Modified Frailty Index and outcomes after liver transplantation: A multicenter cohort study.

Abstract

Frailty has historically been associated with worse transplant outcomes. We hypothesized that higher scores on the 5-variable Modified Frailty Index would be associated with worse morbidity. We included adults in the TriNetX US Collaborative Network (2015-2025) registry who underwent orthotopic liver transplantation. Patients were stratified into 3 groups based on the Modified Frailty Index: nonfrail (score 0-1), moderately frail (score 2), and severely frail (score ≥3). Propensity score matching balanced demographics, comorbidities, and model for end-stage liver disease components. The primary outcome was 30-day postoperative morbidity, defined as a composite outcome. A sensitivity analysis used an expanded composite that included infections and surgical complications. Secondary outcomes included all-cause mortality at 90 days and 1, 3, and 5 years; acute rejection; and graft failure. Among 13,408 recipients, 4,667 were nonfrail, 4,987 were moderately frail, and 3,751 were severely frail. There were 2,678 matched pairs in the Modified Frailty Index 2 analysis and 1,782 matched patients in the Modified Frailty Index ≥3 analysis. Composite morbidity was significantly higher in both frail groups: 55.9% vs 49.1% (odds ratio, 1.32; 95% confidence interval, 1.20-1.44) among Modified Frailty Index 2, and 57.4% vs 49.3% (odds ratio, 1.39; 95% confidence interval, 1.24-1.54) among Modified Frailty Index ≥3. The expanded composite remained significantly higher in both groups. Frail recipients had lower 90-day mortality (Modified Frailty Index 2: hazard ratio, 0.54; 95% confidence interval, 0.39-0.76; Modified Frailty Index ≥3: hazard ratio, 0.51; 95% confidence interval, 0.34-0.75). By 5 years, Modified Frailty Index ≥3 was associated with higher mortality (hazard ratio, 1.29; 95% confidence interval, 1.07-1.54), whereas Modified Frailty Index 2 was not associated with a significant difference in 5-year mortality. Modified Frailty Index 5 stratifies short-term and long-term risk after liver transplantation. Frailty was associated with significantly greater morbidity, rejection, and late mortality, supporting its integration into pretransplant evaluation and perioperative planning.