Socio-economic and health determinants of transitions to adult dependency in South Korea, 2008-2014

Abstract

Objectives: The aim of this study is to identify the determinants of transitions to and possibly back from dependence.

Study design: The Korean Longitudinal Study of Aging, 2006-2014.

Methods: The transitions between non-dependence and difficulties in activities of daily living -instrumental (IADL) or not (ADL)-are distinguished between stability, deterioration, death, or recovery in multilevel logistic regressions.

Results: Controlling for other covariates, women are more likely to remain without difficulty than men, dependants are more likely out of the labor force or unemployed, city dwellers are more likely dependent. Subjective health helps predict health two years later, as grip power, score of cognition, depression, cardiac and cerebrovascular diseases, and the number of difficulties in IADL (but not in ADL). Dependants with difficulties in IADL reporting no caregiver survive longer but are less likely to recover. Difficulties in ADL overwhelm any other available determinant. The Gompertz-like increase in the death rate with age no longer holds true for ADL dependants. Cardiac and cerebrovascular pathologies and smoking and drinking favor the transition to disability.

Conclusions: Socio-economic and medical factors identify a multifactorial determination of the risk to dependence and changes in dependence status, controlling for each effect and selection bias.

Keywords: Aging; Difficulties in activities of daily living; Mortality at old age; Multilevel logistic model; Transitions to dependency.