Do childhood cognitive ability or smoking behaviour explain the influence of lifetime socio-economic conditions on premature adult mortality in a British post war birth cohort?

Poor childhood and adult socio-economic conditions, lower childhood cognitive ability and cigarette smoking are all associated with adult mortality risk. Using data on 4458 men and women aged 60 years from a British birth cohort study, we investigated the extent to which these risk factors are part of the same pathway linking childhood experience to adult survival. Compared with women from non-manual origins, men from non-manual origins, women and men from manual origins, and those with missing data on father's social class had about double the risk of mortality between 26 and 60 years. Cox proportional hazards models showed that these differences were reduced but remained significant after adjusting for childhood cognitive ability, adult socio-economic conditions and smoking. Higher childhood ability increased survival chances by securing better adult socio-economic conditions, such as home ownership, which was strongly associated with survival. These findings were similar for cardiovascular and cancer mortality.