Childhood socioeconomic position and adult cardiovascular mortality: the Boyd Orr Cohort

Statistical methods for mediation analysis in the era of high-throughput genomics: Current successes and future challenges

Mediation analysis investigates the intermediate mechanism through which an exposure exerts its influence on the outcome of interest. Mediation analysis is becoming increasingly popular in high-throughput genomics studies where a common goal is to identify molecular-level traits, such as gene expression or methylation, which actively mediate the genetic or environmental effects on the outcome. Mediation analysis in genomics studies is particularly challenging, however, thanks to the large number of potential mediators measured in these studies as well as the composite null nature of the mediation effect hypothesis. Indeed, while the standard univariate and multivariate mediation methods have been well-established for analyzing one or multiple mediators, they are not well-suited for genomics studies with a large number of mediators and often yield conservative p-values and limited power. Consequently, over the past few years many new high-dimensional mediation methods have been developed for analyzing the large number of potential mediators collected in high-throughput genomics studies. In this work, we present a thorough review of these important recent methodological advances in high-dimensional mediation analysis. Specifically, we describe in detail more than ten high-dimensional mediation methods, focusing on their motivations, basic modeling ideas, specific modeling assumptions, practical successes, methodological limitations, as well as future directions. We hope our review will serve as a useful guidance for statisticians and computational biologists who develop methods of high-dimensional mediation analysis as well as for analysts who apply mediation methods to high-throughput genomics studies.

Intergenerational effects of early adversity on survival in wild baboons

Early life adversity can affect an individual's health, survival, and fertility for many years after the adverse experience. Whether early life adversity also imposes intergenerational effects on the exposed individual's offspring is not well understood. We fill this gap by leveraging prospective, longitudinal data on a wild, long-lived primate. We find that juveniles whose mothers experienced early life adversity exhibit high mortality before age 4, independent of the juvenile's own experience of early adversity. These juveniles often preceded their mothers in death by 1 to 2 years, indicating that high adversity females decline in their ability to raise offspring near the end of life. While we cannot exclude direct effects of a parent's environment on offspring quality (e.g., inherited epigenetic changes), our results are completely consistent with a classic parental effect, in which the environment experienced by a parent affects its future phenotype and therefore its offspring's phenotype.

Socio-economic trajectories and cardiovascular disease mortality in older people: the English Longitudinal Study of Ageing

Background

Socio-economic status from early life has been linked to cardiovascular disease risk, but the impact of life-course socio-economic trajectories, as well as the mechanisms underlying social inequalities in cardiovascular disease risk, is uncertain.

Objectives

We assessed the role of behavioural, psychosocial and physiological (including inflammatory) factors in the association between life-course socio-economic status and cardiovascular disease mortality in older adults.

Methods

Participants were 7846 individuals (44% women) from the English Longitudinal Study of Ageing, a representative study of individuals aged ≥ 50 years, established in 2002-03. Comprising four indicators of socio-economic status (father's social class, own education, occupational position and wealth), we computed an index of socio-economic trajectory and a lifetime cumulative socio-economic score. Behavioural (smoking, physical activity, alcohol consumption, body mass index) and psychosocial (social relations, loneliness) factors, physiological (blood pressure, total cholesterol, triglycerides) and inflammatory markers (C-reactive protein, fibrinogen), measured repeatedly over time, were potential explanatory variables. Cardiovascular disease mortality was ascertained by linkage of study members to a national mortality register. Mediation was calculated using the traditional 'change-in-estimate method' and alternative approaches such as counterfactual mediation modelling could not be applied in this context.

Results

During the 8.4-year follow-up, 1301 study members died (438 from cardiovascular disease). A stable low-social-class trajectory was associated with around double the risk of cardiovascular disease mortality (hazard ratio; 95% confidence interval: 1.94, 1.37; 2.75) compared with a stable high social class across the life course. Individuals in the lowest relative to the highest life-course cumulative socio-economic status group were also more than twice as likely to die of cardiovascular disease (2.57, 1.81; 3.65). Behavioural factors and inflammatory markers contributed most to explaining this gradient, whereas the role of psychosocial and other physiological risk factors was modest.

Conclusions

In a population-based cohort of older individuals living in England, we provide evidence that disadvantage across the life course is linked to cardiovascular mortality. That behavioural factors and inflammatory markers partially explain this gradient may provide insights into the potential for intervention.

The association of early life socioeconomic position on breast cancer incidence and mortality: a systematic review

OBJECTIVES

We conducted a systematic review of the literature relating early life socioeconomic position (SEP) to breast cancer incidence and mortality from a critical period and life-course trajectory perspective.

METHODS

PubMed, EMBASE and Web of Science were searched to identify cohort studies that evaluated the impact of early life SEP indicators on the incidence and/or mortality from breast cancer in adulthood.

RESULTS

Nine distinct studies evaluated the relationship between early life SEP and breast cancer between 1990 and 2016. Five reports assessed breast cancer incidence and five assessed breast cancer mortality as outcomes; one study assessed both incidence and mortality. While lower early life SEP was associated with reduced breast cancer incidence and increased breast cancer mortality in the US, studies conducted in Europe were unable to establish a consistent association.

CONCLUSIONS

We found moderate support for the association between early life SEP and incidence and mortality from breast cancer. The impact of early life SEP on breast cancer incidence and mortality appeared to vary between countries. We urge further investigation of the role of lifelong SEP trajectories in breast cancer outcomes.

From cradle to grave: tracking socioeconomic inequalities in mortality in a cohort of 11 868 men and women born in Uppsala, Sweden, 1915-1929

BACKGROUND

Ample evidence has shown that early-life social conditions are associated with mortality later in life. However, little attention has been given to the strength of these effects across specific age intervals from birth to old age. In this paper, we study the effect of the family's socioeconomic position and mother's marital status at birth on all-cause mortality at different age intervals in a Swedish cohort of 11 868 individuals followed across their lifespan.

METHODS

Using the Uppsala Birth Cohort Multigenerational Study, we fitted Cox regression models to estimate age-varying HRs of all-cause mortality according to mother's marital status and family's socioeconomic position.

RESULTS

Mother's marital status and family's socioeconomic position at birth were associated with higher mortality rates throughout life (HR 1.18 (95% CI 1.12 to 1.26) for unmarried mothers; 1.19 (95% CI 1.12 to 1.25) for low socioeconomic position). While the effect of family's socioeconomic position showed little variation across different age groups, the effect of marital status was stronger for infant mortality (HR 1.47 (95% CI 1.23 to 1.76); p=0.04 for heterogeneity). The results remained robust when early life and adult mediator variables were included.

CONCLUSIONS

Family's socioeconomic position and mother's marital status involve different dimensions of social stratification with independent effects on mortality throughout life. Our findings support the importance of improving early-life conditions in order to enhance healthy ageing.

Socioeconomic position in childhood and cancer in adulthood: a rapid-review

Background

The relationship of childhood socioeconomic position (SEP) to adult cancer has been inconsistent in the literature and there has been no review summarising the current evidence focused solely on cancer outcomes.

Methods and results

We performed a rapid review of the literature, which identified 22 publications from 13 studies, primarily in the UK and northern European countries that specifically analysed individual measures of SEP in childhood and cancer outcomes in adulthood. Most of these studies adjusted for adult SEP as a critical mediator of the relationship of interest.

Conclusions

Results confirm that childhood socioeconomic circumstances have a strong influence on stomach cancer and are likely to contribute, along with adult circumstances, to lung cancer through cumulative exposure to smoking. There was also some evidence of increased risk of colorectal, liver, cervical and pancreatic cancers with lower childhood SEP in large studies, but small numbers of cancer deaths made these estimates imprecise. Gaps in knowledge and potential policy implications are presented.

Socioeconomic Conditions in Childhood, Adolescence, and Adulthood and the Risk of Ischemic Stroke

BACKGROUND AND PURPOSE

The association between socioeconomic status in adulthood and the risk of stroke is well established; however, the independent effects of socioeconomic conditions in different life phases are less understood.

METHODS

Within a population-based stroke registry, we performed a case-control study with 470 ischemic stroke patients (cases) aged 18 to 80 years and 809 age- and sex-matched stroke-free controls, randomly selected from the population (study period October 2007 to April 2012). We assessed socioeconomic conditions in childhood, adolescence, and adulthood, and developed a socioeconomic risk score for each life period.

RESULTS

Socioeconomic conditions were less favorable in cases regarding paternal profession, living conditions and estimated family income in childhood, school degree, and vocational training in adolescence, last profession, marital status and periods of unemployment in adulthood. Using tertiles of score values, low socioeconomic conditions during childhood (odds ratio 1.77; 95% confidence interval 1.20-2.60) and adulthood (odds ratio 1.74; 95% confidence interval 1.16-2.60) but not significantly during adolescence (odds ratio 1.64; 95% confidence interval 0.97-2.78) were associated with stroke risk after adjustment for risk factors and other life stages. Medical risk factors attenuated the effect of childhood conditions, and lifestyle factors reduced the effect of socioeconomic conditions in adolescence and adulthood. Unfavorable childhood socioeconomic conditions were particularly associated with large artery atherosclerotic stroke in adulthood (odds ratio 2.13; 95% confidence interval 1.24-3.67).

CONCLUSIONS

This study supports the hypothesis that unfavorable childhood socioeconomic conditions are related to ischemic stroke risk, independent of established risk factors and socioeconomic status in adulthood, and fosters the idea that stroke prevention needs to begin early in life.

A life course approach to mortality in Mexico

OBJECTIVE

Research on early life socioeconomic status (SES), education and mortality is less established in developing countries. This analysis aims to determine how SES and education are patterned across the life course and associated with adult mortality in Mexico.

MATERIALS AND METHODS

Data comes from 2001-2012 Mexican Health & Aging Study (Mexican adults age 50+, n= 11,222). Cox proportional hazard models predict mortality using baseline covariates.

RESULTS

In unadjusted analyses, similar mortality was seen across levels of early life SES. Lower early life SES was associated with better survival after accounting for education in the younger cohort. Lower education was only associated with mortality in the younger cohort.

CONCLUSIONS

Early life SES was associated with education but the relationship between education and mortality differed across cohorts in Mexico. Selective survival and differential returns to education may explain differences.

Early determinants of the ageing trajectory

Over the past 250 years, human life expectancy has increased dramatically and continues to do so in most countries worldwide. Genetic factors account for about one third of variation in life expectancy so that most inter-individual variation in lifespan is explained by stochastic and environmental factors. The ageing process is plastic and is driven by the accumulation of molecular damage causing the changes in cell and tissue function which characterise the ageing phenotype. Early life exposures mark the developing embryo, foetus and child with potentially profound implications for the individual's ageing trajectory. Maternal factors including age, smoking, socioeconomic status, infections, nutritional status and season of birth influence offspring life expectancy and the development of age-related diseases. Although the mechanistic processes responsible are poorly understood, many of these factors appear to affect foetal growth directly or via effects on placental development. Those born relatively small i.e. which did not achieve their genetic potential in utero, appear to be at greatest disadvantage especially if they become overweight or obese in childhood. Early life events and exposures which enhance ageing are likely to contribute to molecular damage and/or reduce the repair of such damage. Such molecular damage may produce immediate defects in cellular or tissue function that are retained into later life. In addition, there is growing evidence that early life exposures produce aberrant patterns of epigenetic marks that are sustained across the life-course and result in down-regulation of cell defence mechanisms.

Economic stress in childhood and adulthood, and self-rated health: a population based study concerning risk accumulation, critical period and social mobility

BACKGROUND

Research in recent decades increasingly indicates the importance of conditions in early life for health in adulthood. Only few studies have investigated socioeconomic conditions in both childhood and adulthood in relation to health testing the risk accumulation, critical period, and social mobility hypotheses within the same setting. This study investigates the associations between economic stress in childhood and adulthood, and self-rated health with reference to the accumulation, critical period and social mobility hypotheses in life course epidemiology, taking demographic, social support, trust and lifestyle factors into account.

METHODS

The public health survey in Skåne (southern Sweden) in 2008 is a cross-sectional postal questionnaire study based on a random sample, in which 28,198 persons aged 18-80 years participated (55% participation). Logistic regression models were used to investigate associations between economic stress in childhood and adulthood, and self-rated health.

RESULTS

Three life-course socioeconomic models concerning the association between economic stress and self-rated health (SRH) were investigated. The results showed a graded association between the combined effect of childhood and adulthood economic stress and poor SRH in accordance with the accumulation hypothesis. Furthermore, upward social mobility showed a protecting effect and downward mobility increased odds ratios of poor SRH in accordance with the social mobility hypothesis. High/severe economic stress exposures in both stages of life were independently associated with poor SRH in adulthood. Furthermore, stratifying the study population into six age groups showed similar odds ratios of poor SRH regarding economic stress exposure in childhood and adulthood in all age groups among both men and women.

CONCLUSIONS

The accumulation and social mobility hypotheses were confirmed. The critical period model was confirmed in the sense that both economic stress in childhood and adulthood had independent effects on poor SRH. However, it was not confirmed in the sense that a particular window in time (in childhood or adulthood) had a specifically high impact on self-rated health.

Socioeconomic status and subclinical atherosclerosis in older adults

OBJECTIVE

This study investigated the long-term effects of socioeconomic status (SES) on atherosclerosis.

METHODS

Data from the Epidemiology of Hearing Loss Study and the Beaver Dam Eye Study (Beaver Dam, WI, 1998-2000), were used to examine adult SES (education, household income, and longest-held job) and childhood SES (household density and parental home ownership at age 13) associations with carotid intima-media thickness (IMT) and carotid plaque in a cohort of 2042 men and women aged 53 to 94 years.

RESULTS

For education, income, and occupation (women), those in the lowest SES group had statistically larger age-sex-adjusted IMT than those in the highest SES group (<12 vs. >12 years education: 0.92 vs. 0.86 mm respectively, P<0.0001), (<$10,000 vs. >$45,000: 0.97 vs. 0.87 mm, P<0.0001), (operator/fabricator/labor vs. manager/professional: 0.89 vs. 0.82 mm, P<0.001). Associations were similar using carotid plaque as the outcome. Participants with low levels of both adult and childhood SES measures had age-sex-adjusted IMT greater than those with persistently high levels of SES (0.93 vs. 0.84 mm, P<0.0001).

CONCLUSIONS

Measures of SES at two points in the life-span were associated with subclinical atherosclerosis.

Childhood socioeconomic position and objectively measured physical capability levels in adulthood: a systematic review and meta-analysis

BACKGROUND

Grip strength, walking speed, chair rising and standing balance time are objective measures of physical capability that characterise current health and predict survival in older populations. Socioeconomic position (SEP) in childhood may influence the peak level of physical capability achieved in early adulthood, thereby affecting levels in later adulthood. We have undertaken a systematic review with meta-analyses to test the hypothesis that adverse childhood SEP is associated with lower levels of objectively measured physical capability in adulthood.

METHODS AND FINDINGS

Relevant studies published by May 2010 were identified through literature searches using EMBASE and MEDLINE. Unpublished results were obtained from study investigators. Results were provided by all study investigators in a standard format and pooled using random-effects meta-analyses. 19 studies were included in the review. Total sample sizes in meta-analyses ranged from N = 17,215 for chair rise time to N = 1,061,855 for grip strength. Although heterogeneity was detected, there was consistent evidence in age adjusted models that lower childhood SEP was associated with modest reductions in physical capability levels in adulthood: comparing the lowest with the highest childhood SEP there was a reduction in grip strength of 0.13 standard deviations (95% CI: 0.06, 0.21), a reduction in mean walking speed of 0.07 m/s (0.05, 0.10), an increase in mean chair rise time of 6% (4%, 8%) and an odds ratio of an inability to balance for 5s of 1.26 (1.02, 1.55). Adjustment for the potential mediating factors, adult SEP and body size attenuated associations greatly. However, despite this attenuation, for walking speed and chair rise time, there was still evidence of moderate associations.

CONCLUSIONS

Policies targeting socioeconomic inequalities in childhood may have additional benefits in promoting the maintenance of independence in later life.

Do different measures of early life socioeconomic circumstances predict adult mortality? Evidence from the British Whitehall II and French GAZEL studies

BACKGROUND

Father's occupational position, education and height have all been used to examine the effects of adverse early life socioeconomic circumstances on health, but it remains unknown whether they predict mortality equally well.

METHODS

We used pooled data on 18,393 men and 7060 women from the Whitehall II and GAZEL cohorts to examine associations between early life socioeconomic circumstances and all-cause and cause-specific mortality.

RESULTS

During the 20-y follow-up period, 1487 participants died. Education had a monotonic association with all mortality outcomes; the age, sex and cohort-adjusted HR for the lowest versus the highest educational group was 1.45 (95% CI 1.24 to 1.69) for all-cause mortality. There was evidence of a U-shaped association between height and all-cause, cancer and cardiovascular mortality robust to adjustment for the other indicators (HR 1.41, 95% CI 1.03 to 1.93 for those shorter than average and HR 1.36, 95% CI 0.98 to 1.88 for those taller than average for cardiovascular mortality). Greater all-cause and cancer mortality was observed in participants whose father's occupational position was manual rather than non-manual (HR 1.11, 95% CI 1.00 to 1.23 for all-cause mortality), but the risks were attenuated after adjusting for education and height.

CONCLUSIONS

The association between early life socioeconomic circumstances and mortality depends on the socioeconomic indicator used and the cause of death examined. Height is not a straightforward measure of early life socioeconomic circumstances as taller people do not have a health advantage for all mortality outcomes.

Coronary heart disease from a life-course approach: findings from the health and retirement study, 1998-2004

OBJECTIVE

Guided by a life-course approach to chronic disease, this study examined the ways in which childhood deprivation (low parental education and father's manual occupation) may be associated with coronary heart disease (CHD).

METHOD

Multilevel modeling techniques and a nationally representative sample of Americans above age 50 from the Health and Retirement Study (HRS; N = 18,465) were used to examine childhood and CHD relationships over the course of 6 years (1998-2004).

RESULTS

Having a father with </=8 years of education was associated with 11% higher odds of CHD, accounting for demographic characteristics, adult socioeconomic status (SES; education, income, and wealth), CHD risks (diabetes, hypertension, cigarette smoking, and obesity), and other factors (childhood health, exercise, stroke, and marital status).

DISCUSSION

Policies and programs aimed at improving the conditions of poor children and their families may effectively reduce the prevalence of CHD in later life.

Childhood economic conditions and length of life: evidence from the UK Boyd Orr cohort, 1937-2005

We study the importance of childhood socioeconomic conditions in predicting differences in life expectancy using data from a large sample of children collected in 16 locations in England and Scotland in 1937-39, who have been traced through official death records up to 2005. We estimate a number of duration of life models that control for unobserved family heterogeneity. Our results confirm that childhood conditions such as household income and the quality of the home environment are significant predictors of longevity. Importantly, however, the role of socioeconomic status appears to differ across cause of death, with household income being a significant predictor of death from smoking-related cancer. Moreover, we find that (1) poor housing conditions in childhood is associated with reduced longevity, that (2) early doctor-assessed childhood health conditions significantly predict a reduced length of life, that (3) children born in a location with relatively high infant mortality rates live significantly fewer years, and that (4) there is a high correlation in longevity across children from the same family across all causes of death. We estimate that the difference in life expectancy between those with the 'best' and 'worst' observable characteristics is about 9 years, which increases to 20 years when we take into account the 'best' and 'worst' observable and unobservable household characteristics.

Health disparities beginning in childhood: a life-course perspective

In this article we argue for the utility of the life-course perspective as a tool for understanding and addressing health disparities across socioeconomic and racial or ethnic groups, particularly disparities that originate in childhood. Key concepts and terms used in life-course research are briefly defined; as resources, examples of existing literature and the outcomes covered are provided along with examples of longitudinal databases that have often been used for life-course research. The life-course perspective focuses on understanding how early-life experiences can shape health across an entire lifetime and potentially across generations; it systematically directs attention to the role of context, including social and physical context along with biological factors, over time. This approach is particularly relevant to understanding and addressing health disparities, because social and physical contextual factors underlie socioeconomic and racial/ethnic disparities in health. A major focus of life-course epidemiology has been to understand how early-life experiences (particularly experiences related to economic adversity and the social disadvantages that often accompany it) shape adult health, particularly adult chronic disease and its risk factors and consequences. The strong life-course influences on adult health could provide a powerful rationale for policies at all levels--federal, state, and local--to give more priority to investment in improving the living conditions of children as a strategy for improving health and reducing health disparities across the entire life course.

Childhood socioeconomic position and disability in later life: results of the health and retirement study

OBJECTIVES

We used a life course approach to assess the ways in which childhood socioeconomic position may be associated with disability in later life.

METHODS

We used longitudinal data from the nationally representative Health and Retirement Study (1998-2006) to examine associations between parental education, paternal occupation, and disabilities relating to activities of daily living (ADLs) and instrumental activities of daily living (IADLs).

RESULTS

Respondents whose fathers had low levels of education and those whose fathers were absent or had died while they were growing up were at increased risk of disability in later life, net of social, behavioral, and pathological health risks in adulthood. Social mobility and health behaviors were also important factors in the association between low childhood socioeconomic position and ADL and IADL disabilities.

CONCLUSIONS

Our findings highlight the need for policies and programs aimed at improving the well-being of both children and families. A renewed commitment to such initiatives may help reduce health care costs and the need for people to use health and social services in later life.

Childhood socioeconomic status and racial differences in disability: evidence from the Health and Retirement Study (1998-2006)

This study used a life course approach to examine the ways in which childhood socioeconomic status (SES) may account for some of the racial differences in disability in later life. Eight years (5 waves) of longitudinal data from the US Health and Retirement Study (HRS; 1998-2006), a nationally representative sample of community-dwelling Black and White Americans over age 50 (N=14,588), were used in nonlinear multilevel models. Parental education and father's occupation were used to predict racial differences in activities of daily living (ADL) and instrumental activities of daily living (IADL). The role of adult SES (education, income, and wealth) and health behaviors (smoking, drinking alcohol, exercising, and being obese) were also examined and models were adjusted for health conditions (heart problems, diabetes, stroke, hypertension, cancer, lung disease, and arthritis). With the inclusion of childhood SES indicators, racial differences in ADL and IADL disability were reduced. Adult SES and health behaviors mediated some of the relationship between low childhood SES and disability, though low childhood SES continued to be associated with disability net of these. In support of a life course approach, these findings suggest that socioeconomic conditions in early life may have implications for racial differences in disability between older Black and older White adults.

Historical records as a source of information for childhood socioeconomic status: results from a pilot study of decedents

PURPOSE

The validity of parental occupation recalled by adult children is not established, yet it is commonly used to measure childhood socioeconomic status (SES). We investigated the feasibility of using data from historical records to validate recalled parental SES.

METHODS

Data from death certificates and applications for Social Security numbers (parents' names, date and place of birth) were used to locate birth certificates and 1930 census records of 416 decedents in Forsyth County, NC, to verify parental occupation and childhood residence.

RESULTS

Birth certificates and/or census records were located for 85% of decedents. Of 257 for whom both records were searched, both were found for 60%, only a census record for 10%, and only a birth certificate for 24%. Among those with father's occupation recorded on both records (n = 138), occupational category matched on 89% of records (kappa = 0.86). Place of residence/birth, which can be linked with census-based county socioeconomic indicators, was also highly concordant across records.

CONCLUSIONS

These results demonstrate that birth and census records can be located for most decedents and that the childhood SES data contained therein is highly concordant. Thus they are an alternative to recalled childhood SES and a source of validation data in life course studies.

What do trajectories of childhood socioeconomic status tell us about markers of cardiovascular health in adolescence?

OBJECTIVE

The current study examined trajectories of socioeconomic status (SES) throughout childhood and their relationship to markers of cardiovascular health in adolescence. The goal was to determine whether early-life SES, current SES, cumulative SES, and/or social mobility best explained the relationship between SES experiences across an adolescent's life span and current blood pressure (BP), heart rate (HR), and body mass index (BMI).

DESIGN

One hundred two adolescents completed cardiovascular health assessments including systolic blood pressure, diastolic blood pressure, HR, and BMI. Parents reported on family SES, indicating the number of bedrooms in the family home for each year of the child's life.

RESULTS

Using Jones, Nagin, and Roeder's semiparametric group-based method, four distinct trajectories of childhood SES were identified. Trajectory groups were differentially related to adolescents' systolic blood pressure and diastolic blood pressure. A trajectory showing low early-life SES that increased through childhood was associated with the highest BP in adolescence. Partial correlation analyses specifically examining the various life-course scenarios similarly indicated that early-life SES was the strongest predictor of adolescents' BP. Trajectories of childhood SES were unrelated to HR and BMI.

CONCLUSIONS

Of the life-course models that we tested, an early-life SES model best explained adolescents' current BP. These findings point toward early-life developmental processes as potential candidates for explaining the relationship between SES and risk factors related to cardiovascular disease. They suggest that interventions designed to reduce SES health disparities should take place early in a child's life.

Older adults' perspectives on key domains of childhood social and economic experiences and opportunities: a first step to creating a multidimensional measure

Objectives

Although research has found that childhood socioeconomic status (SES) is associated with physical and mental health in mid- and later life, most of these studies used conventional, single dimension SES measures for the childhood period such as household income or educational attainment of parents. Life course and health disparities research would benefit from identification and measurement of a variety of childhood social and economic experiences and opportunities that might affect health in later life.

Design

This study utilized qualitative research methods to identify key dimensions of childhood experiences related to SES. We conducted in-depth interviews with 25 adults age 55 to 80 years from diverse economic and ethnic backgrounds. Topics included home, neighborhood, school, and work experiences during early childhood and adolescence. Interviews were audio-taped and transcripts were coded to identify thematic domains.

Results

We identified eight thematic domains, many of which had clear subdomains: home and family circumstances, neighborhood, work and money, potential for advancement through schooling, school quality and content, discrimination, influence and support of adults, and leisure activities. These domains highlight individual characteristics and experiences and also economic and educational opportunities.

Conclusion

These domains of childhood social and economic circumstances add breadth and depth to conventional conceptualization of childhood SES. When the domains are translated into a measurement tool, it will allow for the possibility of classifying people along multiple dimensions, such as from a low economic circumstance with high levels of adult support.

Life-course approaches to inequalities in adult chronic disease risk

A life-course approach to chronic-disease epidemiology uses a multidisciplinary framework to understand the importance of time and timing in associations between exposures and outcomes at the individual and population levels. Such an approach to chronic diseases is enriched by specification of the particular manner in which timing in relation to physical growth, reproduction, infection, social mobility, behavioural transitions etc. can influence various adult chronic diseases in different ways, and more ambitiously by how these temporal processes are interconnected and manifested in health inequalities within a population and in population-level disease trends. The paper will discuss some historical background to life-course epidemiology and theoretical models of life-course processes, and will review some of the empirical evidence linking life-course processes to CHD, haemorrhagic stroke, stomach cancer and other chronic diseases in adulthood. It will also underscore that a life-course approach offers a way to conceptualize how underlying socio-environmental determinants of health, experienced at different life-course stages, can differentially influence the development of chronic diseases, as mediated through proximal specific biological processes.

Cohort-specific trends in stroke mortality in seven European countries were related to infant mortality rates

OBJECTIVES

To assess, in a population-based study, whether secular trends in cardiovascular disease mortality in seven European countries were correlated with past trends in infant mortality rate (IMR) in these countries.

STUDY DESIGN AND SETTING

Data on ischemic heart disease (IHD) and stroke mortality in 1950-1999 in the Netherlands, England & Wales, France, and four Nordic countries were analyzed. We used Poisson regression to describe trends in mortality according to birth cohort, for the cohorts born between 1860 and 1939. Pearson correlation coefficients were calculated to determine associations between IMR and IHD, or stroke mortality.

RESULTS

IHD mortality increased for successive cohorts up to 1900, and then started to decline. Stroke mortality levels were virtually stable among birth cohorts up to 1880, but declined rapidly among later cohorts. A strong positive association was found between cohort-specific IMR levels and stroke mortality rates. There were no strong cohort-wise associations between IMR and IHD mortality.

CONCLUSION

These results support other studies in suggesting that living conditions in early childhood may influence population levels of stroke mortality. Future studies should determine the contribution of specific early life factors to the mortality decline in IHD and especially stroke.

Relationship between childhood socio-economic position and mortality risk in adult males of the Korea Labour and Income Panel Study (KLIPS)

OBJECTIVES

Evidence on the relationship between childhood socio-economic position (SEP) and adult mortality risk is mounting, but is sparse in regions outside Europe and North America. The present study aimed to examine this relationship in South Korea.

STUDY DESIGN

Prospective cohort study.

METHODS

First-round data from the Korea Labour and Income Panel Study were linked to data on mortality. Childhood SEP indicators were father's education, own education, father's occupational class at age 14, own first occupational class after age 15, birth place, and residence at age 14. Adulthood SEP indicators included current occupational class, family income, perceived economic hardships, and current residence.

RESULTS

Mortality differentials according to current occupational class, economic hardship and current residence were statistically significant. Mortality risk tended to increase as household income decreased. For all childhood SEP indicators, inverse relationships between childhood SEP and mortality risk were found. These inverse relationships were attenuated but did not disappear with adjustment for each adulthood SEP indicator. However, the statistically significant association between childhood SEP and mortality risk did not persist after full adjustment for four adulthood SEP indicators.

CONCLUSIONS

Both early- and later-life markers of SEP were related to an increased risk of death in South Korea. Future studies need to examine the relationship between childhood SEP and cause-specific mortality.

Association between gross domestic product throughout the life course and old-age mortality across birth cohorts: Parallel analyses of seven European countries, 1950–1999

Mortality levels of national populations have often been studied in relation to levels of gross domestic product (GDP) at time of death. Following the life course perspective, we assessed whether old-age mortality levels for subsequent cohorts are differentially associated with GDP levels prevailing at different ages of the cohorts. We used all-cause and cause-specific mortality data by sex, age at death (65-99), year at death (1950-1999), and year of birth (1865-1924) for Denmark, England and Wales, Finland, France, the Netherlands, Norway, and Sweden. Trends in national GDP per capita between 1865 and 1999 were reconstructed from historical national accounts data. Through Poisson regression analyses, we determined for each country both univariate and multivariate associations across five-year birth cohorts between mortality and GDP levels prevailing at time of death, and at earlier ages of the cohorts (i.e. 0-5, 6-19, 20-49, and 50-64). For the subsequent cohorts, levels of GDP at time of death were strongly inversely associated with all-cause mortality, especially among women, and among men in England and Wales, Finland, and France. In most countries, stronger associations were observed with GDP levels prevailing at earlier ages of the cohorts. After control for GDP at time of death, these associations remained. An independent association of GDP at earlier ages of the cohort was also observed for cause-specific mortality. The associations were negative for ischaemic heart diseases, cerebrovascular diseases, and stomach cancer. They were positive for prostate cancer, breast cancer, COPD (women), and lung cancer (women). GDP prevailing at ages 20-49 (men) and ages 50-64 (women) had the largest associations with old-age mortality. These findings suggest an independent, mostly negative effect of GDP prevailing at earlier ages of subsequent cohorts on old-age mortality. Socio-economic circumstances during adulthood and middle age seem more important in determining old-age mortality trends than those during infancy or childhood.

Family socioeconomic position at birth and future cardiovascular disease risk: findings from the Aberdeen Children of the 1950s cohort study

OBJECTIVES

We assessed the association of father's social class, recorded at the time of birth, with coronary heart disease and stroke in a British cohort of 11106 individuals born in the 1950s.

METHODS

Survival analysis was used to relate social class at birth to the occurrence of either fatal or nonfatal coronary heart disease or stroke.

RESULTS

Rates of coronary heart disease and stroke increased across the social class distribution from highest to lowest, and patterns of association were similar for the 2 outcomes. The gender-adjusted hazard ratio of experiencing either coronary heart disease or stroke comparing the manual and nonmanual social class categories was 1.52 (95% confidence interval [CI]=1.14, 2.02). This ratio fell to 1.41 (95% CI = 1.05, 1.88) after adjustment for indicators of intrauterine and childhood growth. Further adjustment for educational attainment reduced the ratio to 1.28 (95% CI=0.94, 1.75).

CONCLUSIONS

We found that social class at birth was associated with risk of fatal and nonfatal cardiovascular disease among individuals born in the 1950s, a period of relative prosperity and after the introduction of the welfare state in Britain. This relation appeared to be mediated in part through educational attainment.

Genetic and environmental influences on the relation between parental social class and mortality

BACKGROUND

Genetic and maternal prenatal environmental factors as well as the post-natal rearing environment may contribute to the association between childhood socioeconomic circumstances and later mortality. In order to disentangle these influences, we studied all-cause and cause-specific mortality in a cohort of adoptees, in whom we estimated the effects of their biological and adoptive fathers' social classes as indicators of the genetic and/or prenatal environmental factors and the post-natal environment, respectively.

METHODS

In all 12 608 children born 1924-47 in Denmark who were placed early in life with adoptive parents were followed up for causes of death until 2000. Hazard ratios for paternal social class retrieved from adoption records were estimated using Cox regression models.

RESULTS

Adoptees with biological fathers from higher social classes had a lower rate of mortality after their fifth decade of life, mainly due to a lower risk of cardiovascular, infectious, and respiratory diseases. Adoptive father's social class showed no clear relation with adoptee's mortality risk. The risk estimates for paternal social class were slightly attenuated after adjustment for adoptee's adult social class, which as expected was inversely related to mortality from both natural and external causes.

CONCLUSION

Genetic and/or prenatal environmental factors contribute to the development of the relation of paternal social class to mortality from natural causes later in adult life independently of the effect of own social class, whereas there is no evidence for such long-term effect of the rearing environment.

Parental longevity and mortality amongst Japanese men and women: the JACC Study

OBJECTIVES

To examine whether the risk of mortality varies according to parents' age at death.

DESIGN AND SUBJECTS

A large prospective study in Japanese men and women from 45 communities across Japan. A total of 51 485 men and women aged 40-79 years completed self-administered questionnaires at baseline and followed up for 9.6 years.

RESULTS

The risk of mortality from stroke, cardiovascular disease, and all causes was 20-30% lower in men and women with fathers who died at age > or = 80 years, compared with those with fathers whose age at death was <60 years. A similar reduction was found when the age at death of mothers was > or = 85 years compared with <65 years. Furthermore, the risk reduction was more evident amongst persons with both parents being long-lived parents compared with those with being short-lived parents, especially for death from cardiovascular disease.

CONCLUSIONS

Our findings indicate that parental longevity could be a predictor for reduced risk of mortality from stroke, cardiovascular disease, and all causes for both Japanese men and women.

Systematic Review of the Influence of Childhood Socioeconomic Circumstances on Risk for Cardiovascular Disease in Adulthood

PURPOSE

Adverse socioeconomic circumstances in childhood may confer a greater risk for adult cardiovascular disease (CVD). The purpose of this review is to systematically evaluate evidence for an association between socioeconomic circumstances during childhood and specific CVD subtypes, independent of adult socioeconomic conditions.

METHODS

We systematically retrieved individual-level studies of morbidity and mortality from CVD and specific CVD subtypes linked to early life influences, including coronary heart disease (CHD), ischemic and hemorrhagic stroke, peripheral vascular disease, markers of atherosclerosis (carotid intima-media thickness and stenosis), and rheumatic heart disease. Indicators of socioeconomic position in childhood varied, although most studies relied on father's occupation.

RESULTS

We located 40 studies (24 prospective, 11 case-control, and 5 cross-sectional) reported in 50 publications. Thirty-one studies (19 prospective, 7 case-control, and all 5 cross-sectional) found a robust inverse association between childhood circumstances and CVD risk, although findings sometimes varied among specific outcomes, socioeconomic measures, and sex. Case-control studies reported mixed results. The association was stronger for stroke and, in particular, hemorrhagic stroke, than for CHD. Childhood socioeconomic conditions remained important predictors of CVD, even in younger cohorts.

CONCLUSION

Childhood and adulthood socioeconomic circumstances are important determinants of CVD risk. The specific contribution of childhood and adulthood characteristics varies across different CVD subtypes. Disease-specific mechanisms are likely to explain the childhood origins of these adult health inequalities.

Keynote Presentation at the Eight International Congress of Behavioral Medicine: the Pittsburgh common cold studies: psychosocial predictors of susceptibility to respiratory infectious illness

This article provides a selected overview of 20 years of research on the role of psychosocial factors in susceptibility to upper respiratory infections. We present evidence from our laboratory that psychological stress is associated with increased risk for developing respiratory illness for persons intentionally exposed to a common cold virus, that the longer the duration of the stressor the greater the risk, and that stress association with susceptibility may be mediated by stress-induced disruption of the regulation of proinflammatory cytokines. We further provide evidence that social relationships (social integration and social support) are also associated with risk for respiratory illness: Social integration is associated with reduced risk irrespective of stress level and social support protects persons from the pathogenic influences of stress. Finally, we report recent evidence that lower levels of early childhood socio-economic status (SES) are associated with greater risk of viral-induced illness during adulthood, independent of adult SES.

Childhood socioeconomic position, educational attainment, and adult cardiovascular risk factors: the Aberdeen children of the 1950s cohort study

OBJECTIVES

We assessed the associations of childhood socioeconomic position with cardiovascular disease risk factors (smoking, binge alcohol drinking, and being overweight) and examined the roles of educational attainment and cognitive functioning in these associations.

METHODS

Data were derived from a cohort study involving 7184 individuals who were born in Aberdeen, Scotland, between 1950 and 1956; had detailed records on perinatal characteristics, childhood anthropometry, and cognitive functioning; and responded to a mailed questionnaire when they were aged 45 to 52 years.

RESULTS

Strong graded associations existed between social class at birth and smoking, binge drinking, and being overweight. Adjustment for educational attainment completely attenuated these associations. However, after control for adult social class, adult income and other potential confounding or mediating factors, some association remained.

CONCLUSIONS

Educational attainment is an important mediating factor in the relation between socioeconomic adversity in childhood and smoking, binge drinking, and being overweight in adulthood.

Diet in childhood and adult cardiovascular and all cause mortality: the Boyd Orr cohort

OBJECTIVE

To examine the association between childhood diet and cardiovascular mortality.

DESIGN

Historical cohort study.

SETTING

16 centres in England and Scotland.

PARTICIPANTS

4028 people (from 1234 families) who took part in Boyd Orr's survey of family diet and health in Britain between 1937 and 1939 followed up through the National Health Service central register. EXPOSURES STUDIED: Childhood intake of fruit, vegetables, fish, oily fish, total fat, saturated fat, carotene, vitamin C, and vitamin E estimated from household dietary intake.

MAIN OUTCOME MEASURES

Deaths from all causes and deaths attributed to coronary heart disease and stroke.

RESULTS

Higher childhood intake of vegetables was associated with lower risk of stroke. After controlling for age, sex, energy intake, and a range of socioeconomic and other confounders the rate ratio between the highest and lowest quartiles of intake was 0.40 (95% confidence interval 0.19 to 0.83, p for trend 0.01). Higher intake of fish was associated with higher risk of stroke. The fully adjusted rate ratio between the highest and lowest quartile of fish intake was 2.01 (95% confidence interval 1.09 to 3.69, p for trend 0.01). Intake of any of the foods and constituents considered was not associated with coronary mortality.

CONCLUSIONS

Aspects of childhood diet, but not antioxidant intake, may affect adult cardiovascular risk.

Researching income and income distribution as determinants of health in Canada: gaps between theoretical knowledge, research practice, and policy implementation

The research identified gaps in Canadian knowledge and research activity concerning the roles that income and its distribution play in Canadians' population health. 241 Canadian research studies on income and health were considered along eight taxonomies: conceptualization of income or its proxies; theoretical underpinnings; income distribution measures; health measures; who/what was studied, pathways mediating between income and health; complexity of these pathways; research design; and presence of policy implications. The study identified the following areas of weakness: (a) poor conceptualization of income and the means by which it influences health; (b) lack of longitudinal studies of the impact of income-related issues upon health across the life-span; (c) lack of linked data bases that allow complex analyses of how income and related issues contribute to health and well-being, and (d) little inter-disciplinary work in identifying pathways mediating the income and health relationship. Advances in health policy to address the health effects of income and its distribution requires a research infrastructure that draws upon recent theoretical developments in the area and is able to access data sources to test these advanced conceptualizations.

A life course approach to chronic disease epidemiology

A life course approach to chronic disease epidemiology uses a multidisciplinary framework to understand the importance of time and timing in associations between exposures and outcomes at the individual and population levels. Such an approach to chronic diseases is enriched by specification of the particular way that time and timing in relation to physical growth, reproduction, infection, social mobility, and behavioral transitions, etc., influence various adult chronic diseases in different ways, and more ambitiously, by how these temporal processes are interconnected and manifested in population-level disease trends. In this review, we discuss some historical background to life course epidemiology and theoretical models of life course processes, and we review some of the empirical evidence linking life course processes to coronary heart disease, hemorrhagic stroke, type II diabetes, breast cancer, and chronic obstructive pulmonary disease. We also underscore that a life course approach offers a way to conceptualize how underlying socio-environmental determinants of health, experienced at different life course stages, can differentially influence the development of chronic diseases, as mediated through proximal specific biological processes.

Evaluating the evidence for models of life course socioeconomic factors and cardiovascular outcomes: a systematic review

Background

A relatively consistent body of research supports an inverse graded relationship between socioeconomic status (SES) and cardiovascular disease (CVD). More recently, researchers have proposed various life course SES hypotheses, which posit that the combination, accumulation, and/or interactions of different environments and experiences throughout life can affect adult risk of CVD. Different life course designs have been utilized to examine the impact of SES throughout the life course. This systematic review describes the four most common life course hypotheses, categorizes the studies that have examined the associations between life course SES and CVD according to their life course design, discusses the strengths and weaknesses of the different designs, and summarizes the studies' findings.

Methods

This research reviewed 49 observational studies in the biomedical literature that included socioeconomic measures at a time other than adulthood as independent variables, and assessed subclinical CHD, incident CVD morbidity and/or mortality, and/or the prevalence of traditional CVD risk factors as their outcomes. Studies were categorized into four groups based upon life course design and analytic approach. The study authors' conclusions and statistical tests were considered in summarizing study results.

Results

Study results suggest that low SES throughout the life course modestly impacts CVD risk factors and CVD risk. Specifically, studies reviewed provided moderate support for the role of low early-life SES and elevated levels of CVD risk factors and CVD morbidity and mortality, little support for a unique influence of social mobility on CVD, and consistent support for the detrimental impact of the accumulation of negative SES experiences/conditions across the life course on CVD risk.

Conclusions

While the basic life course SES study designs have various methodologic and conceptual limitations, they provide an important approach from which to examine the influence of social factors on CVD development. Some limitations may be addressed through the analysis of study cohorts followed from childhood, the evaluation of CVD risk factors in early and middle adulthood, and the use of multiple SES measures and multiple life course analysis approaches in each life course study.

Cumulative deprivation and cause specific mortality. A census based study of life course influences over three decades

OBJECTIVE

To examine whether increasing cumulative deprivation has an incremental effect on total as well as cause specific mortality.

DESIGN

Census data on housing conditions as indicators of deprivation from 1960, 1970, and 1980 were linked to 1990-98 death registrations. Relative indices of inequalities were computed for housing conditions to measure the cumulative impact of differences in social conditions.

PARTICIPANTS

97 381 (71.1%) 30-49 year old and 70701 (80.0%) 50-69 year old inhabitants of Oslo, Norway, in 1990 with census information on housing conditions and recorded length of education.

MAIN RESULTS

Mortality risk was increased when all censuses' housing conditions were summed in both age groups and sex. The cause specific analysis indicated such an effect particularly for coronary heart disease, chronic obstructive lung disease, and smoking related cancers. Violent deaths were essentially associated with housing conditions closer to the time of death in men in both age groups and in young women.

CONCLUSIONS

To fully account for socially mediated risk of death, a full life course approach should be adopted. The relative importance of each stage seems to vary by cause of death.

Association between childhood socioeconomic status and coronary heart disease risk among postmenopausal women: findings from the British Women's Heart and Health Study

OBJECTIVES

We assessed the association between childhood socioeconomic status (SES) and coronary heart disease among postmenopausal women.

METHODS

We conducted a cross-sectional analysis of 3444 women aged 60 to 79 years.

RESULTS

There was an independent linear association between childhood and adult SES and coronary heart disease. The association between childhood SES and coronary heart disease was attenuated when we adjusted for insulin resistance syndrome, adult smoking, physical activity, biomarkers of childhood nutrition, and passive smoking.

CONCLUSIONS

The association between adverse childhood SES and coronary heart disease is in part mediated through insulin resistance, which may be influenced by poor childhood nutrition, and in part through the association between childhood SES and adult behavioral risk factors.

Childhood socioeconomic status and host resistance to infectious illness in adulthood

OBJECTIVE

Low childhood socioeconomic status (SES) is a risk factor for adult morbidity and mortality primarily attributable to cardiovascular disease. Here, we examine whether childhood SES is associated with adult host resistance to infectious illness, and whether the effect is limited to a critical period of low SES exposure, can be undone by changes in childhood SES, and is explained by adult SES.

METHODS

Three hundred thirty-four healthy volunteers reported their own and their parents' level of education and the ages during their childhood when their parents owned their homes. Volunteers' current home ownership was recorded from real estate records. Subsequently, they were given nasal drops containing 1 of 2 rhinoviruses and were monitored in quarantine for infection and signs/symptoms of a common cold.

RESULTS

For both viruses, susceptibility to colds decreased with the number of childhood years during which their parents owned their home (odds ratios by tertiles adjusted for demographics, body mass, season, and prechallenge viral-specific immunity were 3.7 for fewest years, 2.6 and 1). This decreased risk was attributable to both lower risk of infection and lower risk of illness in infected subjects. Moreover, those whose parents did not own their home during their early life but did during adolescence were at the same increased risk as those whose parents never owned their home. These associations were independent of parent education level, adult education and home ownership, and personality characteristics.

CONCLUSIONS

A marker of low income and wealth during early childhood is associated with decreased resistance to upper respiratory infections in adulthood. Higher risk is not ameliorated by higher SES during adolescence and is independent of adult SES.

Life-course experiences and mortality by adult social class among young men

Circumstances over the life-course may contribute to adult social class differences in mortality. However, it is only rarely that the life-course approach has been applied to mortality studies among young adults. The aim of this study is to determine to what extent social class differences in mortality among young Finnish men are explained by living conditions in the parental home and life paths related to transitions in youth. The data for males born in 1956-60 based on the 1990 census records are linked with death records (3184 deaths) by cause of death for 1991-98, and with information on life-course circumstances from the 1970, 1975, 1980, and 1985 censuses. Controlling for living conditions in the parental home-social class, family type, number of siblings, language and region of residence-reduced the high excess mortality of the lower non-manual (RR 1.51, 95% CI: 1.28-1.79), skilled manual (RR 2.94, 2.54-3.40), and unskilled manual class (RR 4.08, 3.51-4.73) by 10% in all-cause mortality. The equivalent reduction for cardiovascular disease was 28% and for alcohol-related causes 16%. The effect of parental home on mortality differences was mainly mediated through its effect on youth paths (pathway model). Educational, marital, and employment paths had a substantial effect-independent of parental home-on social class differences from various causes of death. When all these variables were controlled for adult social class differences in cause specific mortality were reduced by 75-86%. Most of this reduction in mortality differences can be attributed to educational path. However, marital and employment paths had their independent effects, particularly on the excess mortality of unskilled manual workers with disproportionately common exposure to long-term unemployment and living without a partner. In summary, social class differences in total mortality among men in their middle adulthood were only partly determined by parental home but they were mainly attributable to educational, marital, and employment paths in youth.

Socio-economic inequalities in diabetes complications, control, attitudes and health service use: a cross-sectional study

AIMS

To investigate socio-economic inequalities in diabetes complications, and to examine factors that may explain these differences.

METHODS

Cross-sectional questionnaire survey of 770 individuals with diabetes among 40 general practices in Avon and Somerset. General practice, optometrist and eye hospital records over time (median 7 years) were analysed. Slope indices of inequality, odds ratios and incidence rate ratios were calculated to estimate the magnitude of inequality between the most and least educated, and the highest and lowest earning patients, adjusted for age, sex and type of diabetes, and clustering of outcomes within practices.

RESULTS

The least educated patients were more likely than the most educated patients to have diabetic retinopathy [adjusted odds ratio (OR) 4.3; 95% confidence interval 0.8, 23.7] and heart disease (adjusted OR 3.6; 1.1, 11.8), had higher HbA1c levels (adjusted slope index of inequality 0.9; 0.3, 1.5), felt that diabetes more adversely affected their social and personal lives (adjusted slope index of inequality 0.8; 0.5, 1.1 Diabetes Care Profile units), were more likely to be recorded as non-compliant by their health professionals, and had lower rates of hospital attendance (adjusted rate ratio 0.43; 0.26, 0.71). However, they did not see themselves as less compliant, and had higher general practice attendance rates (adjusted rate ratio 1.5; 1.1, 2.2).

CONCLUSIONS

Less educated and lower earning individuals with diabetes bear a larger burden of morbidity but use hospital care less. Health service resource allocation should reflect the distribution of chronic illness.

Socioeconomic position in early life, birth weight, childhood cognitive function, and adult mortality. A longitudinal study of Danish men born in 1953

OBJECTIVE

To examine the relation between socioeconomic position in early life and mortality in young adulthood, taking birth weight and childhood cognitive function into account.

DESIGN

A longitudinal study with record linkage to the Civil Registration System and Cause of Death Registry. The data were analysed using Cox regression.

SETTING

The metropolitan area of Copenhagen, Denmark.

SUBJECTS

7493 male singletons born in 1953, who completed a questionnaire with various cognitive measures, in school at age 12 years, and for whom birth certificates with data on birth and parental characteristics had been traced manually in 1965. This population was followed up from April 1968 to January 2002 for information on mortality.

MAIN OUTCOME MEASURES

Mortality from all causes, cardiovascular diseases, and violent deaths.

RESULTS

Men whose fathers were working class or of unknown social class at time of birth had higher mortality rates compared with those whose fathers were high/middle class: hazard ratio 1.39 (95% CI 1.15 to 1.67) and 2.04 (95% CI 1.48 to 2.83) respectively. Birth weight and childhood cognitive function were both related to father's social class and inversely associated with all cause mortality. The association between father's social class and mortality attenuated (HR(working class)1.30 (1.08 to 1.56); HR(unknown class)1.81 (1.30 to 2.52)) after control for birth weight and cognitive function. Mortality from cardiovascular diseases and violent deaths was also significantly higher among men with fathers from the lower social classes.

CONCLUSION

The inverse association between father's social class at time of birth and early adult mortality remains, however somewhat attenuated, after adjustment for birth weight and cognitive function.

Cumulative social class and mortality from various causes of adult men

STUDY OBJECTIVE

It is possible that circumstances over the lifecourse contribute to social inequalities in mortality in adulthood. The aim of this study is to assess the cumulative effect of social class at childhood and adulthood on mortality from various causes of death in young adult men.

DESIGN

The data consist of census records for all Finnish men born in 1956-60 (112,735 persons and 895,001 person years), and death records (1834 deaths) by cause of death for 1991-98.

MAIN RESULTS

Mortality from each cause of death increased from the stable non-manual group to mobile groups, and further to the stable manual group. However, mortality in the downwardly mobile group was 150% higher than in the upwardly mobile group. Furthermore, analyses show that mortality was mainly related to current adult social class, though, within each adult social class men with a manual parental background showed slightly increased mortality from cardiovascular disease and from alcohol related causes.

CONCLUSIONS

In these data the effects of adult social class were stronger than childhood class for all causes of death. It is more useful to differentiate between childhood and adulthood effects than to use a combined measure of social class to assess the contribution of social class at different stages of life on mortality.

[Socioeconomic circumstances and premature mortality from chronic diseases]

BACKGROUND AND OBJECTIVE

Our aim was to investigate the association between socioeconomic factors in childhood or adolescence and adulthood and premature mortality from various causes of death.

SUBJECTS AND METHOD

Men and women aged 25-74 years residing on May 1, 1996, in the Autonomous Community of Madrid. For the next 19 months, information on individuals who died and the cause of death were obtained from the Mortality Register. We estimated the mortality from 5 types of cancer and from 4 chronic diseases by the educational level--as an indicator of the socioeconomic circumstances in childhood or adolescence--and by income--as an indicator of the socioeconomic circumstances in adulthood.

RESULTS

When both variables were included in the analysis simultaneously, the relative mortality ratio for men with second grade first phase and lower educational level versus those with second grade, second phase and higher educational level and the relative mortality ratio for men belonging to income quartiles 3 and 4 (lowest) versus those belonging to quartiles 1 and 2 were, respectively: 1.15 (95% confidence interval 1.01-1.31) and 1.22 (1.09-1.36) for lung cancer; 1.46 (1.19-1,93) and 1.13 (0.90-1.41) for gastric cancer; 1.80 (1.32-2.44) and 1.46 (1.18-1.80) for chronic obstructive pulmonary disease; and 1.18 (0.77-1.81) and 0.68 (0.47-0.98) for diabetes mellitus. For women the relative mortality ratios were, respectively: 0.63 (0.43-0.92) and 0.72 (0.52-0.99) for lung cancer; 1.68 (0.99-2.83) and 1.17 (0.86-1.60) for gastric cancer; 0.76 (0.61-0.94) and 0.98 (0.82-1.16) for breast cancer; 1.36 (0.95-1.95) and 1.20 (0.97-1.48) for ischemic heart disease; 1.72 (1.19-2.50) and 0.93 (0.75-1.16) for stroke; and 2.23 (0.94-5.27) and 1.51 (1.02-2.25) for diabetes mellitus.

CONCLUSIONS

Premature mortality in adulthood is associated with several socioeconomic factors acting across the whole course of life. The contribution of these socioeconomic circumstances to mortality varies regarding the cause of death and gender.

Mortality in adults aged 26-54 years related to socioeconomic conditions in childhood and adulthood: post war birth cohort study

OBJECTIVE

To examine premature mortality in adults in relation to socioeconomic conditions in childhood and adulthood.

DESIGN

Nationally representative birth cohort study with prospective information on socioeconomic conditions.

SETTING

England, Scotland, and Wales. STUDY MEMBERS: 2132 women and 2322 men born in March 1946 and followed until age 55 years.

MAIN OUTCOME MEASURES

Deaths between 26 and 54 years of age notified by the NHS central register.

RESULTS

Study members whose father's occupation was manual at age 4, or who lived in the worst housing, or who received the poorest care in childhood had double the death rate during adulthood of those living in the best socioeconomic conditions. All indicators of socioeconomic disadvantage at age 26 years, particularly lack of home ownership, were associated with a higher death rate. Manual origins and poor care in childhood remained associated with mortality even after adjusting for social class in adulthood or home ownership. The hazard ratio was 2.6 (95% confidence interval 1.5 to 4.4) for those living in manual households as children and as adults compared with those living in non-manual households at both life stages. The hazard ratio for those from manual origins who did not own their own home at age 26 years was 4.9 (2.3 to 10.5) compared with those from non-manual origins who were home owners.

CONCLUSIONS

Socioeconomic conditions in childhood as well as early adulthood have strongly influenced the survival of British people born in the immediate post war era.

Life-course socioeconomic and behavioral influences on cardiovascular disease mortality: the collaborative study

OBJECTIVES

This study sought to demonstrate life-course influences on cardiovascular disease (CVD).

METHODS

Data were derived from a prospective observational study in which the main outcome measure was death resulting from CVD.

RESULTS

Combining 4 socioeconomic and behavioral risk indicators into a measure of life-course exposure produced 5 groups whose relative risks of CVD mortality ranged from 1.00 (the group with the most favorable life-course exposures) to 4.55 (the group with the least favorable life-course exposures). If the entire study population had had the CVD mortality risk of the subsample with the most favorable risk factor profile, approximately two thirds of cardiovascular deaths would not have occurred.

CONCLUSIONS

CVD risk is influenced in a cumulative fashion by socioeconomic and behavioral factors acting throughout the life course.

Height in young adulthood and risk of death from cardiorespiratory disease: a prospective study of male former students of Glasgow University, Scotland

To investigate the association between height in young, socially homogeneous males and cause-specific mortality, the authors conducted a prospective study of 8,361 male former students who underwent medical examinations while attending Glasgow University, Scotland, from 1948 to 1968. The mean age at examination was 20.5 (range, 16.1-30.0) years. The median follow-up time was 41.3 years. There were 863 deaths. In Cox proportional hazards modeling, there was no association between height and all-cause mortality with age-adjusted hazard ratios per 10-cm increase in height (hazard ratio = 0.92, 95% confidence interval: 0.83, 1.02). Height was inversely associated with all cardiovascular disease and coronary heart disease mortality, with hazard ratios per 10-cm increase in height of 0.78 (95% confidence interval: 0.66, 0.93) and 0.76 (95% confidence interval: 0.62, 0.93), respectively. Sizeable inverse associations with stroke and respiratory disease were also found, although these did not reach conventional levels of significance. There was no association with cancer or noncardiorespiratory disease mortality. There was a positive, although nonsignificant, association between height and mortality from aortic aneurysm. Controlling for confounding variables had little effect on these results. The findings suggest that factors operating in early life, and which influence height, also influence future cardiovascular health in men.

Childhood housing conditions and later mortality in the Boyd Orr cohort

STUDY OBJECTIVES

To examine associations between five measures of housing conditions during childhood and subsequent mortality from all causes, coronary heart disease, stroke, and cancer.

DESIGN

Historical cohort study.

SETTING

Data on housing conditions were collected from survey centres in 16 areas of England and Scotland.

PARTICIPANTS

Children of families participating in the Carnegie Survey of Family Diet and Health in pre-war Britain (1937-1939). Analyses are based on a subset of 4168 people who were traced and alive on 1 January 1948.

MAIN RESULTS

Poorer housing conditions were generally associated with increased adult mortality. After adjustment for childhood and adult socioeconomic factors, statistically significant associations were only found between lack of private indoor tapped water supply and increased mortality from coronary heart disease (hazard ratio 1.73, (95% CI 1.13, 2.64); and between poor ventilation and overall mortality (hazard ratio for people from households with poorest ventilation relative to best ventilation 1.30, 95% CI 0.97, 1.74).

CONCLUSIONS

This study provides evidence that associations between housing conditions in childhood and mortality from common diseases in adulthood are not strong, but are in some respects distinguishable from those of social deprivation.