Frailty index and gender-specific mortality in Korean adults: Findings from the Korean Longitudinal Study of Aging (2006–2018)

Abstract

Aims: To examine the predictive ability of the frailty index in estimating gender-specific mortality in a population of Korean adults. Design: A descriptive and prospective longitudinal design. Methods: Data were used from the Korean Longitudinal Study of Aging conducted from 2006 through 2018. A total of 10,254 adults aged 45–98 years at baseline were included. A 41-item deficit accumulation frailty index was measured, based on multi-domain assessment such as self-rating of health, physical condition, mental status, cognitive function, activities of daily living, instrumental activities of daily living and chronic conditions. We categorized the frailty index into robust (≤0.10), prefrail (0.10–0.25) and frail (≥0.25). Cox's proportional hazards regression analysis was employed to determine the association between the frailty index and all-cause mortality. Results: A total of 4705 individuals (45.9%) were categorized as robust, 4178 (40.7%) as prefrail and 1371 (13.4%) as frail. The frailty index increased with age, and females were found to have a higher frailty index than males. The survival probabilities were significantly lower in older adults (aged ≥65) compared with adults and significantly lower in males compared with females. Compared with the robust group, the risk of mortality in the prefrail and frail groups was 1.37 and 2.57 times higher, respectively. The association between frailty status and all-cause mortality was similar in adults and older adults, while the hazard ratios were higher in frail group of males than that of females. Conclusion: The frailty index had a predictive ability for all-cause mortality with respect to age and sex. Impact: Using a frailty index among community-dwelling adults could be beneficial to support healthcare providers in early detection of individuals with frailty and facilitate the development of more effective interventions for reducing mortality. © 2022 John Wiley & Sons Ltd.