Frailty: why does it matter in kidney transplantation?

Abstract

Background:
Kidney transplantation is the optimal form of renal replacement therapy for suitable adults, yet it requires recipients to withstand significant physiological stress. Candidates must tolerate general anaesthesia, major surgery and lifelong immunosuppression. Accurately identifying individuals with the physiological reserve to withstand these challenges remains difficult, with clinicians often relying on subjective assessments or unvalidated tools. The 2020 KDIGO ‘Clinical Practice Guideline on Evaluation and Management of Candidates for Kidney Transplantation’ has suggested that the assessment of frailty, a state of reduced physiological reserve, be incorporated into the transplant evaluation process. The overarching objective of this research was to investigate different measures of assessing physiological reserve in adult waitlisted kidney transplant candidates.

Methods:
A retrospective analysis was conducted to evaluate the use of a self-reported functional capacity metric in the assessment of kidney transplant candidates in Northern Ireland. In parallel, a prospective observational cohort study was undertaken to examine multiple frailty assessment tools. The study assessed frailty prevalence, agreement between tools, changes in frailty following transplantation and the association between frailty and post-transplant outcomes.

Key Findings:
Frailty was common among waitlisted candidates, but its prevalence varied depending on the assessment tools. Different tools frequently identified different individuals as frail. For most recipients, frailty improved after transplantation. None of the metrics of physiological reserve were able to reliably or consistently predict adverse post-transplant outcomes.

Conclusions:
While frailty is conceptually relevant in the context of kidney transplantation, current evidence does not support the routine use of frailty assessment in the evaluation of candidates. Variation between tools, lack of predictive accuracy and post-transplant reversibility all limit the utility of frailty assessments for kidney transplantation.

Date of Award	Dec 2025
Original language	English
Awarding Institution	Queen's University Belfast
Sponsors	HSC Research & Development Northern Ireland
Supervisor	Peter Maxwell (Supervisor) & Emma Cunningham (Supervisor)