Patient Frailty and Functional Use of Hemodialysis Vascular Access: A Retrospective Study of the US Renal Data System

Abstract

Rationale & objective: Despite the high prevalence of frailty among dialysis patients, it is unknown whether frailty is associated with dialysis vascular access failure. This study examined the association between frailty and functional use of vascular access.

Study design: Retrospective observational study.

Setting & participants: Patients who initiated hemodialysis through a tunneled catheter in the US Renal Data System database from 2012 through 2017 and underwent subsequent creation of an arteriovenous fistula or graft.

Predictors: The "claims-based frailty indicator" (CFI) was calculated using a validated claims-based disability status model anchored to a well-described frailty phenotype.

Outcomes: Time to functional use for fistulas and grafts defined as the time from initiation of hemodialysis to treatments using the index vascular access with 2 needles.

Analytical approach: Fine and Gray competing risk models separately examining fistula and graft outcomes. Patient survival was modeled for the entire cohort using Cox proportional hazards regression.

Results: A total of 41,471 patients met inclusion criteria, including 33,212 who underwent fistula creation and 8,259 who underwent graft placement. Higher CFI quartiles were associated with a greater rate of mortality. Patients in the highest CFI quartile had more than 2 times the rate of mortality compared with patients in the lowest CFI quartile (hazard ratio [HR], 2.49 [95% CI, 2.41-2.58]). In multivariable analyses, the highest CFI quartile was significantly associated with longer time to functional use of fistulas (HR, 0.65 [95% CI, 0.62-0.69]) and grafts (HR, 0.88 [95% CI, 0.79-0.98]).

Limitations: Generalizability may be limited by the requirement of 12 months of Medicare claims availability before initiation of dialysis. There were no data on patient anatomic characteristics or surgeon characteristics and limited patient-specific sociodemographic data.

Conclusions: Higher degrees of frailty are associated with longer times to vascular access functional use. Frailty may be useful for informing clinical decision-making regarding choice of vascular access.

Keywords: AVF maturation; Frailty; US Renal Data System (USRDS); arteriovenous fistula (AVF); arteriovenous graft (AVG); claims-based frailty index; end-stage renal disease (ESRD); fistula first; hemodialysis; mortality; vascular access.