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Background: Due to the excess demand for deceased donor kidneys, risk quantification scores were developed to help with kidney allocation. The kidney donor risk index (KDRI) is used in the US kidney allocation system. We currently use expanded criteria (UNOS) and Remuzzi scoring for allocation of deceased donor kidneys and the utility of KDRI in our cohort is unknown. We aim to evaluate the association of KDRI with relation to 5 year graft and patient survival. Methods: Retrospective cohort study of 225 adults who received a deceased donor kidney transplant between 1 Nov 2005 and 30 June 2014. Patients were followed up for 5 years or until graft-loss or death. Implant biopsies of donor kidneys were done and the Remuzzi score was calculated. Results: The median age was 48 (IQR 42, 52.5) years and 50.7% were male. KDRI-USA, KDRI-THAI, and KDRI-AUST were found to have no correlation with 5 year graft survival. Donor characteristics which define an expanded criteria donor kidney, not associated with 5 year graft survival are age (p = 0.58), terminal creatinine (p = 0.71) and history of hypertension (p = 0.35). Donor cerebrovascular accident (CVA) as a cause of death (p = 0.02) and Remuzzi score were associated with graft survival at 5 years, with 75.8% with Remuzzi score ≤ 3 vs 24.2% with Remuzzi score of > 3 achieving 5 year graft survival (p = 0.001). Conclusion: The association of KDRI with graft and patient survival was not demonstrated in our cohort. Histological assessment of the transplant kidney remains the best method of predicting long-term survival during donor selection. [ABSTRACT FROM AUTHOR]

Background Proper assessment of donor organ quality is crucial for optimal kidney allocation and best long-term outcomes. The aim of this study was to analyze the association between the Kidney Donor Risk Index (KDRI) and histological parameters in early post-transplant graft biopsy in a Polish cohort of kidney transplant recipients. Methods In 418 consecutive kidney transplant recipients, a histological evaluation of very early [at median 11 (9–13) post-transplant day] protocol core needle biopsy was performed and analyzed according to the Banff classification. Subjects were divided into quartiles of the KDRI value. Kidney graft function, patient and graft survival were also analyzed over a median follow-up period of 44 (26–56) months. Results There was a significant trend toward greater intensity of chronic histology changes along the KDRI quartiles (χ2 = 20.8; P  < .001), including interstitial fibrosis, tubular atrophy, mesangial matrix increase and arteriolar hyalinosis. Stepwise multivariate regression analysis revealed that only higher KDRI value independently increased the severity of chronic graft injury (rpartial = 0.340, P  < .001). KDRI values were valuable in the determination of both early and long-term graft function. Conclusion The KDRI values correlate with chronic histological changes found in early post-implantation kidney biopsies and can also be helpful in the prediction of graft outcome. [ABSTRACT FROM AUTHOR]

Kidney transplantation offers better mortality and quality of life outcomes to patients with end-stage renal failure compared to dialysis. Specifically, living donor kidney transplantation is the best treatment for end-stage renal disease, since it offers the greatest survival benefit compared to deceased donor kidney transplant or dialysis. However, not all patients from all racial/ethnic backgrounds enjoy these benefits. While black and Hispanic patients bear the predominant disease burden within the United States, they represent less than half of all kidney transplants in the country. Other factors such as cultural barriers that proliferate myths about transplant, financial costs that impede altruistic donation, and even biological predispositions create a complex maze and can also perpetuate care inaccessibility. Therefore, blanket efforts to increase the overall donation pool may not extend access to vulnerable populations, who may require more targeted attention and interventions. This review uses US kidney transplantation data to substantiate accessibility differences amongst racial minorities as well as provides examples of successful institutional and national systemic level changes that have improved transplantation outcomes for all. [ABSTRACT FROM AUTHOR]

Background: The UK kidney offering scheme introduced a kidney donor risk index (UK-KDRI) to improve the utility of deceased-donor kidney allocations. The UK-KDRI was derived using adult donor and recipient data. We assessed this in a paediatric cohort from the UK transplant registry. Methods: We performed Cox survival analysis on first kidney-only deceased brain-dead transplants in paediatric (<18 years) recipients from 2000-2014. The primary outcome was death-censored allograft survival >30 days posttransplant. The main study variable was UK-KDRI derived from seven donor risk-factors, categorised into four groups (D1-low risk, D2, D3 and D4-highest risk). Follow-up ended on 31-December-2021. Results: 319/908 patients experienced transplant loss with rejection as the main cause (55%). The majority of paediatric patients received donors from D1 donors (64%). There was an increase in D2-4 donors during the study period, whilst the level of HLA mismatching improved. The KDRI was not associated with allograft failure. In multi-variate analysis, increasing recipient age [adjusted HR and 95%CI: 1.05(1.03-1.08) per-year, p<0.001], recipient minority ethnic group [1.28(1.01-1.63), p<0.05), dialysis before transplant [1.38(1.04-1.81), p<0.005], donor height [0.99 (0.98-1.00) per centimetre, p<0.05] and level of HLA mismatch [Level 3: 1.92(1.19-3.11); Level 4: 2.40(1.26-4.58) versus Level 1, p<0.01] were associated with worse outcomes. Patients with Level 1 and 2 HLA mismatches (0 DR +0/1 B mismatch) had median graft survival >17 years regardless of UK-KDRI groups. Increasing donor age was marginally associated with worse allograft survival [1.01 (1.00-1.01) per year, p=0.05]. Summary: Adult donor risk scores were not associated with long-term allograft survival in paediatric patients. The level of HLA mismatch had the most profound effect on survival. Risk models based on adult data alone may not have the same validity for paediatric patients and therefore all age-groups should be included in future risk prediction models. [ABSTRACT FROM AUTHOR]

Managing organ transplant networks is a complex task. It intertwines between locating the organ procurement and distribution organization (OPDO) (long-term decision) and allocating organs to the suitable destination (short-term decision). The literature lacks deliberation on the effect of those long-term decisions on short-term ones under the influence of clinical and non-clinical factors. This paper addresses this gap using a k-sum model for locational choice, and a discrete simulation approach for the allocation procedure for a real-life case study from a developing economy perspective. The study explores the trade-off between efficiency (distance-centric models) and equity (the result of time-centric allocation models). Our analysis of the efficiency of locational models and equity of the allocation policies reveal strong inter-dependence of both these decisions, a significant finding of this research. These findings offer an integrated model for high-level decision-makers, which can be used during the locational planning stage and provide input to design standard operating procedures for transplantation schemes. [ABSTRACT FROM AUTHOR]

Changes in kidney allocation coupled with the COVID‐19 pandemic have placed tremendous strain on current systems of organ distribution and logistics. Although the number of deceased donors continues to rise annually in the United States, the proportion of marginal deceased donors (MDDs) is disproportionately growing. Cold ischemia times and kidney discard rates are rising in part related to inadequate planning, resources, and shortages. Complexity in kidney allocation and distribution has contributed to this dilemma. Logistical issues and the ability to reperfuse the kidney within acceptable time constraints increasingly determine clinical decision‐making for organ acceptance. We have a good understanding of the phenotype of "hard to place" MDD kidneys, yet continue to promote a "one size fits all" approach to organ allocation. Allocation and transportation systems need to be agile, mobile, and flexible in order to accommodate the expanding numbers of MDD organs. By identifying "hard to place" MDD kidneys early and implementing a "fast‐track" or open offer policy to expedite placement, the utilization rate of MDDs would improve dramatically. Organ allocation and distribution based on location, motivation, and innovation must lead the way. In the absence of change, we are sacrificing utility for futility and discard rates will continue to escalate. [ABSTRACT FROM AUTHOR]

Abstract Background Kidney transplantation is the best treatment for people with End-Stage Renal Disease (ESRD). Kidney allocation is the most important challenge in kidney transplantation process. In this study, a Fuzzy Inference System (FIS) was developed to rank the patients based on kidney allocation factors. The main objective was to develop an expert system, which would mimic the expert intuitive thinking and decision-making process in the face of the complexity of kidney allocation. Methods In the first stage, kidney allocation factors were identified. Next, Intuitionistic Fuzzy Analytic Hierarchy Process (IF-AHP) has been used to weigh them. The purpose of this stage is to develop a point scoring system for kidney allocation. Fuzzy if-then rules were extracted from the United Network for Organ Sharing (UNOS) dataset by constructing the decision tree, in the second stage. Then, a Multi-Input Single-Output (MISO) Mamdani fuzzy inference system was developed for ranking the patients on the waiting list. Results To evaluate the performance of the developed Fuzzy Inference System for Kidney Allocation (FISKA), it was compared with a point scoring system and a filtering system as two common approaches for kidney allocation. The results indicated that FISKA is more acceptable to the experts than the mentioned common methods. Conclusion Given the scarcity of donated kidneys and the importance of optimal use of existing kidneys, FISKA can be very useful for improving kidney allocation systems. Countries that decide to change or improve the kidney allocation system can simply use the proposed model. Furthermore, this model is applicable to other organs, including lung, liver, and heart.

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 sought to evaluate the association between KAS250 and likelihood of deceased-donor kidney transplantation (DDKT) among waitlisted candidates, and whether the policy has differentially affected centers with shorter vs. longer waiting time., Study Design: Retrospective cohort study., Setting: & Participants: 160,941 candidates waitlisted at 176 transplant centers between 3/2017-3/2024., 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% C.I. 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% C.I. 1.15-1.26), whereas centers with previously short median waiting times (6-24mo.; HR=0.88, 0.84-0.92) experienced decreased likelihood of DDKT., Limitations: Retrospective study of allocation policy changes, confounded by multiple changes over the study timeframe., Conclusion: Association between KAS250 and DDKT varied across centers. For one-in-four centers, DDKT was less likely after KAS250 relative to pre-KAS250 trends. Candidates at centers with previously long waiting times experienced 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., (Copyright © 2024. Published by Elsevier Inc.)

Rationale & Objective: The US Kidney Allocation System (KAS) prioritizes candidates with a≤20% estimated posttransplant survival (EPTS) to receive high-longevity kidneys defined by a≤20% Kidney Donor Profile Index (KDPI). Use of EPTS in the KAS deprioritizes candidates with older age, diabetes, and longer dialysis durations. We assessed whether this use also disadvantages race and ethnicity minority candidates, who are younger but more likely to have diabetes and longer durations of kidney failure requiring dialysis., Study Design: Observational cohort study., Setting & Participants: Adult candidates for and recipients of kidney transplantation represented in the Scientific Registry of Transplant Recipients from January 2015 through December 2020., Exposure: Race and ethnicity., Outcome: Age-adjusted assignment to≤20% EPTS, transplantation of a≤20% KDPI kidney, and posttransplant survival in longevity-matched recipients by race and ethnicity., Analytic Approach: Multivariable logistic regression, Fine-Gray competing risks survival analysis, and Kaplan-Meier and Cox proportional hazards methods., Results: The cohort included 199,444 candidates (7% Asian, 29% Black, 19% Hispanic or Latino, and 43% White) listed for deceased donor kidney transplantation. Non-White candidates had significantly higher rates of diabetes, longer dialysis duration, and were younger than White candidates. Adjusted for age, Asian, Black, and Hispanic or Latino candidates had significantly lower odds of having a ETPS score of≤20% (odds ratio, 0.86 [95% CI, 0.81-0.91], 0.52 [95% CI, 0.50-0.54], and 0.49 [95% CI, 0.47-0.51]), and were less likely to receive a≤20% KDPI kidney (sub-hazard ratio, 0.70 [0.66-0.75], 0.89 [0.87-0.92], and 0.73 [0.71-0.76]) compared with White candidates. Among recipients with≤20% EPTS scores transplanted with a≤20% KDPI deceased donor kidney, Asian and Hispanic recipients had lower posttransplant mortality (HR, 0.45 [0.27-0.77] and 0.63 [0.47-0.86], respectively) and Black recipients had higher but not statistically significant posttransplant mortality (HR, 1.22 [0.99-1.52]) compared with White recipients., Limitations: Provider reported race and ethnicity data and 5-year post transplant follow-up period., Conclusions: The US kidney allocation system is less likely to identify race and ethnicity minority candidates as having a≤20% EPTS score, which triggers allocation of high-longevity deceased donor kidneys. These findings should inform the Organ Procurement and Transplant Network about how to remedy the race and ethnicity disparities introduced through KAS's current approach of allocating allografts with longer predicted longevity to recipients with longer estimated posttransplant survival., Plain-Language Summary: The US Kidney Allocation System prioritizes giving high-longevity, high-quality kidneys to patients on the waiting list who have a high estimated posttransplant survival (EPTS) score. EPTS is calculated based on the patient's age, whether the patient has diabetes, whether the patient has a history of organ transplantation, and the number of years spent on dialysis. Our analyses show that Asian, Black or African American, and Hispanic or Latino patients were less likely to receive high-longevity kidneys compared with White patients, despite having similar or better posttransplant survival outcomes., (Copyright © 2024 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Organs for transplantation are a scarce resource. Markedly, the transplant community's primary challenge is the stark disparity between the number of patients awaiting deceased donor organ transplants and the rate at which organs become available. However, the allocation of a limited number of organs poses another constant challenge: maintaining an equilibrium between renal transplant utility and equity, that is, striking a balance between the utilitarian argument of medical efficiency and the principle of equity. In this comprehensive overview, the authors delve into the challenge of maintaining an acceptable balance between equity and efficiency and elaborate on some of the factors that might inform a decisionmaker's evaluation of the extent to which a given allocation scheme is efficient or equitable. [ABSTRACT FROM AUTHOR]

Introduction: Differences in transplant characteristics limit the application of kidney donor profile index (KDPI) and estimated post‐transplant survival (EPTS) models developed in Western countries to Asian populations. Methods: We analyzed data of the Thai Transplant Registry and the Thai Red Cross Society on 2558 DDKTs performed between 2001 and 2014. Thai KDPI and EPTS models were developed using Cox regression, and validation against the US models. Results: Thai KDPI was developed based on seven donor factors: age, height, best estimated glomerular filtration rate, diabetes mellitus, hypertension, cerebrovascular accident, and adrenaline infusion. The Thai and US donor risk index had comparable predictive abilities for transplant survival (C‐statistics.5871 vs..5548; P =.429). KTs from donors with a US KDPI > 70% demonstrated significantly worse 5‐year transplant survival. The Thai EPTS model was developed from four recipient factors: age, body weight, diabetes mellitus, and hepatitis C infection. The C‐statistics of the Thai and US EPTS models were comparable (.5924 vs..6039; P =.360). A US EPTS > 70% was revealed in only 2.5% of our cohort. Conclusions: The first simplified KDPI and EPTS models for an Asian population were developed. Our models are available at www.thai‐kdpi‐epts.org. [ABSTRACT FROM AUTHOR]

Background: Kidney transplantation is the best treatment for people with End-Stage Renal Disease (ESRD). Kidney allocation is the most important challenge in kidney transplantation process. In this study, a Fuzzy Inference System (FIS) was developed to rank the patients based on kidney allocation factors. The main objective was to develop an expert system, which would mimic the expert intuitive thinking and decision-making process in the face of the complexity of kidney allocation.Methods: In the first stage, kidney allocation factors were identified. Next, Intuitionistic Fuzzy Analytic Hierarchy Process (IF-AHP) has been used to weigh them. The purpose of this stage is to develop a point scoring system for kidney allocation. Fuzzy if-then rules were extracted from the United Network for Organ Sharing (UNOS) dataset by constructing the decision tree, in the second stage. Then, a Multi-Input Single-Output (MISO) Mamdani fuzzy inference system was developed for ranking the patients on the waiting list.Results: To evaluate the performance of the developed Fuzzy Inference System for Kidney Allocation (FISKA), it was compared with a point scoring system and a filtering system as two common approaches for kidney allocation. The results indicated that FISKA is more acceptable to the experts than the mentioned common methods.Conclusion: Given the scarcity of donated kidneys and the importance of optimal use of existing kidneys, FISKA can be very useful for improving kidney allocation systems. Countries that decide to change or improve the kidney allocation system can simply use the proposed model. Furthermore, this model is applicable to other organs, including lung, liver, and heart. [ABSTRACT FROM AUTHOR]

Abstract Background Matching survival of a donor kidney with that of the recipient (longevity matching), is used in some kidney allocation systems to maximize graft-life years. It is not part of the allocation algorithm for Australia. Given the growing evidence of survival benefit due to longevity matching based allocation algorithms, development of a similar kidney allocation system for Australia is currently underway. The aim of this research is to estimate the impact that changes to costs and health outcomes arising from ‘longevity matching’ on the Australian healthcare system. Methods A decision analytic model to estimate cost-effectiveness was developed using a Markov process. Four plausible competing allocation options were compared to the current kidney allocation practice. Models were simulated in one-year cycles for a 20-year time horizon, with transitions through distinct health states relevant to the kidney recipient. Willingness to pay was considered as AUD 28000. Results Base case analysis indicated that allocating the worst 20% of Kidney Donor Risk Index (KDRI) donor kidneys to the worst 20% of estimated post-transplant survival (EPTS) recipients (option 2) and allocating the oldest 25% of donor kidneys to the oldest 25% of recipients are both cost saving and more effective compared to the current Australian allocation practice. Option 2, returned the lowest costs, greatest health benefits and largest gain to net monetary benefits (NMB). Allocating the best 20% of KDRI donor kidneys to the best 20% of EPTS recipients had the lowest expected incremental NMB. Conclusion Of the four longevity-based kidney allocation practices considered, transplanting the lowest quality kidneys to the worst kidney recipients (option 2), was estimated to return the best value for money for the Australian health system.

Since 2021, the Organ Procurement and Transplantation Network has reported a nearly 10-fold rise in out-of-sequence (OOS) kidney allocation, generating concern and halting development of continuous distribution policies. We report contemporary (2022-2023) practice patterns in OOS allocation using Organ Procurement and Transplantation Network data. We examined in sequence vs OOS donors with multivariable logistic regression and skipped vs OOS-accepting recipients with conditional logistic regression. Nearly 20% of kidney placements were OOS, varying from 0% to 43% acsoss organ procurement organizations; the 5 highest OOS-organ procurement organizations accounted for 29% of all OOS. Of OOS kidneys, 33% were declined ≥100 times in the standard allocation sequence and 51% were declined by ≥10 centers before OOS allocation began; 4.5% were made without any in-sequence declines. Nearly, all OOS offers were open offers. OOS kidneys were more likely to be from female, Black, older, donation after cardiac death, hypertensive, diabetic, and elevated creatinine donors. Candidates receiving OOS kidneys were more likely female, Asian, and older than skipped candidates. Higher-volume centers and centers with more White, fewer Hispanic, and more educated waiting list patients underwent transplantation disproportionately with more OOS kidneys. These findings suggest that the current, highly variable, discretionary use of OOS might exacerbate disparities, yet the impact of OOS on organ utilization cannot be determined with data now collected., Competing Interests: Declaration of competing interest The authors of this manuscript have no conflicts of interest to disclose as described by the American Journal of Transplantation., (Copyright © 2024 American Society of Transplantation & American Society of Transplant Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: Previously, transplant centers in Turkey were free in selecting a potential recipient from their own local waiting list of deceased donor renal transplantation, and commonly patients with lower risk were selected. In May 2008, the Turkish Health Ministry issued a national cadaveric kidney allocation policy based on a pointing system. This system increased the equity but might have decreased the utility by elevating the risk of complications with possibly worse graft and patient survivals. We aimed to determine the short and medium-term effects of the new system on graft and patient survival. Methods: Forty-seven cadaveric renal transplant recipients who were transplanted before this system and 80 cadaveric renal transplant recipients who were transplanted under the new system were included. Short and medium-term transplant-related parameters were compared between the groups. Results: Patients transplanted after 2008 were older, had longer cold ischemia time, higher rates of delayed graft function, and early acute rejection. However, medium-term glomerular filtration rate, graft, and patient survivals were not different between patients transplanted before and after 2008. Conclusion: The new system in Turkey increased the opportunity for transplantation of previously disadvantageous patients and did not have a significant negative effect on medium-term renal functions. [ABSTRACT FROM AUTHOR]

The Birmingham H&I laboratory performed HLA typing on 456 potential deceased solid organ donors in the UK between 2014 and 2016. Accurate DPB1 typing is essential for determining HLA compatibility in transplantation, thus we report HLA‐DPB1 for potential deceased solid organ donors. To correctly interpret HLA typing data, laboratories must understand both international and local HLA allele frequencies. In this analysis, we determined HLA‐DPB1 allele and genotype frequencies for these 456 donors. HLA‐DPB1 diversity was evaluated against the common and well‐documented (CWD) alleles 2.0.0 catalogue, the European Federation for Immunogenetics (EFI) CWD catalogue and the common, intermediate and well‐documented (CIWD) 3.0.0 catalogue. Additionally, we determined which alleles are common in our local deceased donor population. We observed 27 HLA‐DPB1 alleles with DPB1*04:01 being the most frequently observed (allele frequency = 0.4342). All alleles detected locally were present in CIWD 3.0.0, however, DPB1*124:01 and *135:01 were not present in CWD 2.0.0 and DPB1*104:01 and *135:01 were not present in EFI CWD. Twenty of 27 DPB1 alleles identified were defined as locally common and also listed as common in CIWD 3.0.0 representing 62.5% of common alleles in the subset of CIWD 3.0.0 from individuals of a European geographic, ancestral or ethnic background. The alleles HLA‐DPB1*16:01 and *20:01 are locally common but not listed as common in EFI CWD and DPB1*104:01 is not listed as common in CWD 2.0.0 catalogue. Our analysis showed that the detected alleles and locally common alleles within our population were aligned with the CIWD 3.0.0 catalogue. [ABSTRACT FROM AUTHOR]

When allocating scarce resources such as organs or public housing units, the policy maker needs to carefully balance two conflicting objectives: maximizing the reward from matching and minimizing inequity across different types of candidates. We consider an implementable class of policies that ranks the candidates by the sum of their waiting score and matching score. Similar policies had been proposed for allocating deceased-donor kidneys to patients on the transplant waitlist. This article provides a modeling framework to characterize the waitlist system under this type of ranking policy. This framework allows the policy maker to predict and compare the allocation outcome under different ranking policies. When the efficiency and fairness measurements take certain forms, we derive a closed-form scoring formula that optimizes the outcome of the system in the long run. We consider a one-sided bipartite matching queueing system (OBMQ) with customers and resources of multiple types, where different customer-resource combinations can generate different rewards. Each resource is allocated on arrival to the customer with the highest score (or index), which is the sum of the customer's waiting score and matching score, so we call it an M+W index. We assume that the waiting score is an increasing function of a customer's waiting time and that the matching score is a function of both the customer's and the resource's types. Unmatched customers wait in the queue until being matched or will abandon the waitlist after a random duration. We study the fluid sample path in such a system, which provides an approximate to the system dynamics. We show that a fluid sample path can be computed over any finite horizon. We propose an efficient algorithm to check whether a steady state of the fluid sample path exists or not. When a steady state exists, the algorithm also computes one efficiently. We prove that there can be at most one steady state and that the fluid sample path will be attracted to the unique steady state under mild conditions. These results enable a policy designer to predict the behavior of an OBMQ when using an M+W index and to choose an indexing formula that optimizes a given set of performance metrics. We derive a closed-form index that optimizes the steady-state performance according to some well-known efficiency and fairness metrics. [ABSTRACT FROM AUTHOR]

Abstract Background Kidney allocation is a multi-criteria and complex decision-making problem, which should also consider ethical issues in addition to the medical aspects. Leading countries in this field use a point scoring system to allocate kidneys. Hence, the purpose of this study is to identify and weight the kidney allocation criteria considering the balance between utility and equity. Methods To do this, a new fuzzy hybrid approach is proposed, which consists of two steps: In the first step, Fuzzy Delphi Method (FDM) is used to identify the effective criteria in the kidney allocation algorithm. In the second step, Intuitionistic Fuzzy Analytic Hierarchy Process (IF-AHP) is employed to determine the weight of the criteria. Results The results showed that the highest weight belongs to “Medical emergency” criterion and the lowest weight to “5 HLA mismatches”, which is similar to Euro-transplant kidney allocation system (ETKAS). The developed method is evaluated in two steps. First, the proposed model is implemented using a real case study from the Iranian Kidney Allocation System. It was shown that the proposed model has the potential to improve allocation outcome. Second, the proposed model’s superiority to the current model is approved by the experts using the results display in the profile matrix. Finally, sensitivity analysis is performed to check the robustness of the proposed model. Conclusions This paper contributes to the kidney allocation literature by doing the following: (a) developing a comprehensive framework for identification and weightings of criteria for kidney allocation, (b) using, for the first time, the IF-AHP technique to consider hesitancy of decision makers and uncertainty in organ allocation, and (c) proposing an appropriate framework for the countries that intend to improve or modify their organ allocation system.

We analyzed in a cohort of 68,606 first deceased donor kidney transplantations reported to the Collaborative Transplant Study whether an epitope-based matching of donor-recipient pairs using the Predicted Indirectly ReCognizable HLA Epitopes algorithm (PIRCHE-II) is superior to currently applied HLA antigen matching. PIRCHE-II scores were calculated based on split antigen HLA-A, -B, -DRB1 typing and adjusted to the 0–6 range of HLA mismatches. PIRCHE-II scores correlated strongly with the number of HLA mismatches (Spearman ρ = 0.65, P < 0.001). In multivariable analyses both parameters were found to be significant predictors of 5-year death-censored graft loss with high prognostic power [hazard ratio (HR) per adjusted PIRCHE-II score = 1.102, per HLA mismatch = 1.095; z-value PIRCHE-II: 9.8, HLA: 11.2; P < 0.001 for both]. When PIRCHE-II scores and HLA mismatches were analyzed simultaneously, their predictive power decreased but remained significant (PIRCHE-II: P = 0.002; HLA: P < 0.001). Influence of PIRCHE-II was especially strong in presensitized and influence of HLA mismatches in non-sensitized recipients. If the level of HLA-incompatibility was low (0–3 mismatches), PIRCHE-II scores showed a low impact on graft survival (HR = 1.031) and PIRCHE-II matching did not have additional significant benefit (P = 0.10). However, if the level of HLA-incompatibility was high (4–6 mismatches), PIRCHE-II improved the positive impact of matching compared to applying the traditional HLA matching alone (HR = 1.097, P = 0.005). Our results suggest that the PIRCHE-II score is useful and can be included into kidney allocation algorithms in addition to HLA matching; however, at the resolution level of HLA typing that is currently used for allocation it cannot fully replace traditional HLA matching.

We analyzed in a cohort of 68,606 first deceased donor kidney transplantations reported to the Collaborative Transplant Study whether an epitope-based matching of donor-recipient pairs using the Predicted Indirectly ReCognizable HLA Epitopes algorithm (PIRCHE-II) is superior to currently applied HLA antigen matching. PIRCHE-II scores were calculated based on split antigen HLA-A, -B, -DRB1 typing and adjusted to the 0–6 range of HLA mismatches. PIRCHE-II scores correlated strongly with the number of HLA mismatches (Spearman ρ = 0.65, P < 0.001). In multivariable analyses both parameters were found to be significant predictors of 5-year death-censored graft loss with high prognostic power [hazard ratio (HR) per adjusted PIRCHE-II score = 1.102, per HLA mismatch = 1.095; z -value PIRCHE-II: 9.8, HLA: 11.2; P < 0.001 for both]. When PIRCHE-II scores and HLA mismatches were analyzed simultaneously, their predictive power decreased but remained significant (PIRCHE-II: P = 0.002; HLA: P < 0.001). Influence of PIRCHE-II was especially strong in presensitized and influence of HLA mismatches in non-sensitized recipients. If the level of HLA-incompatibility was low (0–3 mismatches), PIRCHE-II scores showed a low impact on graft survival (HR = 1.031) and PIRCHE-II matching did not have additional significant benefit (P = 0.10). However, if the level of HLA-incompatibility was high (4–6 mismatches), PIRCHE-II improved the positive impact of matching compared to applying the traditional HLA matching alone (HR = 1.097, P = 0.005). Our results suggest that the PIRCHE-II score is useful and can be included into kidney allocation algorithms in addition to HLA matching; however, at the resolution level of HLA typing that is currently used for allocation it cannot fully replace traditional HLA matching. [ABSTRACT FROM AUTHOR]

Problem definition: Deceased-donor kidney transplant candidates in the United States are ranked according to characteristics of both the donor and the recipient. We seek the ranking policy that optimizes the efficiency–equity tradeoff among all such policies, taking into account patients' strategic choices. Academic/practical relevance: Our approach considers a broad class of ranking policies, which provides approximations to the previously and currently used policies in practice. It also subsumes other policies proposed in the literature previously. As such, it facilitates a unified way of characterizing good policies. Methodology: We use a fluid model to approximate the transplant waitlist. Modeling patients as rational decision makers, we compute the resulting equilibria under a broad class of ranking policies, namely the achievable region. We then develop an algorithm that optimizes the system performance over the achievable region. Results: We show analytically that it suffices to restrict attention to priority scores that are affine in the patient's waiting time. We also show through a numerical study that the total quality-adjusted life-years can be increased substantially by allowing patient rankings to depend on the kidney quality. Last, we observe that there is almost no improvement if only the healthier patients are prioritized for certain kidney types. Managerial implications: Our results verify that ranking patients differently for kidneys of different quality can reduce the survival mismatch and the kidney wastage significantly. Consequently, the policy change in 2014, that implemented prioritizing the healthiest patients when allocating the highest 20% quality organs, is a step in the right direction. For further improvement, one may consider revising the new policy by also prioritizing the least healthy patients on the waitlist for the lowest-quality organs. [ABSTRACT FROM AUTHOR]

We evaluated the impact of human leukocyte antigen (HLA) disparity (immunogenicity; IM) on long-term kidney allograft survival. The IM was quantified based on physicochemical properties of the polymorphic linear donor/recipient HLA amino acids (the Cambridge algorithm) as a hydrophobic, electrostatic, amino acid mismatch scores (HMS\AMS\EMS) or eplet mismatch (EpMM) load. High-resolution HLA-A/B/DRB1/DQB1 types were imputed to calculate HMS for primary/re-transplant recipients of deceased donor transplants. The multiple Cox regression showed the association of HMS with graft survival and other confounders. The HMS integer 0–10 scale showed the most survival benefit between HMS 0 and 3. The Kaplan–Meier analysis showed that: the HMS=0 group had 18.1-year median graft survival, a 5-year benefit over HMS>0 group; HMS ≤ 3.0 had 16.7-year graft survival, a 3.8-year better than HMS>3.0 group; and, HMS ≤ 7.8 had 14.3-year grafts survival, a 1.8-year improvement over HMS>7.8 group. Stratification based on EMS, AMS or EpMM produced similar results. Additionally, the importance of HLA-DR with/without -DQ IM for graft survival was shown. In our simulation of 1,000 random donor/recipient pairs, 75% with HMS>3.0 were re-matched into HMS ≤ 3.0 and the remaining 25% into HMS≥7.8: after re-matching, the 13.5 years graft survival would increase to 16.3 years. This approach matches donors to recipients with low/medium IM donors thus preventing transplants with high IM donors.

Despite the shortage of kidneys for transplantation in the United States, approximately 18%‐20% of deceased donor kidneys are discarded each year. These discarded kidneys can offer a survival benefit to suitable patients. Revisions to the current kidney allocation policy may be needed to reduce deceased donor kidney discard. We surveyed transplant physicians and patients to assess their perceived acceptability of policy proposals to reduce the discard of deceased donor kidneys. Members of professional societies (AST, ASTS) and a patient organization (AAKP) were invited to complete the survey. Responses were obtained from 97 physicians and 107 patients. The majority of physicians (73.4%) and patients (73.8%) "somewhat" or "completely" accepted a policy for fast‐tracking kidneys at risk of discard. Physicians and patients also supported returning a proportion of waiting time to patients who accept KDPI >85 kidneys and experience graft failure within the first 12 months, with 36% of physicians and 50% of patients electing to return 100% of the waiting time. The majority of physicians (75%) "somewhat or completely" accepted a policy to skip less aggressive centers for KDPI 90 + offers. Physicians and patients provided insights into factors researchers, and policymakers should consider in the design and implementation of these policies. [ABSTRACT FROM AUTHOR]

We evaluated the impact of human leukocyte antigen (HLA) disparity (immunogenicity; IM) on long-term kidney allograft survival. The IM was quantified based on physicochemical properties of the polymorphic linear donor/recipient HLA amino acids (the Cambridge algorithm) as a hydrophobic, electrostatic, amino acid mismatch scores (HMS\AMS\EMS) or eplet mismatch (EpMM) load. High-resolution HLA-A/B/DRB1/DQB1 types were imputed to calculate HMS for primary/re-transplant recipients of deceased donor transplants. The multiple Cox regression showed the association of HMS with graft survival and other confounders. The HMS integer 0–10 scale showed the most survival benefit between HMS 0 and 3. The Kaplan–Meier analysis showed that: the HMS=0 group had 18.1-year median graft survival, a 5-year benefit over HMS>0 group; HMS ≤ 3.0 had 16.7-year graft survival, a 3.8-year better than HMS>3.0 group; and, HMS ≤ 7.8 had 14.3-year grafts survival, a 1.8-year improvement over HMS>7.8 group. Stratification based on EMS, AMS or EpMM produced similar results. Additionally, the importance of HLA-DR with/without -DQ IM for graft survival was shown. In our simulation of 1,000 random donor/recipient pairs, 75% with HMS>3.0 were re-matched into HMS ≤ 3.0 and the remaining 25% into HMS≥7.8: after re-matching, the 13.5 years graft survival would increase to 16.3 years. This approach matches donors to recipients with low/medium IM donors thus preventing transplants with high IM donors. [ABSTRACT FROM AUTHOR]

Background: Matching survival of a donor kidney with that of the recipient (longevity matching), is used in some kidney allocation systems to maximize graft-life years. It is not part of the allocation algorithm for Australia. Given the growing evidence of survival benefit due to longevity matching based allocation algorithms, development of a similar kidney allocation system for Australia is currently underway. The aim of this research is to estimate the impact that changes to costs and health outcomes arising from 'longevity matching' on the Australian healthcare system.Methods: A decision analytic model to estimate cost-effectiveness was developed using a Markov process. Four plausible competing allocation options were compared to the current kidney allocation practice. Models were simulated in one-year cycles for a 20-year time horizon, with transitions through distinct health states relevant to the kidney recipient. Willingness to pay was considered as AUD 28000.Results: Base case analysis indicated that allocating the worst 20% of Kidney Donor Risk Index (KDRI) donor kidneys to the worst 20% of estimated post-transplant survival (EPTS) recipients (option 2) and allocating the oldest 25% of donor kidneys to the oldest 25% of recipients are both cost saving and more effective compared to the current Australian allocation practice. Option 2, returned the lowest costs, greatest health benefits and largest gain to net monetary benefits (NMB). Allocating the best 20% of KDRI donor kidneys to the best 20% of EPTS recipients had the lowest expected incremental NMB.Conclusion: Of the four longevity-based kidney allocation practices considered, transplanting the lowest quality kidneys to the worst kidney recipients (option 2), was estimated to return the best value for money for the Australian health system. [ABSTRACT FROM AUTHOR]

Background The US Kidney Donor Risk Index (KDRI) and the UK KDRI were developed to estimate the risk of graft failure following kidney transplantation. Neither score has been validated in the Australian and New Zealand (ANZ) population. Methods Using data from the Australia and New Zealand Organ Donor (ANZOD) and Dialysis and Transplant (ANZDATA) Registries, we included all adult deceased donor kidney-only transplants performed in ANZ from 2005 to 2016 (n  = 6405). The KDRI was calculated using both the US donor-only and UK formulae. Three Cox models were constructed (Model 1: KDRI only; Model 2: Model 1 + transplant characteristics; Model 3: Model 2 + recipient characteristics) and compared using Harrell's C-statistics for the outcomes of death-censored graft survival and overall graft survival. Results Both scores were strongly associated with death-censored and overall graft survival (P < 0.0001 in all models). In the KDRI-only models, discrimination of death-censored graft survival was moderately good with C-statistics of 0.63 and 0.59 for the US and UK scores, respectively. Adjusting for transplant characteristics resulted in marginal improvements of the US KDRI to 0.65 and the UK KDRI to 0.63. The addition of recipient characteristics again resulted in marginal improvements of the US KDRI to 0.70 and the UK KDRI to 0.68. Similar trends were seen for the discrimination of overall graft survival. Conclusions The US and UK KDRI scores were moderately good at discriminating death-censored and overall graft survival in the ANZ population, with the US score performing slightly better in all models. [ABSTRACT FROM AUTHOR]

The demand for kidney transplantation continues to exceed the availability of deceased donor kidneys. Balancing the overarching principles of the optimal use of (utility) and equal access to (equity) this scarce resource requires a sophisticated allocation system. This review will examine how various factors are addressed in allocation systems around the world to strike a balance between utility and equity. SUMMARY AT A GLANCE: This paper summarizes organ allocation for deceased donor kidneys across the globe. It presents a contemporary view of a fairly fast moving field relevant to any nephrologist caring for patients with end stage renal disease. [ABSTRACT FROM AUTHOR]

Allocation of scarce heterogeneous life-saving goods confronts society with profound challenges that are analytically complex and morally laden. Deceased-donor kidneys for transplant are heterogeneous in terms of relational and intrinsic quality. In 2014, the Organ Procurement and Transplantation Network implemented a new allocation system that more explicitly takes account of intrinsic quality. We trace the evolution of the new allocation system with particular attention to the role of evidence and the ways that concerns about equity were solicited, assessed, and taken into account in modifying the original proposal. These deliberations show the potential for stakeholder rulemaking to integrate evidence and values. [ABSTRACT FROM AUTHOR]

Given the perennial imbalance and chronic scarcity between the demand for and supply of available organs, organ allocation is one of the most critical decisions in the management of organ transplantation networks. Organ allocation systems undergo rapid revisions for the sake of improved outcomes in terms of both equity and medical efficiency. This paper presents a Data Envelopment Analysis (DEA)-based model to evaluate the efficiency of possible patient-organ pairs for kidney allocation in order to enhance the fitness of organ allocation under inherent uncertainty in such problem. Eligible patient-kidney pairs are regarded as decision making units (DMUs) in a Credibility-based Fuzzy Common Weights DEA (CFCWDEA) approach and are ranked based on efficiency scores. Using a common set of weights for all DMUs ensures a high degree of fairness in the assessment and ranking of DMUs. The proposed model is also the first allocation method capable of coping with the vague and intervallic medical and nonmedical allocation factors by the aid of fuzzy programming. Verification and validation of the proposed approach are performed in two steps using a real case study from the Iranian kidney allocation system. First, the superiority of the proposed deterministic model in enhancing allocation outcomes is demonstrated and analyzed. Second, the applicability of the proposed fuzzy DEA method is demonstrated using a series of data realizations for different credibility levels. [ABSTRACT FROM AUTHOR]

Kidney transplantation offers better mortality and quality of life outcomes to patients with end-stage renal failure compared to dialysis. Specifically, living donor kidney transplantation is the best treatment for end-stage renal disease, since it offers the greatest survival benefit compared to deceased donor kidney transplant or dialysis. However, not all patients from all racial/ethnic backgrounds enjoy these benefits. While black and Hispanic patients bear the predominant disease burden within the United States, they represent less than half of all kidney transplants in the country. Other factors such as cultural barriers that proliferate myths about transplant, financial costs that impede altruistic donation, and even biological predispositions create a complex maze and can also perpetuate care inaccessibility. Therefore, blanket efforts to increase the overall donation pool may not extend access to vulnerable populations, who may require more targeted attention and interventions. This review uses US kidney transplantation data to substantiate accessibility differences amongst racial minorities as well as provides examples of successful institutional and national systemic level changes that have improved transplantation outcomes for all., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Zhang and Mathur.)

Background Recently, transplant societies have had to change their allocation policies to counter global organ shortages. However, strategies differ significantly and long-term outcomes and cross-regional applicability remain to be evaluated. Methods Therefore, we retrospectively analysed the Kidney Donor Profile Index (KDPI) of 987 adult kidney transplants at our centre using data from the Organ Procurement and Transplantation Network (OPTN) as a reference. Results In our cohort, the median KDPI was 66%, with a higher proportion of >85% KDPI kidneys compared with the US cohort (32.3% versus 9.2%). Among elderly patients (≥65 years of age), 62% received >95% KDPI kidneys, which were primarily allocated within the Eurotransplant Senior Program (ESP). After 10 years, the rate of death-censored graft survival was 70.5%. Recipients of >85% KDPI kidneys were significantly older, demonstrating higher mortality, poorer graft survival and lower estimated glomerular filtration rate. Patients receiving ≥99% KDPI kidneys had a satisfactory 5-year death-censored graft survival (72.9%). The 5-year survival rate of patients living with a functioning graft exceeded the matched OPTN data in the whole KDPI range, despite a higher proportion of elderly recipients. Multivariate analysis revealed KDPI as an independent risk factor for graft loss (hazard ratio 1.14/10%, P < 0.001), although C-statistics of 0.62 indicated limited discriminative ability for individuals. Conclusion The analysis demonstrated KDPI as a potentially useful tool for donor quality assessment in a European cohort. Most importantly, our analysis revealed acceptable outcomes even for very high KDPI kidneys. [ABSTRACT FROM AUTHOR]

Nonaccepted kidneys grafts enter the rescue allocation ( RA) process to avoid discards. In December 2013, recipient oriented extended allocation ( REAL) was introduced to improve transparency. The aim of this study was to evaluate the influence of REAL on recipients′ selection and graft function compared to the formerly existing RA as well as to identify factors that influence graft outcome. Therefore, a multicenter study of 10 transplant centers in the same region in Germany was performed. All transplantations after RA or REAL from December 1, 2012, until December 31, 2014, with a follow-up time until December 31, 2015 were analyzed. 113 of 941 kidney transplantations were performed after RA or REAL (12%). With REAL, the number of refusals before transplantation had increased (12 ± 7.1 vs. 8.6 ± 8.6, P = 0.036), and cold ischemia time has decreased (13.6 ± 3.6 vs. 17.2 ± 4.8 h, P = 0.019). Recipients after REAL needed significantly more allocation points compared to RA to receive a kidney. One-year graft survival was comparable. If kidneys from the same donor were transplanted to two recipients at one center, the greater the difference in recipient age, the greater the difference in serum creatinine after 12 months (-0.019 mg/dl per year, P = 0.011) was, that is older recipients showed lower creatinine. REAL influences selection of the recipients compared to the former RA era for successful organ receipt. Graft function is comparable and seems to be influenced by recipient age. [ABSTRACT FROM AUTHOR]

Nondirected living donors ( NDLDs) are an important and growing source of kidneys to help reduce the organ shortage. In its infancy, NDLD transplantation was clustered at a few transplant centers and rarely benefited African American ( AA) recipients. However, NDLDs have increased 9.4-fold since 2000, and now are often used to initiate kidney paired donation chains. Therefore, we hypothesized that the initial geographic clustering and racial disparities may have improved. We used Scientific Registry of Transplant Recipients data to compare NDLDs and their recipients between 2008-2015 and 2000-2007. We found that NDLD increased an average of 12% per year, from 20 in 2000 to 188 in 2015 ( IRR: 1.12, 95% CI: 1.11-1.13, P < .001). In 2000-2007, 18.3% of recipients of NDLD kidneys were AA; this decreased in 2008-2015 to 15.7%. NDLD transplants initially became more evenly distributed across centers (Gini 0.91 in 2000 to Gini 0.69 in 2011), but then became more clustered at fewer transplant centers (Gini 0.75 in 2015). Despite the increased number of NDLDs, racial disparities have worsened and the center-level distribution of NDLD transplants has narrowed in recent years. [ABSTRACT FROM AUTHOR]