Frailty prevalence using Frailty Index, associated factors and level of agreement among frailty tools in a cohort of Japanese older adults

Frailty prevalence defined by the deficit accumulation model (Frailty Index) has limited exploration in a Japanese population. The objective of this paper is to investigate the prevalence of frailty by Frailty Index among a cohort of healthy Japanese older adults, define risk factors associated with pre-frailty and frailty status and evaluate Frailty Index's agreement with Frailty Phenotype and Kihon checklist. Methods: Data from 673 participants of the 2014 wave of the Nagoya Longitudinal Study - Healthy Elderly were used. Annual assessments include investigation of mood, memory, health status, nutrition, physical performance and oral health. The Frailty Index was compared to Frailty Phenotype and Kihon Checklist, and factors associated to Frailty Index were investigated through univariate and multivariate logistic regression. Results: Frailty prevalence was 13.5% (n = 91) by Frailty Index, 1.5% (n = 10) by Frailty Phenotype and 4% (n = 27) by Kihon Checklist. Although the correlations between the three scales were moderate to high, the agreement between the scales was poor. In terms of risk factors, age, polypharmacy and physical activity level were associated with being pre-frail and frail. Having a higher waist circumference was associated with being pre-frail, and lower handgrip strength and lower walking speed were associated with being frail. Conclusions: The Frailty Index showed similar metrics and agreement comparable to findings of previous studies, and was able to identify a higher number of individuals who were pre-frail and frail. Age, polypharmacy, physical activity, waking speed and waist circumference were associated with pre-frailty and frailty by frailty index.