Association between initial type of hemodialysis access used in the elderly and mortality.

We hypothesized that certain subpopulations (elderly and those with greater comorbidity) may not have significant benefit from "fistula first" initiative. A cohort of incident hemodialysis patients from 2005 to 2007, who were ≥70 years old, was derived from the United States Renal Data System. Primary variable of interest was type of vascular access used at first outpatient hemodialysis (i.e., fistula, graft, or central catheter), with primary outcome of all-cause mortality (time to death measured from the first outpatient hemodialysis). A cohort of 82,202 patients was stratified by age (70 to ≤80, 81 to ≤90, and >90). Each group demonstrated a survival benefit with the use of an arterio-venous fistula compared with catheter (hazard ratio [HR] 0.56 [P < 0.001], HR 0.55 [P < 0.001], and HR 0.69 [P = 0.007], respectively). Comparing graft to with a catheter, both groups, 70 to ≤80 and 81 to ≤90, had significant benefit compared with catheter (HR 0.73, P < 0.001 and HR 0.74, P < 0.001, respectively). However, significance was lost in those ≥90 (HR 0.83, P = 0.354). When substratified by comorbidity, those 81 to ≤90 years old with a history of malignancy or peripheral vascular disease also did not reach significant benefit compared with a catheter (HR 0.88, P = 0.423 and HR 0.85, P = 0.221, respectively). While specific subgroups in the hemodialysis population exist where use of fistulas and grafts at time of dialysis initiation is not of proven statistical benefit to survival, elderly hemodialysis patients with comorbidities still appear to benefit from the use of fistulas and grafts.