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

Matthew H. Iveson,Chris Dibben,Ian J. Deary

doi:10.1332/175795919x15762565000695

Abstract

Older adults are particularly prone to function-limiting health issues that adversely affect their well-being. Previous work has identified factors from across the life course –childhood socio-economic status, childhood cognitive ability and education – that predict later-life functional outcomes. However, the independence of these contributions is unclear 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, using path analyses to examine the direct and indirect associations between life-course predictors and the risk of functional limitation at ages 55 (N = 2,374), 65 (N = 1,971) and 75 (N = 1,534). The odds of reporting a function-limiting long-term condition increased across later life. At age 55, reporting a functional limitation was significantly less likely in those with higher childhood socio-economic status, higher childhood cognitive ability and higher educational attainment; these associations were only partly mediated by other predictors. At age 65, adult socio-economic status emerged as a mediator of several associations, although direct associations with childhood socio-economic status and childhood cognitive ability were still observed. At age 75, only childhood socio-economic status and adult socio-economic status directly predicted the risk of a functional limitation, particularly those associated with disease or illness. A consistent pattern and direction of associations was observed with self-rated health more generally. These results demonstrate that early-life and adult circumstances are associated with functional limitations later in life, but that these associations are partly a product of complex mediation between life-course factors.

Highlights

Average life expectancy has increased in developed countries, ‘disabilityfree’ or ‘healthy’ life expectancy has generally not kept pace (Salomon et al, 2012, for example)
The present study examined the association between the risk of a function-limiting long-term condition in later life and factors from across the life course
Age 3 socio-economic status (SES), age 11 cognitive ability, lifetime educational attainment and adult SES were shown to be important though relatively weak predictors of functional limitation outcomes at age 55 and beyond

Summary

Introduction

Average life expectancy has increased in developed countries, ‘disabilityfree’ or ‘healthy’ life expectancy has generally not kept pace (Salomon et al, 2012, for example). Three early-life factors – higher childhood socio-economic status (SES), higher childhood cognitive ability and more education – have been consistently associated with a variety of later health-related outcomes, including lower morbidity risk (see, for example, Cohen et al, 2010; Hagger-Johnson et al, 2010; Smith et al, 2015). In the Medical Research Council National Survey of Health and Development (MRC NSHD), lower childhood social class has been associated with an increased risk of poor strength, balance and chair-rising at age 53 (Guralnik et al, 2006) This association was not attenuated once an individual’s own adult social class was accounted for (see Hurst et al, 2013). Early-life advantage in childhood SES (Luo and Waite, 2005; Haas, 2008, both using the US Health and Retirement Survey), childhood cognitive ability (Poranen-Clark et al, 2016, using the Helsinki Birth Cohort), and education

Methods

Discussion

Conclusion