Evaluating the Associations Between the Liver Frailty Index and Karnofsky Performance Status With Waitlist Mortality

Frailty has emerged as a critical determinant of mortality in patients with cirrhosis. Currently, the United Network for Organ Sharing registry only includes the Karnofsky Performance Status (KPS) scale, which captures a single component of frailty. We determined the associations between frailty, as measured by the Liver Frailty Index (LFI), and KPS with waitlist mortality.

Included were 247 adult patients with cirrhosis listed for liver transplantation without hepatocellular carcinoma from February 2014 to June 2019, who underwent outpatient assessments using the LFI and KPS within 30 days of listing. "Frail" was defined using the established LFI cutoff of ≥4.4. Competing risk models assessed associations between the LFI and KPS with waitlist mortality (death/delisting for sickness).

At a median 8 months follow-up, 25 (10%) patients died/were delisted. In this cohort, median Model for End-Stage Liver Disease-Sodium was 17, LFI was 3.9 (interquartile range 3.4-4.5), and KPS was 80 (interquartile range 70-90). In multivariable analysis, LFI (sub-hazard ratio 1.07, per 0.1 unit; 95% confidence interval, 1.01-1.12) was associated with waitlist mortality while KPS was not (sub-hazard ratio 1.00, per 10 units; 95% confidence interval, 0.78-1.29).

Our data suggest that frailty, as measured by the LFI, may be more appropriate at capturing mortality risk than KPS and provide evidence in support of using the LFI more broadly in clinical transplant practice in the outpatient setting.