Kidney transplant program waitlisting rate as a metric to assess transplant access

Abstract

Kidney transplant program performance in the United States is commonly measured by posttransplant outcomes. Inclusion of pretransplant measures could provide a more comprehensive assessment of transplant program performance and necessary information for patient decision-making. In this study, we propose a new metric, the waitlisting rate, defined as the ratio of patients who are waitlisted in a center relative to the person-years referred for evaluation to a program. Furthermore, we standardize the waitlisting rate relative to the state average in Georgia, North Carolina, and South Carolina. The new metric was used as a proof-of-concept to assess transplant-program access compared to the existing transplant rate metric. The study cohorts were defined by linking 2017 United States Renal Data System (USRDS) data with transplant-program referral data from the Southeastern United States between January 1, 2012 and December 31, 2016. Waitlisting rate varied across the 9 Southeastern transplant programs, ranging from 10 to 22 events per 100 patient-years, whereas the program-specific waitlisting rate ratio ranged between 0.76 and 1.33. Program-specific waitlisting rate ratio was uncorrelated with the transplant rate ratio (r = -.15, 95% CI, -0.83 to 0.57). Findings warrant collection of national data on early transplant steps, such as referral, for a more comprehensive assessment of transplant program performance and pretransplant access.

Keywords: Scientific Registry for Transplant Recipients (SRTR); ethics and public policy; health services and outcomes research; kidney disease; kidney transplantation/nephrology; patient referral; quality of care/care delivery; registry/registry analysis.

FIGURE 1

Waitlist rate denominator: all referred patients in GA, NC, and SC over study years 2012–2015

FIGURE 2

Transplant rate denominator: all waitlisted patients in GA, NC, and SC over study years 2012–2015

FIGURE 3

Program-specific ratios of observed to expected transplant and waitlisting rates in GA, NC, and SC, study years 2012–2015; transplant programs are arranged in ascending order of the waitlisting ratio metric. Expected rates adjusted for patient age, sex, race, insurance status, and comorbidities at ESRD start. The solid black line denotes perfect agreement between the observed and expected waitlist and transplant rates at the program, respectively [Color figure can be viewed at wileyonlinelibrary.com]

FIGURE 4

Association between transplant rate and waitlisting rate ratios at transplant programs in GA, NC, and SC, study years 2012–2016. Expected rates adjusted for patient age, sex, race, insurance status, and comorbidities at ESRD start. The dotted black lines denote agreement of observed and expected rates for waitlisting (vertical) and transplantation (horizontal), respectively [Color figure can be viewed at wileyonlinelibrary.com]