The rapidly shifting calibration between kidney donor risk index, kidney donor profile index, and graft survival: Is it time to stop moving the goalposts?

We sought to understand the potential impacts of a rapidly evolving donor pool on the annual recalibration of the kidney donor profile index (KDPI). Using Organ Procurement and Transplantation Network data, we examined the kidney donor risk index (KDRI) among deceased donors whose kidneys were recovered for transplantation from 2011 to 2024. We mimicked the Organ Procurement and Transplantation Network's annual remapping process to measure the KDRI-to-KDPI calibration drift and used Cox regression to translate this drift into all-cause graft failure rate differences. The 50th/75th/95th KDRI percentile among donors whose kidneys were recovered rose from 1.19/1.47/2.0 in 2011 to 1.40/1.77/2.36 in 2024. For donors with the same KDRI, the KDPI assigned in 2024 was as much as 13 points lower than the KDPI assigned in 2012. Holding other factors constant, the KDRI-KDPI calibration shift equated to 7 years of increased age (65 vs 58 years) for KDPI 86% donors. Five-year graft failure risk was 9% higher (relative risk: 1.0871.0931.097) for a kidney assigned a KDPI of 86% in 2024 versus 2012. Organ recovery practices have changed. The relationship between KDPI and organ quality has become a moving target, complicating shared decision-making and altering the meaning of allocation policy thresholds. Alternative solutions to annually remapping KDPI, such as establishing a fixed reference cohort or migrating away from KDPI, could be considered.