Consequences of eliminating HLA-B in deceased donor kidney allocation to increase minority transplantation

Operations Research to Solve Kidney Allocation Problems: A Systematic Review

BACKGROUND

Operations research techniques enable health care administrators to optimize resource allocation and to find solutions to staff and patient scheduling problems. We aimed to conduct the first systematic review of the international literature on the use of operations research for allocating deceased-donor kidneys.

METHODS

We searched the MEDLINE, EMBASE, and PubMed databases from inception to February 2023. Two reviewers independently screened the title/abstract and subsequently the full text of potentially eligible articles and abstracted the data. Quality assessment of the final set of studies was conducted using Subben's checklist.

RESULTS

Of the 302 citations identified, 5 studies were included. These studies covered three themes, including (1) provider-facing decision aids to determine the timing of transplant for single or multiple patients; (2) system-level planning on kidney allocation based on blood type matching rules; and (3) patient-facilitated wait times estimation using incomplete information. Markov models, sequential stochastic assignment models, and queuing models were amongst the most used techniques. Although we found all included studies to meet Subben's criteria, we believe the checklist in its current form lacks items to assess the validity of model inferences. As such, we ended this review with a set of practical recommendations.

CONCLUSIONS

Our review demonstrated the utility of operations research techniques in assisting the system, healthcare providers, and patients in the transplantation process. More research is needed to reach a consensus on a model that can be used to support the decision-making of different stakeholders for efficient kidney allocation, with the ultimate goal of reducing the gap between kidney supply and demand and enhancing the population's well-being.

A Systematic Review of Kidney Transplantation Decision Modelling Studies

BACKGROUND

Genome-based precision medicine strategies promise to minimize premature graft loss after renal transplantation, through precision approaches to immune compatibility matching between kidney donors and recipients. The potential adoption of this technology calls for important changes to clinical management processes and allocation policy. Such potential policy change decisions may be supported by decision models from health economics, comparative effectiveness research and operations management.

OBJECTIVE

We used a systematic approach to identify and extract information about models published in the kidney transplantation literature and provide an overview of the status of our collective model-based knowledge about the kidney transplant process.

METHODS

Database searches were conducted in MEDLINE, Embase, Web of Science and other sources, for reviews and primary studies. We reviewed all English-language papers that presented a model that could be a tool to support decision making in kidney transplantation. Data were extracted on the clinical context and modelling methods used.

RESULTS

A total of 144 studies were included, most of which focused on a single component of the transplantation process, such as immunosuppressive therapy or donor-recipient matching and organ allocation policies. Pre- and post-transplant processes have rarely been modelled together.

CONCLUSION

A whole-disease modelling approach is preferred to inform precision medicine policy, given its potential upstream implementation in the treatment pathway. This requires consideration of pre- and post-transplant natural history, risk factors for allograft dysfunction and failure, and other post-transplant outcomes. Our call is for greater collaboration across disciplines and whole-disease modelling approaches to more accurately simulate complex policy decisions about the integration of precision medicine tools in kidney transplantation.

Kidney Organ Allocation System: How to Be Fair

Transplantation is a life-saving medical intervention that unfortunately is constrained by scarcity of available organs. An ideal system for allocating organs should seek to achieve the greatest good for the greatest number of people. It also must be fair and not disadvantage certain populations. However, policies aimed at reducing disparities also must be balanced with considerations of utility (graft outcomes), cost, efficiency, and any adverse effects on organ utilization. Here, we discuss the ethical challenges of creating a fair and equitable organ allocation system, focusing on the principles governing deceased donor kidney transplant waitlists around the world. The kidney organ allocation systems in the United States, Australia, and Hong Kong are used as illustrations.

Cost-utility analysis in chronic kidney disease patients undergoing kidney transplant; what pays? A systematic review

Background

Health systems are under pressure to deliver more effective care without expansion of resources. This is particularly pertinent to diseases like chronic kidney disease (CKD) that are exacting substantial financial burden to many health systems. The aim of this study is to systematically review the Cost Utility Analysis (CUA) evidence generated across interventions for CKD patients undergoing kidney transplant (KT).

Methods

A systemic review of CUA on the interventions for CKD patients undergoing KT was carried out using a search of the MEDLINE, CINAHL, EMBASE, PsycINFO and NHS-EED. The CHEERS checklist was used as a set of good practice criteria in determining the reporting quality of the economic evaluation. Quality of the data used to inform model parameters was determined using the modified hierarchies of data sources.

Results

A total of 330 articles identified, 16 met the inclusion criteria. Almost all (n = 15) the studies were from high income countries. Out of the 24 characteristics assessed in the CHEERS checklist, more than 80% of the selected studies reported 14 of the characteristics. Reporting of the CUA were characterized by lack of transparency of model assumptions, narrow economic perspective and incomplete assessment of the effect of uncertainty in the model parameters on the results. The data used for the economic model were satisfactory quality. The authors of 13 studies reported the intervention as cost saving and improving quality of life, whereas three studies were cost increasing and improving quality of life. In addition to the baseline analysis, sensitivity analysis was performed in all the evaluations except one. Transplanting certain high-risk donor kidneys (high risk of HIV and Hepatitis-C infected kidneys, HLA mismatched kidneys, high Kidney Donor Profile Index) and a payment to living donors, were found to be cost-effective.

Conclusions

The quality of economic evaluations reviewed in this paper were assessed to be satisfactory. Implementation of these strategies will significantly impact current systems of KT and require a systematic implementation plan and coordinated efforts from relevant stakeholders.

Cost-effectiveness of Deceased-donor Renal Transplant Versus Dialysis to Treat End-stage Renal Disease: A Systematic Review

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Deceased-donor renal transplant (DDRT) is an expensive and potentially risky health intervention with the prospect of improved life and lower long-term costs compared with dialysis. Due to the increasing shortage of kidneys and the associated rise of transplantation costs, certain patient groups may not benefit from transplantation in a cost-effective manner compared with dialysis. The objective of this systematic review was to provide a comprehensive synthesis of evidence on the cost-effectiveness of DDRT relative to dialysis to treat adults with end-stage renal disease and patient-, donor-, and system-level factors that may modify the conclusion. A systematic search of articles was conducted on major databases including MEDLINE, Embase, Scopus, EconLit, and the Health Economic Evaluations Database. Eligible articles were restricted to those published in 2001 or thereafter. Two reviewers independently assessed the suitability of studies and excluded studies that focused on recipients with age <18 years old and those of a living-donor or multiorgan transplant. We show that while DDRT is generally a cost-effective treatment relative to dialysis at conventional willingness-to-pay thresholds, a range of drivers including older patient age, comorbidity, and long wait times significantly reduce the benefit of DDRT while escalating healthcare costs. These findings suggest that the performance of DDRT on older patients with comorbidities should be carefully evaluated to avoid adverse results as evidence suggests that it is not cost-effective. Delayed transplantation may reduce the economic benefits of transplant which necessitates targeted policies that aim to shorten wait times. More recent findings have demonstrated that transplantation using high-risk donors may be a cost-effective and promising alternative to dialysis in the face of a lack of organ availability and fiscal constraints. This review highlights key concepts of health economic evaluations and the relevance of cost-effectiveness to inform care and decision-making in renal programs.

Cost-benefit estimation of cadaveric kidney transplantation: the case of a developing country

BACKGROUND

In this paper we have estimated the cost savings for the health care system and quality-of-life improvement for patients from an increased number of kidney transplants in Chile. We compared the present value of dialysis and transplantation costs and quality of life over a 20-year horizon.

METHODS

We used Markov models and introduced some degree of uncertainty in the value of some of the parameters that built the model. Using Monte Carlo simulations, we estimated the confidence intervals for our results.

RESULTS

Our estimates suggested that a kidney transplant showed an expected savings value of US$28,000 for the health care system. If the quality-of-life improvement was also considered, the expected savings rise to US$ 102,000. These results imply that increasing donation rate by 1 donor per million population would achieve an estimated cost saving of US$827,000 per year, or near US$3 million per year considering the effect on the quality of life.

CONCLUSION

These results demonstrated that kidney transplantation along with a better quality of life for patients are a cost-saving decision for developing countries.

A comparative study of the traditional method, and a point-score system for allocation of deceased-donor kidneys: a national multicenter study in Mexico

BACKGROUND

The National Transplant Center in Mexico has ruled that deceased-donor kidney allocation is a function of each hospital's Internal Transplant Committee. The aim of this study was to compare and analyze results for of the traditional method and a point-score system in the allocation of deceased patient's kidneys.

METHODS

The 12 major kidney transplant centers in the country having a deceased-donor program were invited to participate. Only 3 of them replied to the invitation during 2010. A point-score system was proposed to them, comprising blood group, waiting list time, HLA type, and donor and recipient ages. Once the final recipient was chosen, an explanation of reasons for the choice was requested. Thirty-eight transplants were presented. Kappa coefficient was used to measure degree of agreement in both allocation systems. Organs donated for transplantation came from patients between 4 and 54 years old, including 52% female, 52% O+ blood type, 31% A+, and 11% B+, 44% cranial-encephalic trauma, and 44% brain hemorrhage.

RESULTS

Global agreement was 52.6% (kappa = 0.343), and partial agreement was 76.3% (weighted kappa = 0.204), assigning more intensity to extreme values, but with a lower correlation index. A more intense agreement, without discriminating by hospital, was found for "A" category (blood group), followed by "B" category (waiting list time).

DISCUSSION

Taking into consideration the determining factors for long-term graft survival, it is indispensable to include criteria such as donor and recipient ages and HLA typife in the allocation process. This first draft of a point-score system in organ allocation included waiting list time, blood group, urgency related to vascular/peritoneal access for dialysis, clinical condition, donor/recipient age ratio, and HLA antigenic compatibility.

A review of the costs and cost effectiveness of interventions in chronic kidney disease: implications for policy

Given rising healthcare costs and a growing population of patients with chronic kidney disease (CKD), there is an urgent need to identify health interventions that provide good value for money. For this review, the English-language literature was searched for studies of interventions in CKD reporting an original incremental cost-utility (cost per QALY) or cost-effectiveness (cost per life-year) ratio. Published cost studies that did not report cost-effectiveness or cost-utility ratios were also reviewed. League tables were then created for both cost-utility and cost-effectiveness ratios to assess interventions in patients with stage 1-4 CKD, waitlist and transplant patients and those with end-stage renal disease (ESRD). In addition, the percentage of cost-saving or dominant interventions (those that save money and improve health) was compared across these three disease categories. A total of 84 studies were included, contributing 72 cost-utility ratios, 20 cost-effectiveness ratios and 42 other cost measures. Many of the interventions were dominant over the comparator, indicating better health outcomes and lower costs. For the three disease categories, the greatest number of dominant or cost-saving interventions was reported for stage 1-4 CKD patients, followed by waitlist and transplant recipients and those with ESRD (91%, 87% and 55% of studies reporting a dominant or cost-saving intervention, respectively). There is evidence of opportunities to lower costs in the treatment of patients with CKD, while either improving or maintaining the quality of care. In order to realize these cost savings, efforts will be required to promote and effectively implement changes in treatment practices.

Transplanting kidneys without points for HLA-B matching: consequences of the policy change

In 2003, the US kidney allocation system was changed to eliminate priority for HLA-B similarity. We report outcomes from before and after this change using data from the Scientific Registry of Transplant Recipients (SRTR). Analyses were based on 108 701 solitary deceased donor kidney recipients during the 6 years before and after the policy change. Racial/ethnic distributions of recipients in the two periods were compared (chi-square); graft failures were analyzed using Cox models. In the 6 years before and after the policy change, the overall number of deceased donor transplants rose 23%, with a larger increase for minorities (40%) and a smaller increase for non-Hispanic whites (whites) (8%). The increase in the proportion of transplants for non-whites versus whites was highly significant (p < 0.0001). Two-year graft survival improved for all racial/ethnic groups after implementation of this new policy. Findings confirmed prior SRTR predictions. Following elimination of allocation priority for HLA-B similarity, the deficit in transplantation rates among minorities compared with that for whites was reduced but not eliminated; furthermore, there was no adverse effect on graft survival.

Non-medical factors influencing access to renal transplantation

Considering the scarcity of available donor kidneys and the increasing number of patients with end-stage renal disease (ESRD) who would potentially benefit from renal transplantation, objective and equitable patient selection and equitable access to renal transplantation bear substantial importance. Inequalities in access to renal transplantation have been extensively documented over the last 2 decades with regard to age, gender, ethnicity, socioeconomic and psycho-social factors. In this paper we review a wide spectrum of social, patient and system-related factors along the transplantation process that may be associated with disparities, and we aim to describe the complex interrelationship between these factors that might influence treatment decisions by patients and health-care professionals. Understanding potentially modifiable barriers to kidney transplantation may allow designing targeted interventions in order to guarantee fair recipient selection and equal access to renal transplantation.

Living donor kidney transplantation across positive crossmatch: the University of Illinois at Chicago experience

BACKGROUND

To increase living donation for kidney transplantation, we investigated desensitization of recipients with positive crossmatch against a potential living donor.

METHODS

Between June 2001 and March 2007, 57 consecutive sensitized candidates for kidney transplantation, with crossmatch positive potential living donors, were treated with various desensitization protocols. All patients received plasmapheresis every other day with intravenous immune globulin 100 mg/kg starting 1 week before the scheduled transplant. Postoperatively, the recipients continued to receive every other day plasmapheresis with intravenous immune globulin for the initial week. Immunosuppression therapy consisted of induction with thymoglobulin and a combination of tacrolimus, mycophenolate, and corticosteroids.

RESULTS

Six patients failed to convert with pretransplant immunomodulation and were not transplanted; 51 underwent live donor kidney transplant. Mean follow-up was 23 months and 36 patients have more than 1-year follow-up. One-year patient and graft survivals were 95% and 93%, respectively. There were 25 episodes of biopsy-proven or clinically presumed rejection in 22 patients in the first year. Of the 17 biopsy-proven episodes, 12 were antibody-mediated rejection and five were acute cellular rejection. Of the patients with antibody-mediated rejection (biopsy proven or empiric), two patients (12%) lost their graft by 1 year. The median modification of diet in renal disease at 6 and 12 months was 55 mL/min (range 9-104 mL/min) and 48 mL/min (range 8-99), respectively.

CONCLUSIONS

Despite increased rejection rates, graft and patient survivals indicate that desensitization of positive crossmatch patients is a reasonable alternative for a sensitized patient who could potentially wait 10 or more years for a suitable cadaveric kidney.

Principles for allocation of scarce medical interventions

Allocation of very scarce medical interventions such as organs and vaccines is a persistent ethical challenge. We evaluate eight simple allocation principles that can be classified into four categories: treating people equally, favouring the worst-off, maximising total benefits, and promoting and rewarding social usefulness. No single principle is sufficient to incorporate all morally relevant considerations and therefore individual principles must be combined into multiprinciple allocation systems. We evaluate three systems: the United Network for Organ Sharing points systems, quality-adjusted life-years, and disability-adjusted life-years. We recommend an alternative system-the complete lives system-which prioritises younger people who have not yet lived a complete life, and also incorporates prognosis, save the most lives, lottery, and instrumental value principles.

Lifetime cost-effectiveness of calcineurin inhibitor withdrawal after de novo renal transplantation

After renal transplantation, immunosuppressive regimens associated with high short-term survival rates are not necessarily associated with high long-term survival rates, suggesting that regimens may need to be optimized over time. Calcineurin inhibitor (CNI) withdrawal from a sirolimus-based immunosuppressive regimen may maximize the likelihood of long-term graft and patient survival by minimizing CNI-associated nephrotoxicity. In this study, a lifetime Markov model was created to compare the cost-effectiveness of a sirolimus-based CNI withdrawal regimen (sirolimus plus steroids) with other common CNI-containing regimens in adult de novo renal transplantation patients. Long-term graft survival was estimated by renal function and data from published studies and the US transplant registry, including short- and long-term outcomes, utility weights, and health-state costs were incorporated. Drug costs were based on average daily consumption and wholesale acquisition costs. The model suggests that treatment with sirolimus plus steroids is more efficacious and less costly than regimens consisting of a CNI, mycophenolate mofetil, and steroids; therefore, CNI withdrawal not only shows potential for long-term clinical benefits but also is expected to be cost-saving over a patient's life compared with the most commonly prescribed CNI-containing regimens.

Economic impact and long-term graft outcomes of mycophenolate mofetil dosage modifications following gastrointestinal complications in renal transplant recipients

INTRODUCTION

Gastrointestinal (GI) complications are common following renal transplantation. Discontinuing or reducing the dosage of mycophenolate mofetil can improve GI tolerability but adversely affect graft outcomes. This analysis was undertaken to assess the 3-year economic and clinical impact of mycophenolate mofetil dosage modifications or discontinuation following post-transplant GI events compared with no dosage modification.

METHODS

Adult renal transplant recipients with a Medicare-covered mycophenolate mofetil prescription at the time of GI complication between 1995 and 2000 were drawn from the US Renal Data System (USRDS). The 3-year graft survival rates after first diagnosis of a GI complication were obtained in four cohorts of patients according to mycophenolate mofetil administration within 6 months of initial GI diagnosis: (i) no dosage change in mycophenolate mofetil (NC); (ii) one or more episodes of mycophenolate mofetil dosage reduction <50% of the initial dosage, lasting >30 days (DR <50%); (iii) one or more episodes of mycophenolate mofetil dosage reduction >or=50% of the initial dosage, lasting >30 days (DR >or=50%); and (iv) one or more episodes of mycophenolate mofetil discontinuation >30 days (DC).Two multivariate models were used to estimate the association between DR and DC and graft survival <6 months after GI diagnosis and 6-36 months after diagnosis. In each cohort, Medicare costs for maintaining a patient with stable function were calculated using regression and were augmented with cost of graft failure, resumed maintenance dialysis and death post-graft loss using Medicare data supplied by the USRDS. Survival and cost outcomes were integrated in a 3-year Markov model with 6-month cycles. The perspective was that of Medicare, and costs and outcomes were discounted by 3% per annum.

RESULTS

Adult patients (n = 3589) with a mycophenolate mofetil prescription at time of diagnosis of GI event were identified: NC = 2230 (62.1%); DR <50% = 247 (6.9%); DR >or=50% = 348 (9.7%); and DC = 764 (21.3%). In the first 6 months after GI diagnosis, DC was associated with increased risk of graft failure (hazard ratio [HR] 3.20; 95% CI 1.71, 5.99; p < 0.0001). During the period 6-36 months after GI diagnosis, the HR for graft loss was higher for the DR >or=50% group (HR 1.32; 95% CI 1.02, 1.70; p < 0.05) and DC group (HR 1.35; 95% CI 1.09, 1.69; p < 0.01) relative to the NC group.Expected 3-year cumulative Medicare costs per patient were USD 68,495 for the NC and DR <50% groups, USD 70,886 for the DR >or=50% group, USD 79,015 for the DC group and USD 70,967 overall. Respective QALYs were 2.32, 2.30, 2.27 and 2.31. In sensitivity analysis, reducing the rate of DR and DC by 25% would have lowered expected costs by USD 2.2 million in the study population and increased QALYs by 11.2. Monte Carlo simulation indicated a 93% probability that such reduction in the relative risk of mycophenolate mofetil DR/DC was cost saving or cost neutral.

CONCLUSION

Dosage reduction or discontinuation of mycophenolate mofetil in the first 6 months after diagnosis of GI complications is associated with significantly increased risk of graft failure and increased healthcare costs in adult renal transplant recipients.

The economics and ethics of kidney transplantation: perspectives in 2006

PURPOSE OF REVIEW

The field of kidney transplantation has made impressive progress, which has led to marked improvements in both patient and allograft survival. The economic and ethical consequences of these advances have recently garnered increasing attention in the medical literature. This review highlights key articles published in 2005 and 2006.

RECENT FINDINGS

Major areas of focus in the health economics literature pertaining to kidney transplantation include the most cost-effective strategies for immunosuppressive therapies, the management of posttransplant complications, and the optimal utilization of the current pool of deceased-donor kidneys. Ethical challenges include various aspects of living donation, strategies to expand the donor pool, and the impact of financial policies for immunosuppressive agents on long-term patient and allograft survival.

SUMMARY

Given the rising demand for kidney transplantation within a setting of scarce resources, the economic and ethical dimensions of transplant medicine are of increasing interest to patients, providers, and payers. Research in these areas will help uncover ways to utilize this important medical technology in the most ethical and cost-effective manner.

A systematic review of barriers in access to renal transplantation among African Americans in the United States

BACKGROUND

African-American patients with end-stage renal disease are less likely than white patients to undergo renal transplantation. The development of strategies to address this disparity requires an evidence-based understanding of the barriers that impede access to renal transplantation among African Americans in the United States.

METHODS

In September 2005, we searched MEDLINE, EMBASE, and CENTRAL for articles that identified the barriers that impeded African Americans' access to renal transplantation. Two reviewers independently extracted relevant data from the included studies. Barriers were broadly divided under two categories: (i) patient-related barriers; and (ii) healthcare-related barriers.

RESULTS

We obtained 76 potentially relevant articles of which 11 studies were included in the final review. Several patient-related barriers--personal and cultural beliefs about transplantation, lower socioeconomic status and levels of education, and healthcare-related barriers--physician perception about survival of African Americans post-transplantation, inadequate transplant work-up despite being referred, and HLA-mismatching were identified at different stages of the transplantation process. Personal and cultural beliefs of African-American patients were consistently identified as patient-related barriers among several studies. Physicians' perception about post-transplantation survival of African Americans was the most commonly identified healthcare-related barrier.

CONCLUSIONS

A wide spectrum of patient-related barriers including their personal and cultural beliefs about transplantation and several healthcare-related barriers at different stages of the transplant process impedes access to renal transplantation among African Americans in the United States. A multisectoral approach focusing on these barriers needs to be evaluated to reduce disparities in renal transplantation in the United States.