Association of Kidney Transplantation with Survival in Patients with Long Dialysis Exposure

Abstract

Background and objectives: Evidence that kidney transplantation is associated with better survival compared to dialysis stems from data in populations with short durations of dialysis exposure. Recent changes in allocation policy increase access to transplantation for patients with longer dialysis exposure. The objective of this study was to determine the association of transplantation with survival in patients with ≥10 years of dialysis treatment.

Design, setting, participants, & measurements: Our study of n=5365 patients in the Scientific Registry of Transplant Recipients determined the adjusted relative risk of death in recipients of a deceased donor kidney transplant after ≥10 years of dialysis treatment compared with waitlisted patients with the same dialysis exposure in a time-dependent nonproportional hazards analysis.

Results: The adjusted relative risk of death in n=2320 transplant recipients compared with patients on dialysis who had equal lengths of follow-up from their 10-year dialysis anniversary was 0.60 (95% confidence interval, 0.53 to 0.68), and this benefit was observed in a variety of patient subgroups, including patients ≥65 years of age and patients with diabetes. However, transplant recipients were at higher risk of death for 180 days after transplantation and did not derive survival benefit until 657 days after transplantation, despite receiving good-quality kidneys. The study patients were younger and had higher expected post-transplant survival than patients currently waitlisted with ≥10 years of dialysis.

Conclusions: Transplantation is associated with better survival in patients who were actively waitlisted with dialysis exposure ≥10 years. Whether transplantation is associated with better survival in currently waitlisted patients with similar dialysis exposure and whether transplantation of lower-quality deceased donor kidneys is associated with better survival are uncertain.

Keywords: Confidence Intervals; Follow-Up Studies; Graft Survival; Humans; Registries; Risk; Tissue Donors; Transplant Recipients; cadaver organ transplantation; diabetes mellitus; kidney; kidney transplantation; renal dialysis; survival.

Graphical abstract

Figure 1.

Flow chart describing the identification of the study cohort.

Figure 2.

Deceased donor transplant recipients were at higher risk of death for a period of 180 days after the date of transplant surgery and then, had a lower risk of death. Because of this higher risk of death early after transplantation, survival between transplant recipients and patients who conitnued treatment with dialysis duid not equalize until 657 days after transplantation. The figure shows the adjusted relative risk of death in n=2320 kidney transplant recipients compared with waitlisted patients who had the same duration of dialysis treatment. The reference group (relative risk, 1.0) included the n=5365 waitlisted patients with at least 10 years of dialysis exposure. Patients in both groups had the same length of follow-up from the date of their 10-year dialysis anniversary. Values were adjusted for differences in patient age, sex, race, cause of kidney failure, body mass index, comorbid conditions, sensitization, and year of first chronic dialysis treatment.