Evaluating the survival benefit of kidney retransplantation

Background. The magnitude of the survival benefit associated with kidney retransplantation has not been well studied. Methods. Using data from the Canadian Organ Replacement Register (CORR), we studied patients (n = 3,067) initiating renal replacement therapy during 1981-1998 who had received a transplant and experienced graft failure (GF). Such patients were followed until death, loss to follow-up or the end of the observation period (December 31, 1998). Using Cox regression, we estimated the post-GF covariate-adjusted hazard ratio (HR) for retransplant versus dialysis, and determined whether the contrast differed across patient subgroups. Through nonproportional hazards models, we also examine patterns in the retransplant/dialysis HR with time following retransplant. Results. Overall, retransplantation is associated with a covariate-adjusted 50% reduction in mortality, relative to remaining on dialysis (HR=0.50; P < 0.0001). This benefit is most pronounced in the 18- to 59-year age group. Retransplanted patients were at significantly higher risk of death relative to patients on dialysis only during the first month posttransplant (HR = 1.66; P = 0.047), and experienced significantly reduced mortality thereafter. Conclusions. Following primary graft failure, retransplantation is associated with significantly reduced mortality rates among Canadian end-stage renal disease patients. Further study should be undertaken to assess the applicability of our findings to other patient populations.