Origins of health inequalities in a national population sample

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 body-mass 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.