This study seeks to investigate what influences intelligence in early childhood. The Singapore Cohort Study of the Risk Factors of Myopia (SCORM) is used to assess determinants of childhood IQ and changes in IQ. This longitudinal data set, collected in 1999, includes a wealth of demographic, socioeconomic and prenatal characteristics. The richness of the data allows various econometric approaches to be employed, including the use of ordered and multinomial logit analysis. Mother's education is found to be a consistent and key determinant of childhood IQ. Father's education and school quality are found to be key drivers for increasing IQ levels above the average sample movement.

Catastrophic spending on health care through out-of-pocket payment is a huge problem in most low- and middle-income countries all over the world. The collapse of health systems and poverty have resulted in the proliferation of the private health sector in Cambodia, but very few studies have examined the fairness in ease of utilization of these services based on mode of payment. This study examined the utilization of health services for sickness or injury and identified its relationship with people's ability to pay for treatment seeking at various instances. Based on cross-sectional data from the Cambodian 2007 Demographic and Health Survey, the economic index estimated through principal component analysis and Lorenz curve was used to quantify the degree of fairness and equality in utilization and payment burden among the respondents. A distinct level of fairness was found in health care utilization and out-of-pocket payments. Specifically, use of private health care facilities and over-the-counter remedies dominate, and out-of-pocket payments cut across all socioeconomic strata. As many countries in low- and middle-income regions, and most importantly those in transition such as Cambodia, are repositioning their health systems, efforts should be made towards maintaining equitable access through adoption of finance mechanisms that make utilization of health care services fair and equitable.

Many abortion seekers in India attempt to induce abortion on their own, by accessing oral medication/preparations from a chemist without a prescription or from an unauthorized provider, and present at registered facilities if these attempts fail. However, little is known about those whose efforts fail or the ways in which programmes and policies may address the needs of such women. This paper explores the experiences of women whose efforts failed, including their socio-demographic profile, the preparations they used, and the extent to which they experienced serious complications, delayed seeking care from an authorized provider, or delayed abortion until the second trimester of pregnancy. Data come from a larger study assessing the feasibility of the provision of medical abortion by non-physicians; a total of 3394 women who sought medical abortion from selected clinical settings in Bihar and Jharkhand between 2008 and 2010 constitute the sample. Prior to visiting the clinic, nearly a third of these women (31%) had made at least one unsuccessful attempt to terminate the unwanted pregnancy by using a range of oral medications/preparations available over-the-counter in medical shops. Logistic regression analysis suggests that educated women (OR 1.6–1.7), those from urban areas (OR 6.2) and those from Bihar (OR 1.6) were significantly more likely than women with no education, rural women and those from Jharkhand to have used such medication. Also notable is that the average gestational age of women who had made a previous attempt to terminate their pregnancy was almost identical to that of women who had not done so when they presented at the registered facility. These findings may inform policies and programmes that seek to identify and reduce the potential risks associated with unauthorized abortion-seeking practices, and highlight the need to fully inform women, chemists and providers about oral medications, what works and what does not, and how effective medication must be taken.

The majority of studies of the birth spacing–child survival relationship rely on retrospective data, which are vulnerable to errors that might bias results. The relationship is re-assessed using prospective data on 13,502 children born in two Nairobi slums between 2003 and 2009. Nearly 48% were first births. Among the remainder, short preceding intervals are common: 20% of second and higher order births were delivered within 24 months of an elder sibling, including 9% with a very short preceding interval of less than 18 months. After adjustment for potential confounders, the length of the preceding birth interval is a major determinant of infant and early childhood mortality. In infancy, a preceding birth interval of less than 18 months is associated with a two-fold increase in mortality risks (compared with lengthened intervals of 36 months or longer), while an interval of 18–23 months is associated with an increase of 18%. During the early childhood period, children born within 18 months of an elder sibling are more than twice as likely to die as those born after an interval of 36 months or more. Only 592 children experienced the birth of a younger sibling within 20 months; their second-year mortality was about twice as high as that of other children. These results support the findings based on retrospective data.

The prevalence of consanguinity in eight provinces of Afghanistan has recently been reported by Saify & Saadat (2012). The present cross-sectional study was done in order to illustrate the prevalence and types of consanguineous marriages among other populations of Afghanistan. Data on types of marriages were collected using a simple questionnaire. The total number of couples in this study was 5200 from the following provinces: Farah, Ghazni, Herat, Hilmand, Kabul, Kandahar, Logar, Parwan and Wardak. Consanguineous marriages were classified by the degree of relationship between couples: double first cousins, first cousins, first cousins once removed, second cousins and beyond second cousins. The coefficient of inbreeding (F) was calculated for each couple and the mean coefficient of inbreeding (α) estimated for each population. The α in the country was 0.0226, ranging from 0.0203 in Farah province to 0.0246 in Herat province. There were significant differences between provinces for frequencies of different types of marriages (p<0.001). First cousin marriages (21.7%) were the most common type of consanguineous marriages, followed by second cousins (16.0%), first cousins once removed (14.0%), beyond second cousins (6.9%) and double first cousins (1.6%). There was significant difference between ethnic groups for the types of marriages (p<0.001). Tajiks (Soni) and Sadats showed the lowest (α=0.0215) and highest (α=0.0242) levels of consanguinity among ethnic groups in Afghanistan, respectively. The present study shows that the Afghani populations, the same as other Islamic populations, have high levels of consanguinity.

The relationship between inter-generational social mobility of sons and daughters between 1958 and 1991 and biosocial variables, i.e. birth order, number of children in family, father's social class, region, educational attainment of child and father, educational and cognitive test scores (reading, mathematics, verbal and non-verbal IQ tests), was studied in a large British cohort study. The data used were collected as part of the British National Child Development Study (NCDS). The extent of social class mobility was determined inter-generationally and was categorized as none (no change in social class between the father's and index child's social class), upwardly mobile (where the index child moved up one or more social classes compared with their father) or downwardly mobile (where the index child moved down one or more social classes compared with their father). All of the biosocial variables were associated with social mobility when analysed separately. Multivariate analyses revealed that the most significant predictor of mobility categories in both sexes was education of the cohort member, followed by social class of the father. In both sexes mathematics score was a significant predicator, while in sons reading and non-verbal IQ scores were also important predictors. In the light of these results, it appears that social mobility in Britain takes place largely on meritocratic principles.

Understanding the level, trend, geographical variations and determinants of use of modern family planning (FP) plays a major role in designing effective interventions leading to increased usage. This study assessed these characteristics of FP use in Nigeria using data from the 2003, 2005 and 2007 National HIV/AIDS and Reproductive Health Survey, a national population-based household survey. A Bayesian geo-additive procedure was used, which provides flexible modelling of non-linear and spatial effects at a highly disaggregated level of states. The findings reveal considerable geographical variation in the use of modern FP in Nigeria, with a distinct north–south divide. Furthermore, a significant trend in the use of modern FP was evident, with an increase between 2003 and 2005 followed by a decline between 2005 and 2007. The effect of respondent's age was non-linear, and use of modern FP was found to differ significantly between never-married and currently/formerly married respondents. Awareness of FP methods and knowledge of where to get/buy FP services/methods were found to be significantly associated with usage. The findings provide policymakers with tools to prioritize the use of scarce resources for implementing FP and reproductive health interventions.

Several studies have documented increased prevalence of overweight and obesity in inhabitants of rural regions, but determinants of their prevalence are complex and not always in one direction. The aim of this study was to estimate both the prevalence and extent of overweight and obesity among rural girls in Poland between 1987 and 2001, as well as to assess differentiation of the phenomenon between regions of different social structures. The data come from two series of cross-sectional studies; the first in 1987 included 7764 girls, and the second in 2001 included 9431 girls aged 9–18. Body mass index (according to the International Obesity Task Force, IOTF) and the EOW index (extent of overweight), which shows by what mean BMI value the overweight boundaries are exceeded, were calculated. Overweight and obesity prevalences in the whole sample, were, respectively, 14.9% and 2.7% in 1987 and 15.5% and 2.5% in 2001, but significant differentiation in the direction of the changes was observed between the examined regions. In one of them, characterized by sudden, mass and long-term unemployment, there was a considerable decrease in overweight and obesity prevalence, whereas in a relatively wealthier region no changes were observed during the 14-year period. Two other regions with a relatively low standard of living and low incomes and education status presented a significant increase in overweight and obesity prevalence. The EOW index increased from 1.9 to 2.1 in the whole examined sample, and it also confirmed significant differences in expansion of overweight and obesity between the examined regions. The complex character of political and socioeconomic changes in Poland during the 1990s has resulted in two-directional changes in biological measures of living conditions. The analysis of the whole sample led to different results in comparison to separate analyses of each of the examined regions.

This paper describes a simple question module to assess community stigma in rural India. Fear of stigma is known to prevent people from seeking HIV testing and to contribute to further disease transmission, yet relatively little attention has been paid to community stigma and ways of measuring it. The module, based on a vignette of a fictional HIV-positive woman, was administered to 494 married women and 186 unmarried male and female adolescents in a village in rural Maharashtra, India. To consider the usefulness of the question module, a series of hypotheses were developed based on the correlations found in other studies between HIV-related stigma and socio-demographic characteristics (age, education, discussion of HIV with others, knowing someone living with HIV, knowledge about its transmission and whether respondents acknowledged stigmatizing attitudes as their own or attributed them to others). Many of the study's hypotheses were confirmed. Among married women, correlates of stigma included older age, lack of discussion of HIV and lack of knowledge about transmission; among adolescents, lower education and lack of discussion of HIV were the most significant correlates. The paper concludes that the question module is a useful tool for investigating the impact of interventions to reduce stigma and augment social support for people living with HIV in rural India.

Young people, especially university students, are at high risk of HIV infections because of little or no parental or administrative prohibitions in campus environments. The aim of this study was to ascertain the level of condom use among university students in Zimbabwe; that is, condom use at last sex and consistent condom use among both regular and casual partners. The study draws on self-completed questionnaires administered to university students. The results reveal that, while 78.3% of sexually active respondents had used condoms in penetrative sexual encounters before, only 56.2% had used condoms at their last sexual encounter. As expected, consistent condom use was lower in regular sexual partnerships than it was in casual partnerships (30.6% versus 54.6%). Condom use at first sex and high personal HIV risk perception were found to be the most important factors in explaining condom use at last sex and consistent condom use with casual partners. Condom use intentions were high, as 75% of respondents indicated that they would use condoms at their next sexual encounters. Whilst this is commendable, use rates should ideally be higher still. Campus HIV/AIDS programmers should endeavour to ensure that condoms are available at all times in order to help translate these intentions into actual condom use. In addition, promotional programmes should encourage those who have not yet initiated sexual intercourse to use condoms at their first sex and also to improve personal HIV risk perceptions in order to trigger initiation of protective sexual behaviours.

Research on gender power in contraceptive use has focused on whether women have an active role in household decision-making (the participation model) or on the extent of their control of domestic decisions (the control model); it has also addressed the joint effects of power, age, education and work. Findings published in this journal (Woldemicael, 2009) suggest a third power model according to which wives make joint decisions with their husbands on important domestic areas and autonomous decisions on secondary matters (the egalitarian model). In analyses of Demographic and Health Survey data sets from 46 countries, the egalitarian model explained contraceptive use better than the control and participation models in 19 out of 20 countries outside sub-Saharan Africa; its superiority was less overwhelming in this sub-continent. Power effects on contraceptive use that depend on women's education, age and work for cash are larger in sub-Saharan Africa than in other world regions, whereas independent power effects differ little regionally, suggesting the action of a personality factor. Situational specification of decision importance and direct measurement of women's assertiveness are needed to improve the explanation of contraceptive behaviour.

The present study aims at modelling the effects of maternal socio-demographic characteristics on the birth weight distribution in Greece. The analysis is based on nationwide vital registration micro-data; 103,266 single live births recorded in 2006 are considered. Quantile regression models, allowing for the effects of covariates to vary across the conditional distribution of the dependent variable, birth weight, are applied to preterm and term births separately. The statistical analysis shows that the effects of most factors differentiate across the birth weight distributions. Ordinary Least Squares (OLS) coefficients, on the other hand, systematically underestimate effects at the lower tail and overestimate effects among heavier babies. Hence, quantile regression has a strong advantage over the OLS method. The findings also indicate that birth weight distributions of term and preterm infants are distinct and should be analysed separately. For both distributions female sex, primiparity, age of mother over 35 and prior history of stillbirths and child deaths are related to lower birth weight while higher educational attainment has a protective effect. Among term births, illegitimacy, living in big metropolitan areas and immigrant status of the mother are also significant predictors. For preterm births the impact of age of mother, parity and, in particular, prior stillbirths or deceased children is very pronounced.

The study objective was to analyse the association between food insecurity and the weight and height status of adolescents from a low-income area in the metropolitan region of Rio de Janeiro, Brazil. The population-based cross-sectional survey included 523 adolescents aged 12–18 years, selected by a three-stage cluster sample. Dietary intake was ascertained with a food frequency questionnaire and family food insecurity was assessed with a validated questionnaire. The analysis estimated weighted means of energy and nutrient intakes by families' socioeconomic characteristics and the association between dietary intake with overweight and stunting. The prevalence of mild family food insecurity was 36%, and 24% of the families reported moderate or severe food insecurity. Overweight prevalence was 24%, and the prevalence of stunting was 9%, with no significant differences between sex or age groups. Family food insecurity was associated with unfavourable socioeconomic characteristics, but there was no association between socioeconomic characteristics (including family food insecurity) and overweight or stunting. Moderate or severe family food insecurity was inversely associated with intake of protein and calcium. In addition, stunting was associated with low calcium and iron intake. The co-existence of family food insecurity with overweight and stunting implies a high nutritional risk for adolescents from poor areas of Rio de Janeiro. Nevertheless, the observed absence of a statistical association between family food insecurity and weight status attests to the complexity of this issue.

The present analysis compares the distribution of surnames by means of spatial autocorrelation analysis in the Spain–Portugal border region. The Spanish National Institute of Statistics provides a database of surnames of residents in the western Spanish provinces of Zamora, Salamanca, Cáceres, Badajoz and Huelva. The Spanish and Portuguese patterns of surname distribution were established according to various geographic axes. The results obtained show a low diversity of surnames in this region – especially in the centre – which can be explained by the absence of any major geographic barriers, with the exception of the mountain ranges between hydrographic basins, and by the presence of traditional roads that have existed since Roman times. The latter have resulted in a constant migratory flow over short–median distances, which, as can be deduced from the surnames, fits two north/south territorial axes running parallel to the border between Spain and Portugal. The distribution patterns of Portuguese and Spanish surnames differ with regard to their frequencies in the five provinces studied, which can be attributed to their respective historical, economic and social conditions. It is concluded that the border delimiting these two countries has affected the migratory flow, thereby conditioning the demographic and genetic structure of the western Spanish regions.

This study uses Swedish occupational register data to examine whether the proportion of men in administrative workplaces in the Swedish public service affects all-cause mortality risks amongst both males and females of working age. Using piecewise constant survival models to analyse occupational data from the Swedish administrative registers from 1995 to 2007, it was found that for males, a 1% increase in the proportion of males was associated with a 1.3% increase in mortality risk (hazard ratio, HR 1.013, 95% CI 1.007–1.020, p<0.001), but no association was found for females (HR 1.004, 95% CI 0.996–1.012, p=0.297). Adjustments were made for age, family status, education, occupational status, occupational segregation by sex, the total number of individuals in the workplace, level of government, region, period and variables reflecting the workplace structure by age, age by sex, occupation and education. A higher proportion of males may be related to (i) an increased exposure to risky health behaviours such as alcohol consumption and unhealthy dietary patterns, (ii) a tendency towards sickness presenteeism, and (iii) an increase in the levels of several well-established emotional stressors in the workplace, leading to an increased level of psychosocial stress. The findings and potential extensions of this research are discussed.

The secondary sex ratio (the ratio of boys to girls at birth) may demonstrate a decline following community stress-inducing major destructive events. This study aims to investigate whether or not moderate adverse life events, in conjunction with endogenous psychological characteristics, can induce sufficient community stress to affect the sex ratio. From April 3rd to May 8th 2006 a moderate sized earthquake sequence occurred offshore the Greek island of Zakynthos, which had been hit by a destructive earthquake half a century earlier. The monthly sex ratio after the earthquake sequence was estimated and compared with that of previous and following years. Eleven months after the onset of the earthquakes the sex ratio fell to 1.000, and during the next two months (March and April) it declined further to 0.612. The sex ratio one year before its decline was 1.158 and over a total 6-year period, 3 years before and 3 years after the sequence, it was 1.063; the March–April decline in male births is significant (OR=0.53, 95% CI=0.32–0.86, p=0.013, and OR=0.57, 95% CI=0.36–0.91, p=0.023, respectively). Also, the number of boys relative to girls in March–April 2007 was significantly lower than during the same months 3 years before and after the sequence (OR=0.50, 95% CI=0.31–0.82, p=0.007). The findings suggest that basic biological characteristics, such as the sex ratio, can be affected by psychological stressors interwoven with the pertaining psychology of the population.

During famines females generally have a mortality advantage relative to males, and the highest levels of mortality occur in the very young and the elderly. One popular hypothesis is that the sex differential in mortality may reflect the greater body fatness combined with lower metabolism of females, which may also underpin the age-related patterns of mortality among adults. This study evaluated the ‘body fat’ hypothesis using a previously published and validated mathematical model of survival during total starvation. The model shows that at a given body weight females would indeed be expected to survive considerably longer than males in the absence of food. At a mass of 70 kg for example a female aged 30 would survive for 144 days compared with life expectancy of only 95 days for a male of the same age and weight. This effect is contributed to by both the higher body fatness and lower metabolism of the females at a given body weight. However, females are generally smaller than males and in addition to a sex effect there was also a major effect of body size – heavier individuals survive longer. When this body size effect was removed by considering survival in relation to BMI the sex effect was much reduced, and could be offset by a relatively small difference in pre-famine BMI between the sexes. Nevertheless, combining these predictions with observed mean BMIs of males and females across 48 countries at the low end of the obesity spectrum suggests that in the complete absence of food females would survive on average about 40% longer (range 6 to 64.5%) than males. The energy balance model also predicted that older adult individuals should survive much longer than younger adult individuals, by virtue of their lower resting metabolic rates and lower activity levels. Observations of the female survival advantage in multiple famines span a much wider range than the model prediction (5% to 210%). This suggests in some famines body fatness may be a significant factor influencing the mortality differential between the sexes, but in other famines other factors are likely to be more important. Moreover, the pattern of mortality in relation to age is completely opposite that predicted. These data emphasize the complex nature of famine mortality and suggest that a simple model of energy utilization alone is inadequate to explain the major aspects of this phenomenon.

Utah has the highest total fertility of any state in the United States and also the highest proportion of population affiliated with the Church of Jesus Christ of Latter-day Saints (the LDS or Mormon Church). Data were used from the 1996 Utah Health Status Survey to investigate how annual household income, education and affiliation with the LDS Church affect fertility (children ever born) for married women in Utah. Younger age and higher education were negatively correlated with fertility in the sample as a whole and among non-LDS respondents. Income was negatively associated with fertility among non-LDS respondents. However, income was positively correlated with fertility among LDS respondents. This association persisted when instrumental variables were used to address the potential simultaneous equations bias arising from the potential endogeneity of income and fertility. The LDS religion's pronatalist stance probably encourages childbearing among those with higher income.

In genetics, a consanguineous marriage means union between couples who are related as second cousins or closer. The present cross-sectional study was carried out in order to illustrate the prevalence and types of consanguineous marriages in the Shi'a population living in widespread territories in Lebanon including the Bekaa Valley, the south of Lebanon and the southern suburb of Beirut. Data on types of marriages were collected using a simple questionnaire. The total number of couples in the study was 1203. Consanguineous marriage was classified by the degree of relationship between couples. The overall frequency of consanguinity was found to be 28.4%, with first cousin marriages (21.3%) being the most common type followed by first cousins once removed (5.5%), then double first cousins (0.8%). The frequencies of second cousin and beyond second cousin marriages were the same at 0.4% of all the marriages. The mean inbreeding coefficient (α) was estimated at about 0.0161 for the population. There were no significant differences between the three studied territories for frequencies of different types of marriages (p>0.1), nor were there significant differences between the rural and urban areas (p>0.1).

Variation in height among young adults has been linked to the living conditions of different social groups. The aim of this study was to measure variation in the height and knee height of young adults by head of household employment level and family income. The sample comprised 180 individuals (90 girls) aged 16 and 17 years living in the city of Merida, Mexico. Height and knee height were measured by anthropometry, and individuals' family social and economic data collected from their mothers. Variation in these measurements was analysed by three categories of employment and family income terciles. One-way ANOVAs were done by sex to compare mean height and knee height by employment and family income. Coefficients of variation were calculated and a Bartlett test applied. Significant differences in height and knee height were observed only between family income terciles. Both sexes were taller at the highest levels of family income (p<0.05) and men had the highest (p<0.05) knee height. Highest family income individuals exhibited the least variation in height and knee height. Similarity in socioeconomic conditions for families in the lowest family income tercile and with employee heads of household was not associated with lower variation of height and knee height.