area than in rural areas, while that by females was similar in both areas. Conspicuous gender inequality with respect to labour hours in rural areas seems to diminish when people move to urban areas, reflecting the different subsistence regime between rural and urban environments.

This paper presents a new approach to cost analysis of family planning programmes that focuses on behaviour change of programme clients as the final ‘output’ rather than units of contraceptive services delivered, as does the familiar couple-years-of-protection index. It is useful to know how much it costs to deliver a unit of contraceptive services, but it would also seem useful to know how much it costs to change a prospective client’s behaviour. The proposed approach rests on the familiar ‘steps to behaviour change’ paradigm and: (1) develops a methodology for applying a client-behaviour-change-centred cost analysis to programme activities; (2) tests the methodology and concepts by applying them retrospectively to a case study of mass media interventions in Egypt; (3) derives cost per unit of behaviour changes for these Egyptian communications campaigns to demonstrate the workability of the approach. This framework offers a new approach to impact evaluation that would seem to be applicable to other components of family planning and reproductive health programmes.

During the century before its final evacuation in 1930 the population of St Kilda declined from over 100 to 36. While undoubtedly emigration and natural disasters played a part in this depopulation, ongoing processes were also important. In particular, replacement levels were never sufficient to maintain a constant population size. In the early part of this period the main factor responsible was heavy neonatal mortality, almost all from tetanus (‘eight-day sickness’), but latterly the fertility of those who survived was low, even though mortality rates had declined. In part at least, this decline in fertility could be ascribed to a lower frequency of marriage—a phenomenon seen elsewhere in the Outer Hebrides during the latter part of the 19th century.

Estimates of the opportunity for selective pressure on the population suggest very high levels, due earlier mainly to high pre-reproductive mortality and later to lowered fertility.

The attitudes of women of reproductive age to IVF therapy and human embryo research were investigated. A questionnaire was given to 1920 consecutive women attending clinics for family planning (1050), ante-natal care (705) and infertility (165). This paper reports the analysis of 1701 returned questionnaires, all from women of reproductive age. The great majority (94%) were in favour of IVF treatment. Sixty-seven percent approved of research on human embryos up to 14 days to improve IVF treatment, and a further 10% supported research on embryos designed to avoid birth defects. The majority (79%) thought women should be allowed to donate ova for research. The social characteristics of the infertility group were similar to those of the ante-natal group except for lower parity. In the family planning and ante-natal groups attitudes were not related to age, social class or parity, but were influenced by religious beliefs.

The life course perspective in social inequalities in health research has resulted in an increased interest in status attainment processes. Adult status is commonly measured as occupational class, income level or educational attainment, and the latter was applied in this study. The study objective was to estimate the relative contribution of parental and early individual characteristics on educational attainment. The study population comprised all males born in Norway in 1967–1971, and alive at age 28 years (n=160,914). Data on social and biological variables were compiled from birth onwards in several national registers. Information on educational attainment at age 28 years was derived from Statistics Norway. Mean years of education was 12.62 years (SD 2.24). Educational attainment was strongly associated with general ability score at age 18 years and parental educational attainment. Parental income had more limited influence; all other early factors had only marginal effect. Path analysis results suggest that the direct effect of general ability was of the same size as the combined direct and indirect effect of parental education and income. The results suggest that status attainment in this young male population is mainly dependent on general ability and parental education level.

Academic disciplines like anthropology and epidemiology provide a niche for researchers to speak the same language, and to interrogate the assumptions that they use to investigate problems. How anthropological and epidemiological methods communicate and relate to each other affects the way public health policy is created but the philosophical underpinnings of each discipline makes this difficult. Anthropology is reflective, subjective and investigates complexity and the individual; epidemiology, in contrast, is objective and studies populations. Within epidemiological methods there is the utilitarian concept of potentially sacrificing the interests of the individual for the benefits of maximizing population welfare, whereas in anthropology the individual is always included. Other strengths of anthropology in the creation of public health policy include: its attention to complexity, questioning the familiar; helping with language and translation; reconfiguring boundaries to create novel frameworks; and being reflective. Public health requires research that is multi-, inter- and trans-disciplinary. To do this, there is a need for each discipline to respect the ‘dignity of difference’ between disciplines in order to help create appropriate and effective public health policy.

Globally, HIV/AIDS remains a public health issue, especially in sub-Saharan Africa (SSA). Despite the increased advocacy and dissemination of comprehensive HIV/AIDS information in SSA, it appears that little progress has been made to reduce the incidence of HIV/AIDS in the sub-region. This study, therefore, examined the association between comprehensive HIV/AIDS knowledge and safer sex negotiation among adolescent girls and young women in SSA. Data were taken from the Demographic and Health Surveys conducted between 2010 and 2019 in 30 countries in SSA. The study sample comprised 37,364 adolescent girls and young women aged 15–24. A multivariable binary logistic regression analysis was done to test the hypothesis that there is a positive association between comprehensive HIV/AIDS knowledge and safer sex negotiation. Adolescent girls and young women who had comprehensive knowledge on HIV/AIDS were more likely to negotiate for safer sex compared with those who had no comprehensive knowledge on HIV/AIDS (AOR=1.31, 95% CI: 1.22–1.41). At the country level, the positive association between comprehensive knowledge on HIV/AIDS and safer sex negotiation was significant in Chad, Congo DR, Gambia, Guinea, Liberia, Ethiopia and Malawi. On the other hand, in Togo, adolescent girls and young women who had comprehensive HIV/AIDS knowledge were less likely to negotiate for safer sex. These findings can inform policies and programmes on the crucial role of comprehensive HIV/AIDS education and knowledge in increasing safer sex negotiation among adolescent girls and young women in SSA. The study recommends that Togo needs to address certain practices such as intimate partner violence against adolescent girls and young women, which prevent them from negotiating for safer sex, despite their higher knowledge on comprehensive HIV/AIDS. Lessons can be learnt from Chad, Congo DR, Gambia, Guinea, Liberia, Ethiopia and Malawi about the scale-up of programmes and interventions targeted at young women.

The effect of four progestational drugs on the amount of milk yield in a group of lactating Egyptian women was estimated during the first year of lactation. The milk yield was highest in the women given Depo-Provera, followed by those receiving Deladroxone and quingestanol acetate. Only in those women given chlormadinone acetate was the milk yield, on average, lower than in the control group of non-medicated women.

Early onset of menarche has been shown to be associated with breast cancer and ischaemic heart disease. Studies on age at menarche of the Malaysian population are poorly documented. This study aimed to determine the influence of anthropometric and socio-demographic factors on the age at menarche of university students in Malaysia. Data were obtained in 2010–11 from 961 students between the ages of 18 and 25 years from the University of Malaya using stratified sampling, and multiple regression analysis was applied. Sixty-three per cent of students reached menarche at the age of 12 or 13 years, with the mean and median of age at menarche being 12.45±1.17 and 12.01 years, respectively. Menarcheal age was positively associated with height (p<0.05) and negatively associated with BMI (p<0.001). Students from urban areas attained menarche earlier than those from rural areas (p<0.05). Students from small-sized families attained menarche earlier than those from larger families (p<0.05). First-born students experienced menarche earlier than those who were seventh-born or later. Obese and overweight students reached menarche earlier than students who were underweight or of normal weight (p<0.01). The variations in age at menarche among the Malaysian ethnic groups were statistically insignificant. The results suggest that heavier and first-born students from small families are more likely to attain menarche earlier than their counterparts.

This paper documents expectations of old age support in rural Nepal. Current living arrangements of the elderly have been analysed with a focus on the ownership of land holdings. It is argued that the inter-generational transfer of property through inheritance from the older to the younger generation, especially among sons, together with the Nepali normative prescription that sons care for their aged parents, provides a mechanism for old age support. However, land is becoming a scarce resource, cultural traditions are breaking down through modernisation and the living conditions of the elderly are likely to deteriorate as this process continues.

Data showing the relative ages of husbands and wives at marriage in one post-war year are available for many countries, and show that the age distribution of wives for men of a given age varies appreciably from country to country. So also does the age distribution of husbands for a given age of bride. The range of the average ages of marriage partners, from country to country within Europe, is about 2 years for either sex.

The first part of the paper investigates how far these variations are associated with the corresponding international differences in the supply of men and women available for marriage. There is some correlation—mostly positive at the younger and older marriage ages and negative at the central marriage ages. The results show an affinity with those of a similar study based on time trends in one country alone: England and Wales.

In so far as age distributions at marriage are not directly associated with the supply of people available as partners, international variations may be regarded as the expression of differences in social custom, in economic history or in taste. In the second part of the paper such differences are exhibited and discussed. For a given age of one spouse, partners in most countries are older than in Britain but younger wives are found in some Communist countries and also in the Commonwealth.

In the final section, the development of the marriage age experience in two countries—France, and England and Wales—is compared over the period 1911–61, and some interesting differences are revealed, especially in relation to the effects of world wars, of economic depressions and the history of contraceptives. In 1911, appreciably older husbands and younger wives were found in France than in Britain, but today the differences between the two countries are much smaller.

This paper examines the effect of age at first marriage, number of wives and type of marital union on fertility among Yoruba females in Western Nigeria. The evidence indicates that age at first marriage and hunband's number of wives do not have a significant effect on completed fertility. Type of marital union, on the other hand, seems to have an effect on fertility. Women in de facto unions experience lower fertility than women in formal marriages.

Globally, female sterilization is one of the most popular contraceptive methods despite concerns about quality of care for women who report being sterilized. In this study, informed choice among sterilized women was quantified using Demographic and Health Survey (DHS) data from 2000 to 2012 for countries in South Asia and Latin America. Three responses measured informed choice and knowledge about whether women were informed by a health worker or provider: that sterilization is permanent, the potential side-effects of sterilization and other methods of contraception. An ascending composite Method Information Index with scores ranging from 0 (women received no information) to 3 (women received information across all three indicators) was used. Using ordinal logistic regression analysis, the results indicated that women younger than 25 and older than 35 at the time of sterilization, and those at high parities, had lower odds of a high score on the index, while the opposite was true for women sterilized in the private sector in Latin America. Educated women in India had higher odds of a high score on the index, while the same was true for educated and wealthy women in Colombia. These findings indicate that not enough health care providers spend time informing women in South Asia and Latin America about different aspects of sterilization, and that there are specific groups of women that are more affected. There is an urgent need to improve quality of care within health systems providing sterilization for this very important and effective type of contraception.

The resolution of parent–offspring conflict (POC) might sway in favour of the offspring if the parent relies on offspring-supplied information about need. Here, three hypotheses from a resolution model of POC were tested using data on sickness histories and mother–infant interactions from 24 Karo Batak women and their young children from two rural villages in North Sumatra, Indonesia. First, as predicted, offspring with greater need (measured as age and propensity to illness) tended to fuss more often. Second, as expected, observed fussiness predicted the number of suckling occurrences observed during sampling periods. Third, contrary to the prediction, the duration of fussing observed after breast-feeding occurrences was longer than the duration of the breast-feeding occurrences themselves. Parental decisions were made based on offspring-supplied information about need, but offspring failed to garner resources in excess of the parental optimum. This suggests that a POC interpretation is unnecessary to account for these results.

The strong association of very low birth weight (VLBW; <1500 g) with infant mortality is well known. There are no data related to VLBW trends in Brazil although findings from some large surveys carried out in small- and medium-sized cities have demonstrated an increase in low birth weight (LBW; <2500 g) rates over the last 30 years. The aim of this study was to evaluate the secular trend of VLBW in the city of Porto Alegre, a large city in a developed area in southern Brazil, and the potential determinants of this trend during the 1990s and early 2000s. This is a registry-based study. Data were obtained from birth certificates of all live births in the city from 1994 to 2005. The variables analysed were: VLBW as the dependent variable and maternal age and schooling, type of delivery, type of hospital, number of live births, gestational age, newborn gender and unemployment rate. The incidence ratio rate (IRR) using Poisson regression was calculated to identify possible trends in VLBW rates. Poisson regressions were performed in order to assess the influence of some independent variables on VLBW. A total of 257,740 singleton newborns were delivered in the city during the period, with a steady reduction in the total number of live births per year from 23,296 in 1994 to 18,325 in 2005. The results showed a small but significant increase in VLBW (p for trend=0.049). There was a significant trend towards adequacy for gestational age per birth weight, suggesting a reduction in rates of intrauterine growth restriction (IUGR) (p<0.001). The findings showed a significant increase of 1% per year in the probability of VLBW. The main risk factors were related to VLBW mothers with low levels of schooling, public hospitals and multiparity and nulliparity. After adjustment, nulliparity remained as a significant risk factor. The interaction between type of hospital and type of delivery indicated that the probability for VLBW was 3.6 times higher (p<0.001) among those born in public hospitals by Caesarean section than those born in private hospitals by vaginal delivery. The results show that southern Brazil is going through a demographic transition characterized by a significant decrease in number of live births associated with a small increase in VLBW rates, a decrease in IUGR rates and stabilization of LBW.

Son preference is strong in Vietnam, according to attitudinal surveys and studies of contraceptive prevalence and birth hazards. These techniques assume a single model is valid for all families, but it is more plausible that son preference is found for some, but not all, families. Heterogeneous preferences may be addressed with a mixture model. This paper specifies and estimates a two-Weibull regression model, applied to the interval between the second and third births. The data come from the Vietnam Living Standards Survey of 1992–93. Applying information criteria, graphs, and martingale-based residuals, the two-Weibull model is found to fit better than a one-Weibull model. Roughly half of parents have son preference and, curiously, a propensity for fewer children. The other group has more children, no son preference, and is colourless in the sense that the birth interval is difficult to predict on the basis of the regressors used.