Life-course socioeconomic position and health in older adulthood: a causal mediation analysis in the 1958 British Birth Cohort

Background Childhood socioeconomic position (SEP) influences later health, but how inequalities persist into early older age and operate through adult SEP remains unclear. Quantifying these pathways is important for identifying opportunities to reduce health inequalities over the life course. We therefore used an interventional causal mediation framework to quantify the contribution of four distinct dimensions of adult SEP to childhood socioeconomic inequalities in self-reported and objective health outcomes in early older age. Methods We analysed data from the 1958 British Birth Cohort collected at birth, ages 33 and 55, and the most recent sweep, when participants were aged 60–66 years. Sample sizes ranged from 4014 to 8363 depending on the outcome. We examined the extent to which four dimensions of adult SEP — adult occupational class, education, housing tenure, and income — mediated associations between childhood SEP, measured by paternal occupational class at birth, and self-rated health (SRH), C-reactive protein (CRP), cholesterol ratio, glycated haemoglobin (HbA1c), and NT-proBNP. Findings Among men, occupational class mediated 39% of the association with poorer SRH (indirect effect RR 0.90, 95%: CI 0.86–0.95), and education mediated 27% (0.93, 0.90–0.96). Among women, mediation was smaller and most evident via education (10%; 0.95, 0.91–0.98) and housing tenure (6%; 0.97, 0.94–0.99). Mediation was limited for CRP and minimal for cholesterol ratio, HbA1c, and NT-proBNP. Interpretation Improving adult SEP could reduce, but is unlikely to eliminate, early older-age health inequalities associated with childhood SEP, highlighting the importance of interventions across the life course. Funding UK Economic and Social Research Council.