Trends in Kidney Allograft Failure Among First-Time Transplant Recipients in the United States.

Rationale & objective: The management and outcomes of kidney transplant recipients have evolved over the past three decades. This study of U.S patients whose first kidney allograft failed sought to understand long-term trends in subsequent waitlisting, re-transplantation, and all-cause mortality.

Study design: Retrospective cohort study.

Setting & participants: Patients recorded in the United States Renal Data System (USRDS) whose first kidney allograft failed between 1990 and 2019.

Exposure: The 5-year period in which the allograft failure occurred: 1990-1994, 1995-1999, 2000-2004, 2005-2009, 2010-2014, or 2015-2019.

Outcomes: 1) Waitlisting for re-transplantation, 2) re-transplantation, and 3) all-cause mortality following first allograft failure.

Analytical approach: Competing risk survival analyses using the approach described by Fine and Gray were used for the outcomes of waitlisting and re-transplantation. Cox proportional hazards models were used for the outcome of all-cause mortality.

Results: The absolute number of patients whose allograft failed and started dialysis increased from 3,197 in 1990 to 5,821 in 2019. Compared to 1990-1994, the rate of waitlisting for a second transplant increased with each subsequent 5-year period, peaking between 2005-2009 before decreasing again subsequently. The rate of re-transplantation following allograft failure decreased by 9%, 14%, 18%, 7%, and 11% in the sequential 5-year eras; and the mortality rate was 25% lower in 2015-2019 (HR=0.75, 95% CI, 0.72-0.77) compared to 1990-1994. Women had a reduced rate of waitlisting (HR 0.93, 95% CI 0.91-0.95) and lower rate of re-transplantation (HR 0.93, 95% CI 0.91, 0.95) compared to men. Compared to White patients, African-American and Hispanic patients had significantly lower rates of waitlisting, re-transplantation, and mortality.

Limitations: Retrospective data that lacks granular clinical information.

Conclusions: During the past three decades, among patients whose first kidney allograft failed and subsequently initiated dialysis, the rates of waitlisting for re-transplantation increased while the rates of re-transplantation and mortality decreased. Race-, ethnicity-, and sex-based disparities in waitlisting and re-transplantation were observed and warrant further investigation.