Dynamic frailty trajectories, multidimensional resilience, and risk of incident hip fracture: A prospective cohort study with competing risk analysis

BACKGROUND: Hip fractures represent a major public health challenge in aging populations. While frailty is a recognized risk factor, evidence regarding the protective association of multidimensional resilience trajectories remains insufficient. METHODS: Data from five waves of the China Health and Retirement Longitudinal Study (CHARLS, 2011-2020), including 7105 participants aged ≥ 60. A multidimensional resilience index (MDRI) was quantified via the system-level residual method. Latent Class Growth Modelling (LCGM) identified dynamic trajectories of frailty and resilience. Fine-Gray models evaluated their associations with incident hip fracture risk, treating death as a competing risk. RESULTS: = 0.177), the association was more pronounced in individuals aged < 75 years (SHR = 0.42; 95% CI: 0.27-0.67). CONCLUSIONS: Rising frailty trajectories, rather than baseline status alone, are strong predictors of incident hip fractures. MDRI confers a robust and independent protective association, reducing fracture risk by 56%. Fracture prevention strategies should move beyond static risk assessments towards monitoring the dynamic acceleration of frailty and actively promoting resilience-building assets in older populations.