Temporal progression and bidirectional dynamics of frailty and ADL impairment in middle-aged and older Chinese: A nationwide longitudinal study.

Frailty, a clinical syndrome linked to aging, is associated with ADL impairment. This study elucidates the interplay between frailty and ADL dysfunction and forecasts their progression over time using longitudinal data from CHARLS. Employing the Latent Growth Curve Model and cross-lagged panel analysis, the research evaluates the interrelations among BADL, IADL, and frailty, as well as the influence of functional limitations on frailty trajectory. The cohort of 8638 middle-aged and older adults had baseline frailty scores of 0.07 ± 0.09, BADL limitations of 0.29 ± 0.85, and IADL limitations of 0.36 ± 0.90. Frailty and ADL limitations increased nonlinearly with age. LGCM indicated a significant correlation between the non-linear progression of frailty and dysfunction in BADL and IADL. Cross-lagged panel analyses revealed a reciprocal predictive relationship between ADL limitations and frailty. These findings underscore the importance of preserving and enhancing ADL capabilities to prevent and treat frailty in aging populations.