Variation in Dialysis Exposure Prior to Nonpreemptive Living Donor Kidney Transplantation in the United States and Its Association With Allograft Outcomes

Background: The impact of dialysis exposure before nonpreemptive living donor kidney transplantation on allograft outcomes is uncertain. Study Design: Retrospective cohort study. Setting & Participants: Adult first-time recipients of kidney-only living donor transplants in the United States who were recorded within the Scientific Registry of Transplant Recipients for 2000 to 2016. Factors: Duration of pretransplantation dialysis exposure. Outcomes: Kidney transplant failure from any cause including death, death-censored transplant failure, and death with allograft function. Results: Among the 77,607 living donor transplant recipients studied, longer pretransplantation dialysis exposure was independently associated with progressively higher risk for transplant failure from any cause, including death beginning 6 months after transplantation. Compared with patients with 0.1 to 3.0 months of dialysis exposure, the HR for transplant failure from any cause including death increased from 1.16 (95% CI, 1.07-1.31) among patients with 6.1 to 9.0 months of dialysis exposure to 1.60 (95% CI, 1.43-1.79) among patients with more than 60.0 months of dialysis exposure. Pretransplantation dialysis exposure varied markedly among centers; median exposures were 11.0 and 18.9 months for centers in the 10th and 90th percentiles of dialysis exposure, respectively. Centers with the highest proportions of living donor transplantations had the shortest pretransplantation dialysis exposures. In multivariable analysis, patients of black race, with low income, with nonprivate insurance, with less than high school education, and not working for income had longer pretransplantation dialysis exposures. Dialysis exposure in patients with these characteristics also varied 2-fold between transplantation centers. Limitations: Why longer dialysis exposure is associated with transplant failure could not be determined. Conclusions: Longer pretransplantation dialysis exposure in nonpreemptive living donor kidney transplantation is associated with increased risk for allograft failure. Pretransplantation dialysis exposure is associated with recipients' socio-demographic and transplantation centers' characteristics. Understanding whether limiting pretransplantation dialysis exposure could improve living donor transplant outcomes will require further study.