Mel Bartley

Can we disentangle life course processes of accumulation, critical period and social mobility? An analysis of disadvantaged socio-economic positions and myocardial infarction in the Stockholm Heart Epidemiology Program

The accumulation hypothesis would propose that the longer the duration of exposure to disadvantaged socio-economic position, the greater the risk of myocardial infarction. However there may be a danger of confounding between accumulation and possibly more complex combinations of critical periods of exposure and social mobility. The objective of this paper is to investigate the possibility of distinguishing between these alternatives. We used a population based case-control study (Stockholm Heart Epidemiology Programme) of all incident first events of myocardial infarction among men and women, living in the Stockholm region 1992-94. The analyses were restricted to men 53-70 years, 511 cases and 716 controls. From a full occupational history each subject was categorized as manual worker or non-manual at three stages of the life course, childhood (from parents occupation), at the ages 25-29 and 51-55, resulting in 8 possible socio-economic trajectories. We found a graded response to the accumulation of disadvantaged socio-economic positions over the life course. However, we also found evidence for effects of critical periods and of social mobility. A conceptual analysis showed that there are, for theoretical reasons, only a limited number of trajectories available, too small to form distinct empirical categories of each hypothesis. The empirical task of disentangling the life course hypotheses of critical period, social mobility and accumulation is therefore comparable to the problem of separating age, period, and cohort effects. Accordingly, the interpretation must depend on prior knowledge of more specific causal mechanisms.

Relation between socioeconomic status, employment, and health during economic change, 1973-93

Abstract Objective: To investigate the association between the national unemployment rate and class differences in the relation between health and employment during the period 1973-93. Design: Data from general household surveys, 1973-93. Comparison of rates of employment, unemployment, and economic inactivity among those with and without limiting longstanding illness in different socioeconomic groups and how these varied over 20 years. Subjects: All men aged 20-59 years in each survey between 1973 and 1993. Main outcome measures: Change over time in class specific rates of employment, unemployment, and economic inactivity in those with and without limiting longstanding illness. Results: Men in socioeconomic groups 1 and 2 with no longstanding illness experienced little decrease in their chances of being in paid employment as the general unemployment rate rose. Those most affected were men in manual groups with limiting longstanding illness. The likelihood of paid employment was affected far less by such illness in non-manual than in manual groups. In group 1 about 85% of men with such illness were in paid employment in 1979 and 75% by 1993; in group 4 the equivalent proportions were 70% and 40%. In men in manual groups with limiting longstanding illness there was no sign of employment rates rising again as the economy recovered. Conclusion: Socioeconomic status makes a large difference to the impact of illness on the ability to remain in paid employment, and this impact increases as unemployment rises. Men with chronic illness in manual occupations were not drawn back into the labour force during the economic recovery of the late 1980s.

Health and the life course: why safety nets matter.

Abstract This article argues that a life course approach is necessary to understand social variations in health. This is needed in order to take into account the complex ways in which biological risk interacts with economic, social, and psychological factors in the development of chronic disease. Such an approach reveals biological and social “critical periods” during which social policies that will defend individuals against an accumulation of risk are particularly important. In many ways, the authors of modern welfare states were implicitly addressing these issues, and the contribution of these policies to present day high standards of health in developed countries should not be ignored.

Employment status, employment conditions, and limiting illness: prospective evidence from the British household panel survey 1991–2001

Objectives: To assess the relation of the incidence of, and recovery from, limiting illness to employment status, occupational social class, and income over time in an initially healthy sample of working age men and women. Methods: Cox proportional hazards models. Results: There were large differences in the risk of limiting illness according to occupational social class, with men and women in the least favourable employment conditions nearly four times more likely to become ill than those in the most favourable. Unemployment and economic inactivity also had a powerful effect on illness incidence. Limiting illness was not a permanent state for most participants in the study. Employment status was also related to recovery. Conclusions: Having secure employment in favourable working conditions greatly reduces the risk of healthy people developing limiting illness. Secure employment increases the likelihood of recovery. These findings have considerable implications for both health inequality and economic policies.

Health selection in the Whitehall II study, UK

There has been considerable debate over the importance of the health selection hypothesis for explaining social gradients in health. Although studies have argued that it may not be an important explanation of social gradients in health, previous analyses have not estimated, simultaneously, the relative effect of health on changes in social position and of social position on changes in health (social causation). Cross-lagged longitudinal analyses using structural equation models enable the estimation of the relative size of these pathways which would be useful in determining the relative importance of the health selection hypothesis over the social causation hypothesis. Data from four phases of the Whitehall II study (initially consisting of 10,308 men and women aged 35-55 in the British civil service) were collected over a 10 year period. There was no evidence for an effect of mental (GHQ-30 and SF36) or physical health (SF-36) on changes in employment grade. When financial deprivation was used as a measure of social position, there was a significant effect of mental health on changes in social position among men although this health selection effect was over two and a half times smaller than the effect of social position on changes in health. The results suggest that the development of social gradients in health in the Whitehall II study may not be primarily explained in terms of a health selection effect.

A Life Course Approach to Assessing Causes of Dental Caries Experience: The Relationship between Biological, Behavioural, Socio-Economic and Psychological Conditions and Caries in Adolescents

The objective of this study was to further elucidate the relationship between relevant biological, behavioural, socio-economic and psychological conditions, experienced in very early life and along the life course, and dental caries experience using the life course approach. A two-phase study was carried out in Brazil. In the first phase, 652 13-year-olds were clinically examined and interviewed. In the second phase, 330 families were randomly selected for interview to collect information on the teenagers’ early years of life. Clinical assessment included dental caries, periodontal and traumatic dental injury status. The data analysis involved multiple logistic regression analysis. Adolescents born in a non-brick house, those with a low birth weight and those who were the second or later child in the family were statistically significantly more likely to have a high DMF-T. In conclusion, the results of this study show that there is an association between socio-economic and biological factors in very early life and levels of caries in adolescents.

Health and social precursors of unemployment in young men in Great Britain.

OBJECTIVE: To identify health and socioeconomic factors in childhood that are precursors of unemployment in early adult life and to examine the hypothesis that young men who become unemployed are more likely to have accumulated risks to health during childhood. DESIGN: Longitudinal birth cohort study. The amount of unemployment experienced in early adult life up to age 32 years was the outcome measure used. Exposure measures to indicate vulnerability to future ill health were: height at age 7 years and the Bristol social adjustment guide (BSAG) at age 11 years, a measure of behavioural maladjustment. Socioeconomic measures were: social class at birth, crowding at age 7, qualifications attained before labour market entry, and region of residence. SETTING: Great Britain. SUBJECTS: Altogether 2256 men with complete data from the national child development study (NCDS). The NCDS has collected data on all men and women born in one week in 1958 and has followed them up using interviews, self completion questionnaires, and medical examinations at birth and at ages 7, 11, 16, 23 and 33 years. RESULTS: A total of 269 men (11.9%) experienced more than one year of unemployment between ages 22 and 32 years. Poor socioeconomic conditions in childhood and a lack of qualifications were associated with an increased risk of unemployment. Geographical region was also significant in determining the risk of unemployment. Men with short stature and poor social adjustment in childhood were more likely to experience unemployment in adult life, even after controlling for socioeconomic background, education, and parental height. These differences remained when those with chronic childhood illnesses were excluded from the analysis. The adjusted relative odds for experiencing more than one year of unemployment between ages 22 and 32 years for men who were in the top fifth of the BSAG distribution (most maladjusted) compared with those in the bottom fifth were 2.36 (95% CI 1.49, 3.73). The adjusted relative odds for experiencing more than one year of unemployment between ages 22 and 32 years for men who were in the bottom fifth of the distribution of height at age 7 years (indicating slowest growth) compared with those in the top fifth, were 2.41 (95% CI 1.43, 4.04). Adult height was not significantly associated with unemployment. CONCLUSION: The relationship between unemployment and poor health arises, in part, because men who become unemployed are more likely to have accumulated risks to health during childhood, reflected by slower growth and a greater tendency to behavioural maladjustment. Short stature in childhood is a significant indicator of poor socioeconomic circumstances in childhood and reflects earlier poor development.

Birth weight and later socioeconomic disadvantage: evidence from the 1958 British cohort study

Abstract Objective: To investigate the relation between birth weight and socioeconomic disadvantage during childhood and adolescence in a birth cohort study. Design: Longitudinal analysis of birth weight in relation to social class, household amenities and overcrowding, and financial difficulties as reported by parents at interview when participants were aged 7, 11, and 16 years; and receipt of unemployment or supplementary benefits as reported by participants at age 23. Subjects: Male participants in the 1958 birth cohort (national child development study) born to parents resident in Great Britain during the week of 3-9 March 1958. Data on birth weight and financial difficulties between birth and 23 years were available for 4321; data on housing conditions and social class at ages 7, 11, and 16 years were available for 3370. Main outcome measures: Socioeconomic disadvantage at later ages in men weighing 6 lb (2721g) or under at birth compared with those weighing over 6 lb and between fifths of the distribution of birth weight. Results: Cohort members who weighed 6 lb or under at birth were more likely to experience socioeconomic disadvantage subsequently. Those in lower fifths of the distribution were more likely to experience socioeconomic disadvantage. Conclusion—Low birth weight is associated with socioeconomic disadvantage in childhood and adolescence. Studies of the association of indicators of early development and adult disease need to take into account experiences right through from birth to adulthood if they are to elucidate the combination of risks attributable to developmental problems and socioeconomic disadvantage.

Family conflict and slow growth

AIMS Having previously observed that slow growth in childhood is associated with subsequent labour market disadvantage, an attempt was made to determine whether family conflict is associated with slow growth to age 7 years, independently of material disadvantage. METHODS A total of 6574 children born between 3 and 9 March 1958 who were members of the British National Child Development Study were used in these analyses. Slow growth at age 7 years was indicated by short stature defined as the lowest fifth of the height distribution. In multivariate analysis, adjustment was made for fully attained adult height as a measure of genetically predetermined height. RESULTS A total of 31.1% of children who had experienced family conflict were of short stature compared with 20.2% of those who had not, representing relative odds of 1.79 (95% confidence interval (CI) 1.39 to 2.30). After adjustment for social class, crowding, sex, and predetermined height, the relative odds were slightly reduced to 1.62 (95% CI 1.18 to 2.23). A total of 44.0% of children from the most crowded households were of short stature compared with 16.4% of those from the least crowded. The unadjusted relative odds were 3.99 (95% CI 2.94 to 5.41) and after adjustment for the potential confounding variables they were 3.07 (95% CI 2.08 to 4.51). Low social class was also a risk for short stature at age 7 years, but this was not statistically significant after adjustment for the other confounding factors. CONCLUSIONS Family conflict during childhood was independently associated with slow growth to age 7 years. Key messages Stress caused by family conflict results in slow growth to age 7 years A higher proportion of the shortest 20% of 7 year old children have experienced psychosocial stress Slow growth may indicate impaired psychological development caused by stress Family conflict may have lifelong consequences for some children Slow growth may be a useful marker for psychosocial stress

The sociology of health inequalities

Introduction. Beyond the Black Report: Mel Bartley (International Center for Health and Society), David Blane (Imperial School of Science Technology and Medicine), and George Davey Smith (Bristol University Medical School). Part I: Understanding the social dynamics of health inequalities:. 1. Mortality, the social environment, crime and violence: Richard G. Wilkinson (University of Sussex), Ichiro Kawachi (Harvard School of Public Health) and Bruce Kennedy (Harvard School of Public Health). 2. The psycho--social perspective on social inequalities in health: Jon Ivar Elstad (Norwegian Social Research). 3. Theorizing inequalities in health: the place of lay knowledge: Jennie Popay (University of Salford), Gareth Williams (University of Salford), Carol Thomas (University of Lancaster). 4. Is there a place for geography in the analysis of health inequality?: Sarah Curtis and Ian Rees Jones (Queen Mary and Westfield College, University of London). Part II: Social and spatial inequalities in health:. 5. Gender and disadvantage in health: mena s health for a change: Elaine Cameron (University of Wolverhampton). 6. Changing the map: health in Britain 1951 -- 1991: Mary Shaw, Danny Dorling and Nic Brimblecombe (University of Bristol). 7. Genetic, cultural or socio--economic vulnerability? Explaining ethnic inequalities in health: James Nazroo (Policy Studies Institute, London). 8. Mortgage debt, insecure home ownership and health: an exploratory analysis: Sarah Nettleton and Roger Burrows (University of York). 9. A lifecourse perspective on socio--economic inequalities in health: H. Dike van de Mheen, Karien Stronks and Johann P. Mackenback (University of Rotterdam). Notes on Contributors. Index.