Comparison of Multiple Frailty Scoring Metrics in Renal Transplant Candidates: A Large Single-center Cohort Study

Background. Pretransplant patients are not required to undergo objective frailty testing, although current listing and allocation policies do record functional metrics. Multiple different metrics exist for assessing frailty. Methods. We investigated different frailty metrics in patients presenting for renal transplant evaluation. Four hundred thirty patients underwent both cross-sectional imaging and retrospective chart review to calculate a psoas muscle area (PMA) and modified Frailty Risk Score (FRS), respectively. Of these patients, 264 were also evaluated using the Fried frailty phenotype (FFP). Expected Posttransplant Survival scores for posttransplant patients were calculated. Results. In total, 220 (52.2%) patients were considered frail by at least 1 metric. Of evaluated patients 8.3%, 30.7%, and 24.9% were frail by FFP, FRS, and PMA respectively, compared with 6.6%, 26.4%, and 24.0% of listed patients who were frail by FFP, FRS, and PMA respectively. PMA and FRS identified more frail patients compared with FFP ( P = 0.0001). Concordance between metrics was poor, with kappa coefficients of <0.1 for all comparisons. Estimated Posttransplant Survival score at time of transplant was not different between frail and nonfrail patients ( P = 0.3289). Conclusions. Ultimately, patients successfully listed for transplant did not vary in frailty metrics from those who were not listed. These findings suggest that standardized metrics are needed for the evaluation and listing of patients.