Frailty index transitions over eight years were frequent in The Irish Longitudinal Study on Ageing

HRB Open Res. 2021 Jun 9;4:63. doi: 10.12688/hrbopenres.13286.1. eCollection 2021.


Background: The frailty index (FI) is based on accumulation of health deficits. FI cut-offs define non-frail, prefrail and frail states. We described transitions of FI states in The Irish Longitudinal Study on Ageing (TILDA). Methods: Participants aged ≥50 years with information for a 31-deficit FI at wave 1 (2010) were followed-up over four waves (2012, 2014, 2016, 2018). Transitions were visualized with alluvial plots and probabilities estimated with multi-state Markov models, investigating the effects of age, sex and education. Results: 8174 wave 1 participants were included (3744 men and 4430 women; mean age 63.8 years). Probabilities from non-frail to prefrail, and non-frail to frail were 18% and 2%, respectively. Prefrail had a 19% probability of reversal to non-frail, and a 15% risk of progression to frail. Frail had a 21% probability of reversal to prefrail and 14% risk of death. Being older and female increased the risk of adverse FI state transitions, but being female reduced the risk of transition from frail to death. Higher level of education was associated with improvement from prefrail to non-frail. Conclusions: FI states are characterized by dynamic longitudinal transitions and frequent improvement. Opportunities exist for reducing the probability of adverse transitions.

Keywords: Aged; Frailty; Longitudinal; Multi-state; Surveys; Transition.

Associated data

  • figshare/10.6084/m9.figshare.14681292.v1

Grant support

This study was funded by a grant from Science Foundation Ireland under grant number 18/FRL/6188. TILDA is funded by Atlantic Philanthropies, the Irish Department of Health and Irish Life. Peter Hartley is funded by a fellowship from the Cambridge Biomedical Research Centre and The Addenbrooke’s Charitable Trust [grant reference: 03/20 A].