Examining utilization of kidneys as a function of procurement performance

Associations Among Circle-Based Kidney Allocation, Center Waiting Time, and Likelihood of Deceased-Donor Kidney Transplantation

RATIONALE & OBJECTIVE

The kidney allocation system (KAS250), using circle-based distribution, attempts to address geographic disparities through broader sharing of deceased-donor kidney allografts. This study evaluated the association between KAS250 and likelihood of deceased-donor kidney transplantation (DDKT) among wait-listed candidates, and whether the policy has differentially affected centers with shorter versus longer waiting time.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

160,941 candidates waitlisted at 176 transplant centers between March 2017 and March 2024.

EXPOSURE

KAS250 allocation policy.

OUTCOME

Rate of DDKT.

ANALYTICAL APPROACH

Multivariable Cox regression, modeling KAS250 as a time-dependent variable.

RESULTS

KAS250 was not independently associated with likelihood of DDKT overall (HR, 1.01 vs pre-KAS250 [95% CI, 0.97-1.04]). KAS250's association with likelihood of DDKT varied across centers from HR, 0.18 (DDKT less likely after KAS250), to HR, 17.12 (DDKT more likely) and varied even among neighboring centers. KAS250 was associated with decreased DDKT at 25.6% and increased DDKT at 18.2% of centers. Centers with previously long median waiting times (57+months) experienced increased likelihood of DDKT after KAS250 (HR, 1.20 [95% CI, 1.15-1.26]) whereas centers with previously short median waiting times (6-24 months; HR, 0.88 [95% CI, 0.84-0.92]) experienced decreased likelihood of DDKT.

LIMITATIONS

Retrospective study of allocation policy changes, confounded by multiple changes over the study time frame.

CONCLUSIONS

Association between KAS250 and DDKT varied across centers. For 1 in 4 centers, DDKT was less likely after KAS250 relative to pre-KAS250 trends. Candidates at centers with previously long waiting times experienced an increased likelihood of DDKT after KAS250. Thus, broader distribution of kidneys may be associated with improved equity in access to DDKT, but additional strategies may be needed to minimize disparities between centers.

PLAIN-LANGUAGE SUMMARY

This study examines how a recent policy change, KAS250, aimed at broadening the geographic sharing of deceased-donor kidneys, has impacted likelihood of kidney transplantation in the United States. Historically, kidney allocation occurred within local geographic boundaries, leading to unequal rates of transplantation across regions. KAS250, implemented in March 2021, replaced this system with a broader allocation radius of 250 miles around the donor hospital. Using national registry data, the study found that while there was no overall significant increase in the likelihood of transplantation nationally under KAS250, the policy's effect varied widely even among neighboring transplant centers. One quarter of centers experienced a decrease in the likelihood of DDKT after KAS250. In contrast, centers with longer pre-KAS250 waiting times experienced an increased likelihood of transplantation, suggesting some success in reducing disparities between centers. Ongoing surveillance will be needed to ensure KAS250 is meeting the intended aim of more equitably distributing organs.

Assessing LSAM's ability to account for changes in organ donation and transplant center behavior

The Liver Simulated Allocation Model (LSAM) is used to evaluate proposed organ allocation policies. Although LSAM has been shown to predict the directionality of changes in transplants and nonused organs, the magnitude is often overestimated. One reason is that policymakers and researchers using LSAM assume static levels of organ donation and center behavior because of challenges with predicting future behavior. We sought to assess the ability of LSAM to account for changes in organ donation and organ acceptance behavior using LSAM 2019. We ran 1-year simulations with the default model and then ran simulations changing donor arrival rates (ie, organ donation) and center acceptance behavior. Changing the donor arrival rate was associated with a progressive simulated increase in transplants, with corresponding simulated decreases in waitlist deaths. Changing parameters related to organ acceptance was associated with important changes in transplants, nonused organs, and waitlist deaths in the expected direction in data simulations, although to a much lesser degree than changing the donor arrival rate. Increasing the donor arrival rate was associated with a marked decrease in the travel distance of donor livers in simulations. In conclusion, we demonstrate that LSAM can account for changes in organ donation and organ acceptance in a manner aligned with historical precedent that can inform future policy analyses. As Scientific Registry of Transplant Recipients develops new simulation programs, the importance of considering changes in donation and center practice is critical to accurately estimate the impact of new allocation policies.

High-Functioning Deceased Donor Kidney Transplant System Characteristics: The British Columbia Experience With an Opt-In System

Rationale & Objective

A high level of cooperation between organ procurement organizations and transplant programs may help maximize use of deceased donor kidneys. The practices that are essential for a high functioning organ donation and transplant system remain uncertain. We sought to report metrics of organ donation and transplant performance in British Columbia, Canada, and to assess the association of specific policies and practices that contribute to the system's performance.

Study Design

A retrospective observational study.

Setting & Participants

Referred deceased organ donors in British Columbia were used in the study from January 1, 2016, to December 31 2019.

Exposures

Provincial, organ procurement organization, and center level policies were implemented to improve donor referral and organ utilization.

Outcomes

Assessment of donor and kidney utilization along steps of the critical pathway for organ donation.

Analytical Approach

Deceased donors were classified according to the critical pathway for organ donation and key donation and transplant metrics were identified.

Results

There were 1,948 possible donors referred. Of 1,948, 754 (39%) were potential donors. Of 754 potential donors, 587 (78%) were consented donors. Of 587 consented donors, 480 (82%) were eligible kidney donors. Of 480 eligible kidney donors, 438 (91%) were actual kidney donors. And of 438 actual kidney donors, 432 (99%) were utilized kidney donors. One-year all-cause allograft survival was 95%. Practices implemented to improve the system's performance included hospital donor coordinators, early communication between the organ procurement organization and transplant nephrologists, dedicated organ recovery and implant surgeons, aged-based kidney allocation, and hospital admission of recipients before kidney recovery.

Limitations

Assignment of causality between individual policies and practices and organ donation and utilization is limited in this observational study.

Conclusions

In British Columbia, consent for donation, utilization of donated kidneys, and transplant survival are exceptionally high, suggesting the importance of an integrated deceased donor and kidney transplant service.

What is visible is fixable: Visual dashboards for multi-domain assessment of organ procurement organization performance

With stakeholder focus on the United States organ procurement system, there is a need for tools that permit comparative assessment of organ procurement providers. We developed a public-facing dashboard for organ procurement organizations (OPOs), using data from multiple sources, to create an online, readily accessible visualization of OPO practice conditions and performance for the period 2010-2020. With this tool, OPOs can be compared on the CMS metric of donors procured per 100 donation-consistent deaths, as well as donation after circulatory death procurement, procurement of older and minority patient populations, procurement in smaller hospitals, and procurement of patients without a significant drug history. Patterns of higher performance were identified, and 74% of differences in overall donor procurement rates could be explained using model variables. Procurement differences were affected to a greater and more reproducible degree by OPO performance among Black and non-White patient populations, as well as in smaller hospitals, than by donation service area characteristics. Dashboards such as ours support OPOs and stakeholders in quality improvement actions, through leveraging benchmarked performance data among organ procurement clinical providers.

Population Characteristics and Organ Procurement Organization Performance Metrics

Importance

In 2020, the Centers for Medicare & Medicaid Services (CMS) issued a final rule updating the Organ Procurement Organization (OPO) Conditions for Coverage. This rule evaluates OPO performance based on an unadjusted donation rate and an age-adjusted transplant rate; however, neither considers other underlying population differences.

Objective

To evaluate whether adjusting for age and/or area deprivation index yields the same tier assignments as the cause, age, and location consistent (CALC) tier used by CMS.

Design, Setting, and Participants

This retrospective cross-sectional study examined the performance of 58 OPOs from 2018 to 2020 across the entire US. A total of 12 041 778 death records were examined from the 2017 to 2020 National Center for Health Statistics' Restricted Vital Statistics Detailed Multiple Cause of Death files; 399 530 of these met the definition of potential deceased donor. Information about 42 572 solid organ donors from the Scientific Registry of Transplant Recipients was also used. Statistical analysis was performed from January 2017 to December 2020.

Exposure

Area deprivation of donation service areas and age of potential donors.

Main Outcome and Measures

OPO performance as measured by donation and transplant rates.

Results

A total of 399 530 potential deceased donors and 42 572 actual solid donor organs were assigned to 1 of 58 OPOs. Age and ADI adjustment resulted in 19.0% (11 of 58) to 31.0% (18 of 58) reclassification of tier ratings for the OPOs, with 46.6% of OPOs (27 of 58) changing tier ranking at least once during the 3-year period. Between 6.9% (4 of 58) and 12.1% (7 of 58) moved into tier 1 and up to 8.6% (5 of 58) moved into tier 3.

Conclusions and Relevance

This cross-sectional study of population characteristics and OPO performance metrics found that adjusting for area deprivation and age significantly changed OPO measured performance and tier classifications. These findings suggest that underlying population characteristics may alter processes of care and characterize donation and transplant rates independent of OPO performance. Risk adjustment accounting for population characteristics warrants consideration in prospective policy and further evaluation of quality metrics.

Temporal changes in the utilization of kidneys from hepatitis C virus-infected donors in the United States

Despite data demonstrating increased utilization of kidneys from hepatitis C virus (HCV)-infected donors, it is unknown whether this is due to an increase in the donor pool or improved organ utilization and whether data from early pilot trials were temporally associated with changes in organ utilization. We used data from the Organ Procurement and Transplantation Network on all kidney donors and recipients of kidney transplants from January 1, 2015, to March 31, 2022 to evaluate temporal changes using joinpoint regression. Our primary analyses compared donors on the basis of their HCV viremic status (HCV-infected vs HCV-negative). Kidney utilization changes were assessed by evaluating the kidney discard rate and kidneys transplanted per donor. A total of 81 833 kidney donors were included in the analysis. There was a statistically significant decrease in the discard rates of HCV-infected kidney donors from 40% to just over 20% over a 1-year period, with a concurrent increase in kidneys transplanted per donor. This increased utilization occurred in tandem with the publication of pilot trials involving HCV-infected kidney donors in HCV-negative recipients rather than an increase in the donor pool. Ongoing clinical trials may strengthen existing data, which could result in this practice becoming the accepted standard of care.

Information design to support growth, quality, and equity of the US transplant system

The Organ Procurement and Transplantation Network, an arm of the Health Resources and Services Administration, has a contract with the United Network for Organ Sharing since 1986 to provide central oversight of organ donation and transplants in the United States. The United Network for Organ Sharing has recently come under scrutiny, prompting a review by the National Academies of Sciences, Engineering, and Medicine as summarized in its recent report and also by the US Senate Finance Committee. The national news services have opined about organ donation ethics, access to transplantation particularly for medically underserved populations, and management of organ transplantation data. These critiques raise important concerns that deserve our best response as a transplant community. Broadly, we suggest that the data management approach of the Organ Procurement and Transplantation Network be replaced with a patient-centric omnichannel network in which all donor and recipient data exist in a single longitudinal record that can be used by all applications. A more comprehensive and standardized approach to donor data collection would drive quality improvement across organ procurement organizations and help address inequities in transplantation. Finally, a substantial increase in organ donation would be prompted by considering organ donors as a public health resource, meriting transparent publicly available data collection with respect to organ donor referral, screening, and management.

Progress towards solving the donor organ shortage

Organ transplantation is not an independent risk factor for death from COVID-19 when data are adequately adjusted for other comorbidities³.

The performance of US Organ Procurement Organizations is not driven by the organ acceptance and utilization rates of local transplant centres⁵; policy changes could increase organ recovery, allocation and utilization.

Successful transplantation of genetically modified pig kidneys into recently deceased humans is encouraging for the potential future of clinical xenotransplantation^7,8.