Evolution of Vascular Access Use among Incident Patients during the First Year on Hemodialysis: A National Cohort Study

Background Although the arteriovenous fistula (AVF) confers superior benefits over central venous catheters (CVCs), utilization rates remain low among prevalent patients on hemodialysis (HD). The goal of this study was to determine the evolution of vascular access type in the first year of dialysis and identify factors associated with conversion from CVC to a functioning AVF. Methods We studiedadult patients (n=610) who began HD between the January 1, 2015 and December 31, 2016 and were treated for at least 90 days, using data from the National Kidney Disease Clinical Patient Management System in the Irish health system. Prevalence of vascular access type was determined at days 90 and 360 after dialysis initiation and at 30-day intervals. Multivariable logistic regression explored factors associated with CVC at day 90, and Cox regression evaluated predictors of conversion from CVC to AVF on day 360. Results CVC use was present in 77% of incident patients at day 90, with significant variation across HD centers (from 63% to 91%, P<0.001), which persisted after case-mix adjustment. From day 90 to day 360, AVF use increased modestly from 23% to 41%. Conversion from CVC to AVF increased over time, but the likelihood was lower for older patients (for age >77 years versus referent, adjusted hazard ratio [HR], 0.43; 95% CI, 0.19 to 0.96), for patients with a lower BMI (per unit decrease in BMI, HR, 0.95; 95% CI, 0.93 to 0.98), and varied significantly across HD centers (from an HR of 0.25 [95% CI, 0.08 to 0.74] to 2.09 [95% CI, 1.04 to 4.18]). Conclusion CVCs are the predominant type of vascular access observed during the first year of dialysis, with low conversion rates from CVC to AVF. There is substantial center variation in the Irish health system that is not explained by patient-related factors alone.