Frailty Changes Predict Mortality in 4 Longitudinal Studies of Aging

Area of Science:

• Gerontology
• Public Health
• Biostatistics

Background:

• Baseline frailty index (FI) predicts mortality in older adults.
• Limited understanding of how changes in FI impact mortality risk.

Purpose of the Study:

• To investigate the association between changes in frailty index (FI) and mortality in older adults.
• To determine if frailty trajectories predict mortality independently of baseline FI.

Main Methods:

• Analysis of data from four large, population-based cohorts (HRS, SHARE, ELSA, LASA) with 24,961 participants (65+).
• Utilized up to 9 repeated FI assessments and up to 23 years of mortality follow-up.
• Employed joint regression models for longitudinal and time-to-event data to analyze time-varying FI effects.

Main Results:

• Both current and baseline FI levels were consistently associated with increased mortality risk.
• Steeper increases in FI over time significantly elevated mortality risk across all cohorts.
• An annual FI growth of 0.01 increased mortality risk, with hazard ratios ranging from 1.24 to 1.71 depending on the cohort.

Conclusions:

• Frailty index (FI) changes independently predict mortality, beyond baseline levels.
• Repeated frailty assessments and trajectory analysis can identify individuals at higher risk.
• Monitoring frailty progression may aid in anticipating health deterioration and informing clinical decision-making.