Early-life circumstances and the risk of function-limiting long-term conditions in later life

Older adults are particularly prone to function-limiting health issues which impact their ability to live independent and productive lives, and which detrimentally affect their wellbeing. Previous work has identified factors from across the life course – particularly childhood socioeconomic status, childhood cognitive ability and education – which are statistically associated with functional outcomes in later life. However, the independence of these contributions is unclear, particularly as later-in-the-life-course predictors are themselves affected by earlier ones. The present study capitalised on the recent linkage of the Scottish Mental Survey 1947 with the Scottish Longitudinal Study, and used path analyses to examine the direct and indirect associations between life-course predictors and the risk of functional limitation at ages 55 (N = 2374), 65 (N = 1971) and 75 (N = 1534). The odds of reporting a function-limiting long-term condition increased across later life. At age 55, reporting a function-limiting long-term condition was significantly less likely in those with higher childhood socioeconomic status, higher childhood cognitive ability, and higher educational attainment; these associations were only partly mediated by other predictors. At age 65, adult socioeconomic status emerged as an important mediator of several associations, although direct associations with childhood socioeconomic status and childhood cognitive ability were still observed. At age 75, only childhood socioeconomic status and adult socioeconomic status directly predicted the risk of a function-limiting long-term condition. Upon further analysis of the types of function-limiting long-term condition reported, higher socioeconomic status was associated with reduced risk of a functional limitation resulting from disease or illness, rather than other function-limiting conditions such as visual impairment. These results demonstrate that early life and adult circumstances, particularly adult socioeconomic status, are associated with functional ability in later life. However, the results also demonstrate that these associations are partly a product of complex mediation with life-course factors.