Equations used to place patients on transplant waitlists may create disparities

Different equations used to qualify patients for the kidney transplant waitlist may result in inequities, according to a study that will be presented at ASN Kidney Week 2015 November 3¬-8 at the San Diego Convention Center in San Diego, CA.

Approximately 4% to 6% of patients on the kidney transplant waitlist die each year. Therefore, patients may benefit from being placed on the list sooner. Benjamin J. Lee, MD (University of California, San Francisco) and his colleagues assessed the relative performance of 3 commonly used kidney function equations (termed Cockroft-Gault, MDRD, and CKD-EPI) used when placing patients on the waiting list.

The team found that the equations yield discordant results for waitlist qualification. Furthermore, choice of equation led to significant and consistent differences in qualification time when applied to 3 different patient cohorts: a group of waitlisted patients at 1 major US academic center and 2 national, multicenter study groups of CKD patients, 1 with only African Americans and the other with predominantly Caucasians. The Cockroft-Gault equation most often disadvantaged patients as compared with the MDRD and CKD-EPI equations. On average, time to waitlist qualification would be delayed on the order of 1 to 2 years by using the Cockroft-Gault equation, as compared with the MDRD equation or CKD-EPI equation.

"Given the high observed mortality rates for patients on the waitlist and median wait times of 1.4 to 3.3 years, depending on geographic location, for deceased donor transplants in the United States, the magnitude of these differences is concerning," said Dr. Lee. "The Organ Procurement and Transplantation Network may need to revise the language in kidney transplantation policies so that consistent methods to assess kidney function are adopted and patients are not inadvertently disadvantaged."