Gender-Based Utilization and Outcomes of Autogenous Fistulas and Prosthetic Grafts for Hemodialysis Access

Abstract

To evaluate gender-based patterns of utilization and outcomes of arteriovenous fistulas (AVFs) and grafts (AVGs) in a population-based cohort of hemodialysis (HD) patients. A retrospective analysis of all patients in the United States Renal Data System who had an AVF or AVG placed for HD access (January 2007 to December 2014). Outcomes were access maturation, conduit patency, infection, and mortality. Chi-square, Student's t, Kaplan-Meier, and multivariable Cox regression analyses were employed accordingly. There were 456,693 (57%) males and 341,571 (43%) females who initiated HD via AVF (16%), AVG (4%) and HD catheter (80%). There was a 30% decrease in odds of initiating HD with AVF in females compared with males (adjusted odds ratio [aOR]: 0.70; 95% confidence interval [CI]: 0.69-0.71, P<0.001). The use of HD catheter as a bridge to AVF was 36% higher in females compared with males (aOR: 1.36; 95% CI: 1.33-1.39, P<0.001). Preemptive AVF maturation was 78% for males and 76% for females (P<0.001). The risk-adjusted analyses showed a 7% decrease in AVF maturation comparing females with males (adjusted hazard ratio [aHR]: 0.93; 95% CI: 0.92-0.95, P<0.001) but no difference in AVG maturation (aHR: 0.99; 95% CI: 0.97-1.01, P=0.46) After risk adjustment, primary (AVF: aHR-0.87; AVG: aHR-0.96), primary-assisted (AVF: aHR-0.84; AVG: aHR-0.97), and secondary (AVF: aHR-0.85; AVG: aHR-0.98) patency were lower for females compared with males (all P<0.05). Initiation of HD with a catheter and conversion to AVF was associated with lower patency in males (aHR: 0.29; 95% CI: 0.28-0.29; P<0.001) and females (aHR: 0.31; 95% CI: 0.30-0.31; P<0.001) compared with AVF initiates. Patient survival was higher for females compared with males who received AVF (aHR: 1.08; 95% CI: 1.07-1.09; P<0.001) and AVG (aHR: 1.13; 95% CI: 1.11-1.15; P<0.001). Initiation with HD catheter and subsequent conversion to AVF was associated with an increase in mortality for males (aHR: 1.45; 95% CI: 1.43-1.47; P<0.001) and females (aHR: 1.44; 95% CI: 1.44-1.52; P<0.001) compared with initiation via AVF. There was no significant difference in severe AVG infection comparing females with males (aHR: 1.05; 95% CI: 0.98-1.13; P=0.16). Female gender is associated with a lower prevalence of preemptive AVF's, higher utilization of catheters as a bridge to AVF, and lower patency compared with males. There was no difference in access maturation but patient survival was higher for females compared with males.