Waiting time on dialysis as the strongest modifiable risk factor for renal transplant outcomes - A paired donor kidney analysis

Background. Waiting time on dialysis has bee shown to be associated with worse outcomes after living and cadaveric transplantation. To validate an quantify end-stage renal disease (ESRD) time as independent risk factor for kidney transplantation we compared the outcome of paired donor kidney destined to patients who had ESRD more than 2 year compared to patients who had ESRD less than months. Methods. We analyzed data available from the U. Renal Data System database between 1988 and 1998 by Kaplan-Meier estimates and Cox proportional hazard models to quantify the effect of ESRD time on paired cadaveric kidneys and on all cadaveric kidneys con pared to living-donated kidneys. Results. Five- and 10-year unadjusted graft survival rates were significantly worse in paired kidney recipients who had undergone more than 24 months of dialysis (58% and 29%, respectively) compared to paired kidney recipients who had undergone less than months of dialysis (78% and 63%, respectively; P < 0.001 each). Ten-year overall adjusted graft survival for cadaveric transplants was 69% for preemptive trans plants versus 39% for transplants after 24 months on dialysis. For living transplants, 10-year overall ad adjusted graft survival was 75% for preemptive trans plants versus 49% for transplants after 24 month on dialysis. Conclusions. ESRD time is arguably the strongest independent modifiable risk factor for renal trans plant outcomes. Part of the advantage of living-donor versus cadaveric-donor transplantation may be ex plained by waiting time. This effect is dominant enough that a cadaveric renal transplant recipient with an ESRD time less than 6 months has the equivalent graft survival of living donor transplant recipients who wait on dialysis for more than 2 years.