Sex, race, and hemodialysis vascular access processes.

Abstract

Hemodialysis (HD) patients who are female or black receive fewer arteriovenous fistulas (AVF) and more grafts (AVG). We evaluated race- and sex-based differences for three process exposures: access surgery, peripherally-inserted central catheters (PICCs), and vascular imaging. US Renal Data System with linked Medicare claims for patients initiating HD between April 2010 - December 2011 were used to identify PICC placement, imaging, AVF and AVG surgeries, and the vascular accesses in use at individual HD treatments. Poisson, logistic, and Cox regression models adjusted for clinical and demographic variables were used to evaluate relationships between process exposures, vascular access outcomes, and sex. Among 18,883 individuals initiating HD with catheters with at least one surgical claim for AVF or AVG, women had 16% more PICC and 5% more imaging (p = 0.002), were 43% less likely to have AVF surgery and 68% more likely to have AVG surgery (p<0.001). The odds of AVF surgery producing a working AVF were 18% lower and of AVG surgery producing a working AVG 38% higher (p<0.001). Black patients had 24% more PICCs and 12% more imaging, were 48% less likely to have AVF surgery and 84% more likely to have AVG surgery (p<0.001). The odds of achieving a working AVF were 8% lower and of a working AVG were 38% higher. The hazard of future catheter use after AVF creation was 25% higher for women (p<0.001), but did not differ by race. Divergences in vascular access by race and sex were partly related to differential process exposures. Black and female patients had more AVG and less AVF surgery, and more PICC and imaging. Success rates were lower for AVF surgery and higher for AVG surgery. Further work is needed to determine whether choices of process exposures arise from differential ability to detect veins on physical examination.