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Socio-economic inequalities in academic achievement emerge early in life and are observed across the globe. Cognitive ability and “non-cognitive” attributes (such as self-regulation) are the focus of many early years’ interventions. Despite this, little research has compared the contributions of early cognitive and self-regulation abilities as separate pathways to inequalities in academic achievement. We examined this in two nationally representative cohorts in the UK (Millennium Cohort Study, n = 11,168; 61% original cohort) and Australia (LSAC, n = 3028; 59% original cohort). An effect decomposition method was used to examine the pathways from socio-economic disadvantage (in infancy) to two academic outcomes: ‘low’ maths and literacy scores (based on bottom quintile) at age 7–9 years. Risk ratios (RRs, and bootstrap 95% confidence intervals) were estimated with binary regression for each pathway of interest: the ‘direct effect’ of socio-economic disadvantage on academic achievement (not acting through self-regulation and cognitive ability in early childhood), and the ‘indirect effects’ of socio-economic disadvantage acting via self-regulation and cognitive ability (separately). Analyses were adjusted for baseline and intermediate confounding. Children from less advantaged families were up to twice as likely to be in the lowest quintile of maths and literacy scores. Around two-thirds of this elevated risk was ‘direct’ and the majority of the remainder was mediated by early cognitive ability and not self-regulation. For example in LSAC: the RR for the direct pathway from socio-economic disadvantage to poor maths scores was 1.46 (95% CI: 1.17–1.79). The indirect effect of socio-economic disadvantage through cognitive ability (RR = 1.13 [1.06–1.22]) was larger than the indirect effect through self-regulation (1.05 [1.01–1.11]). Similar patterns were observed for both outcomes and in both cohorts. Policies to alleviate social inequality (e.g. child poverty reduction) remain important for closing the academic achievement gap. Early interventions to improve cognitive ability (rather than self-regulation) also hold potential for reducing inequalities in children's academic outcomes., Highlights • We decomposed pathways from socio-economic disadvantage to mid-childhood academic ability. • 2/3 effect of socio-economic disadvantage was direct (not through cognitive ability or self-regulation). • The indirect effect was mainly through cognitive ability. • Early interventions to improve cognitive ability hold potential. • But policies to alleviate social inequality remain essential for inequality reduction.

Evidence is lacking on whether the duration and timing of low socioeconomic position (SEP) across a person's life course may be associated with incidence of type 2 diabetes mellitus (T2D). The authors’ objectives were to investigate associations between cumulative SEP and the incidence of T2D in the Framingham Offspring Study (n = 1,893; 52% women; mean baseline age = 34 years). Pooled logistic regression analyses demonstrated that age-adjusted cumulative SEP was associated with T2D in women (for low vs. high cumulative SEP, odds ratio (OR) = 1.92, 95% confidence interval (CI): 1.08, 3.42). Age-adjusted analyses for young-adulthood SEP (7.85 for ≤12 vs. >16 years of education, OR = 2.84, 95% CI: 1.03), active professional life SEP (for laborer vs. professional/executive/supervisory/technical occupations, OR = 2.40, 95% CI: 1.05, 5.47), and social-mobility frameworks (for declining life-course SEP, OR = 2.99, 95% CI: 1.39, 6.44; for stable low vs. stable high life-course SEP, OR = 1.85, 95% CI: 1.02, 3.35) all demonstrated associations between low SEP and T2D incidence in women. No association was observed between childhood SEP and T2D in women for father's education (some high school or less vs. any postsecondary education, OR = 1.26, 95% CI: 0.72, 2.22). In men, there was little evidence of associations between life-course SEP and T2D incidence. These findings suggest that cumulative SEP is inversely associated with incidence of T2D in women, and that this association may be primarily due to the women's educational levels and occupations.

Cumulative exposure to socioeconomic disadvantage across the life course may be inversely associated with coronary heart disease (CHD); the mechanisms are not fully clear. An objective of this study was to determine whether cumulative life-course socioeconomic position (SEP) is associated with CHD incidence in a well-characterized US cohort that had directly assessed childhood and adulthood measures of SEP and prospectively measured CHD incidence. Furthermore, analyses aimed to evaluate whether adjustment for CHD risk factors reduces the association between cumulative life-course SEP and CHD. The authors examined 1,835 subjects who participated in the Framingham Heart Study Offspring Cohort from 1971 through 2003 (mean age, 35.0 years; 52.4% women). Childhood SEP was measured as father's education; adulthood SEP was assessed as own education and occupation. CHD incidence included myocardial infarction, coronary insufficiency, and coronary death. Cox proportional hazards analyses indicated that cumulative SEP was associated with incident CHD after adjustment for age and sex (hazard ratio = 1.82, 95% confidence interval: 1.17, 2.85 for low vs. high cumulative SEP score). Adjustment for CHD risk factors reduced that magnitude of association (hazard ratio = 1.29, 95% confidence interval: 0.78, 2.13). These findings underscore the potential importance of CHD prevention and treatment efforts for those whose backgrounds include low SEP throughout life.

Objective To determine whether differences in combination DTaP vaccine types at 2, 4 and 6 months of age were associated with mortality (all-cause or non-specific), within 30 days of vaccination. Design Observational nationwide cohort study. Setting Linked population data from the Australian Childhood Immunisation Register and National Death Index. Participants Australian infants administered a combination trivalent, quadrivalent or hexavalent DTaP vaccine (DTaP types) between January 1999 and December 2010 at 2, 4 and 6 months as part of the primary vaccination series. The study population included 2.9, 2.6, & 2.3 million children in the 2, 4 and 6 month vaccine cohorts, respectively. Main outcome measures Infants were evaluated for the primary outcome of all-cause mortality within 30 days. A secondary outcome was non-specific mortality (unknown cause of death) within 30 days of vaccination. Non-specific mortality was defined as underlying or other cause of death codes, R95 ‘Sudden infant death syndrome’, R96 ‘Other sudden death, cause unknown’, R98 ‘Unattended death’, R99 ‘Other ill-defined and unspecified cause of mortality’ or where no cause of death was recorded. Results The rate of 30 day all-cause mortality was low and declined from 127.4 to 59.3 deaths per 100,000 person-years between 2 and 6 month cohorts. When compared with trivalent DTaP vaccines, no elevated risk in all-cause or non-specific mortality was seen with any quadrivalent or hexavalent DTaP vaccines, for any cohort. Conclusion Use of routine DTaP combination vaccines with differing disease antigens administered during the first six months of life is not associated with infant mortality.

Objective: The objective of this study was to assess the prevalence and sociodemographic characteristics of cesarean section in Ethiopia. Methods: We used data collected for Ethiopia Demographic and Health Surveys (DHS) conducted in 2000, 2005, 2011, and 2016. A two-stage, stratified, clustered random sampling design was used to gather information from women who gave birth within the 5-year period before each of the surveys. We analyzed the data to identify sociodemographic characteristics associated with cesarean section using log-Poisson regression models. Results: The national cesarean section rate increased from 0.7% in 2000 to 1.9% in 2016, with increases across seven of the eleven administrative regions of Ethiopia. Addis Ababa had the highest cesarean section rate (21.4%) in 2016 and the greatest increase since 2000. In the adjusted analysis, women who gave birth in private health facility had a 78.0% higher risk of cesarean section (adjusted prevalence ratio (aPR) (95% CI) 1.78 (1.22, 2.58)) compared with women who gave birth in public health facility. Having four or more births was associated with a lower risk of cesarean section compared with first births (aPR (95% CI) 0.36 (0.16, 0.79)). Conclusions: The Ethiopian national cesarean section rate is about 2%, but the rate varies widely among administrative regions, suggesting unequal access. Cesarean sections were highest among urban mothers, first births, births to women with higher education, and births to women from the richest quintile of household wealth. Refereed/Peer-reviewed

ObjectivesTo quantify emergency department (ED) presentations by individuals within vulnerable populations compared with other adults and the extent to which these are potentially preventable.DesignPeriod prevalence study from 2005-2006 to 2010–2011.SettingPerson-linked, ED administrative records for public hospitals in South Australia.ParticipantsAdults aged 20 or more in South Australia’s metropolitan area presenting to ED and categorised as Refugee and Asylum Seeker Countries of birth (RASC); Aboriginal; those aged 75 years or more; or All others.Main outcome measuresUnadjusted rates of ambulatory care sensitive condition (ACSC), general practitioner (GP)–type presentations and associated direct ED costs among mutually exclusive groups of individuals.ResultsDisparity between RASC and All others was greatest for GP-type presentations (423.7 and 240.1 persons per 1000 population, respectively) with excess costs of $A106 573 (95% CI $A98 775 to $A114 371) per 1000 population. Aboriginal had highest acute ACSC presenter rates (125.8 against 51.6 per 1000 population) with twice the risk of multiple presentations and $A108 701 (95% CI $A374 to $A123 029) per 1000 excess costs. Those aged 75 or more had highest chronic ACSC presenter rates (119.7vs21.1 per 1000), threefold risk of further presentations (incidence rate ratio 3.20, 95% CI 3.14 to 3.26) and excess cost of $A385 (95% CI $A178 160 to $A184 609) per 1000 population.ConclusionsVulnerable groups had excess ED presentations for a range of issues potentially better addressed through primary and community healthcare. The observed differences suggest inequities in the uptake of effective primary and community care and represent a source of excess cost to the public hospital system.

ObjectiveTo examine the impact of caesarean section on breastfeeding indicators—early initiation of breastfeeding, exclusive breastfeeding under 6 months and children ever breastfed (at least once)—in sub-Saharan Africa.DesignSecondary analysis of Demographic and Health Surveys (DHS).SettingThirty-three low-income and middle-income countries with a survey conducted between 2010 and 2017/2018.ParticipantsWomen aged 15–49 years with a singleton live last birth during the 2 years preceding the survey.Main outcome measuresWe analysed the DHS data to examine the impact of caesarean section on breastfeeding indicators using the modified Poisson regression models for each country adjusted for potential confounders. For each breastfeeding indicator, the within-country adjusted prevalence ratios (aPR) were pooled in random-effects meta-analysis.ResultsThe within-country analyses showed, compared with vaginal birth, caesarean section was associated with aPR for early initiation of breastfeeding that ranged from 0.24 (95% CI 0.17 to 0.33) in Tanzania to 0.89 (95% CI 0.78 to 1.00) in South Africa. The aPR for exclusive breastfeeding under 6 months ranged from 0.58 (95% CI 0.34 to 0.98) in Angola to 1.93 (95% CI 0.46 to 8.10) in Cote d'Ivoire, while the aPR for children ever breastfed ranged from 0.91 (95% CI 0.82 to 1.02) in Gabon to 1.02 (95% CI 0.99 to 1.04) in Gambia. The meta-analysis showed caesarean section was associated with a 46% lower prevalence of early initiation of breastfeeding (pooled aPR, 0.54 (95% CI 0.48 to 0.60)). However, meta-analysis indicated little association with exclusive breastfeeding under 6 months (pooled aPR, 0.94 (95% CI 0.88 to 1.01)) and children ever breastfed (pooled aPR, 0.98 (95% CI 0.98 to 0.99)) among caesarean versus vaginally born children.ConclusionsCaesarean section had a negative influence on early initiation of breastfeeding but showed little difference in exclusive breastfeeding under 6 months and children ever breastfed in sub-Saharan Africa.

Whereas the influence of pregnancy diet and milk feeding on children’s health and development is well characterized, the role of early food intake and eating behaviors is largely unexplored. This study aimed to determine whether the degree of adherence to complementary feeding guidelines was associated with dietary, obesity, cardiovascular, and cognitive outcomes at 7–8 y of age. Data were analyzed from the Avon Longitudinal Study of Parents and Children using parent-completed dietary questionnaires at 6 mo of age to calculate a Complementary Feeding Utility Index score. Regression analysis was used to explore associations between the index score and dietary patterns derived via principal component analysis (n = 4326), body-mass index (BMI) (n = 4801), waist circumference (n = 4798), blood pressure (n = 4685), and lipids (n = 3232) measured at age 7 y; and intelligence quotient (IQ) measured at age 8 y (n = 4429) after adjustment for covariates. The index score was negatively associated with a “processed” dietary pattern [β = −0.16 (95% CI: −0.20, −0.13); P < 0.001] but positively associated with a “health conscious” dietary pattern [β = 0.18 (95% CI: 0.14, 0.21); P < 0.001]. A higher index score was also positively associated with total, verbal, and performance IQ scores at 8 y of age [β = 1.92 (95%CI: 1.38, 2.47); P < 0.001 for total IQ). The index score was weakly associated with waist circumference [β = −0.15 (95%CI: −0.31, −0.002); P = 0.046] and diastolic blood pressure [β = −0.24 (95%CI: −0.47, −0.01); P = 0.043] at 7 y of age but was not associated with BMI or other cardiovascular risk factors. These findings suggest that adherence to current complementary feeding guidelines may have implications for some, but not all, health and development outcomes in childhood Refereed/Peer-reviewed

Objective: To examine trends in reports of child maltreatment to the Northern Territory Department of Children and Families among Aboriginal and non-Aboriginal children. Design, setting and subjects: A historical cohort study using administrative data collections of notifications and substantiated cases of maltreatment among children aged from 0 to 17 years. Main outcome measures: Annual rates of notification and substantiation of different types of child maltreatment. Results: From 1999 to 2010, the overall annual rates of notification for maltreatment of Aboriginal children showed an average increase of 21% (incidence rate ratio [IRR], 1.21; 95% CI, 1.19–1.24). The greatest increases were in notifications for neglect and emotional abuse. There were parallel increases in rates of substantiated cases of maltreatment. Among non-Aboriginal children, the overall annual rates of notification also increased (IRR, 1.10; 95% CI, 1.07–1.14); however, changes in annual rates of substantiated cases for all types of maltreatment were not statistically significant. Conclusion: There have been considerable increases in both notifications and substantiated cases of child maltreatment, most prominently among Aboriginal children. It is possible that the observed increases reflect increasing incidence of maltreatment; however, they are also consistent with a mix of increased surveillance, improved service access, changes in policy and a shift in public attitudes. Refereed/Peer-reviewed

Dietary patterns are a useful summary measure of diet. Few studies have examined the nutrient profiles underpinning the dietary patterns of young children. The study aim is to determine whether dietary patterns at 6 and 15 months of age are associated with nutrient intakes at 8 and 18 months, respectively. Participants were children from the Avon Longitudinal Study of Parents and Children who had complete dietary pattern and nutrient intake data (n = 725 at 6–8 months, n = 535 at 15–18 months). The association between tertiles of dietary pattern scores and nutrient intake was examined using a non-parametric test for trend. Scores on the home-made traditional pattern (6–8 months) were positively associated with median energy intake. Each dietary pattern had different associations with energy-adjusted intakes of macro- and micro-nutrients. At both times, the discretionary pattern was positively and the ready-prepared baby foods pattern was negatively associated with sodium intake. At 6–8 months, calcium and iron intakes decreased across scores on the home-made traditional and breastfeeding patterns, but increased across the ready-prepared baby food patterns. These findings highlight that dietary patterns in infants and toddlers vary in their underlying energy and nutrient composition.

Diet supplies the nutrients needed for the development of neural tissues that occurs over the first 2 years of life. Our aim was to examine associations between dietary patterns at 6, 15 and 24 months and intelligence quotient (IQ) scores at 8 years. Participants were enrolled in an observational birth cohort (ALSPAC study, n = 7,097). Dietary data was collected by questionnaire and patterns were extracted at each time using principal component analysis. IQ was measured using the Wechsler Intelligence Scale for Children at 8 years. Associations between dietary patterns and IQ were examined in regression analyses adjusted for potential confounding and by propensity score matching, with data imputation for missing values. At all ages, higher scores on a Discretionary pattern (characterized by biscuits, chocolate, sweets, soda, crisps) were associated with 1–2 point lower IQ. A Breastfeeding pattern at 6 months and Homemade contemporary patterns at 15 and 24 months (herbs, legumes, cheese, raw fruit and vegetables) were associated with 1-to-2 point higher IQ. A Home-made traditional pattern (meat, cooked vegetables, desserts) at 6 months was positively associated with higher IQ scores, but there was no association with similar patterns at 15 or 24 months. Negative associations were found with patterns characterized by Ready-prepared baby foods at 6 and 15 months and positive associations with a Ready-to-eat foods pattern at 24 months. Propensity score analyses were consistent with regression analyses. This study suggests that dietary patterns from 6 to 24 months may have a small but persistent effect on IQ at 8 years. Refereed/Peer-reviewed

The complementary feeding period is an important stage of child development. The study aim was to develop an index reflecting the degree of adherence to complementary feeding guidelines, evaluate its convergent validity, and explore associations with socio-demographic factors and dietary pattern scores in childhood. Data were analyzed from the Avon Longitudinal Study of Parents and Children (n = 6065) using parent-completed dietary questionnaires at 6 mo of age, socio-demographic information, and dietary patterns derived by principal component analysis at age 3 y. The Complementary Feeding Utility Index (CFUI) consists of 14 components: breastfeeding duration, feeding to appetite, timing of introduction to solids, exposure to iron-rich cereals, fruit and vegetable intake, exposure to high-fat/-salt/-sugar foods including sugary drinks, food texture, and meal/snack frequency. Regression analyses were undertaken to investigate associations between index scores, socio-demographic factors, food and nutrient intakes, and dietary pattern scores at age 3 y. Milk and food intake at 6 mo and nutrient intake at 8 mo of age varied across quintiles of index score in largely the expected directions. Associations were found among index score, maternal age, education, social class, maternal smoking history, and prepregnancy BMI. After adjustment for socio-demographic factors, the index score was associated with "processed" [β = -0.234 (95% CI = -0.260, -0.209)] and "healthy" [β = 0.185 (95% CI = 0.155, 0.215)] dietary pattern scores at age 3 y. The CFUI is able to discriminate across food intake, nutrient intake, and socio-demographic factors and is associated with later dietary patterns. Refereed/Peer-reviewed

Background: The portrayal of diet over time is a natural progression from the characterization of diet at single time points. The transition dietary period, a dynamic period of rapid dietary change spanning infancy and toddlerhood when children shift from a milk-based to a food-based diet, has not been characterized. Objective: The objective was to summarize variation in dietary intakes spanning infancy and toddlerhood. Design: A prospective principal components analysis was applied to dietary intakes from 3 successive follow-ups of children enrolled in the ALSPAC (Avon Longitudinal Study of Parents and Children). The frequency of food and beverage consumption was assessed via questionnaire at ages 6, 15, and 24 mo (n = 2169). Results: Two types of transition diet were identified. The first transition diet was characterized by the consumption of home-prepared and raw foods (“healthy”) at all time points and the second by ready-prepared and discretionary foods (“less healthy”) consistently over time. Higher educational level and maternal age were associated with higher scores on the “healthy” diet, whereas younger maternal age and a lower educational level were associated with higher scores on the “less healthy” diet. Maternal BMI, number of older siblings, and lower social class were associated with the less-healthy transition diet but not with the healthy transition diet. Conclusions: Unique transition diets, including a less-healthy type, emerge by age 2 y. These diets are consistent with childhood and adult dietary patterns reported at single time points and show convergent validity both with known maternal sociodemographic predictors of childhood diet and with intake gradients across diet scores. Refereed/Peer-reviewed

Objective: Identify preventable pre-pregnancy risk factors that may affect the prevalence of miscarriage among a cohort of Australian Indigenous women. Methods: Data from 1,009 Indigenous women of childbearing age who participated in a 1999-2000 health screening program in far-north Queensland were linked to Queensland hospitalisation data. Women who attended hospital after their health check (censor date: March 2008) for a pregnancy-related condition were identified. Characteristics associated with becoming pregnant and subsequent miscarriage were analysed using generalised linear models. Results: After adjusting for age and ethnicity, women who became pregnant were more likely to be smokers and to have low red cell folate at baseline. The risk of miscarriage increased with age. Women who reported risky drinking or had elevated gamma-glutamyl transferase were also at higher risk. After further adjustment for risky drinking, the presence of chlamydia or gonorrhoea before pregnancy was associated with miscarriage. The presence of both infections at baseline compared with women who had no infection, again after further adjustment for risky drinking, was strongly associated with miscarriage; these women had more than a four-fold increase in risk (PR: 4.57 [2.21-9.46]). Elevated body mass index, high blood pressure and smoking were not statistically significantly associated with risk of miscarriage. Conclusions and implications: A high prevalence of pre-pregnancy sexually transmitted infections and high rates of risky drinking are associated with miscarriage among young Indigenous women in rural and remote communities in north Queensland. Refereed/Peer-reviewed

Background— Childhood blood pressure is largely uninfluenced by medical treatment and behavioral changes associated with hypertension diagnosis. Examining secular trends in childhood blood pressure and its contributing factors will help us better understand population-level determinants of blood pressure and hypertension. Methods and Results— Data were from 4 waves of the Korean National Health and Nutrition Examination Survey between 1998 and 2008, including a total of 5909 boys and girls 10 to 19 years of age. Over the past 10 years, age- and height-adjusted mean systolic blood pressure decreased substantially from 115.6 to 106.9 mm Hg (by 8.7 mm Hg) among boys and from 111.8 to 101.8 mm Hg (by 10.0 mm Hg) among girls. Associated childhood hypertension and prehypertension/hypertension prevalences decreased by 52% to 86%. These remarkable decreases were found among all age and socioeconomic groups and were not explained by secular changes in childhood obesity (body mass index and waist circumferences), health behaviors (cigarette smoking and physical activity), nutritional factors (sodium, potassium, total energy, protein, and fat intake), psychological factors (perceived stress and sleep duration), and sociodemographic factors (annual household income and family size). Conclusions— We observed important population declines in blood pressure in Korea over a 10-year period in children 10 to 19 years of age, but the likely causes for these secular trends remain to be determined.

This study examined the predictive ability of mother’s age, antenatal depression, education, financial difficulties, partner status, and smoking for a range of poor maternal and offspring outcomes assessed up to 61 months postnatally. Outcomes obtained from the Avon Longitudinal Study of Parents and Children (ALSPAC) were maternal postnatal depression at 8 weeks (n = 10,070), never breastfeeding (n = 7,976), feelings of poor attachment (n = 8,253) and hostility (n = 8,159) at 47 months, and not in employment, education or training (NEET, n = 8,265) at 61 months. Only a small proportion of women with each outcome were aged less than 20 years when they were pregnant. At least half of the women experiencing these outcomes, and up to 74.7% of women with postnatal depression, could be identified if they had at least one of the predictors measured during pregnancy (age

OBJECTIVES. The purpose of this work was to examine whether the positive association between birth weight and childhood cognitive ability is seen within siblings from the same family, as well as between nonsiblings, and to determine whether these associations vary with age. METHODS. We compared the association of birth weight with cognitive ability measured at ages 5 to 6, 7 to 9, and 11 to 12 years among a total of 5402 children from different families with that among 2236 to 3083 sibships from the National Longitudinal Study of Youth 1979-Children. RESULTS. In the whole cohort, there were positive associations between birth weight and cognitive ability at all ages, with the association increasing with age from a 0.81-point increase at ages 5 to 6 years to 1.30 and 1.44 points at ages 7 to 9 and 11 to 12 years, respectively, per 1 SD of gestational age- and gender-adjusted birth weight z score. With adjustment for covariates, there was marked attenuation of these associations. Mean differences were 0.28 points in children aged 5 to 6 years, 0.67 points in those aged 7 to 9 years, and 0.52 points in those aged 11 to 12 years after adjusting for child's gender, race or ethnicity, year of birth, and age at test; maternal age, height, parity, education, smoking during pregnancy, and cognitive ability; and household income. Our family-based analyses that separated within- and between-family effects found that the between-family associations were much stronger than the within-family associations. However, adjustment for potential confounders attenuated the between-family associations, and there was no evidence for a difference in association comparing the between- and within-family associations. CONCLUSIONS. In these data, the positive association between birth weight and childhood cognitive ability at ages 5 to 12 years is explained largely by family characteristics rather than a specific intrauterine effect.

Objective: To update a systematic review on the association between childhood socioeconomic circumstances and cause-specific mortality. Studies published since 2003 include a far greater number of deaths than was previously available justifying an update of the previous systematic review. Methods: Individual-level studies examining childhood socioeconomic circumstances and adult overall and cause-specific mortality published between 2003 and April 2007. Results and conclusions: The new studies confirmed that mortality risk for all causes was higher among those who experienced poorer socioeconomic circumstances during childhood. As already suggested in the original systematic review, not all causes of death were equally related to childhood socioeconomic circumstances. A greater proportion of new studies included women and showed that a similar pattern is valid for both genders. In addition, the new studies show that this association persists among younger birth cohorts, despite temporal general improvements in childhood conditions across successive birth cohorts. The difficulties of establishing a particular life-course model were highlighted.

The reasons for social inequality in breast cancer survival are far from established. Our study aims to study the importance of a range of socioeconomic factors and comorbid disorders on survival after breast cancer surgery in Denmark where the health care system is tax-funded and uniform. All 25,897 Danish women who underwent protocol-based treatment for breast cancer in 1983-1999 were identified in a clinical database and information on socioeconomic variables and both somatic and psychiatric comorbid disorders was obtained from population-based registries. We used Cox proportional hazards models to estimate the association between socioeconomic position and overall survival and further to analyse breast cancer specific deaths in a competing risk set-up regarding all other causes of death as competing risks. The adjusted hazard ratio (HR) for death was reduced in women with higher education (HR, 0.91; 95% confidence interval (CI), 0.85-0.98), with higher income (HR, 0.93; 95% CI, 0.87-0.98) and with larger dwellings (HR, 0.90; 95% CI, 0.85-0.96 for women living in houses larger than 150 m(2)). Presence of comorbid disorders increased the HR. An interaction between income and comorbid disorders resulting in a 15% lower survival 10 year after primary surgery in poor women with low-risk breast cancer having comorbid conditions ( approximately 65%) compared to rich women with similar breast cancer prognosis and comorbid conditions ( approximately 80%) suggests that part of the explanation for the social inequality in survival after breast cancer surgery in Denmark lies in the access to and/or compliance with management of comorbid conditions in poorer women. (c) 2007 Wiley-Liss, Inc.

We investigated the contribution of the large-scale immigration of White Europeans into the US between 1850 and 1930 to the timing and extent of the epidemic pattern of heart disease between 1900 and 1980. The analyses are based on data collected through the United States Federal Census from 1850 to the present. The hardcopy historical record confirms that census reports themselves and related monographs were concerned from 1850 with excessive mortality from heart disease of immigrants, particularly of Northern European origin and initially at least, their first-generation native-born children. Our analysis of the electronic database indicates a strong relationship between the percentage of US population foreign born and native born of foreign parentage and age adjusted mortality from heart disease. We identified a lag of 50 years giving the maximum linear correlation coefficient for men (r(2) = 0.92), and for women a shorter lag of 38 years and an earlier decline in Coronary Heart Disease (CHD) rates (r(2) = 0.96). Both the rise and fall of the CHD epidemic over an 80-year period correspond closely to the rise and fall of the foreign population in previous years. For the foreign born only, age adjusted negative binomial general estimated equation (GEE) models calculate the relative risk of dying of heart disease per 10% increase in proportion foreign born. There is an independent influence for men until 1930 and for women throughout the period from 1910 onwards. We conclude there is an impact of immigration on the pattern of the epidemic, mediated through a combination of factors, such as accumulated life-course susceptibility, deprived socio-economic conditions upon arrival, and the enthusiastic uptake of behaviours related to the classic risk factors of smoking, high saturated fat and salt diet. Our analysis provides a more contextualised understanding of the scale and timing of the epidemic of CHD in the US.

This is the second part of a glossary on indicators of socioeconomic position used in health research (the first part was published in the January issue of the journal).

BACKGROUND Our objective was to investigate the contribution of childhood and adult socioeconomic position (SEP) to adult obesity and smoking behaviour, in particular to establish the role of childhood circumstances across different studies in Europe and the US. METHODS Seven population-based surveys in six Western countries (Britain, Denmark, Finland, Netherlands, Sweden, US) were examined, with participants aged 30-50 yr and born between 1910 and 1960. Adult smoking was analysed using three outcomes (ever, current, or ex-) and adult obesity was defined as body mass index (kg/m(2)) > or =30. RESULTS A strong effect of adult social position was observed for smoking outcomes and obesity. For example, manual SEP in adulthood increased the risk of ever smoking (adjusted odds ratio (OR) 1.47-2.00 for men; 0.94-1.81 for women), and obesity (adjusted OR 1.06-2.24 for men, 1.21-3.26 for women). In most studies, childhood position was not associated with ever-smoking. For current smoking, manual childhood position was associated among women (adjusted OR 1.09-1.54), but no consistent pattern was seen for men. For ex-smoking, manual childhood origins lowered the chance of quitting among women (adjusted OR 0.64-0.81) except in the US (OR = 1.17); among men this association was seen in fewer studies (adjusted OR 0.74-1.09). For obesity, manual origins increased the risk for women (adjusted OR 0.96-2.50); effects were weaker among men but mostly in the same direction (adjusted OR 0.79-1.42). CONCLUSIONS As expected, adult SEP was an important influence on smoking behaviour and obesity. In addition, factors related to disadvantaged social origins appeared to increase the risk of obesity and reduce the probability of quitting smoking in adulthood, particularly in women.

This article describes U.S. income inequality and 100-year national and 30-year regional trends in age- and cause-specific mortality. There is little congruence between national trends in income inequality and age- or cause-specific mortality except perhaps for suicide and homicide. The variable trends in some causes of mortality may be associated regionally with income inequality. However, between 1978 and 2000 those regions experiencing the largest increases in income inequality had the largest declines in mortality (r= 0.81, p < 0.001). Understanding the social determinants of population health requires appreciating how broad indicators of social and economic conditions are related, at different times and places, to the levels and social distribution of major risk factors for particular health outcomes.

An ideological climate has persisted in Korea that has discouraged public discussion of social inequalities. Thus studies on inequalities in mortality remain undeveloped. This study is to examine age- and cause-specific socioeconomic mortality differentials for both men and women representative of the Korean population.Using Korea's 1995 Census and 1995-2000 Death Certificate data, age-, sex-, and education-specific mortality rates were measured, after which education-specific rate ratios, and relative indices of inequality were calculated.Graded educational differentials in mortality were observed among both sexes with higher mortality rates related to lower educational attainment in most causes of death. However, positive associations were identified between education levels and mortality rates with respect to ischaemic heart disease among older males and breast cancer among older females. The magnitude of educational inequality in mortality was not constant across causes and in some cases differed by sex.The changing relation between educational attainment and mortality rates from ischaemic heart disease and breast cancer likely reflects changes in the social distribution of risk factors that emerged in the process of Korea's rapid economic development. Studies on specific exposures over the life course influencing the occurrence of and survival after specific diseases would help provide a more complete understanding of patterns and trends in socioeconomic mortality differentials in Korea.

Study objectives: To identify and quantify a hypothesised collective effect of the neighbourhood on individual use of anxiolytic-hypnotic drugs (AHD). To analyse the general impact of neighbourhood social participation on use of AHD, adjusting for individual characteristics. Design: Cross sectional analysis performed by multilevel logistic regression with women at the first level and neighbourhoods at the second level. Setting: Malmö (250 000 inhabitants), Sweden. Participants:15 456 women aged 45 to 73, residing in 95 neighbourhoods in Malmö, who took part in the Malmö diet and cancer study (1991–1996). Main results: The prevalence of AHD use was 5.5% in the study sample. Overall, 1.7% of the total individual differences in the propensity for using AHD were explained by the neighbourhood level. This percentage, however, differed between different individuals. Low level of social participation in the neighbourhood was associated with higher probability of AHD use (OR = 3.10 (95% CI 1.51 to 6.41)), independently of individual age, low social participation, low educational level, and living alone. This association was reduced (OR = 2.01 (95% CI 0.97 to 4.14)) after the additional accounting for individual disability pension, low self rated health, stress, and medication for somatic disorders. Conclusions: The neighbourhood level of social participation seems to affect individual use of AHD, possibly through individual characteristics. However, neighbourhood boundaries play a minor part in understanding individual AHD use in the city of Malmö.

Purpose: This study aims to measure the impact of HRT use at the time of screening on rates of screen-detected invasive breast cancer (IBC) and ductal carcinoma in situ (DCIS), interval cancers and investigative procedures, within a well-established population-based mammography screening program. Methods: Using South Australian BreastScreen data from 1998 to 2009 pertaining to 819,722 screening episodes, Poisson regression models were undertaken to estimate the incidence risk ratios (IRR) for various screening outcomes at both the first and subsequent screening rounds, among women who had been using HRT in the 6 months prior to screening compared with those who had not. Results: Current HRT use was associated with increased risk of recall for assessment, biopsy procedures, and breast cancer diagnosis among BreastScreen participants. Risk of screen-detected breast cancer was increased at subsequent screening rounds (IRR = 1.30, 95 % confidence interval 1.18-1.34), but not at women's first screening round (1.05, 0.88-1.25). This increased risk applied to IBC (1.35, 1.27-1.45), but not to DCIS (1.04, 0.89-1.23). Interval cancer risk was elevated among HRT users following both the first screen (1.77, 1.33-2.37) and subsequent screening episodes (1.92, 1.72-2.15). Conclusions: Increased risks of recall, biopsy rates, screen-detected, and interval cancers among HRT users have important implications for population-based breast cancer screening programs. Our findings support the concept that HRT use may increase the growth of preexisting cancers. Lack of effect on DCIS could imply different etiology or time frames for DCIS and IBC development or increased transition from preinvasive to invasive disease due to HRT use. Refereed/Peer-reviewed

OBJECTIVE: We aimed to examine the ability of mother's age, and other factors measured during pregnancy (education, financial difficulties, partner status, smoking, and depression), to predict child development outcomes up to age 5 years. METHODS: Data were obtained from the Avon Longitudinal Study of Parents and Children (ALSPAC). Poor child development was defined as scoring in the worst 10% of a parent-reported ALSPAC developmental scale (ADS) at 18 months (n = 7546), the Strengths and Difficulties Questionnaire (SDQ) at 47 months (n = 8328), or teacher-reported School Entry Assessment (SEA) scores at 4 to 5 years (n = 7345). RESULTS: Only a small proportion of children with poor development had mothers aged younger than 20 years at their birth (3.3%, 6.4%, and 9.2%, for the ADS, SDQ, and SEA, respectively). A greater proportion with each measure of poor development would be identified (48.9%, 63.6%, and 74.4%, respectively) if all 6 predictors were used and a woman had at least 1 of these. Model discrimination was poor using maternal age only (area under the receiver operator characteristic curve ∼0.5 for all 3 outcomes). This improved when all 6 predictors were included in the model (ADS: 0.56; SDQ: 0.66; SEA: 0.67). Calibration also improved with the model including all 6 predictors. CONCLUSIONS: Even if programs targeted at teen-aged mothers are successful in improving child development, they will have little impact on population levels of poor child development if young maternal age is the sole or main means of identifying eligibility for the program.

Objective : To assess the effect of South Australian Kindergarten Union participation on adult cardiovascular behavioural risk factors. Methods : Using a retrospective cohort design, this study examined the effect of attendance at a Kindergarten Union preschool from 1940 to 1972 on behavioural risk factors for cardiovascular disease in adults 34-67 years. Dichotomous outcomes were analysed using a generalised linear model (Poisson distribution) with robust variance estimates. Outcomes with more than two categories were analysed with a multinomial logistic model. Results : There was a beneficial effect of preschool on high physical activity relative to sedentary and on ever smoking, but a negative effect on fruit consumption. Preschool attendance was not associated with alcohol risk or vegetable consumption under traditional criteria, however the point estimate for vegetable consumption was in the beneficial direction. The point estimates from the multinomial model suggested a step-wise decreasing risk for preschool attendees to have less risk of experiencing multiple behavioural risk factors (e.g. risk of five risk factors for preschool participants compared with non-participants). Conclusions and implications: Attendance at a Kindergarten Union preschool was associated with a reduced risk of two and an indication of benefit in a third behavioural risk factor in adulthood. This study provides some evidence for the potential health benefit of interventions outside of the health sector to prevent cardiovascular diseases, which are strongly associated with lifelong social disadvantage. Refereed/Peer-reviewed

Potential upstream determinants of coronary heart disease (CHD) include life-course socioeconomic position (e.g., childhood socioeconomic circumstances, own education and occupation); however, several plausible biological mechanisms by which socioeconomic position (SEP) may influence CHD are poorly understood. Several CHD risk factors appear to be more strongly associated with SEP in women than in men; little is known as to whether any CHD risk factors may be more strongly associated with SEP in men. Objectives were to evaluate whether cumulative life-course SEP is associated with a measurement of subclinical atherosclerosis, the ankle-brachial index (ABI), in men and women. This study was a prospective analysis of 1,454 participants from the Framingham Heart Study Offspring Cohort (mean age 57 years, 53.8% women). Cumulative SEP was calculated by summing tertile scores for father's education, own education, and own occupation. ABI was dichotomized as low (1.1 to 1.4). After adjustment for age and CHD risk factors cumulative life-course SEP was associated with low ABI in men (odds ratio [OR] 2.04, 95% confidence interval [CI] 1.22 to 3.42, for low vs high cumulative SEP score) but not in women (OR 0.86, 95% CI 0.56 to 1.33). Associations with low ABI in men were substantially driven by their own education (OR 4.13, 95% CI 1.86 to 9.16, for lower vs higher than high school education). In conclusion, cumulative life-course SEP was associated with low ABI in men but not in women. Refereed/Peer-reviewed

Purpose One of the specific aims of life course epidemiology is to assess the explanatory utility of three general hypotheses, namely the critical period hypothesis, the accumulation of risk hypothesis, and the effect modification hypothesis. Methods A structured regression approach to this problem is illustrated with data from an ongoing longitudinal study of children and their families established in Adelaide in 1998−2000. A series of nested models that correspond to the alternative life course hypotheses were fit in an investigation of the effects of maternal depressive states in early childhood on internalizing child behavior at 9.5 years. Both linear and logistic regression models were considered. Results The structured regression framework showed the accumulation hypothesis was most plausible for these data. The analyses also provided some evidence of a critical period for the effect of maternal depressive status around child age 2 years on internalizing behavior at 9.5 years. Conclusions The findings of this study suggest that comparing a suite of nested models to a full model can be useful in attempting to disentangle life course processes.

Background: Previous research has suggested that dehydration in infancy may lead to high blood pressure in later life because of sodium retention. The purpose of this study was to examine the effect of poor hygiene of the child, poor social and poor housing conditions at home and diarrhoea in childhood as proxies for dehydration on high blood pressure in later life. Methods: Data were from a subset of participants in the Kuopio Ischaemic Heart Disease Risk Factor Study,a population-based cohort study in eastern Finland.Information on childhood factors was collected from school health records (n¼952), from the 1930s to the1950s. Adult data were obtained from baseline examinations of the Kuopio Ischaemic Heart Disease Risk Factor Study cohort (n¼2682) in 1984e1989. Results: Men who had poor hygiene in childhood had on average 4.07 mm Hg (95% CI 0.53 to 7.61) higher systolic blood pressure than men who had good or satisfactory hygiene in childhood in the age-adjusted analysis. Reports of diarrhoea were not associated with adult blood pressure. Conclusions: The authors’ findings suggest that poor hygiene and living in poor social conditions in childhood are associated with higher systolic blood pressure in adulthood. Reported childhood diarrhoea did not explain the link between hygiene and high blood pressure in adulthood. Refereed/Peer-reviewed

Associations between life course socioeconomic position (SEP) and novel biological risk markers for coronary heart disease such as inflammatory markers are not well understood. Most studies demonstrate inverse associations of life course SEP with C-reactive protein (CRP), interleukin-6 (IL-6) and fibrinogen, however little is known about associations between life course SEP and other inflammatory markers including intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor II (TNFR2), lipoprotein phospholipase A2 (Lp-PLA2) activity, monocyte chemoattractant protein-1 (MCP-1) or P-selectin. The objectives of this analysis were to determine whether three life course SEP frameworks ("accumulation of risk", "social mobility" and "sensitive periods") are associated with the aforementioned inflammatory markers. We examined 1413 Framingham Offspring Study participants (mean age 61.2+/-8.6 years, 54% women), using multivariable regression analyses. In age- and sex-adjusted regression analyses, cumulative SEP ("accumulation of risk" SEP framework), for low vs. high SEP, was inversely associated with CRP, IL-6, ICAM-1, TNFR2, Lp-PLA2 activity, MCP-1 and fibrinogen. We found that there were few consistent trends between social mobility trajectories and most inflammatory markers. Own educational attainment was inversely associated with 7 of 8 studied inflammatory markers, while father's education, father's occupation and own occupation were inversely associated with 4, 5 and 4 inflammatory markers, respectively, in age- and sex-adjusted analyses. The strengths of association between SEP and inflammatory markers were typically substantially accounted for by CHD risk markers (smoking, body mass index, systolic blood pressure, total:HDL cholesterol ratio, fasting glucose, medications, depressive symptomatology) suggesting these may be important mechanisms that explain associations between SEP and the studied inflammatory markers.

Objectives. We assessed life expectancy increases in the past several decades in South Korea by age and specific causes of death. Methods. We applied Arriaga's decomposition method to life table data (1970–2005) and mortality statistics (1983–2005) to estimate age- and cause-specific contributions to changes in life expectancy. Results. Reductions in infant mortality made the largest age-group contribution to the life expectancy increase. Reductions in cardiovascular diseases (particularly stroke and hypertensive diseases) contributed most to longer life expectancy between 1983 and 2005 (30% in males and 28% in females). Lower rates of stomach cancer, liver disease, tuberculosis, and external-cause mortality accounted for 30% of the male and 20% of the female increase in longevity. However, higher mortality from ischemic heart disease, lung and bronchial cancer, colorectal cancer, breast cancer, diabetes, and suicide offset gains by 10% in both genders. Conclusions. Rapid increases in life expectancy in South Korea were mostly achieved by reductions in infant mortality and in diseases related to infections and blood pressure.

Background: Studies suggest that sex differences in blood pressure (BP) are established early in life. Sex differences in BP increases that occur during adolescence may be due to differences in changes in anthropometric characteristics. Methods: Using sex-specific individual growth models, we assessed the effect of height, body mass index (BMI; kg/m2), waist circumference, and triceps and subscapular skinfold thickness on changes in systolic BP in a cohort of 1293 adolescents in Montreal, Canada. BP and anthropometry were assessed biannually (1999/2000, 2002, 2004) at mean ages 12.8, 15.2, and 17.0. Results: On average, systolic BP increased by 11.1 mm Hg in boys and 3.2 mm Hg in girls during 5 years. Changes in height explained half of the overall increase in systolic BP in boys and virtually all of the increase in systolic BP in girls. No meaningful sex differences were observed in the association of changes in BMI, waist circumference, and triceps and subscapular skinfold thickness with systolic BP change during 5 years. Increases in 1 BMI unit, 1 cm waist circumference, or 1 mm triceps or subscapular skinfold thickness were associated with increases of 0.7, 0.24, 0.3, and 0.4 mm Hg systolic BP, respectively. Conclusions: Although sex differences in mean systolic BP changes during adolescence were largely attributable to differences in gains in height, the effect of gaining weight or body fat on systolic BP change was similar in boys and girls. Refereed/Peer-reviewed

Objectives. We examined the socioeconomic distribution of adolescent exposure to bullying internationally and documented the contribution of the macroeconomic environment. Methods. We used an international survey of 162 305 students aged 11, 13, and 15 years from nationally representative samples of 5998 schools in 35 countries in Europe and North America for the 2001–2002 school year. The survey used standardized measures of exposure to bullying and socioeconomic affluence. Results. Adolescents from families of low affluence reported higher prevalence of being victims of bullying (odds ratio [OR] = 1.13; 95% confidence interval [CI] = 1.10, 1.16). International differences in prevalence of exposure to bullying were not associated with the economic level of the country (as measured by gross national income) or the school, but wide disparities in affluence at a school and large economic inequality (as measured by the Gini coefficient) at the national level were associated with an increased prevalence of exposure to bullying. Conclusions. There is socioeconomic inequality in exposure to bullying among adolescents, leaving children of greater socioeconomic disadvantage at higher risk of victimization. Adolescents who attend schools and live in countries where socioeconomic differences are larger are at higher risk of being bullied.

Background: Breast cancer is the most commonly diagnosed cancer and the second leading cause of cancer death among women in the United States and varies systematically by race-ethnicity and socioeconomic status. Previous research has often focused on disparities between particular groups, but few studies have summarized disparities across multiple subgroups defined by race-ethnic and socioeconomic position. Methods: Data on breast cancer incidence, stage, mortality, and 5-year cause-specific probability of death (100 − survival) were obtained from the Surveillance, Epidemiology, and End Results program and data on mammography screening from the National Health Interview Survey from 1987 to 2005. We used four area-socioeconomic groups based on the percentage of poverty in the county of residence ( Results: From 1987 to 2004, area-socioeconomic disparities declined by 20% to 30% for incidence, stage at diagnosis, and 5-year cause-specific probability of death, and by roughly 100% for mortality, whether measured on the absolute or relative scale. In contrast, relative area-socioeconomic disparities in mammography use increased by 161%. Absolute race-ethnic disparities declined across all outcomes, with the largest reduction for mammography (56% decline). Relative race-ethnic disparities for mortality and 5-year cause-specific probability of death increased by 24% and 17%, respectively. Conclusions: Our analysis suggests progress towards race-ethnic and area-socioeconomic disparity goals for breast cancer, especially when measured on the absolute scale. However, greater progress is needed to address increasing relative socioeconomic disparities in mammography and race-ethnic disparities in mortality and 5-year cause-specific probability of death. (Cancer Epidemiol Biomarkers Prev 2009;18(1):121–31)

Objectives. We examined the association between childhood socioeconomic position and incidence of type 2 diabetes and the effects of gender and adult body mass index (BMI). Methods. We studied 5913 participants in the Alameda County Study from 1965 to 1999 who were diabetes free at baseline (1965). Cox proportional hazards models estimated diabetes risk associated with childhood socioeconomic position and combined childhood socioeconomic position–adult BMI categories in pooled and gender-stratified samples. Demographic confounders and potential pathway components (physical inactivity, smoking, alcohol consumption, hypertension, depression, health care access) were included as covariates. Results. Low childhood socioeconomic position was associated with excess diabetes risk, especially among women. Race and body composition accounted for some of this excess risk. The association between childhood socioeconomic position and diabetes incidence differed by adult BMI category in the pooled and women-only groups. Adjustment for race and behaviors attenuated the risk attributable to low childhood socioeconomic position among the obese group only. Conclusions. Childhood socioeconomic position was a robust predictor of incident diabetes, especially among women. A cumulative risk effect was observed for both childhood socioeconomic position and adult BMI, especially among women.

Background Patients living under better socioeconomic circumstances often receive more active treatments after an acute myocardial infarction (AMI) compared to less affluent patients. However, most previous studies were performed in countries with less comprehensive coverage for medical services. In this Swedish nation-wide longitudinal study we wanted to evaluate long-term survival after AMI in relation to socioeconomic position (SEP) and use of revascularization. Methods From the Swedish Myocardial Infarction Register we identified all 45 to 84-year-old patients (16,041 women and 30,366 men) alive 28 days after their first AMI during the period 1993 to 1996. We obtained detailed information on the use of revascularization, cumulative household income from the 1975 and 1990 censuses and 5-year survival after the AMI. Results Patients with the highest cumulative income (adding the values of the quartile categories of income in 1975 and 1990) underwent a revascularization procedure within one month after their first AMI two to three times as often as patients with the lowest cumulative income and had half the risk of death within five years. The socioeconomic differences in the use of revascularization procedures could not be explained by differences in co-morbidity or type of hospital at first admission. Patients who underwent revascularization showed a similar lowered mortality risk in the different income groups, while there were strong socioeconomic differences in long-term mortality among patients who did not undergo revascularization. Conclusion This nationwide Swedish study showed that patients with high income had a better long-term survival after recovery from their AMI compared to patients with low income. Furthermore, even though the use of revascularization procedures is beneficial, low SEP groups receive it less often than high SEP groups.

Background: Socioeconomic inequalities in health are ubiquitous in developed countries; however, whether these inequalities differ between women and men over time is less clear. Objective: To estimate the potentially different health effects of changes in socioeconomic position (SEP) on changes in health for working-age women and men over a 10-year period. Three main questions were addressed: (1) are there health differences between women and men over time, (2) do changes in SEP lead to health inequalities and (3) do changes in SEP impact health differently for women and men? Methods: Generalised estimating equations models were used to analyse cycles 1–5 of the Canadian National Population Health Survey for four measures of health, number of chronic conditions, self-rated health, functional health and mental distress, and three measures of SEP, income, education and employment status. Results: Health inequalities by sex/gender and by changes in SEP were present for all four outcomes in age-adjusted models; however, after controlling for time-dependent social structure, behaviour, and psychosocial factors the relationships persisted only for chronic conditions and psychological distress. There was no evidence that these effects differed, over time, between women and men. Conclusions: Men and women in this nationally representative sample of Canadians do not differentially embody changes in SEP, although both sex/gender and changes in SEP independently impact health.

Background Odds ratio (OR), a relative measure for health inequality, has frequently been used in prior studies for presenting inequality trends in health and health behaviors. Since OR is not a good approximation of prevalence ratio (PR) when the outcome prevalence is quite high, an important problem may arise when OR trends are used in data in which the outcome variable (e.g., smoking or ill-health) is of relatively high prevalence and varies significantly over time. This study is to compare time trends of odds ratio (OR) and prevalence ratio (PR) for examining time trends in socioeconomic inequality in smoking. Methods A total of 147,805 subjects (71,793 men and 76,017 women) aged 25–64 from three Social Statistics Surveys of Korea from 1999 to 2006 were analyzed. Socioeconomic position indicators were occupational class and education. Results While there were no significant p values for trend in ORs of occupational class among men, trends for PRs were significant. In women, p values for OR trends were similar to those for PR trends. In males, RII by log-binomial regression showed a significant increasing tendency while RII by logistic regression was stable between years. In females, trends of RIIs by logistic regression and log-binomial regression produced a similar level of p values. Conclusion Different methods of measuring trends in socioeconomic health inequalities may lead to different conclusions about whether relative inequalities are increasing or decreasing. Trends in ORs may overstate or understate trends in relative inequality in health when the outcome is of relatively high prevalence and that prevalence varies significantly with time.

The contributions of material, psychosocial, and behavioral factors in explaining socioeconomic inequalities in health have been explored in many Western studies. Most prior investigations have looked at relative abilities to explain such inequalities. In addition, little research focuses on Asian countries, despite the fact that the prevalence and socioeconomic distribution of risk factors for mortality are different there. This study examined relative and absolute abilities of material, psychosocial, and behavioral pathways to explain educational and occupational inequalities in mortality in a nationally representative sample from South Korea. The 1998 and 2001 National Health and Nutrition Examination Survey data were pooled and linked to national mortality data. Of 8366 men and women over 30 years of age, 310 died between 1999 and 2005. Nine pathway variables were examined: three material factors (income, health insurance, and car ownership status), three psychosocial factors (depression, stress, and marital status), and three behavioral factors (smoking, alcohol consumption, and physical exercise). The relative risk and relative index of inequality were used as measures of relative inequality, and risk differences and the slope index of inequality were used as measures of absolute inequality. Material factors explained a total of 29.0% of the excess in relative risk for education and 50.0% of the excess in relative risk for occupational class. Material factors explained 78.6% of the excess in absolute mortality difference for education and 41.1% for occupational class. Psychosocial factors for both education and occupational class had a relative and absolute explanatory power of less than 15%. Behavioral factors showed a relative explanatory power of about 15%, but absolute explanatory power reached 84.0% for education and 105.4% for occupational class. However, the number of deaths used to calculate the absolute explanatory power was small. Results of this study suggest that absolute socioeconomic mortality inequalities could be substantially reduced if behavioral risk factors were reduced in the whole population. Refereed/Peer-reviewed

Background Education level is one indicator of socioeconomic position which, in several countries including South Korea, is provided though death certificate data. Its validity determines the usefulness of death certificate data for exploring the association between socioeconomic position and mortality. This study was to compare education recorded on the death certificate with that reported before death in a nationally representative cohort of participants in the National Health and Nutrition Examination Survey (NHANES). Methods The 1998/2001 NHANES data contained unique 13-digit personal identification numbers that were individually linked to death certificate data from the Korean National Statistical Office. Duration of mortality follow-up was 7.1 years. The data from 513 deaths were used to determine sensitivity and specificity of education in death certificate and estimate agreement rates of education level between NHANES data and death certificate data. Odds ratios for agreement in education were also estimated. Covariates considered in the analyses were gender, age, duration between NHANES and death, and cause of death. Results The proportion of deaths without recorded education in death certificate was very low (0.2%). A total of 29.4% discordant pairs were found. Sensitivity and specificity for college or higher education were 0.84 (95% confidence interval 0.71–0.97) and 0.99 (0.98–1.00). However, sensitivity was poor for middle school education. The overall agreement rate was 70.7% (66.8%–74.6%) when education was categorized into five groups and increased up to 88.9% (86.2%–91.6%) when three education categories were used. The magnitude of validity and reliability for education did not generally vary with age, duration between health survey and death, and cause of death. However, a significantly smaller likelihood of agreement was found for middle and elementary school education after adjusting for covariates. Conclusion Low percentage of missing information on education in South Korean death certificate data could provide a great potential to monitor mortality inequalities. A more collapsed categorization in education would be recommended when a more definitive conclusion on educational mortality inequality is required.

Objective: To measure the childhood and life course socioeconomic exposures of people born between 1871 and 1949, and then to estimate the probability of death between 1965 and 1994, the probability of functional limitation in 1994, and the combined probability of dying or experiencing functional limitation during this period. Setting, participants and design: Data were from the Alameda County Study (California) and pertained to people aged 17–94 years (n = 6627) in 1965 (baseline). Socioeconomic position (SEP) in childhood was based on respondent’s reports of their father’s occupation, and life course disadvantage was measured by cross-classifying childhood SEP and the respondent’s education and household income in 1965. The health outcomes were all-cause mortality (n = 2420) and functional limitation measured using the Nagi index (n = 453, 17.4% of those alive in 1994). Relationships were examined before and after adjustment for changed socioeconomic circumstances after 1965. Results: Those from a low SEP in childhood, and those exposed to a greater number of episodes of disadvantage over the life course before 1965, were subsequently more likely to die, to report functional limitation and to experience the greatest health-related burden. Conclusions: All-cause mortality, functional limitation and overall health-related burden in middle and late adulthood are shaped by socioeconomic conditions experienced during childhood and cumulative disadvantage over the life course. The contributions made to adult health by childhood SEP and accumulated disadvantage suggest that each constitutes a distinct socioeconomic influence that may require different policy responses and intervention options.

Background Some of the most consistent evidence in favour of an association between income inequality and health has been among US states. However, in multilevel studies of mortality, only two out of five studies have reported a positive relationship with income inequality after adjustment for the compositional characteristics of the state's inhabitants. In this study, we attempt to clarify these mixed results by analysing the relationship within age-sex groups and by applying a previously unused analytical method to a database that contains more deaths than any multilevel study to date. Methods The US National Longitudinal Mortality Study (NLMS) was used to model the relationship between income inequality in US states and mortality using both a novel and previously used methodologies that fall into the general framework of multilevel regression. We adjust age-sex specific models for nine socioeconomic and demographic variables at the individual level and percentage black and region at the state level. Results The preponderance of evidence from this study suggests that 1990 state-level income inequality is associated with a 40% differential in state level mortality rates (95% CI = 26-56%) for men 25-64 years and a 14% (95% CI = 3-27%) differential for women 25-64 years after adjustment for compositional factors. No such relationship was found for men or women over 65. Conclusions The relationship between income inequality and mortality is only robust to adjustment for compositional factors in men and women under 65. This explains why income inequality is not a major driver of mortality trends in the United States because most deaths occur at ages 65 and over. This analysis does suggest, however, the certain causes of death that occur primarily in the population under 65 may be associated with income inequality. Comparison of analytical techniques also suggests coefficients for income inequality in previous multilevel mortality studies may be biased, but further research is needed to provide a definitive answer.

There is inconsistent evidence regarding the presence of a socioeconomic differential in adolescent all-cause and cause-specific mortality. This study examines possible socioeconomic mortality differentials in Korean adolescents. Method A total of 330 321 boys and 311 830 girls aged 10-19, who are health insurance beneficiaries for civil servants and private school teachers of Korean Health Insurance Cooperation, were followed for 9 years (1995-2003). Parental income information was linked to national death certificate data.For boys, all-cause mortality showed a graded inverse relationship with income level in both 10-14 year olds (RR = 1.64, 95% CI: 1.40-1.91) and 15-19 year olds (RR = 1.68, 95% CI: 1.40-1.91). The major contributor was mortality differentials from external causes, with differentials of transport accident death the most important. Mortality from circulatory disease was higher in the lowest income groups in 15-19 year olds (RR = 2.21, 95% CI: 1.09-4.50). A significant socioeconomic gradient of non-external cause mortality was found in 15-19 year olds. For girls, socioeconomic differentials were less evident than boys. The all-cause mortality gradient for girls was smaller than for boys and only significant between the lowest and the highest tertile in both 10-14 year olds and 15-19 year olds (RR = 1.33, 95% CI: 1.02-1.72, RR = 1.38, 95% CI: 1.11-1.72, respectively). There were significant socioeconomic mortality differentials in all external causes and transport accidents and a marginally significant difference in suicide mortality for 10-19 year olds. Mortality from non-external causes showed no social gradient in girls.Socioeconomic differentials in all-cause mortality were observed in adolescents, even in early youth. This pattern might also apply to mortality from non-external causes, especially cardiovascular disease in 15-19 year old males.

Socioeconomic position (SEP) has been shown to be related to obesity and weight gain, especially among women. It is unclear how different measures of socioeconomic position may impact weight gain over long periods of time, and whether the effect of different measures vary by gender and age group. We examined the effect of childhood socioeconomic position, education, occupation, and log household income on a measure of weight gain using individual growth mixed regression models and Alameda County Study data collected over thirty four years(1965-1999).Analyses were performed in four groups stratified by gender and age at baseline: women, 17-30 years (n = 945) and 31-40 years (n = 712); men, 17-30 years (n = 766) and 31-40 years (n = 608).Low childhood SEP was associated with increased weight gain among women 17-30 (0.13 kg/year, p0.001). Low educational status was associated with increased weight gain among women 17-30 (0.14 kg/year, p = 0.030), 31-40 (0.14 kg/year, p = 0.014), and men 17-30 (0.20 kg/year, p = 0.001).Log household income was inversely associated with weight gain among men 31-40 (-0.10 kg/yr, p = 0.16). Long-term weight gain in adulthood is associated with childhood SEP and education in women and education and income in men.

The social determination of health outcomes is well established in literature. These studies usually show how health outcomes vary on the basis of current socioeconomic position (SEP) However, recent evidence suggests that current health out-comes depend on SEP in different periods in the life course.1 Also, past SEP may modify the effect of the individual’s current socioeconomic situation on health. Several studies have shown that adverse socioeconomic conditions in childhood determine adult mortality rates, even when present socioeconomic situation is controlled for. Mortality rates from stroke and stomach cancer were 1.87 and 2.03 times higher in men whose fathers were manual workers compared with those whose fathers were not manual workers, while the all-cause mortality rate ratio was 1.22, in a Scottish cohort study of working men.2 In a census-based Finnish study, manual social class in childhood increased all-cause mortality by 20% among non-manual workers in adulthood, while having no effect among manual workers, whose mortality rate was three times higher than for subjects who always belonged to non-manual class. For cardiovascular mortality, childhood manual class was associated with increased rates for both manual and non-manual adult workers.3 Height has been shown to be related to childhood social class and financial hardship in infancy,4 and despite the increase in mean population height, differences between the richest and the poorest have not changed significantly.5 Nutrition and diseases in childhood are believed to be the main environmental factors determining height, and, thus, the effect of childhood social class is probably more important then adulthood social class. However, a study from the UK showed that upward social class mobility (from the age of 7–33 years) was associated with increased height for children originally from lower classes. On the other hand, children from the upper classes who moved down the social ladder were not different from those who remained wealthy.6 This study did not try to establish the causal direction—it could be either the improvement of social position leading to taller young adults or selective social mobility of taller individuals. Obesity and overweight are increasing in most parts of the world,7 and their relation with SEP has been the focus of many studies. In Brazil, overweight and obesity have shown, overall, a steep increase. From 1975–97, obesity increased from 2.4 to 6.9% among men and from 7 to 12.5% among women.8 This change, however, was not consistent for all socioeconomic groups. Among men, all groups showed an increase in obesity over time, but poorer men present less obesity than the richer. Among women, the poorer show an increase of obesity more than 2-fold. The richer, on the other hand, peak in 1989 (12.8%) and then show a decrease to 9.2%. A similar trend was found, analysing the same surveys, comparing the trends in the poorer North-east of the country with the richer South-east.9 A recent review showed that in developing countries obesity tends to either increase or not to vary with wealth in men, while among women the association tends to be inverse.10 In the present study we explore how past and current SEP affects the height and weight of 19-year-old adults in a Brazilian birth cohort. This analysis may bring new light to the understanding of how these characteristics depend on SEP, not only at one point in time, as most studies have approached, but in terms of SEP change over time.

BACKGROUND: Various studies have investigated urban/rural differences in cause-specific mortality. A separate body of literature has analysed effects of socioeconomic environment on mortality. Almost no studies have attempted to disentangle effects of population density and socioeconomic environment on mortality, beyond the effects of individual characteristics. METHODS: Considering all individuals living in the region of Scania, Sweden, from 1970-93, we performed 10 year mortality follow-ups on (i) individuals aged 55, (ii) individuals aged 65, and (iii) individuals aged 75 years at baseline. Cox multilevel models adjusted for individual factors allowed us to investigate the independent effects of population density and median income in the parish of residence on mortality from ischaemic heart disease (IHD), lung cancer, and chronic obstructive pulmonary disease (COPD) among individuals who had lived in the same parish for at least 10 years prior to mortality follow-up. RESULTS: In females, as in males, after adjustment for individual and contextual socioeconomic status, we found a dose-response association between population density and mortality from lung cancer and COPD in all age groups investigated, and from IHD especially in the youngest age group. Overall, the population density effect was the strongest on lung cancer mortality. Median income had an additional impact only in 2 out of 16 subgroups of age x gender x cause of death. CONCLUSIONS: In our region-wide study conducted at the parish level, contextual disparities in mortality were dominated by the population density effect. However, it may be unwise to conclude that truly contextual effects exist on mortality, before identification of plausible mediating processes through which urbanicity may influence mortality risk.

BackgroundTo more efficiently reduce social inequalities in mortality, it is important to establish which causes of death contribute the most to socioeconomic mortality differentials. Few studies have investigated which diseases contribute to existing socioeconomic mortality differences in specific age groups and none were in samples of the whole population, where selection bias is minimized. The aim of the present study was to determine which causes of death contribute the most to social inequalities in mortality in each age group in the whole population of Scania, Sweden.MethodsData from LOMAS (Longitudinal Multilevel Analysis in Skåne) were used to estimate 12-year follow-up mortality rates across levels of socioeconomic position (SEP) and workforce participation in 975,938 men and women aged 0 to 80 years, during 1991–2002.ResultsThe results generally showed increasing absolute mortality differences between those holding manual and non-manual occupations with increasing age, while there were inverted u-shaped associations when using relative inequality measures. Cardiovascular diseases (CVD) contributed to 52% of the male socioeconomic difference in overall mortality, cancer to 18%, external causes to 4% and psychiatric disorders to 3%. The corresponding contributions in women were 55%, 21%, 2% and 3%. Additionally, those outside the workforce (i.e., students, housewives, disability pensioners, and the unemployed) showed a strongly increased risk of future mortality in all age groups compared to those inside the workforce. Even though coronary heart disease (CHD) played a major contributing role to the mortality differences seen, stroke and other types of cardiovascular diseases also made substantial contributions. Furthermore, while the most common types of cancers made substantial contributions to the socioeconomic mortality differences, in some age groups more than half of the differences in cancer mortality could be attributed to rarer cancers.ConclusionCHD made a major contribution to the socioeconomic differences in overall mortality. However, there were also important contributions from diseases with less well understood mechanistic links with SEP such as stroke and less-common cancers. Thus, an increased understanding of the mechanisms connecting SEP with more rare causes of disease might be important to be able to more successfully intervene on socioeconomic differences in health.

Accepted 29 September 2005Background Economic changes can be powerful determinants of health. In the late 1990s,South Korea experienced a steep economic decline. This study examines whetherthe massive economic changes affected trends in all-cause and cause-specificmortality in South Korea.Method Mid-year population estimates of 5 year age groups (denominators) and deathcertificate data (numerators) from the National Statistical Office of Korea wereused to compute cause-specific age-standardized mortality rates before and afterthe economic crisis.Results All-cause mortality continued to decrease in both sexes and all age groups duringthecrisis.Cerebrovascularaccidents,stomachcancer,andliverdiseasecontributedmost to this decline. A remarkable decrease in transport accident mortality rateswas also observed. The most salient increase in mortality was suicidal death.Mortality from homicide, pneumonia, and alcohol dependence increased duringthe economic crisis, but these accounted for a small proportion of total mortality.Conclusions Short-term mortality effects of the South Korean economic crisis were relativelysmall. It appears that any short-term effects of the economic decline wereoverwhelmedbythemomentumoflargedeclinesincausesofdeathsuchasstroke,stomach cancer, and liver disease, which are probably related to exposures withmuchlongeraetiologicalperiods.However,thisstudyfocusedonratherimmediatemortality effects and follow-up studies are needed to elucidate any longer-termhealth effects of the South Korean economic crisis.Keywords Economic recession, socioeconomic factors, mortality, South Korea