Comparing the Fried frailty phenotype versus the Veterans Affairs frailty index among dialysis dependent patients

INTRODUCTION Frailty in dialysis patients is a modifiable disease state which can increase mortality if left untreated but remains underdiagnosed as frailty evaluations can be arduous or time consuming. We evaluate the agreement between a clinical frailty construct (Fried frailty phenotype, FFP) against and an electronic health record-based Veterans Affairs Frailty Index (VAFI) and their association with mortality. METHODS A retrospective cohort analysis of 764 participants from the ACTIVE/ADIPOSE study was performed. Frailty as measured by VAFI and FFP was obtained and Kappa statistic estimating concordance between the two scores were calculated. Differences in mortality risk were analyzed according to presence or absence of frailty. FINDINGS When assessing agreement between the VAFI and FFP, the kappa statistic was 0.09 (95% confidence interval [CI] 0.02-0.16) suggesting a low level of agreement. Frailty was independently associated with higher mortality risk (hazards ratio [HR] 1.40-1.42 in fully adjusted models depending upon frailty construct). Discordantly frail patients by construct had a higher risk of mortality though this was not statistically significant after adjustment. However, concordantly frail patients had much higher mortality risk compared to concordantly nonfrail (adjusted HR 2.08, 95% CI 1.44-3.01). DISCUSSION Poor agreement between constructs is likely reflective of the multifactorial definition of frailty. While further longitudinal studies are needed to determine if the VAFI would be beneficial in the reassessment of frailty, it may be beneficial as a cue for further frailty testing (e.g., with FFP) with the combination of multiple frail constructs providing improved prognostic information.