Elsevier

The Lancet

Volume 350, Issue 9091, 29 November 1997, Pages 1584-1589
The Lancet

Articles
Origins of health inequalities in a national population sample

https://doi.org/10.1016/S0140-6736(97)07474-6Get rights and content

Summary

Background

Explanations for social inequalities in health are often explored but remain largely unresolved. To elucidate the origins of health inequalities, we investigated the extent to which adult-disease risk factors vary systematically according to social position over three decades of early life.

Methods

We used the 1958 birth cohort (all children born in England, Scotland, and Wales on March 3–9, 1958) with data up to age 33 years from parents, teachers, doctors, and cohort members (n=11 407 for age 33 interview).

Findings

Social class of origin was associated with physical risk factors (birthweight, height, and adult bodymass index); economic circumstances, including household overcrowding, basic amenities, and low income; health behaviour of parents (breastfeeding and smoking) and of participants (smoking and diet); social and family functioning and structure, such as divorce or separation of participants or their parents, emotional adjustment in adolescence, social support in early adulthood; and educational achievement and working career, in particular no qualifications, unemployment, job strain, and insecurity. With few exceptions, there were strong significant trends of increasing risk from classes I and II to classes IV and V. Self-perceived health status and symptoms were worse in participants with lower class origins.

Interpretation

An individual's chance of encountering multiple adverse health risks throughout life is influenced powerfully by social position. Social trends in adult-disease risk factors do not emerge exclusively in mid-life, but accumulate over decades. Investment in educational and emotional development is needed in all social groups to strengthen prevention strategies relating to health behaviour, work-place environment, and income inequality.

Introduction

Inequalities in health are believed to result from differences in exposure to an accumulation of health-damaging or health-promoting physical and social environments among different groups.1 Although exposure to adverse factors occurs at different stages in life and accumulates over time, current evidence on disease risk and social position is predominantly either cross-sectional or from studies with limited information on early life. One especially informative example is the Whiteheall II study,2 which showed systematic variation by employment grade in several potential biological, behavioural, and psychosocial risk factors, with adverse factors clustering in the lower grades. A 1997 study3 of Finnish men also showed that adult-disease risks vary systematically, but in this case with indicators of social position in childhood.

What has not been established is the extent to which risks accumulate differentially by social position at each stage in life over a substantial period of the lifespan. Few studies have the necessary longitudinal data that include a record of early-life factors. There is evidence, however, that several early-life factors should be considered in relation to adult disease, even though the processes linking early and late life remain contentious.4, 5 For example, growth in utero and during infancy may affect the risk of chronic adult diseases, such as cardiovascular disease, obstructive lung disease, and diabetes.6, 7 Height is associated with mortality, particularly for respiratory and cardiovascular disease,8, 9 which suggests that childhood socioeconomic circumstances might have long-lasting effects on mortality. When investigators examined childhood socioeconomic status more directly, with information on the father's occupation or economic status, they found associations with adult mortality—in some instances reflecting the link between childhood socioeconomic status and later education or adult position.10, 11, 12 An accumulation of both childhood and adulthood factors was related to adult respiratory morbidity, including, as risk factors, childhood respiratory illness, low socioeconomic status, atmospheric pollution, and smoking.13 Other studies have shown associations between parental divorce and psychological health and longevity in adulthood.14, 15 This finding is believed to reflect other factors, such as parental conflict, rather than parental loss. Given that many childhood adversities may operate partly through intermediate factors, such as educational achievement,5 both early and intermediate influences on health inequalities must be explored.

Using early-life risk factors for adult disease identified from previous reports, we examined the extent to which social trends in these factors vary systematically throughout early life (from birth to young adulthood). We used longitudinal data from the 1958 birth cohort in England, Scotland, and Wales, from the original birth survey through to age 33 years. Our study thus provides data on differential accumulation of risk in the same individuals followed up over three decades.

Section snippets

Study sample

The 1958 birth cohort includes all children born in England, Wales, and Scotland during March 3–9, 1958. The study originated in the Perinatal Mortality Study, which recorded information on 17 414 (98%) births. Follow-up surveys were undertaken when the participants were aged 7, 11, 16, 23, and 33 years, with 11 407 participants interviewed in the latest survey.16 Those remaining in the study are generally representative of the original sample.16, 17 Information at ages 23 and 33 was obtained

Morbidity in early adulthood and social-class origins

Table 1 shows health status at age 33 according to class at birth. A social gradient was evident for several health measures, with increasing prevalence from classes I and II to classes IV and V. The trends were especially strong for men and women with poor-rated health, respiratory symptoms, and psychological distress, and for women with menstrual problems. Weaker trends were evident for long-standing illness, back pain, and migraine among women but not among men. Few health indicators showed

Discussion

In a cohort of people who have been followed up for 33 years since birth, strong associations have emerged between social class at birth and accumulation of risk factors for adult health. These multiple health risks are not predetermined, but are greatly influenced by social origins. By age 33, health gradients are already well established. In this study, health gradients cannot be attributed to selective social mobility because social class was based on the father's occupation in 1958 and was

References (38)

  • DJP Barker

    Mothers, babies and disease in later life

    (1994)
  • DA Leon et al.

    Adult height and mortality in London: early life, socio economic confounding or shrinkage?

    J Epidemiol Community Health

    (1995)
  • G Wannamethee et al.

    Influence of father's social class on cardiovascular disease in middle-aged men

    Lancet

    (1996)
  • MD Gliksman et al.

    Childhood socioeconomic status and risk of cardiovascular disease in middle aged US women: a prospective study

    J Epidemiol Community Health

    (1995)
  • SL Mann et al.

    Accumulation of factors influencing respiratory illness in members of a national birth cohort and their offspring

    J Epidemiol Community Health

    (1992)
  • PR Amato et al.

    Parental divorce and adult well-being: a metaanalysis

    J Marriage Fam

    (1991)
  • E Ferri

    Life at 33: the fifth follow-up of the National Child Development Study

    (1993)
  • C Power et al.

    Health and class: the early years

    (1991)
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