Early Changes in Kidney Transplantation following Implementation of the Increasing Organ Transplant Access Model

BACKGROUND: The Increasing Organ Transplant Access (IOTA) model is a mandatory experimental payment model that aims to improve kidney transplant access using financial incentives and penalties for transplant centers randomized to model participation, based primarily on growth in transplant volume. METHODS: We used national transplant registry data to conduct a retrospective cohort study of US kidney transplant centers. We identified centers randomized to IOTA participation based on the published list of center participants. Using a difference-in-differences approach, we compared IOTA participants to non-participants on changes in overall, deceased donor, and living donor kidney transplant volume per 30 days in the period before IOTA randomization status was announced versus the 9 months following IOTA implementation. Separately among IOTA participants and among non-participants, we compared the proportional change in transplant volume when stratifying centers by pre-IOTA transplant volume, organ offer acceptance rate, and transplant rate ratio. RESULTS: Among 177 included centers, 97 (55%) were IOTA participants and 80 (45%) non-participants. Most IOTA participants (53%) and non-participants (55%) experienced a fall in overall transplant volume after model implementation. However, IOTA participants exhibited a 5% increase in transplant volume per 30 days, whereas non-participants exhibited a 3% decrease (P=0.01). The difference between groups was seen for deceased donor transplants (participants +5% vs. non-participants -9%, P<0.001), while living donor transplants rose in both groups (+7 vs. +19%, P=0.24). Among IOTA participants, there were no statistically significant differences in changes in transplant volume when comparing centers categorized by pre-IOTA transplant volume, organ offer acceptance rate, or transplant rate ratio. CONCLUSIONS: Centers randomized to IOTA participation outperformed model non-participants in changes in kidney transplant volume after model implementation, driven by an increase in deceased donor transplant volume among model participants but a fall among non-participants.