Center-effect of incident hemodialysis vascular access use: Analysis of a bi-national registry

Abstract

Background: Commencing hemodialysis (HD) with an arteriovenous access is associated with superior patient outcomes compared to a catheter but the majority of patients in Australia and New Zealand (ANZ) initiate HD with a central venous catheter. This study examined patient and center factors associated with arteriovenous fistula/graft access use at HD commencement. Methods: All adult patients starting chronic HD in Australia and New Zealand between 2004 and 2015 were included. Access type at HD initiation was analyzed using logistic regression. Patient-level factors included sex, age, race, body mass index (BMI), smoking status, primary kidney disease, late nephrologist referral, comorbidities and prior kidney replacement therapy (KRT). Center-level factors included size, transplant capability, home HD proportion, incident peritoneal dialysis (average number of patients commencing KRT with peritoneal dialysis per year), mean weekly HD hours, average blood flow and achievement of phosphate, hemoglobin and weekly Kt/V targets. The study included 27,123 patients from 61 centers. Results: Arteriovenous access use at HD commencement varied 4-fold from 15% to 62% (median 39%) across centers. Incident arteriovenous access use was more likely in patients aged 51-72 years, males and patients with BMI >25kg/m2 and polycystic kidney disease but less likely in patients with BMI<18.5kg/m2, late nephrologist referral, diabetes mellitus, cardiovascular disease, chronic lung disease and prior KRT. Starting HD with an arteriovenous access was less likely in centers with the highest proportion of home HD and no center factor was associated with higher arteriovenous access use. Adjustment for center-level characteristics resulted in a 25% reduction in observed inter-center variability of arteriovenous access use at hemodialysis initiation compared to the model adjusted for only patient-level characteristics. Conclusions: This study identified several patient- and center-factors associated with incident hemodialysis access use, yet these factors did not fully explain the substantial variability in arteriovenous access use across centers.