A comparative analysis of survival of patients on dialysis and after kidney transplantation

Abstract

Background: Kidney transplant survival benefits are not observed for around 8 months after transplantation because of a higher complications rate in early post-transplant periods. This study compares survival of patients awaiting transplantation with survival of transplant recipients and non-listed dialysis patients in Ireland.

Methods: In this retrospective analysis, the relative-risk (RR) of death was assessed with time-dependent, non-proportional hazards analysis, with adjustment for age, cause of end-stage kidney disease (ESKD), time from first treatment for ESKD to placement on the waiting list and year of initial placement on the list.

Results: A total of 3597 patients were included. Annual death rates per 100 patient-years at risk for all patients on dialysis, waiting-list patients and transplant recipients were 16.5, 2.4 and 1.2, respectively. Death rate was highest among diabetics. The relative risk of death for all patients on dialysis was five times higher than the waiting-list patients [RR, 4.90; 95% confidence interval (CI), 3.70-6.52; P < 0.001]. Time to survival equilibration was 1 year. Thereafter, the 5-year mortality risk was estimated to be 47% lower than that of the patients on the waiting list (RR, 0.53; 95% CI, 0.37-0.77; P = 0.001).

Conclusions: Transplant recipients had a higher risk of death initially, but a better long-term survival. Time to death risk equilibration was longer compared with other studies. This could be explained by better survival rates in our waiting-list cohort.

Keywords: dialysis; kidney transplantation; mortality; survival analysis; waiting list.

Fig. 1.

Relative risk of death for transplant recipients compared with on-pool dialysis patients. Subgroups were classified according to age, sex and diabetes as the cause of ESKD and other causes of ESKD. The relative risk was adjusted for age, sex and diabetes as the cause of ESKD and other causes of ESKD.

Fig. 2.

Adjusted relative risk of death for transplant recipients compared with on-pool dialysis patients during the first 5 years post-transplant. The reference group was the 1157 patients on dialysis who were on the transplant waiting list (RR, 1.0). Values were adjusted for age, sex cause of ESKD, year of placement on the waiting list and time from first treatment for ESKD to placement on the waiting list.