The Association between Frailty and Quality of Life in Older People

Abstract

This thesis examines the association between frailty and quality of life (QoL) in older adults, emphasizing successful aging as a primary goal for individuals and healthcare systems. Frailty and QoL are crucial concepts in understanding aging, as they encompass major concerns and extend into broader domains of successful aging. Using data from the English Longitudinal Study of Ageing, this research comprises three interconnected studies. The first study analyses frailty progression over 18 years, categorized by the number of long-term conditions (LTCs). Findings indicated that frailty increased with the number of LTCs for both genders, with males showing accelerated frailty with one or more LTCs, while females exhibited this acceleration with two or more LTCs. In the second study, several structural factor models for the CASP-12, a measure of quality of life, were tested. The study also examined the consistency of the best model across various demographics and two time periods. The results showed that the CASP-12 with the second-order common factors is a better model, and it maintained strong invariance across genders, age, and education, as well as over two different time points when the sample was divided into three subsamples based on age group. However, this invariance was not observed for net wealth. The third study investigated the two-way relationship between frailty and QoL, revealing a strong inverse and almost linear relationship over time. Although the cross-lagged relationship between QoL and frailty was statistically significant, the impact was minimal. Differences were noted at the group level, considering gender, age, net wealth, and multimorbidity, but not at the within-person level. By considering these findings, healthcare providers and policymakers can develop more effective strategies to support the well-being of older adults.