# Transitions in frailty states and associated factors: a multistate analysis of the Italian Longitudinal Study on Aging population-based cohort

## TL;DR

This study tracks how frailty changes over time in older Italians, finding that about 20% can improve within three years, and socio-psychological factors strongly influence these changes.

## Contribution

The study introduces a multistate modeling approach to analyze frailty transitions and identifies socio-psychological factors as key predictors of frailty progression.

## Key findings

- Frailty remission or improvement is possible for about 20% of individuals within three years.
- Women are more likely to experience worsening frailty, while men have a higher risk of death.
- Depressive symptoms are the strongest predictor of frailty worsening in both sexes.

## Abstract

•1931 frailty transitions observed during ∼9 years in a population-based cohort ≥65.•Multistate modelling to predict transitions and related factors at different time intervals.•Ample chance of frailty remission/improvement for both sexes (∼20 % at 3-year).•Women have a higher probability of frailty worsening (and resilience) while men of death.•Socio-psychological factors play a determinant role in the development of frailty.

1931 frailty transitions observed during ∼9 years in a population-based cohort ≥65.

Multistate modelling to predict transitions and related factors at different time intervals.

Ample chance of frailty remission/improvement for both sexes (∼20 % at 3-year).

Women have a higher probability of frailty worsening (and resilience) while men of death.

Socio-psychological factors play a determinant role in the development of frailty.

Background: Frailty is recognized as a dynamic and potentially reversible process, but comprehensive studies on its progression/regression are rare.

Objective: To investigate the frequency and characteristics of frailty transitions over time in a representative sample of older Italians.

Design and Participants: As secondary analysis of the Italian Longitudinal Study on Aging (ILSA) population-based cohort, we studied all participants (n = 1339; women 47.5 %, age 72.7 ± 5.1) with complete information on changes in frailty status (or death) between consecutive ILSA surveys (T0, T1, T2).

Measurements: Frailty was operationalized according to Fried phenotype, analysing transitions between frailty, or death, during T0-T1, T1-T2 (4-, 5-year length). Transition probability at 1, 3, 5 years was estimated through non-hidden continuous-time Markov models, with death as absorbing state. Factors influencing transitions were evaluated with Cox proportional Hazard Ratios (HR).

Results: We observed 1931 transitions between frailty states and 241 to death. The estimated probability of: maintaining a stable frailty status (∼80 % within 1 year) halved at 5 years; worsening increased steeply over time and was always greater among women; improvement/remission was twice higher at medium (about 20 % among Frail->preFrail women, preFrail->nonFrail men) than short term. Depressive symptoms were the strongest predictor of worsening [nonFrail->Frail: women HR 3.63 (95 %CI 1.45–9.10), men HR 3.78 (95 %CI 2.0–7.13)]. Not having a spouse/partner was associated with a 30 % reduced probability of pre-frailty remission in both sexes.

Conclusions: Our findings confirm the fluctuating nature of frailty with an ample chance of remission/improvement, highlighting the importance of a prompt, multidimensional preventive approach, including psycho-social dimensions.