Coexistent physical and cognitive decline and the development of fear of falling among Korean older adults

Abstract

Objectives: Although hand grip strength and cognitive function are associated with fear of falling (FOF), little is known about whether coexisting physical and cognitive decline is jointly related to FOF. This study examines whether grip strength and cognitive function interact to shape FOF and FOF-related activity restriction (FAR) among Korean older adults. Methods/Design: This study used seven waves of the Korean Longitudinal Study of Ageing (N = 3373 older adults aged 65 or over). Grip strength was assessed by a handgrip dynamometer, and cognitive function by Korean Mini-mental State Examination (K-MMSE). Fixed effects models were estimated to account for time-invariant confounders such as genetic predispositions, innate ability, and health endowments. This study estimated a joint model that included interaction effects between grip strength and cognitive function. Results: Declines in grip strength and cognitive function were independently associated with FOF. Fixed effects estimates suggested that, despite some attenuation, controlling for individual heterogeneity does not confound the associations. The interaction model showed that coexistence of low grip strength and cognitive decline leads to a greater risk of FOF and FAR than having a single condition. Similar patterns were found for FAR. Conclusions: This study provides evidence that coexistent cognitive and physical decline are a significant risk factor for FOF and FAR. Given the well-established adverse effects of FOF on older adults' health and well-being, results of this study lend support to interventions to target old adults with coexistent cognitive and physical decline to remove excessive concerns about FOF.