Association between vascular access type and patient mortality among elderly patients on hemodialysis in Canada

Optimal vascular access in elderly patients requires consideration of the benefits and risks in a population with increased comorbidity and mortality. Our objective was to examine the association between vascular access type and patient mortality by age category among incident adult hemodialysis patients registered in the Canadian Organ Replacement Register between 2001 and 2010. We also describe the secular trend in incident and prevalent vascular access use. We used a Cox proportional hazards model to evaluate the overall mortality in patients aged less than 65, 65-74, 75-85, and greater than 85 years who initiated hemodialysis using a central venous catheter (catheter) or arteriovenous (AV)-access (fistula or graft) using an intention-to-treat approach. The cohort of 39,721 patients consisted of 42%, 27%, 26%, and 5% of patients aged <65, 65-74, 75-85, and >85, respectively. Patients who initiated hemodialysis using an AV-access constituted 21%, 22%, 20%, and 15% of each age category. AV access use was associated with lower adjusted mortality compared with catheter use in each age category (Hazard Ratios [HR], 0.67; 95% Confidence Interval [0.62-0.72]; HR, 0.76 [0.63-0.91]; HR, 0.77 [0.64-0.93], HR, 0.73 [0.56-0.96], respectively). In Canada, use of an AV-access is associated with lower mortality across all age categories, even in the very elderly. Further studies are required to understand the patient preference, complications, and resource use when selecting access type in the elderly.