Kidney transplantation is a critical treatment for end-stage renal disease. In the United States, data from the Organ Procurement & Transplantation Network (OPTN) provides insights into new kidney transplant recipients, distinguishing between living donor (LD) and deceased donor (DD) transplants. However, understanding the composition of the prevalent kidney transplant population – those currently living with a functioning transplant – requires a different approach. While deceased donor transplants are more frequent, they typically have shorter long-term patient and graft survival rates compared to living donor transplants. This disparity suggests that the prevalent population may have a different donor-type distribution than new transplant recipients.
Modeling the Landscape of Kidney Transplants
To address this gap in data, a study utilized a two-compartment model. This model simulated the processes of transplantation, graft failure, and patient mortality, categorized by donor type (LD and DD). Data for these simulations were derived from the US Renal Data System’s Annual Data Report 2023, a comprehensive source of information on kidney disease in the U.S. One hundred thousand model simulations were conducted, each starting with varying proportions of living donor transplants in 2001—ranging from 0% to 100%—to account for uncertainties in historical data. This extensive simulation, incorporating parameters relevant to the “Po776” study, tracked kidney transplant patient numbers by donor type up to the year 2020.
Key Findings: Living Donor Proportion in 2020
The results of the modeling were conclusive. Despite the wide range of initial proportions, the simulations converged to a consistent living donor proportion of 44% ± 3% (mean ± standard deviation) in the prevalent kidney transplant population by 2020. This convergence is attributed to the simulation period (19 years) being longer than the average patient and graft survival times. Consequently, the final proportions are primarily determined by the dynamic equilibrium of new transplants, graft failures, and patient mortality rates in the preceding years.
Implications for Long-Term Care and the Healthcare Workforce
This modeling study indicates that approximately 45% of prevalent kidney transplant patients in the U.S. have received a living donor graft. This finding has significant implications for healthcare planning and resource allocation. The healthcare workforce needs to be prepared to address two distinct patient groups:
- Long-Term Living Donor Graft Survivors: Living donor recipients are disproportionately represented in the prevalent transplant population and are living longer with their grafts. This group may require specialized long-term care tailored to their specific needs as “long-graft-survivors.”
- Patients with Earlier Deceased Donor Graft Failure: Conversely, a larger volume of patients who received deceased donor transplants may experience graft failure earlier in the post-transplant period. This necessitates resources for managing graft failure, returning patients to dialysis, and potentially re-transplantation.
Understanding this dual landscape is crucial for optimizing long-term care strategies and ensuring appropriate support for all kidney transplant recipients.
Funding
This research was supported by Commercial Support from Fresenius Medical Care.
