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A growing body of research has documented associations between adverse childhood environments and DNA methylation, highlighting epigenetic processes as potential mechanisms through which early external contexts influence health across the life course. The present study tested a complementary hypothesis: indicators of children's early internal, biological, and behavioral responses to stressful challenges may also be linked to stable patterns of DNA methylation later in life. Children's autonomic nervous system reactivity, temperament, and mental health symptoms were prospectively assessed from infancy through early childhood, and principal components analysis (PCA) was applied to derive composites of biological and behavioral reactivity. Buccal epithelial cells were collected from participants at 15 and 18 years of age. Findings revealed an association between early life biobehavioral inhibition/disinhibition and DNA methylation across many genes. Notably, reactive, inhibited children were found to have decreased DNA methylation of the DLX5 and IGF2 genes at both time points, as compared to non‐reactive, disinhibited children. Results of the present study are provisional but suggest that the gene's profile of DNA methylation may constitute a biomarker of normative or potentially pathological differences in reactivity. Overall, findings provide a foundation for future research to explore relations among epigenetic processes and differences in both individual‐level biobehavioral risk and qualities of the early, external childhood environment., This study examined whether children's early internal, biological, and behavioral responses to stress were predictive of DNA methylation later in life. Findings revealed an association between early life biobehavioral reactivity and DNA methylation in multiple genes measured at both 15 and 18 years of age. As such, DNA methylation may constitute a biomarker of normative or potentially pathological differences in reactivity.

Background Some cohort studies bank lymphoblastoid cell lines (LCLs) as a renewable source of participant DNA. However, although LCL DNA has proved valuable for genetic studies, its utility in epigenetic epidemiology research is unknown. Methods To assess whether LCL DNA can be used for life-course environmental epigenomics, we carried out a pilot methylomic study (using the Illumina Infinium Human Methylation 450 BeadChip) of nil-passage, Epstein-Barr virus (EBV)-transformed LCLs (n = 42) and 28 matched whole-blood (WB) samples. These were from adult male participants of the British 1958 birth cohort, selected for extremes of social economic position (SEP) in childhood and adulthood, with additional information available on childhood abuse and prenatal tobacco exposure. Results We identified a small number of weak associations between these exposures and methylation levels of both individual CpG sites and genomic regions in WB and LCLs. However, only one of the regional, and none of the individual CpG site associations were common to both sample types. The lack of overlap between the associations detected in LCL compared with those found in WB could either be due to the EBV-transformation process, or to the fact that, unlike WB, LCLs are essentially a single (CD19+) cell type. We provide evidence that the latter is the more potent explanation, by showing that CpG sites known to be differentially methylated between different types of blood cell have significantly lower correlations (R = 0.11) than average (R = 0.2) between WB and LCLs in our datasets, whereas sites known to be affected by EBV-transformation have significantly higher correlations (R = 0.3). Conclusions This small pilot study suggests that the DNA methylation profile of LCLs is more closely related to that of B cells than WB and, additionally, that LCLs may nevertheless be useful for life-course environmental epigenomics.

This paper describes evidence that led to the concept of biological embedding and research approaches designed to elucidates its mechanisms. Biological embedding occurs when experience gets under the skin and alters human biological and developmental processes; when systematic differences in experience in different social environments in society lead to systematically different biological and developmental states; when these differences are stable and long term; and, finally, when they have the capacity to influence health, well-being, learning, or behavior over the life course. Biological embedding emerged from insights in population health on the unique characteristics of socioeconomic gradients: Ubiquity in poor and postscarcity societies alike; gradient seen regardless of whether socioeconomic status is measured by income, education, or occupation; cutting widely across health, well-being, learning, and behavior outcomes; replicating itself on new conditions entering society; and, often, showing that flatter gradients mean better overall societal outcomes. Most important, the gradient begins the life course as a gradient in developmental health, suggesting that the emergence of a multifaceted resilience/vulnerability early in life is the best place to look for evidence of biological embedding. To understand its character, the metaphor of the “archeology of biological embedding” has been used, wherein the surficial stratum of the “dig” is experience and behavior, the shallow stratum is organ system and cellular function, and the deep stratum is gene function. We are now ready to address the fundamental question of biological embedding: How do early childhood environments work together with genetic variation and epigenetic regulation to generate gradients in health and human development across the life course?

BackgroundCortisol levels may be altered in childhood in association with maltreatment (neglect, abuse and witnessing abuse) and other adversities, yet little is known about whether effects on cortisol persist into later life.AimsTo establish whether childhood psychosocial adversities predict cortisol levels in mid-adulthood.MethodChildhood psychosocial adversities were ascertained in the 1958 British birth cohort and cortisol was measured in two saliva samples, one 45 min after awaking (T1) and the other 3 h later the same day (T2), from 6524 participants aged 45 years.ResultsNo association was seen for abuse or household dysfunction in childhood and adult cortisol levels. In women but not men,T1cortisol was lowered by 7.9% per unit increase in childhood neglect score (range 0–3);T1toT2cortisol decline was less steep. High levels of maltreatment (abuse, neglect, witnessed abuse) were associated with >25% lowerT1cortisol in both men and women, and 24% higherT2cortisol for men after adjustment for concurrent depressive/anxiety symptoms.ConclusionsIn a non-clinical population, cumulative maltreatments in childhood were associated with flattened morning cortisol secretion in mid-adult life.

Objectives. We examined the relationship between unemployment and mortality in Germany, a coordinated market economy, and the United States, a liberal market economy. Methods. We followed 2 working-age cohorts from the German Socio-economic Panel and the US Panel Study of Income Dynamics from 1984 to 2005. We defined unemployment as unemployed at the time of survey. We used discrete-time survival analysis, adjusting for potential confounders. Results. There was an unemployment–mortality association among Americans (relative risk [RR] = 2.4; 95% confidence interval [CI] = 1.7, 3.4), but not among Germans (RR = 1.4; 95% CI = 1.0, 2.0). In education-stratified models, there was an association among minimum-skilled (RR = 2.6; 95% CI = 1.4, 4.7) and medium-skilled (RR = 2.4; 95% CI = 1.5, 3.8) Americans, but not among minimum- and medium-skilled Germans. There was no association among high-skilled Americans, but an association among high-skilled Germans (RR = 3.0; 95% CI = 1.3, 7.0), although this was limited to those educated in East Germany. Minimum- and medium-skilled unemployed Americans had the highest absolute risks of dying. Conclusions. The higher risk of dying for minimum- and medium-skilled unemployed Americans, not found among Germans, suggests that the unemployment–mortality relationship may be mediated by the institutional and economic environment.

Objective: Estimates from Canada's first national mental health surveillance initiative-which is based on diagnostic codes in administrative health care utilization databases-indicate that the proportion of Canadians who receive mental health care is more than twice as high as reported in Canada's national mental health survey. Our study examines and clarifies the nature and extent of differences between 2 predominant types of data that are used for mental health services research and planning. Method: A person-by-person data linkage was conducted between the Canadian Community Health Survey: Mental Health and Well-Being and administrative health care utilization records (British Columbia Ministry of Health Services-Medical Services Plan, and Hospital Discharge Abstract Database) within a universal-access, publically funded health care system, to examine the level of agreement between the data sources and respondent characteristics associated with agreement (N = 2378). Results: The prevalence of mental health care from general practitioners (GPs) was higher in administrative data (19.3%; 95% CI 17.7% to 20.9%) than survey data (8.5%; 95% CI 7.5% to 9.8%). Agreement between prevalence estimates from the 2 data sources was associated with age, mental health characteristics, and the number of GP visits. The median number of visits per person was significantly higher in the survey data. Conclusions: GPs saw more than twice as many patients for mental health issues according to administrative data, compared with survey data; however, the number of visits per patient was higher in survey data. Objectif : Les estimations de la premiere initiative nationale de surveillance de la sante mentale au Canada, qui se fondent sur les codes diagnostiques des bases de donnees administratives d'utilisation des soins de sante, indiquent que la proportion de Canathens qui recoivent des soins de sante mentale est plus de deux fois plus elevee que ce qui est rapporte dans les enquetes nationales de sante mentale du Canada. Notre etude examine et clarifie la nature et la portee des differences entre les 2 types predominants de donnees qui sont utilises pour la recherche et la planification des services de sante mentale. Methode : Un couplage des donnees de personne a personne a ete mene entre le volet Sante mentale et bien-etre de l'Enquete sur la sante dans les collectivites canathennes et les dossiers administratifs de l'utilisation des soins de sante (Ministere des Services de sante de la Colombie-Britannique - Regime des services medicaux et Base de donnees sur les conges des patients) au sein d'un systeme de sante d'acces universel, finance publiquement, afin d'examiner le niveau de concordance entre les sources de donnees et les caracteristiques des repondants associees a la concordance (N = 2378). Resultats : La prevalence des soins de sante mentale dispenses par les omnipraticiens (OP) etait plus elevee dans les donnees administratives (19,3 %; IC a 95 % 17,7 % a 20,9 %) que dans les donnees de l'enquete (8,5 %; IC a 95% 7,5 % a 9,8 %). La concordance entre les estimations de prevalence des 2 sources de donnees etait associee avec l'âge, les caracteristiques de sante mentale, et le nombre de visites â l'OP. Le nombre moyen de visites par personne etait significativement plus eleve dans les donnees de l'enquete. Conclusions : Les OP ont vu plus de deux fois plus de patients pour des questions de sante mentale, selon les donnees administratives, comparativement aux donnees de l'enquete; toutefois, le nombre de visites par patient etait plus eleve dans les donnees de l'enquete. Key Words: mental health, general practitioners, surveys, administrative data, data linkage, data sources, ambulatory care Received August 2011, revised, and accepted January 2012. Results of preliminary analyses from this study were presented at the Annual Scientific Symposium of the Canadian Academy of Psychiatric Epidemiology in Toronto, November 2006, and at the International Congress of the International Federation of Psychiatric Epidemiology in Vienna, April 2009. …

BackgroundThe hormone ‘cortisol’ has been associated with cognitive deficits in older ages, and also with childhood cognition. The extent to which the associations of cortisol with cognitive deficits in later life reflect associations with childhood cognition ability is unclear. This study aimed to assess associations between adult cortisol levels and subsequent cognitive functions, while considering childhood cognition and other lifetime covariates.MethodData are from the 1958 British Birth Cohort. Two morning salivary cortisol samples were obtained at 45 years: 45 min after waking (t1) and 3 h later (t2). Standardized tests assessing immediate and delayed verbal memory, verbal fluency and speed of processing were administered at 50 years. Information on cortisol, cognitive outcomes and covariates [e.g. birthweight, lifetime socio-economic position (SEP), education, smoking and drinking habits, body mass index (BMI), menopausal status, and depression/anxiety] was obtained for 4655 participants.ResultsWorse immediate and delayed verbal memory and verbal fluency at 50 years were predicted by elevated t2 cortisol at 45 years. For instance, for 1 standard deviation (s.d.) increase in t2 cortisol, individuals scored −0.05 s.d. lower on verbal memory and fluency tests. Childhood cognition explained about 30% of these associations, but associations with adult cognition remained.ConclusionsThis study suggests that higher cortisol levels in late morning at 45 years are associated with poorer verbal memory and fluency at 50 years, with a contribution from childhood cognition to these associations.

This study is premised on the notion that public health policy should address not only health itself, but also primary determinants of health. We examined the effect of national policies on educational outcomes, in particular, on adolescent reading literacy (ARL). We compared the effect of traditional policy indicators – national income and educational spending – with income inequality, a measure of redistributive policies. We used Organization for Economic Cooperation and Development (OECD) data that provide a rare opportunity to test policy effects after accounting for competing individual-, school-, and country-level explanations. Our sample consisted of 119 814 students, 5126 schools, and 24 countries. Multilevel/Hierarchical regression findings were striking: GDP had a significant, but negligible effect on ARL scores (β=0.002, SE=0.0008), while educational spending had no significant effect. By contrast, income inequality exhibited a larger inverse association (β=−1.15, SE=0.57). Among the wealthy nations in OECD, additional economic prosperity and educational spending is trumped by distribution of income for its effect on ARL. Our study yielded a striking result about education, a major determinant of health. Not only is income inequality a significant determinant of ARL scores, but direct spending on education and overall national economic prosperity are not.

Background Disadvantaged socio-economic position (SEP) in childhood is associated with increased adult mortality and morbidity. We aimed to establish whether childhood SEP was associated with differential methylation of adult DNA. Methods Forty adult males from the 1958 British Birth Cohort Study were selected from SEP extremes in both early childhood and mid-adulthood. We performed genome-wide methylation analysis on blood DNA taken at 45 years using MeDIP (methylated DNA immunoprecipitation). We mapped in triplicate the methylation state of promoters of approximately 20 000 genes and 400 microRNAs. Probe methylation scores were averaged across triplicates and differential methylation between groups of individuals was determined. Differentially methylated promoter sites of selected genes were validated using pyrosequencing of bisulfite-converted DNA. Results Variably methylated probes (9112 from n = 223 359 on the microarray) corresponded to 6176 gene promoters with at least one variable probe. Unsupervised hierarchical clustering of probes obtained from the 500 most variable promoters revealed a cluster enriched with high SEP individuals confirming that SEP differences contribute to overall epigenetic variation. Methylation levels for 1252 gene promoters were associated with childhood SEP vs 545 promoters for adulthood SEP. Functionally, associations with childhood SEP appear in promoters of genes enriched in key cell signalling pathways. The differentially methylated promoters associated with SEP cluster in megabase-sized regions of the genome. Conclusions Adult blood DNA methylation profiles show more associations with childhood SEP than adult SEP. Organization of these associations across the genome suggests a well-defined epigenetic pattern linked to early socio-economic environment.

Marginal zinc deficiency (MZD), the subclinical stage of zinc deficiency, is common in industrialized societies. Serum zinc, the most common biomarker of zinc status, lacks sensitivity and specificity to diagnose this deficiency. Hair zinc, however, is sensitive and specific enough to detect MZD in children. Differences in hair zinc associated with age and sex have been reported. These differences have not been investigated thoroughly; therefore, interpretation of the results of hair analyses is difficult. This cross-sectional study was designed to examine the hair zinc status of a group of Vancouver preschoolers (24-71 months) and assess the age- and sex-based differences in their hair zinc. Hair samples were obtained (n = 719) and analyzed for zinc using inductively coupled plasma mass spectrometry. Our results indicated a mean hair zinc of 115 +/- 43 microg/g with 17% below the low hair zinc cutoff (70 microg/g). Boys and girls had comparable mean hair zinc, while girls had a significantly higher occurrence of low hair zinc than boys (21% vs. 12%). Children4 years of age had significantly lower mean hair zinc and higher rate of low hair zinc compared to childrenor =4. Our study provides important reference values for the hair zinc of healthy North American preschoolers.

Life-course associations among cortisol, cognitive development and educational attainment in the general population are not well understood. Using the 1958 British birth cohort, our aim was to establish whether cortisol patterns at age 45y are associated with childhood cognition and qualification level by adulthood. We measured salivary cortisol in 6527 individuals, 45min after waking (t(1)) and 3h later (t(2)). To identify lack of morning cortisol peak and diurnal rhythm, we defined groups with: (a) t(1) cortisol in the bottom 5% of the distribution, or (b) 'flat't(1)-t(2) cortisol. Data on cognitive tests at ages 7, 11 and 16y and educational level were used. All childhood cognitive tests (maths, reading, verbal and non-verbal ability) were inversely associated, although not always significantly, with low t(1) and flat t(1)-t(2) cortisol. For example, at age 11 for males, a standard deviation (SD) increase in maths score was associated with a 28% decreased odds for lowest t(1) cortisol, and with a 13% decreased odds of flat t(1)-t(2) cortisol. Associations for lowest t(1) and flat t(1)-t(2) cortisol were attenuated after adjustment for qualification level at 33y among males, although adjustment for childhood socio-economic position had little effect. Weaker associations for lowest t(1) cortisol among females were either unchanged or strengthened after adjustment for qualification level. Our results for males, but less so for females, are compatible with a causal relationship in either direction, namely from cortisol to cognitive ability or vice versa.

Summary The influence of adversity over long periods of the life-span on adult cortisol metabolism is not established. We assess whether morning cortisol levels are associated with socio-economic position (SEP) from birth to mid-adulthood, and if so, whether the association is due primarily to SEP in childhood, adulthood or both. Data are from 6335 participants in the 1958 British birth cohort, with salivary cortisol samples collected at 45 yr. Two saliva samples were obtained on the same day: 45 min post-waking (t1) and 3 h later (t2). Median t1 and t2 cortisol values were 18.80 and 7.10 nmol/l for men; 19.60 and 6.60 nmol/l for women. Three outcomes were constructed: (1) extreme t1 cortisol (top and bottom 5%), (2) area-under-curve (AUC), and (3) abnormal t1–t2 pattern. All three outcomes were associated with lifetime SEP but the relative contribution of childhood and adulthood SEP varied by outcome measure. Our results suggest that the impact of less advantaged SEP over a lifetime would lead to an approximate doubling of the proportion of extreme post-waking cortisol levels for both sexes; an 8% and 10% increase, respectively for females and males in AUC, and an increased risk of having an abnormal cortisol pattern of 60% and 91%. SEP differences were independent of time of waking and sample collection, and in most instances, remained after adjustment for smoking and body mas index (BMI). Thus, our study provides evidence for effects of chronic adversity on cortisol in mid-adult life.

Background: Using a large cohort of western Canadian sawmill workers (n=28,794), the association between psychosocial work conditions and attempted and completed suicide was investigated. Methods: Records of attempted and completed suicide were accessed through a provincial hospital discharge registry to identify cases that were then matched using a nested case control method. Psychosocial work conditions were estimated by expert raters using the demand—control model. Univariate and multivariate conditional logistic regression was used to estimate the association between work conditions and suicide. Results: In multivariate models, controlling for sociodemographic (marital status, ethnicity) and occupational confounders (job mobility and duration), low psychological demand was associated with increased odds for completed suicide, and low social support was associated with increased odds for attempted suicides. Conclusions: This study indicates that workers with poor psychosocial working conditions may be at increased risk of both attempted and completed suicide.

This paper uses a comparative case study of Canada and the USA to argue that, in order to fully understand the associations between population health and the socioeconomic environment we must begin to place importance on the dynamic aspect of these factors--examining them as they evolve over time. In particular, for institutional and policy shifts that often unfold over decades, population health must attend to these big, slow moving processes by adopting a historical perspective to the knowledge base. We compare Canada and the USA on basic health outcomes and a range of determinants of health for which routine data have been collected for all or most of the period between 1950 and the present. During the analysis that follows, we are able to establish that, at the level of society (i) greater economic well being and spending on health care does not yield better health outcomes, that (ii) public provision and income redistribution trump economic success where population health is concerned, and (iii) that the gradual development of public provision represents the buildup of social infrastructure that has long-lasting effects on health status. Our case study shows what can be gleaned from a comparative perspective and a long-term view. The long view allows us to detect the gradual divergence in health status between these two societies and to trace potential institutional causes that would otherwise go unnoticed. The perspective introduced here, and in particular the comparison of Canada and the USA, provides strong support for the use of cross-national comparative work, and a historical perspective on the investigation of societies that successfully support population health.

To establish whether effects of birth weight and socioeconomic position on cognition are explained or modified by home or learning environments.Prospective birth cohort (n = 13,980) with math tests at 7, 11, and 16 years of age and qualifications by 33 years of age.For 1 kg increase in birth weight, 7-year math Z score increased 0.23 (0.19 adjusted for parental interest in child's progress) and adult qualifications increased 0.22 (on a 5-point scale). Maternal reading benefited math less among lower than higher birth weights (p.05). The birth weight effect remained unchanged 7 to 16 years of age. For each increment in social class (4 categories; IVV to III), 7-year math increased 0.19 (0.12 adjusted for parental interest). Benefits of mother's reading and father's interest were greatest in classes IVV (interaction p.05). The difference in Z scores between classes III to IVV was 0.57 at 7 years; 1.12 at 16 years of age. Estimates were little affected by home and school factors. Adult qualifications increased 0.40 per unit social class (0.33 adjusted for parental interest). Maternal interest reduced the chances of those from unskilled manual origins gaining few qualifications (p.05). Similarly, interactions were seen for maternal reading and paternal interest.Influences in the home partly underlie associations between social background and cognition, but they do little to explain a birth weight/cognition association.

Background: The objectives of this study were to compare the predictive validity of the demand - control and effort - reward imbalance models using objective measures of physician utilization. Methods: Self-reports for psychosocial work conditions were obtained in interviews with 1,028 workers using the demand - control and effort - reward imbalance models. Physician utilization outcomes were obtained through linkage to the British Columbia Linked Health Database. Outcomes were any visit to a physician for mental health reasons and 30 or more physician visits for any reason. The predictive validity of both models was compared in a longitudinal study using logistic regression. Results: Neither job strain nor effort - reward imbalance predicted either outcome. However, low esteem reward and low status control increased the risk for 30 or more physician visits by, respectively, approximately 60% and 30%. Conclusions: In a sample of middle-aged blue-collar current and ex-sawmill workers in Western Canada, followed prospectively, after controlling for sociodemographic and workplace confounders, and reducing the potential for adverse health selection into high-stress jobs, low esteem reward and low status control were associated with a significantly greater risk for 30 or more physician visits for any reason.

Associations of gaseous air pollutants (including carbon monoxide, sulfur dioxide, nitrogen dioxide, and ozone) with asthma hospitalization, stratified by sex and socioeconomic status, were examined among children 6-12 years of age in Vancouver, British Columbia, Canada, between 1987 and 1998. Relative risks for an exposure increment corresponding to the interquartile range for each gaseous air pollutant were estimated for asthma hospitalization after adjustment for weather conditions, including daily maximum and minimum temperatures as well as average relative humidity. Similar results were obtained by using locally weighted smoothing functions (LOESS) with default convergence criteria and by using natural cubic splines with a more stringent setting. Exposures to nitrogen dioxide were found to be significantly and positively associated with asthma hospitalization for males in the low socioeconomic group but not in the high socioeconomic group. For females, this same pattern of association was observed for exposures to sulfur dioxide. No significantly positive associations were found between carbon monoxide and ozone and asthma hospitalization in either low or high socioeconomic groups.

We evaluated the relationship between daily levels of particulate and gaseous phase pollutants and mortality within a dynamic cohort of approximately 550,000 individuals whose vital status was ascertained between 1986 and 1999. Time-series methods were applied to evaluate whether there were differential pollutant effects on daily aggregated numbers of deaths in the cohort that was stratified into quintiles of income as defined by the 1991 and 1996 Canadian censuses. The percent change in all-cause, cardiovascular, respiratory, and cancer daily mortality was calculated in relation to short-term changes in levels of a number of particulate (PM(2.5), PM(10-2.5), total suspended particle co-efficient of haze PM(10), SO(4)) and gaseous (O(3), CO, SO(2), NO(2)) pollutants. The estimated effects of air pollution on mortality were adjusted for day of week effects, and several meteorologic variables including temperature, change in barometric pressure, and relative humidity. Several gaseous pollutants were associated with an increased risk of mortality. Specifically for an increase equivalent to the difference between the 90th and 10th percentiles, the estimated percent change in daily mortality based on the 3-day average of NO(2), and SO(2) was 4.0% and 1.3%, respectively. The corresponding changes in mortality associated with SO(2) were much higher when analyses were restricted to death from respiratory disease. Specifically, a difference between the 90th and 10th percentiles was associated with a 5.6% (95% CI= -0.7% to 12.3%). The daily mean coarse fraction (PM(10-2.5)) was associated with increased cardiovascular mortality (estimated change=5.9%, 95% CI=1.1-10.8%). PM(2.5) was not found to be an important predictor of mortality. For NO(2), CO, and SO(2), there was some suggestion of increased risk of all-cause and cardiovascular mortality at lower levels of socioeconomic status. However, these results should be interpreted cautiously due to the small number of deaths observed within each stratum of socioeconomic status.

Background Childhood abuse is associated with increased adult disease risk, suggesting that processes acting over the long-term, such as epigenetic regulation of gene activity, may be involved. DNA methylation is a critical mechanism in epigenetic regulation. We aimed to establish whether childhood abuse was associated with adult DNA methylation profiles. Methods In 40 males from the 1958 British Birth Cohort we compared genome-wide promoter DNA methylation in blood taken at 45y for those with, versus those without, childhood abuse (n = 12 vs 28). We analysed the promoter methylation of over 20,000 genes and 489 microRNAs, using MeDIP (methylated DNA immunoprecipitation) in triplicate. Results We found 997 differentially methylated gene promoters (311 hypermethylated and 686 hypomethylated) in association with childhood abuse and these promoters were enriched for genes involved in key cell signaling pathways related to transcriptional regulation and development. Using bisulfite-pyrosequencing, abuse-associated methylation (MeDIP) at the metalloproteinase gene, PM20D1, was validated and then replicated in an additional 27 males. Abuse-associated methylation was observed in 39 microRNAs; in 6 of these, the hypermethylated state was consistent with the hypomethylation of their downstream gene targets. Although distributed across the genome, the differentially methylated promoters associated with child abuse clustered in genome regions of at least one megabase. The observations for child abuse showed little overlap with methylation patterns associated with socioeconomic position. Conclusions Our observed genome-wide methylation profiles in adult DNA associated with childhood abuse justify the further exploration of epigenetic regulation as a mediating mechanism for long-term health outcomes.

Objectives This study tested the reliability and validity of industry- and mill-level expert methods for measuring psychosocial work conditions in British Columbia sawmills using the demand-control model. Methods In the industry-level method 4 sawmill job evaluators estimated psychosocial work conditions at a generic sawmill. In the mill-level method panels of experienced sawmill workers estimated psychosocial work conditions at 3 sawmills. Scores for psychosocial work conditions were developed using both expert methods and applied to job titles in a sawmill worker database containing self-reported health status and heart disease. The interrater reliability and the concurrent and predictive validity of the expert rater methods were assessed. Results The interrater reliability and concurrent reliability were higher for the mill-level method than for the industry-level method. For all the psychosocial variables the reliability for the mill-level method was greater than 0.90. The predictive validity results were inconclusive. Conclusions The greater reliability and concurrent validity of the mill-level method indicates that panels of experienced workers should be considered as potential experts in future studies measuring psychosocial work conditions.

This report presents the process and summative evaluation results from a community-based diabetes prevention and control project implemented in response to the increasing prevalence and impact of non-insulin-dependent diabetes mellitus (NIDDM) in the Canadian Aboriginal population. The 24-month project targeted the registered Indian population in British Columbia's rural Okanagan region. A participatory approach was used to plan strategies by which diabetes could be addressed in ways acceptable and meaningful to the intervention community. The strategies emphasised a combination of changing behaviours and changing environments. The project was quasi-experimental. A single intervention community was matched to two comparison communities. Workers in the intervention community conducted interviews of individuals with or at risk for diabetes during a seven-month pre-intervention phase (n = 59). Qualitative analyses were conducted to yield strategies for intervention. Implementation began in the eighth month of the project. Trend measurements of diabetes risk factors were obtained for 'high-risk' cohorts (persons with or at familial risk for NIDDM) (n = 105). Cohorts were tracked over a 16-month intervention phase, with measurements at baseline, the midpoint and completion of the study. Cross-sectional population surveys of diabetes risk factors were conducted at baseline and the end of the intervention phase (n = 295). Surveys of community systems were conducted three times. The project yielded few changes in quantifiable outcomes. Activation of the intervention community was insufficient to enable individual and collective change through dissemination of quality interventions for diabetes prevention and control. Theory and previous research were not sufficiently integrated with information from pre-intervention interviews. Interacting with these limitations were the short planning and intervention phases, just 8 and 16 months, respectively. The level of penetration of the interventions mounted was too limited to be effective. Attention to process is warranted and to the feasibility of achieving effects within 24 months.

Russia has the lowest life expectancy among industrialised countries, but little is known about other health outcomes and determinants of health in the Russian population. Here we report a cross-sectional study in a national sample of the Russian population of social and psychosocial determinants of two self-reported health indicators: self-rated health (shown to predict mortality in prospective studies) and physical functioning (validated against more objective health measures). A multi-stage sample of the Russian population aged 18 years and more was interviewed (n=1599, response rate 66%). The questionnaire included political attitudes, social and economic circumstances, psychosocial factors, smoking, alcohol consumption, self-rated health and physical functioning (from the SF36 instrument). Scores of perceived control over life and over one's health were calculated from 6 and 3 questions, respectively. Data were analysed in logistic regression for two dichotomised outcomes: poor self-rated health (worse than average) and low physical functioning (less than 60% of maximum). Overall, 25% of subjects rated their health as worse than average; this is substantially more than in western countries. Perceived control over life was strongly related to both outcomes; age- and sex-adjusted OR for 1 standard deviation increase in control were 0.60 (95% CI 0.52-0.69) for poor self-rated health and 0.67 (0.57-0.81) for low physical functioning. Adjustment for a battery of other factors reduced these estimates only slightly. Associations between control over one's health and both outcomes were also significant, but weaker and attenuated in multivariate models. Material deprivation was also strongly related to both outcomes. Education was inversely related to self-rated health, and unmarried men reported poor physical functioning substantially more often. Subjects not approving the economic changes reported poorer health but this association was removed by adjustment for socioeconomic factors and control. Subjects who could not rely on informal social structures when in problems reported worse health; this effect largely persisted in multivariate analyses. These results are consistent with the hypothesis that poor health status in Russia is related to dysfunction of social structures, socioeconomic deprivation, and lack of perceived control. The absence of informal social networks, vital for maintaining general welfare, seems to affect adversely self-rated health. Deprivation and low perceived control may be important mediators between the broad social environment and health in populations undergoing transition and can provide a useful framework for many biological and behavioural factors. Prospective studies are needed to address the issue of temporality and reporting bias, the major problems in interpreting these findings.

Occupational cohort studies conducted to study cancer incidence and mortality require extensive data gathering about workers’ job histories, exposures, and health outcomes. Although this process is expensive, the database created can be looked upon as a resource for broad investigations of the relationship between work and health. This paper presents the example of a retrospective cohort study which began in the traditional way, examining the link between a specific pesticide exposure and mortality and cancer incidence. The cohort register has since been used to investigate whether infertility, adverse reproductive outcomes, and childhood cancers might be associated with this exposure. It is also being used as the basis for studying other sawmill exposures including noise and wood dust, as well as socioeconomic factors including job strain, job mobility, unemployment, and retraining. This approach allows both the efficient use of occupational cohorts as well as providing the opportunity for investigators to develop a more comprehensive perspective on the determinants of the health status of workers and their families.

It has been hypothesized that senile cataract may serve as a marker for generalised tissue aging, since structural changes occurring in the proteins of the lens during cataract formation are similar to those which occur elsewhere as part of the aging process. An earlier analysis we carried out to test this hypothesis revealed a strong age-dependent relationship between undergoing cataract surgery and subsequent mortality. Relative risks for dying over 9 yr of follow-up were particularly increased for individuals who had developed cataract requiring operation between the ages of 50-65. This finding prompted us to test the hypothesis that younger patients undergoing surgery for cataract (those in which surgery was undertaken at 50-65 yr of age) would tend disproportionately to be resident in areas of generally lower socioeconomic status. A population-based linked health data resource containing data on all hospital separations in the province of British Columbia was used to examine this hypothesis. Linkage to Canadian census data was used to assign a socioeconomic decile to the area of residence for all individuals in British Columbia who either did, or did not, undergo cataract surgery over a 3 yr period, and were aged 50-95. Relative to those who resided in the highest socioeconomic areas, odds ratios for undergoing cataract surgery between 50 and 65 yr of age were significantly greater than 1 for the four lowest socioeconomic deciles. This association was observed despite a conservative bias in our setting that favoured those of higher socioeconomic status tending to receive earlier treatment. The results of this ecologic study prompt consideration of whether factors which have the dual attributes of being correlates of socioeconomic status and implicated in the development of cataract may play a role in mediating the processes involved in the well known association of socioeconomic status and mortality.

The purpose of this study was to determine whether exposure to chlorophenate fungicides and their dioxin contaminants is associated with male infertility among sawmill workers. The study was conducted using fertility data compiled from 26,487 sawmill workers in 14 British Columbian sawmills. Our analysis was restricted to workers who had been employed for at least 1 continuous year between 1950 and 1985 and to live-births born at least 1 year after the initiation of employment in the period 1955-1988. We assessed fertility trends by internal comparison using Mantel-Haenszel rate ratios and by calculating standardized fertility ratios using an external and an internal reference population. We identified 19,684 births in the study period. Initially, both external and internal analyses showed that sawmill workers from mills using chlorophenates had lower fertility than workers employed in mills not using chlorophenates. After controlling for time since first hire, however, we found no inverse relation between cumulative exposure to chlorophenate fungicides and fertility. Based on the results of our study, there is little evidence for a reduction in fertility among chlorophenate-exposed sawmill workers in British Columbia. The analyses indicate the importance of time since hire as a potentially strong confounder in this type of investigation.

Objectives: The purposes of this study were to measure household food security and to determine its association with potential predictor variables related to household and community environments, as well as the relationship between household food insecurity and preschool children’s nutritional status. Methods: In this cross-sectional study, household food security was measured in a convenience sample of households (n=142) with children aged 2–5 years in Vancouver in March 2004. We assessed the association between environmental predictors and household food security status, adjusted for household income. Indicators of children’s nutrition were compared between categories of household food security. Results: Household food insecurity was associated with indicators of suboptimal health status in preschoolers. After controlling for household income, parents with less access to food of reasonable quality, fewer kitchen appliances and a lower rating of their cooking skills had greater odds of experiencing household food insecurity. Implications: Our study results support the need to test interventions involving collaborative efforts among government, social planners and public health practitioners to remove barriers to food security for families. Multiple measures, including opportunities to gain practical food skills and household resources that enable convenient preparation of nutrient-dense foods, could be examined. Our findings suggest the need for improved selection and quality at existing small stores and an increase in the number of food outlets in low-income neighbourhoods.

Health care utilization by the elderly has increased during recent times. However, a number of investigators have indicated that this increase has had less to do with increasing numbers of elders than with increasing age-specific utilization rates for a variety of health services. 1985 and 1993 health data for British Columbia were used to examine changes in outpatient surgical utilization among the general population and changes in cataract surgical utilization among the elderly. Utilization increases in the older persons exceeded what would be expected on the basis of population increase. Furthermore, cataract surgery alone accounted for more than 29 percent of the entire utilization increase observed for outpatient surgery. Despite this increase, the average age at cataract surgery has not changed—seniors of all ages are much more likely to receive cataract surgery now than a decade ago. The authors' findings suggest that a part of this observed increase is due to operating on individuals at preoperative levels of better visual function.

Evidence is presented for a pathways model linking early life factors and adult disease, which takes account of the inter-relationships between social and biological risks throughout the lifecourse. Few studies, if any, have yet recorded adequate birth to death information which could be used to quantify the effects of different factors and their timing. Hence, there is only limited understanding of the extent to which biological and social risks experienced at different life stages combine to influence adult disease. However, some of the pathways between early and later life are suggested when evidence from earlier stages of the lifecourse is linked to that from studies at older ages, in which adult disease risk factors have been established. Further support for pathway effects is provided by studies showing that health outcomes of early biological insults can depend on the subsequent social and biological environment. Thus, it is argued that adult disease will be more fully understood when account is taken of the combined effects of social and biological risk occurring at different life stages.

In a recent issue of PNAS, Lam et al. (1) identified three CpG sites associated with early-life socioeconomic status (SES) in adult blood DNA. The authors observed that this small number of associated CpG sites “appears to be at odds” with the 1,252 gene promoters found in our study of 40 adult males stratified by early-life SES (2). The authors suggest that our analysis of the data inflated the statistical significance of methylation associations and wonder whether blood composition may have further inflated the results.

Objective Associations of cortisol and depression vary at different life-stages, yet population-based, prospective studies are scarce. We aimed to assess associations of morning cortisol with depressive symptoms in mid-life taking account of lifetime psychological health. Methods Participants were 5,403 men and women from the 1958 British Birth Cohort whose salivary cortisol was assessed at 45y (45min after waking (T1) and 3h later (T2)) and who completed the 5-item Mental-Health Index (MHI-5) about depressive symptoms at age 50y. Lifetime psychological health was identified from child and adult measures. Results For women, higher T2 cortisol at 45y predicted depression (MHI-5 scores ≤52) at 50y (odds ratio [OR]=1.17; 95% confidence intervals [CI] 1.05,1.30 per standard deviation increase in T2 cortisol), attenuating when adjusted for current (45y) and previous (7-42y) psychological health (OR=1.11; 95% CI 0.98, 1.24). Similarly, an association in women of flatter cortisol delta (T2-T1) with depressive symptoms at 50y weakened after adjustment for current (45y) and previous (7-42y) psychological health. For men, lower T2 cortisol at 45y predicted greater depressive symptoms at 50y and the association strengthened when adjusted for lifetime psychological health. Likewise, lower cortisol AUC predicted higher risk of depression for men after adjusting for prior psychological health (OR=0.85; CI 0.72, 1.00). Associations were largely unaltered by control for covariates. Conclusions In women, higher cortisol in late morning at 45y is prospectively associated with depressive symptoms at 50y through a link with lifetime psychological health. In men, lower cortisol predicts subsequent symptoms, independent of depressive history.

Three cross-sectional surveys were conducted in different regions of British Columbia, using a model of risk perception that divides the community into attitudinal and behavioral subgroups based on awareness and concern about waste management facilities. The three communities differed with respect to their levels of both awareness and concern about facilities, either planned for or situated in their region. Surprisingly, the most polarized community, which had nevertheless accepted a facility, rated this facility as more desirable than the other two communities. The unconcerned group in this community felt well informed, was more trusting of siting and operating agencies, and believed that the facility would generate benefits. The concerned group in this community also felt better informed, was more trusting of siting and operating agencies, and believed that its facility would generate benefits, compared with concerned groups in the other two communities. Longitudinal studies of the attitudes driving the siting process are needed to understand how these relationships evolve over time.

This study examined the relationship between children's hair cortisol and socioeconomic status of the family, as measured by parental education and income. Low family socioeconomic status has traditionally been considered a long-term environmental stressor. Measurement of hair cortisol provides an integrated index of cumulative stress exposure across an extended period of time. The present study is the first to examine the relationship between hair cortisol and parental education as well as parental income in a representative sample of preschoolers. Data on hair cortisol, family income, and parental education were collected for a representative sample of 339 children (Mean age=4.6 years; SD=.5 years) from across 23 neighbourhoods of the city of Vancouver, Canada. As maternal education was shown previously to be associated with hair zinc level, hair zinc measurements were included as well in order to explore potential relationships between hair zinc and hair cortisol. The relationship between hair cortisol and parental education was examined using hierarchical regression, with hair zinc, gender, age, and single parenthood included as covariates. Maternal and paternal education both were correlated significantly with hair cortisol (r=-0.18; p=.001). The relationship remained statistically significant even after controlling for all demographic covariates as well as for hair zinc and after taking the neighbourhood-level clustering of the data into account. Parental income, on the other hand, was not related significantly to children's hair cortisol. This study provides evidence that lower maternal and paternal education are associated with higher hair cortisol levels. As hair cortisol provides an integrated index of cortisol exposure over an extended time period, these findings suggest a possibly stable influence of SES on the function of the hypothalamic-pituitary-adrenal (HPA) axis. Cumulative exposure to cortisol during early childhood may be greater in children from low socio-economic backgrounds, possibly through increased exposure to environmental stressors.

Survey data and provincial administrative health data are the major sources of population estimates of mental health care visits to General Practitioners (GPs). Previous research has suggested that self-reported estimates of the number of mental health-related visits per person to health professionals may exceed estimates obtained from physician reimbursement records.Self-reported data from the 2002 Canadian Community Health Survey (CCHS): Mental Health and Well-being and administrative records from the Medical Services Plan of British Columbia were linked. The analytic sample consisted of 145 CCHS respondents who had at least one mental health visit to a GP in the past 12 months according to both data sources. High Reporters (self-reported visits exceeded number in administrative data), Low Reporters (self-reported visits were less than number in administrative data), and Exact Matches were analyzed in two ways. The first analysis used diagnostic codes to identify mental health-related visits in the administrative data. For the second analysis, all GP visits in the administrative data were counted as "possibly" mental health-related. Differences were described based on the median number of visits.When diagnostic codes were used to identify mental-health-related visitis in the administrative data, High Reporters (49%) substantially exceeded Low Reporters (24%). The remaining 27% were Exact Matches. Based on a broader definition of a mental health visit, 51% were Exact Matches. High reporting was common among people with mental disorders.Self-reported data and administrative data provide different estimates of the number of mental health visits per person to GPs. The discrepancy can be large.

The study sought to determine whether differences in mental health outcomes were observable in a cohort of workers living in rural compared to urban places in the Canadian province of British Columbia. The study was based on a cohort of male sawmill workers. The cohort was probabilistically linked to the BC Linked Health Database in order to yield objective mental health outcomes. A nested case control design was used. Univariate and multivariate models were constructed using conditional logistic regression. While results differed according to the particular mental health outcome, after controlling for socio-economic confounders it was found that workers who remained in or migrated to rural places tended to have better mental health outcomes than workers who remained in or migrated to urban places.

Population-based studies of cortisol and psychological health over long periods are rare. This study aims to establish whether cortisol levels in mid-adulthood are associated with chronicity and life-stage of psychological ill-health onset. We used data from the 1958 British birth cohort (3209 males; 3315 females) with cortisol measures 45 min post-waking (t1) and 3h later (t2) on the same day at 45y. Lifetime psychological health was identified from child and adult measures (ages 7, 11, 16, 23, 33, 42, 45y). t1 cortisol was lower by 3-4% in those with lifetime (child and adult) ill-health than those with no ill-health, after adjustment for socio-economic position and smoking. t1 cortisol was similarly lowered in those with adult onset of ill-health, but not among the group whose ill-health was of recent onset. t2 cortisol was elevated among all lifetime ill-health groups, by 6-9%, except for those whose ill-health did not extend beyond childhood. Simple analyses across the separate ages of follow-up suggest that elevations in t2 cortisol reflect associations for adult ill-health. Our study suggests that psychological ill-health over years and decades "blunts" post-awakening cortisol secretion, possibly reflecting HPA dysregulation due to social stressors.

Data are presented from an interview case-control study (583 cases and 608 controls), performed in southern Ontario, Canada, from October 1984 to September 1986, on the association of cutaneous malignant melanoma with exposure to fluorescent light. Males showed a significant trend with cumulative years of occupational exposure and with various indices of exposure to domestic fluorescent light. The risk was more pronounced for lesions on the arms and for superficial spreading melanomas. There was no consistent association in females. These effects were similar when adjusted for other major risk factors for melanoma, including the amount of time spent outdoors occupationally. Comparisons of melanoma cases interviewed before or after diagnosis revealed no evidence of rumination bias. Comparisons of sample data from the same cases and controls by interview and mail questionnaire showed reasonable levels of reliability with no evidence of recall bias. A small sample of subjects was also selected for exposure validation with employers; this revealed very accurate recall of occupational exposure. On the basis of these results, previous epidemiologic studies, and clinical and animal evidence, the authors conclude that fluorescent light exposure remains a potential risk factor for melanoma.

Background: This is a predictive validity study examining the extent to which developmental vulnerability at kindergarten entry (as measured by the Early Development Instrument, EDI) is associated with children’s basic skills in 4th grade (as measured by the Foundation Skills Assessment, FSA). Methodology/Principal Findings: Relative risk analysis was performed on a large database linking individual-level EDI ratings to the scores the same children obtained on a provincial assessment of academic skills (FSA – Foundation Skills Assessment) four years later. We found that early vulnerability in kindergarten is associated with the basic skills that underlie populations of children’s academic achievement in reading, writing and math, indicating that the Early Development Instrument permits to predict achievement-related skills four years in advance. Conclusions/Significance: The EDI can be used to predict children’s educational trends at the population level and can help select early prevention and intervention programs targeting pre-school populations at minimum cost.

A small but provocative literature suggests that neighbourhood socioeconomic conditions experienced by children early in life influence a variety of health and developmental outcomes later in life. We contribute to this literature by testing the degree to which neighbourhood socioeconomic conditions that children experience in Kindergarten influence their later language and cognitive outcomes in early adolescence, over and above current neighbourhood context and various child-level covariates including scores on a Kindergarten measure of school readiness. Cross-classified random effects modelling (CCREM) analyses were performed on a study population of 2648 urban children residing throughout the province of British Columbia, Canada, who were followed longitudinally from Kindergarten (age 5/6) to Grade 7 (age 12/13). Findings demonstrate that neighbourhood concentrated disadvantage experienced during Kindergarten has a durable, negative effect on children's reading comprehension outcomes seven years later—providing evidence that early social contextual experiences play a critical role in the lives of children. Possible explanations and future directions are discussed.

Objectives: To examine the relationships between exposure to workplace factors (night work, extended working hours, psychosocial work stress) and cortisol secretion, and to test whether workplace factors interact, resulting in combined effects. Methods: Multiple linear and logistic regression was used to test relationships between workplace factors and cortisol secretion in the 1958 British birth cohort at 45 years. Salivary cortisol was measured twice on the same day to capture the post-waking decline, facilitating the analysis of different cortisol patterns: (1) time 1 (T1, 45 minutes post-waking); (2) time 2 (T2, 3 h after T1); (3) average 3 h exposure from T1 to T2 cortisol; and (4) T1 to T2 change. To identify altered diurnal cortisol patterns we calculated: (1) flat T1–T2 change in cortisol; (2) top 5% T1; (3) bottom 5% T1; and (4) T1 hypo-secretion or hyper-secretion. Models were adjusted for socioeconomic position at birth and in adulthood, qualifications, marital status, dependent children, and smoking status. Results: 25% of men and 8% of women were exposed to >1 workplace factor (night work, extended work hours, job strain). Night work was associated with a 4.28% (95% CI 1.21 to 7.45) increase in average 3 h cortisol secretion independently of job strain or work hours. Night workers not exposed to job strain had elevated T1 cortisol (5.81%, 95% CI 1.61 to 10.19), although for T2 cortisol it was night workers exposed to low job control who had elevated levels (11.72%, 95% CI 4.40 to 19.55). Men (but not women) working >48 h/week had lower average 3 h cortisol secretion (4.55%, 95% CI −8.43 to −0.50). There were no main effects for psychosocial work stress. All associations for T2 and average 3 h cortisol secretion weakened slightly after adjustment for confounding factors, but associations for T1 cortisol were unaffected by adjustment. Conclusions: Our study suggests that night work in particular is associated with elevated cortisol secretion and that cortisol dysregulation may exist in subgroups with specific combinations of stressors.

Several types of data are presented concerning the reliability of counting or estimating the density of nevi (moles), a major risk factor for melanoma, using methods typically employed in epidemiologic studies. First, interviewer-derived counts of nevi on the arm produced estimates of inter-observer, inter-subject, temporal and random variability, and their interactions. Second, interviewer-derived arm counts and respondent self-reports of whole body nevus density were compared. Finally, we compared male and female cases and controls with respect to their reported rates of having a relative with a malignant mole. Overall, the intra-observer reliability ranged from 55 to 81%, and was better for observers with more experience. The correlation between the interviewer counts and respondents' self-reported estimates was 0.41. The data on malignant moles in relatives suggest higher reporting rates in male cases and lower reporting in male controls relative to their female counterparts, but there is little difference by sex in the reporting of one's own nevus density.

The relative importance of region, workplace, and individual determinants of health burden is debated.To model the contribution of hospital characteristics to employee mental and musculoskeletal disorders.We linked employment records of nurses and support services' staff with health records, neighbourhood census, and hospital administrative data. We conducted multi-level logistic regression analyses with three levels: year (I), employee characteristics (II), and hospital characteristics (III).Northern region hospitals experienced lower disorder prevalences (odds ratios (OR) 0.58, 95% confidence intervals (0.40, 0.82) for mental and 0.56 (0.44, 0.73) for musculoskeletal disorders). Hospitals with yearly workloads of the highest versus lowest quintiles of inpatient days/1000 employee hours (86.0 vs.42.6) and surgical cases/1000 employee hours (10.5 vs.3.9) had greater odds of mental (1.29 (1.05, 1.57); 1.22 (1.05, 1.42)) and musculoskeletal (1.38 (1.21, 1.58); 1.21 (1.09, 1.34)) disorders.Opportunities exist for reduction in burden with hospital workload reduction. Further exploration of regional effects is needed.

A number of studies demonstrates a relationship between neighbourhood concentration of affluence and disadvantage and the health and development of its residents. We contribute to this literature by testing hypotheses about the relationship between neighbourhood-level concentrated affluence/disadvantage and child-level developmental outcomes in a study population of 37,798 Kindergarten children residing in 433 neighbourhoods throughout the province of British Columbia, Canada. We utilise a previously-validated measure of neighbourhood socioeconomic composition—the Index of Concentration at the Extremes (ICE) —which not only allows for more precise estimation of the competing influences of concentrated affluence and disadvantage, but also facilitates examination of the potential impact of neighbourhood-level income inequality. Our findings show that increases in neighbourhood affluence are associated with increases in children's scores on the Early Development Instrument (EDI) , a holistic measure of Kindergarteners' readiness for school. Particularly noteworthy is that, for four of the five EDI scales (physical, social, emotional, and communication) and the total score, results indicate a significant curvilinear relationship – whereby the highest average child-level outcomes are not found in locations with the highest concentrations of affluence, but rather in locations with relatively equal proportions of affluent and disadvantaged families. This finding suggests, first, that concentrated affluence may have diminishing rates of return on contributing to enhanced child development, and, second, that children residing in mixed-income neighbourhoods may benefit both from the presence of affluent residents and from the presence of services and institutions aimed at assisting lower-income residents. Implications and future directions are discussed.

Past research suggests a link between socioeconomic status (SES) and brain processes in children, but direct evidence from neuroimaging is scarce. The authors investigated the relationships among SES, performance, and the neural correlates of auditory selective attention, by comparing event-related potentials (ERPs) in lower- and higher-SES preadolescent children during a task in which they attended to two types of pure tones but ignored two other types. Our hypothesis was that, at comparable performance levels, higher-SES children ignore distracters (the unattended, irrelevant tones) while lower-SES children attend equally to distracters and to targets (the attended, relevant tones). The authors found that ERP waveform differences between attended and unattended tones (Nd, difference negativity) were significant in the higher-SES but not in the lower-SES group. However, the groups did not differ in reaction times or accuracy. Electroencephalographic power analysis revealed a differential pattern of theta activity concomitant with irrelevant tones for the two groups, indicating that although they performed similarly the children from these groups recruited different neural processes. Lower-SES children, the authors suggest, deployed supplementary resources to also attend to irrelevant information.

Background: The role of social and family environments in the development of mental health problems among children and youth has been widely investigated. However, the degree to which parental working conditions may impact on developmental psychopathology has not been thoroughly studied. Methods: We conducted a case-control study of several mental health outcomes of 19,833 children of sawmill workers and their association with parental work stress, parental socio-demographic characteristics, and paternal mental health. Results: Multivariate analysis conducted with four distinct age groups (children, adolescents, young adults, and adults) revealed that anxiety based and depressive disorders were associated with paternal work stress in all age groups and that work stress was more strongly associated with alcohol and drug related disorders in adulthood than it was in adolescence and young adulthood. Conclusion: This study provides support to the tenet that being exposed to paternal work stress during childhood can have long lasting effects on the mental health of individuals.

Between 1969 and 1985, the British Columbia hospital system allocated an increasing proportion of the province's total hospital days to elderly patients who stayed for 60 days or more. By 1985/86, long stay patients accounted for almost 50% of all days. In this paper, we explore the diagnoses which contributed the greatest number of patient days of increase among the elderly as a first step in evaluating the appropriateness of this response to the pressures of an aging population. Patient days of increase were not distributed smoothly across a large number of diagnoses, but could be explained by a small number of chronic conditions. Most important were conditions related to senility and senile dementia, the chronic sequelae of heart disease and stroke, and persons awaiting admission to adequate facilities elsewhere. Eighty percent of the increases were seen in extended care and rehabilitation beds and 20% in acute care beds. Seventy-seven percent of the increased patient days were attributable to females and only 23% to males. Since the major sources of increase in patient days were not related to conditions for which new, effective hospital care modalities are available, they call into question the appropriateness of the system's response to the health care needs of the elderly population.

Early child development (ECD) – the development of physical, social–emotional, and language–cognitive capacities in the early years – is a foundation of health, well-being, learning, and behaviour across the life course. Consequently, the capacity to monitor ECD is an important facet of a modern society. This capacity is achieved by having in place an ongoing flow of high-quality information on the state of early child development, its determinants, and long-term developmental outcomes. Accordingly, there remains a considerable need for research that merges community-centred, longitudinal, and linked-data approaches to monitoring child development. The current paper addresses this need by introducing one method of summarising and quantifying the developmental trajectories of British Columbian children at the neighbourhood- or district-level: computing the Community Index of Child Development (CICD) for each geographic area. A simple index that describes change in children's developmental trajectories at the aggregate level, the CICD is computable because of our capacity to conduct individual-level linkage of two population data sets: the Early Development Instrument (EDI), a holistic measure of children's readiness for school which is administered at Kindergarten, and the British Columbia Ministry of Education's Foundation Skills Assessment (FSA), a Grade 4 measure of academic skills. In this paper, we demonstrate: (a) wide variation in the CICDs according to the children's district of residence in Kindergarten; (b) an association of the CICDs with an indicator of the socioeconomic character of the neighbourhoods; and (c) contrasting patterns of neighbourhood convergence and divergence in two different school districts – such that, in some areas, children from high vulnerability neighbourhoods tend to catch up between Kindergarten and Grade 4 whereas, in other areas, they tend to fall further behind.

Background We know that the social conditions in which children live exert a strong influence on their health; yet, we do not know how children’s experience of these conditions of daily life shape their perspectives of health. Methods Through ethnographic research methods, the first author spent 1 year with the 14 6-year-old children involved in this research and examined how the contexts of daily life influenced the children’s perspectives of health. The children involved in this study all lived in a neighbourhood characterized as having a complex of mid to high range of neighbourhood factors associated with vulnerability. Results The findings demonstrate that the children were able to articulate the health requirements of physical activity and healthy eating that supports their health. However, there was a disparity between the children’s health knowledge, their perceptions and their contextual realities in relation to health. Children spoke of concerns for their physical safety within their schools and neighbourhoods; their lack of free range of play, and that they had few opportunities to play with or get to know neighbourhood friends. Conclusion Professionals in contact with children and families who live in challenging social conditions need to be aware of how these contexts shape children’s understanding of their own health potential.

Within societies, there is a well-established relation between socioeconomic position and a wide range of outcomes related to well-being, and this relation is known to vary in magnitude across countries. Using a large sample of nations, the authors explored whether differences in social policies explain differences in socioeconomic gradients across nations. Analyses were conducted on reading literacy in 15-year-olds, as an outcome related to cognitive development and to a host of factors that contribute to future well-being, including educational attainment and health. The results show a systematic variation in socioeconomic gradients and average scores across countries. Scores were favorable in countries with a long history of welfare state regimes, but countries where institutional change unfolded more recently and rapidly, or where welfare states are less well developed, clustered at the bottom of the rankings. Strong support was found for the “flattening up” hypothesis, which suggests that nations with higher average scores have less socioeconomic inequality in scores (or flatter gradients). Potential explanations for the observed patterns include differences between nations in the extent and distribution of income and social goods important for children's development.

Objective: To examine smoking behaviors in Canadian youth from late childhood to adolescence. By following participants from as young as 10 and 11 years, the authors proposed to identify distinct developmental pathways of smoking acquisition. Design: Growth mixture modeling was used to identify developmental trajectories of smoking among 10- to 17-year-old participants of the Canadian National Longitudinal Survey of Children and Youth. Main Outcome Measures: Developmental trajectories of trying smoking, smoking frequency, and smoking intensity. Results: Five developmental trajectories related to smoking frequency were identified, of which 2 were acquisition patterns that led to daily smoking at age 16-17, and 3 were experimentation patterns that led to nonsmoking at age 16-17. The largest variability in changes in smoking behavior over time was the reported level of smoking frequency. Conclusion: Analysis showed that there is more than 1 way in which Canadian children and adolescents acquire smoking behaviors over time. The authors were able to differentiate patterns of experimentation from patterns of acquisition. Whereas experimentation has been generally considered as 1 of the stages in the smoking acquisition process leading to regular smoking, these results indicate that experimentation can be described as a distinct process in itself.