Duration of end-stage renal disease and kidney transplant outcome.

BACKGROUND: Patients nearing end-stage renal disease (ESRD) increasingly choose pre-emptive renal transplant (PRT) to avoid pre-transplant dialysis and to minimize ESRD. Compared with long-term dialysis, PRT has been shown to increase allograft survival. However, the merit of short-term dialysis is not well characterized, and it may be the better medical choice in some patients. The goal of the study was to characterize the relationship between the duration of dialysis vs allograft and patient survival.

METHODS: We performed a retrospective nationwide cohort study of all kidney transplants (Tx) between January 1, 1990 and December 31, 1999, with a follow-up period through December 31, 2000. Participants were identified using the United States Renal Data System (USRDS), which tracks all ESRD cases in the nation including patients on dialysis and with kidney Tx. Patients with the history of more than one kidney Tx were excluded. Allograft survival and recipient survival were the primary outcomes of this study. Duration of ESRD as a continuous variable as well as divided into categories (14 days, 15-60 days, 61-180 days, 181-365 days, 1-2 years, 2-3 years, 3-5 years and >5 years) was the primary risk factor of interest. Models were adjusted for multiple donor and recipient factors, including demographics and co-morbidities, as well as for Tx procedure characteristics.

RESULTS: A total of 81,130 patient records were used for analysis (age 44.1+/-14.3 years, 61% males, 24% black, 29% diabetic, pre-transplant ESRD duration 27.1+/-26.4 months, 26% living donors). ESRD duration, as a continuous variable, is associated with a modest increase in the risk of graft failure over time [hazard ratio (HR) 1.02 per year of ESRD duration, P<0.001]. When ESRD is studied as a categorical variable (duration of 0-14 days vs longer durations), the increased risk of allograft failure reached statistical significance only when the time on dialysis was > or =181 days. The duration of ESRD was a significant risk for recipient death (HR 1.04 per year, P<0.001); however, mortality risk reached statistical significance only when the patient had been on dialysis for > or =1 year.

CONCLUSIONS: This study of USRDS records suggests that a short (<6 months) dialysis course has no detrimental effect on graft and patient survival, and should not be deferred if medically indicated.