Center competition and outcomes following liver transplantation

Heterogeneous donor circles for fair liver transplant allocation

The United States (U.S.) Department of Health and Human Services is interested in increasing geographical equity in access to liver transplant. The geographical disparity in the U.S. is fundamentally an outcome of variation in the organ supply to patient demand (s/d) ratios across the country (which cannot be treated as a single unit due to its size). To design a fairer system, we develop a nonlinear integer programming model that allocates the organ supply in order to maximize the minimum s/d ratios across all transplant centers. We design circular donation regions that are able to address the issues raised in legal challenges to earlier organ distribution frameworks. This allows us to reformulate our model as a set-partitioning problem. Our policy can be viewed as a heterogeneous donor circle policy, where the integer program optimizes the radius of the circle around each donation location. Compared to the current policy, which has fixed radius circles around donation locations, the heterogeneous donor circle policy greatly improves both the worst s/d ratio and the range between the maximum and minimum s/d ratios. We found that with the fixed radius policy of 500 nautical miles (NM), the s/d ratio ranges from 0.37 to 0.84 at transplant centers, while with the heterogeneous circle policy capped at a maximum radius of 500 NM, the s/d ratio ranges from 0.55 to 0.60, closely matching the national s/d ratio average of 0.5983. Our model matches the supply and demand in a more equitable fashion than existing policies and has a significant potential to improve the liver transplantation landscape.

Rethinking Second Chances: When Rejected Liver Transplant Candidates Seek Reevaluation Elsewhere

AbstractLiver transplantation offers a lifesaving treatment for patients suffering from end-stage liver failure, but not all candidates in the United States are eligible owing to center-specific criteria. When a patient is rejected at a transplantation center for medical, surgical, or psychosocial issues, they are often referred to other centers. We focus on this practice of reevaluation at a second center when the candidate was rejected for psychosocial reasons. We review the criteria used by health professionals to determine psychosocial eligibility and present three case examples from a large teaching hospital that demonstrate this phenomenon in practice. The cases illustrate the conflicts among autonomy, beneficence, nonmaleficence, and justice. We present arguments for and against this practice and provide concrete solutions as a path forward.

Offer Acceptance Patterns for Liver Donors Aged 70 and Older

Despite a documented survival benefit, older liver donor (OLD, age ≥70) graft offers are frequently declined, with utilization worsening over the last decade. To understand how offer acceptance varies by center, we studied 1113 eventually transplanted OLD grafts from 2009 to 2017 using Scientific Registry of Transplant Recipients (SRTR) data and random-intercept multilevel logistic regression. To understand how center-level acceptance of OLD graft offers might be associated with waitlist and posttransplant outcomes, we studied all adult, actively listed, liver-only candidates and recipients during the study period using Poisson regression (transplant rate), competing risks regression (waitlist mortality), and Cox regression (posttransplant mortality). Among 117 centers, OLD offer acceptance ranged from 0 (23 centers) to 95 acceptances, with a median odds ratio of 2.88. Thus, a candidate may be three times as likely to receive an OLD graft simply by listing at a different center. Centers in the highest quartile (Q4) of OLD acceptance (accepted 39% of OLD offers) accepted more nationally shared organs (Q4 versus Q1: 14.1% versus 0.0%, P < 0.001) and had higher annual liver transplant volume (Q4 versus Q1: 80 versus 21, P < 0.001). After adjustment, nationally shared OLD offers (adjusted odds ratio [aOR]: 0.16, 95% confidence interval [CI]: 0.13-0.20) and offers to centers with higher median Model for End-Stage Liver Disease (MELD) at transplant (aOR: 0.74, 95% CI: 0.62-0.87) were less likely to be accepted. OLD offers to centers with higher annual transplant volume were more likely to be accepted (aOR: 1.21, 95% CI: 1.14-1.30). Additionally, candidates listed at centers within the highest quartile of OLD graft offer acceptance had higher deceased donor liver transplantation (DDLT) rates (adjusted incidence rate ratio: 1.45, 95% CI: 1.41-1.50), lower waitlist mortality (adjusted subhazard ratio: 0.76, 95% CI: 0.72-0.76), and similar posttransplant survival (adjusted hazard ratio: 0.93, 95% CI: 0.86-1.01) when compared with those listed at centers in the lowest quartile of OLD graft offer acceptance. The wide variation in OLD offer acceptance supports the need for optimizing the organ offer process and efficiently directing OLD offers to centers more likely to use them.

Impact of the elimination of the donation service area on United States lung transplant practices and outcomes at high and low competition centers

In November 2017, the donation service area (DSA) was removed as the primary unit of US donor lung allocation. Our primary objective was to evaluate the effect of this change on recipient characteristics, the use of pretransplant extracorporeal membrane oxygenation (ECMO), and on index hospitalization length of stay (LOS) and early posttransplant complications. We also assessed whether these outcomes differed in high and low competition centers, as defined by the Herfindahl-Hirschman Index. Following DSA removal, there was a 9-day decrease in median waitlist time (P = .001) and an increase in median lung allocation score (40 vs 42, P < .0001) but no difference in the need for pretransplant ECMO (incidence rate ratio = 1.16, P = .12). Median LOS increased from 17 to 19 days in the post-DSA era (P = .01). There was no difference in posttransplant outcomes, including prolonged ventilation, new dialysis, or early survival, in the general cohort or between competition groups. High competition centers saw an 18.5-minute increase in ischemic time compared to low competition centers (P = .04) but did not differentially increase single lung transplants or pretransplant ECMO utilization. Overall, DSA elimination was associated with increased posttransplant LOS but no significant differences in pretransplant ECMO or other posttransplant outcomes. Effects were largely similar at low and high competition centers.

Center Variation in Intention-to-Treat Survival Among Patients Listed for Liver Transplant

In the United States, centers performing liver transplant (LT) are primarily evaluated by patient survival within 1 year after LT, but tight clustering of outcomes allows only a narrow window for evaluation of center variation for quality improvement. Alternate measures more relevant to patients and the transplant community are needed. We examined adults listed for LT in the United States, using data submitted to the Scientific Registry of Transplant Recipients. Intention-to-treat (ITT) survival was defined as survival within 1 year from listing, regardless of transplant. Mixed effects/frailty models were used to assess center variation in ITT survival. Between January 2010 and December 2016, there were 66,428 new listings at 113 centers. Overall, median 1-year ITT survival was 79.8% (interquartile range [IQR], 76.1%-83.4%), whereas 1-year waiting-list (WL) survival was 75.8% (IQR, 71.2%-79.4%), and 1-year post-LT survival was 90.0% (IQR, 87.9%-91.8%). Higher rates of ITT mortality were correlated with increased WL mortality (correlation, r = 0.76), increased post-LT mortality (r = 0.31), lower volume centers (r = -0.34), and lower transplant rate ratio (r = -0.25). Similar patterns were observed in the subgroup of WL candidates listed with Model for End-Stage Liver Disease (MELD) ≥25: median 1-year ITT survival was 65.2% (IQR, 60.2%-72.6%), whereas 1-year post-LT survival was 87.5% (IQR, 84.0%-90.9%), and 1-year WL survival was 36.6% (IQR, 27.9%-47.0%). In mixed effects modeling, the transplant center was an independent predictor of ITT survival even after adjustment for age, sex, MELD, and sociodemographic variables. Center variation for ITT survival was larger compared with post-LT survival. The measurement of ITT outcome offers a complementary method to assess center performance. This is a first step toward understanding differences in program quality beyond patient and graft survival after LT.

Striving for more just allocation of liver allografts between patients with and without hepatocellular carcinoma: successes and challenges

PURPOSE OF REVIEW

Recently the United Network for Organ Sharing (UNOS) adopted new rules for the allocation of liver allografts for recipients with hepatocellular carcinoma (HCC) in hopes of removing regional variation in HCC practice and regional differences in patient survival. Understanding how previous changes to HCC allocation have both succeeded and failed to match the pretransplant mortality of HCC and non-HCC patients on the waitlist will help us to better evaluate these changes and predict where we may again fail.

RECENT FINDINGS

Previous revisions of the HCC allocation rules were successful in more accurately matching the waitlist mortality of HCC and non-HCC patients. Efforts to select for less aggressive tumor biology have resulted in better disease free and patient survival. Several articles have also supported the practice of using locoregional therapies to downstage the patients to within Milan criteria. New rules seek to reduce the amount of geographic disparity in the allocation system.

SUMMARY

Over time UNOS has steady improved the liver allocation polices to attempt to match pretransplant mortality for patients with HCC and without HCC. The latest changes to the organ allocation rules succeed in implementing some of these best practices. However, one can also predict several ongoing challenges to fair allocation that may not have been addressed by recent changes.

Do Social Determinants Define "Too Sick" to Transplant in Patients With End-stage Liver Disease?

BACKGROUND

Delisting for being "too sick" to be transplanted is subjective. Previous work has demonstrated that the mortality of patients delisted for "too sick" is unexpectedly low. Transplant centers use their best clinical judgment for determining "too sick," but it is unclear how social determinants influence decisions to delist for "too sick." We hypothesized that social determinants and Donor Service Area (DSA) characteristics may be associated with determination of "too sick" to transplant.

METHODS

Data were obtained from the Scientific Registry of Transplant Recipients for adults listed and removed from the liver transplant waitlist from 2002 to 2017. Patients were included if delisted for "too sick." Our primary outcome was Model for End-Stage Liver Disease (MELD) score at waitlist removal for "too sick." Regression assessed the association between social determinants and MELD at removal for "too sick."

RESULTS

We included 5250 delisted for "too sick" at 127 centers, in 53 DSAs, over 16 years. The mean MELD at delisting for "too sick" was 25.8 (SD ± 11.2). On adjusted analysis, social determinants including age, race, sex, and education predicted the MELD at delisting for "too sick" (P < 0.05).

CONCLUSIONS

There is variation in delisting MELD for "too sick" score across DSA and time. While social determinants at the patient and system level are associated with delisting practices, the interplay of these variables warrants additional research. In addition, center outcome reports should include waitlist removal rate for "too sick" and waitlist death ratios, so waitlist management practice at individual centers can be monitored.

Agree on much, except it is time for change

The imbalance between supply and demand of organs for transplant will not be fully solved by changes to the allocation system. Improved organ donation and utilization must be accomplished through critical reassessment of organ procurement organization (OPO) performance as a partnership between transplant centers, OPOs, and community hospitals. The continued discussion on changes to the organ distribution system should be based on patient-centeredness, enhanced transparency, improved models, and metrics. Focusing too heavily on geography without consideration for the other factors at play risks oversimplification of this complex issue.

Return on investment for financial assistance for living kidney donors in the United States

BACKGROUND

The National Living Donor Assistance Center (NLDAC) enables living donor kidney transplants through financial assistance of living donors, but its return on investment (ROI) through savings on dialysis costs remains unknown.

METHODS

We retrospectively reviewed 2012-2015 data from NLDAC, the United States Renal Data System, and the Scientific Registry of Transplant Recipients to construct 1-, 3-, and 5-year ROI models based on NLDAC applications and national dialysis and transplant cost data. ROI was defined as state-specific federal dialysis cost minus (NLDAC program costs plus state-specific transplant cost), adjusted for median waiting time (WT).

RESULTS

A total of 2425 NLDAC applications were approved, and NLDAC costs were USD $6.76 million. Median donor age was 41 years, 66.1% were female, and median income was $33 759; 43.6% were evaluated at centers with WT >72 months. Median dialysis cost/patient-year was $81 485 (IQR $74 489-$89 802). Median kidney transplant cost/patient-year was $30 101 (IQR $26 832-$33 916). Overall, ROI varied from 5.1-fold (1-year) to 28.2-fold (5-year), resulting in $256 million in savings. Higher ROI was significantly associated with high WT, larger dialysis and transplant costs differences, and more NLDAC applicants completing the donation process.

CONCLUSIONS

Financial support for donor out-of-pocket expenses produces dramatic federal savings through incremental living donor kidney transplants.

Improvement in the Outcomes of MELD ≥ 40 Liver Transplantation: An Analysis of 207 Consecutive Transplants in a Highly Competitive DSA

BACKGROUND

Organ donor shortages continue to persist, especially in regions of the United States where competition is highest and recipients frequently attain a Model for End-Stage Liver Disease (MELD) score of 40 or higher before transplantation. The benefits of Share 35 in highly competitive regions may be underestimated when examining the collective national experience. The purpose of this study was to examine the outcomes of liver transplantation in recipients with a MELD of 40 or higher after implementation of Share 35 in a single center located in region 5.

METHODS

The method used in this study was single-center retrospective analysis of 207 liver transplant recipients who achieved MELD score of 40 or higher from April 21, 2002, to May 15, 2015.

RESULTS

Multivariable analysis identified implementation of Share 35 as the strongest predictor of graft survival in MELD of 40 or higher liver transplantation. The post-Share 35, 1-year graft survival was 94% compared with 75% pre-Share 35 (P = 0.002). Post-Share 35 recipients waited significantly less time until transplantation (10 vs 16 days, P = 0.015), and fewer were hospitalized for more than 28 days before their transplant (6% vs 18%, P = 0.05). Multivariable analysis identified recipients with diabetes at the time of listing as the strongest predictor of posttransplant patient mortality.

CONCLUSIONS

Implementation of the Share 35 allocation policy has a significant effect on outcomes by improving organ access and minimizing candidate waiting times. Recipients achieving a MELD of 40 or higher at our center post-Share 35 had an improved 1-year graft survival. However, nearly 40% remained hospitalized for more than 4 weeks posttransplant, and 20% were discharged to an acute care facility.

Analysis of Liver Offers to Pediatric Candidates on the Transplant Wait List

BACKGROUND & AIMS

Approximately 10% of children on the liver transplant wait-list in the United States die every year. We examined deceased donor liver offer acceptance patterns and their contribution to pediatric wait-list mortality.

METHODS

We performed a retrospective cohort study of children on the US liver transplant wait-list from 2007 through 2014 using national transplant registry databases. We determined the frequency, patterns of acceptance, and donor and recipient characteristics associated with deceased donor liver organ offers for children who died or were delisted compared with those who underwent transplantation. Children who died or were delisted were classified by the number of donor liver offers (0 vs 1 or more), limiting analyses to offers of livers that were ultimately transplanted into pediatric recipients. The primary outcome was death or delisting on the wait-list.

RESULTS

Among 3852 pediatric liver transplant candidates, children who died or were delisted received a median 1 pediatric liver offer (inter-quartile range, 0-2) and waited a median 33 days before removal from the wait-list. Of 11,328 donor livers offered to children, 2533 (12%) were transplanted into children; 1179 of these (47%) were immediately accepted and 1354 (53%) were initially refused and eventually accepted for another child. Of 27,831 adults, 1667 (6.0%; median, 55 years) received livers from donors younger than 18 years (median, 15 years), most (97%) allocated locally or regionally. Of children who died or were delisted, 173 (55%) received an offer of 1 or more liver that was subsequently transplanted into another pediatric recipient, and 143 (45%) died or were delisted with no offers.

CONCLUSIONS

Among pediatric liver transplant candidates in the US, children who died or were delisted received a median 1 pediatric liver offer and waited a median of 33 days. Of livers transplanted into children, 47% were immediately accepted and 53% were initially refused and eventually accepted for another child. Of children who died or were delisted, 55% received an offer of 1 or more liver that was subsequently transplanted into another pediatric recipient, and 45% died or were delisted with no offers. Pediatric prioritization in the allocation and development of improved risk stratification systems is required to reduce wait-list mortality among children.

The donor risk index: A decade of experience

In 2006, derivation of the donor risk index (DRI) highlighted the importance of donor factors for successful liver transplantation. Over the last decade, the DRI has served as a useful metric of donor quality and has enhanced our understanding of donor factors and their impact upon recipients with hepatitis C virus, those with low Model for End-Stage Liver Disease (MELD) score, and individuals undergoing retransplantation. DRI has provided the transplant community with a common language for describing donor organ characteristics and has served as the foundation for several tools for organ risk assessment. It is a useful tool in assessing the interactions of donor factors with recipient factors and their impact on posttransplant outcomes. However, limitations of statistical modeling, choice of donor factors, exclusion of unaccounted donor and geographic factors, and the changing face of the liver transplant recipient have tempered its widespread use. In addition, the DRI was derived from data before the MELD era but is currently being applied to expand the donor pool while concurrently meeting the demands of a dynamic allocation system. A decade after its introduction, DRI remains relevant but may benefit from being updated to provide guidance in the use of extended criteria donors by accounting for the impact of geography and unmeasured donor characteristics. DRI could be better adapted for recipients with nonalcoholic fatty liver disease by examining and including recipient factors unique to this population. Liver Transplantation 23 1216-1225 2017 AASLD.

Distance is associated with mortality on the waitlist in pediatric liver transplantation

The distance to liver transplant centers affects outcomes in adult liver transplantation. Because pediatric patients are particularly vulnerable, we hypothesized that distance adversely affects the time to transplantation and waitlist mortality. The SRTR was queried for isolated pediatric liver transplant registrants (under age 18) with valid ZIP code information from 2003 to 2012. Distance was measured from home ZIP code to listing transplant center. Competing events analysis, adjusted for demographic factors, indication, and PELD, was undertaken for transplantation and death while on the waitlist. The median distance to listing transplant center for 6924 children was 65 (IQR 17.5-189) miles. Median distance traveled increased by listing volume (73.9 vs 33.8 miles, highest vs lowest volume quartile, P<.001 for trend) and varied across the country. Longer distance was not associated with time to transplantation (HR 0.99, longest vs shortest distance quartile, P=.80), but was associated with increased mortality (HR 1.75, P<.001). Larger centers attract patients from a distance, while smaller centers serve local populations. Increasing distance is associated with a higher risk of waitlist death, which may reflect decreased access to specialist and tertiary care associated with a transplant center.

Use of organs from donors with bloodstream infection, pneumonia, and influenza: Results of a survey of infectious diseases practitioners

BACKGROUND

Potential organ donors may be admitted with an infection to an intensive care unit, or contract a nosocomial infection during their stay, increasing the risk of potential transmission to the recipient. Because of a lack of practice guidelines and large-scale data on this topic, we undertook a survey to assess the willingness of transplant infectious diseases (ID) physicians to accept such organs.

METHODS

We performed a 10-question survey of ID providers from the American Society of Transplantation Infectious Disease Community of Practice to determine the scope of practice regarding acceptance of organs from donors with bloodstream infection, pneumonia, and influenza prior to organ procurement, as well as management of such infections following transplantation.

RESULTS

Among 60 respondents to our survey, a majority indicated that organs would be accepted from donors bacteremic with streptococci (76%) or Enterobacteriaceae (73%) without evidence of drug resistance. Acceptance rates varied based on infecting organism, type of organ, and center size. Ten percent of respondents would accept an organ from a donor bacteremic with a carbapenem-resistant organism. Over 90% of respondents would accept an organ other than a lung from a donor with influenza on treatment, compared with 52% that would accept a lung in the same setting.

CONCLUSIONS

This study is the first to our knowledge to survey transplant ID providers regarding acceptance of organs based on specific infections in the donor. These decisions are often based on limited published data and experience. Better characterization of the outcomes from donors with specific types of infection could lead to liberalization of organ acceptance practices across centers.

The Evolution of Organ Allocation for Liver Transplantation: Tackling Geographic Disparity Through Broader Sharing

The liver transplant allocation system has evolved to a ranking system of “sickest-first” system based on objective criteria. Yet, organs continue to be distributed first within OPOs and regions that are largely based on historical practice patterns related to kidney transplantation and were never designed to minimize waitlist death or equalize opportunity for liver transplant. The current proposal is a move to enhance survival though the application of modern mathematical techniques to optimize liver distribution. Like MELDbased allocation, it will never be perfect and should be continually evaluated and revised. However, the disparity in access, which favors those residing in or able to travel to privileged areas, to the detriment of the patients dying on the list in underserved areas, is simply not defensible in 2015.

Gerrymandering for Justice: Redistricting U.S. Liver Allocation

U.S. organ allocation policy sequesters livers from deceased donors within arbitrary geographic boundaries, frustrating the intent of those who wish to offer the livers to transplant candidates based on medical urgency. We used a zero-one integer program to partition 58 donor service areas into between four and eight sharing districts that minimize the disparity in liver availability among districts. Because the integer program necessarily suppressed clinically significant differences among patients and organs, we tested the optimized district maps with a discrete-event simulation tool that represents liver allocation at a per-person, per-organ level of detail. In April 2014, the liver committee of the Organ Procurement and Transplantation Network (OPTN) decided in a unanimous vote of 22-0-0 to write a policy proposal based on our eight-district and four-district maps. The OPTN board of directors could implement the policy after the proposal and public-comment period.Redistricting liver allocation would save hundreds of lives over the next five years and would attenuate the serious geographic inequity in liver transplant offers.

Role of Patient Factors and Practice Patterns in Determining Access to Liver Waitlist

Geographic variability in access to care is a persistent challenge in transplantation. Little is known about how patients with end-stage liver disease are chosen for referral, evaluation and listing. Utilizing death certificate data from the Centers for Disease Control and Prevention from 2002 to 2009, estimated liver demand (ELD) was measured by aggregating annual deaths from liver disease and liver transplants performed in each donor service area (DSA). In DSAs with higher ELD, more patients per capita were listed for transplantation (p < 0.001). In addition, listing rates per ELD varied fivefold across DSAs, with more patients per ELD being transplanted in DSAs with higher listing rates (p < 0.001). After adjusting for liver donor risk index and MELD at transplant, there was no association between listing rate and posttransplant survival (HR 1.002, p = 0.77). In addition, DSAs with lower listing rates were more likely to export organs (p < 0.001) of lower liver donor risk index (p < 0.001). Listing sicker patients was associated with increased access to the waitlist and transplantation and more efficient organ utilization, but had minimal effect on posttransplant outcomes after adjusting for the resulting organ shortage.

Decision support for organ offers in liver transplantation

Organ offers in liver transplantation are high-risk medical decisions with a low certainty of whether a better liver offer will come along before death. We hypothesized that decision support could improve the decision to accept or decline. With data from the Scientific Registry of Transplant Recipients, survival models were constructed for 42,857 waiting-list patients and 28,653 posttransplant patients from 2002 to 2008. Daily covariate-adjusted survival probabilities from these 2 models were combined into a 5-year area under the curve to create an individualized prediction of whether an organ offer should be accepted for a given patient. Among 650,832 organ offers from 2008 to 2013, patient survival was compared by whether the clinical decision was concordant or discordant with model predictions. The acceptance benefit (AB)--the predicted gain or loss of life by accepting a given organ versus waiting for the next organ--ranged from 3 to -22 years (harm) and varied geographically; for example, the average benefit of accepting a donation after cardiac death organ ranged from 0.47 to -0.71 years by donation service area. Among organ offers, even when AB was >1 year, the offer was only accepted 10% of the time. Patient survival from the time of the organ offer was better if the model recommendations and the clinical decision were concordant: for offers with AB > 0, the 3-year survival was 80% if the offer was accepted and 66% if it was declined (P < 0.001). In conclusion, augmenting clinical judgment with decision support may improve patient survival in liver transplantation.

Organisational structure of liver transplantation in the UK

AIM

This review aims to outline the delivery of liver transplant services in the UK.

BACKGROUND

Liver transplantation in the UK is based on seven designated transplant units serving a population of just over 60 million people. Nearly 900 liver transplants were done in 2013/2014.

PROCESS

Potential deceased donors are identified and referred to centrally employed specialist nurses for obtaining family consent and for donor characterisation. Organs are retrieved by a National Organ Retrieval Service, based on seven abdominal and six cardiothoracic retrieval teams providing a 24/7 service which has shown to be capable of retrieving organs from up to ten donors a day. Donated organs are allocated first nationally to those who qualify for super-urgent listing. The next priority is for splitting livers, and if there is no suitable recipient or the liver is not suitable for splitting, then livers are offered first to the local centre; each centre has a designated donor zone, adjusted annually to ensure equity between the number of patients listed and the number of donors. The allocation scheme is being reviewed, and national schemes based on need, utility and benefit are being assessed.

GOVERNANCE

Outcomes are monitored by National Health Service Blood and Transplant (NHSBT), and if there is a possibility of adverse deviation, then further inquiries are made. Outcomes, both from listing and from transplantation, are published by the centre on the NHSBT website ( www.odt.nhs.uk ). NHSBT works closely with stakeholders primarily through the advisory groups with clinicians, patients, lay members and professional societies and aims to provide openness and transparency.

CONCLUSIONS

The system for organ donation and delivery of liver transplant in the UK has developed and is now providing an effective and efficient service, but there remains room for improvement.

Market competition influences renal transplantation risk and outcomes

OBJECTIVE

To evaluate the impact of market competition on patient mortality and graft failure after kidney transplantation.

BACKGROUND

Kidneys are initially allocated within 58 donation service areas (DSAs), which have varying numbers of transplant centers. Market competition is generally considered beneficial.

METHODS

The Scientific Registry of Transplant Recipients database was queried and the Herfindahl-Hirschman index (HHI), a measure of market competition, was calculated for each DSA from 2003 to 2012. Receipt of low-quality kidneys (Kidney Donor Profile Index ≥ 85) was modeled with multivariable logistic regression, and Cox proportional hazards models were created for graft failure and patient mortality.

RESULTS

A total of 127,355 adult renal transplants were performed. DSAs were categorized as 7 no (HHI = 1), 17 low (HHI = 0.52-0.97), 17 medium (HHI = 0.33-0.51), or 17 high (HHI = 0.09-0.32) competition. For deceased donor kidney transplantation, increasing market competition was significantly associated with mortality [hazard ratio (HR): 1.11, P = 0.01], graft failure (HR: 1.18, P = 0.0001), and greater use of low-quality kidneys (odds ratio = 1.39, P < 0.0001). This was not true for living donor kidney transplantation (mortality HR: 0.94, P = 0.48; graft failure HR: 0.99, P = 0.89). Competition was associated with longer waitlists (P = 0.04) but not with the number of transplants per capita in a DSA (P = 0.21).

CONCLUSIONS

Increasing market competition is associated with increased patient mortality and graft failure and the use of riskier kidneys. These results may represent more aggressive transplantation and tolerance of greater risk for patients who otherwise have poor alternatives. Market competition should be better studied to ensure optimal outcomes.

Competition in liver transplantation: helpful or harmful?

Improved outcomes of liver transplantation have led to increases in the numbers of US transplant centers and candidates on the list. The resultant and ever-expanding organ shortage has created competition among centers, especially in regions with multiple liver transplant programs. Multiple reports now document that competition among the country's transplant centers has led to the listing of increasingly high-risk patients and the utilization of more marginal liver allografts. The transplant and medical communities at large should carefully re-evaluate these practices and promote innovative approaches to restoring trust in the allocation of donor organs and confirming that there is nationwide conformity in the guidelines used for evaluating and listing potential candidates for this scarce resource.

Competitive Market Analysis of Transplant Centers and Discrepancy of Wait-Listing of Recipients for Kidney Transplantation

BACKGROUND

There are over 250 kidney transplant programs in the USA.

OBJECTIVE

To determine if highly competitive regions, defined as regions with a higher number of transplant centers, will approve and wait-list more end-stage renal disease (ESRD) candidates for transplant despite consistent incidence and prevalence of ESRD nationwide.

METHODS

ESRD Network and OPTN data completed in 2011 were obtained from all transplant centers including listing data, market saturation, market share, organs transplanted, and ESRD prevalence. Herfindahl-Hirschman Index (HHI) was used to measure the size of firms in relation to the industry to determine the amount of competition.

RESULTS

States were separated into 3 groups (HHI<1000 considered competitive; HHI 1000-1800 considered moderate competition; and HHI>1800 considered highly concentrated). The percentage of ESRD patients listed in competitive, moderate, and highly concentrated regions were 19.73%, 17.02%, and 13.75%, respectively. The ESRD listing difference between competitive versus highly concentrated was significant (p<0.05).

CONCLUSION

When there is strong competition without a dominant center as defined by the HHI, the entire state tends to list more patients for transplant to drive up their own center's market share. Our analysis of the available national data suggests a discrepancy in access for ESRD patient to transplantation due to transplant center competition.

D-MELD risk capping improves post-transplant and overall mortality under markov microsimulation

AIM: To hypothesize that the product of calculated Model for End-Stage Liver Disease score excluding exception points and donor age (D-MELD) risk capping ± Rule 14 could improve post liver transplant and overall survival after listing.

METHODS: Probabilities derived from the United Network for Organ Sharing database between 2002 and 2004 were used to simulate potential outcomes for all patients listed for transplantation. The Markov simulation was then modified by screening matches using a 1200 or 1600 D-MELD risk cap ± allowing transplants for Model for End-Stage Liver Disease (MELD) ≤ 14 (Rule 14). The differential impact of the rule changes was assessed.

RESULTS: The Markov simulation accurately reproduced overall and post transplant survival. A 1200 D-MELD risk cap improved post-transplant survival. Both the 1200 and 1600 risk caps improved overall survival for waitlisted patients. The addition of Rule 14 further improved post transplant and overall survival by redistribution of donor livers to recipients in higher MELD subgroups. The mechanism for improved overall and post-transplant survival after listing was due to shifting a larger percentage of transplants to the moderate MELD score subgroup (MELD 15-29) while also ensuring that high MELD recipients have livers of high quality to achieve excellent post transplant survival.

CONCLUSION: A 1200 D-MELD risk cap + Rule 14 provided the greatest overall benefit primarily by focusing liver transplantation towards the moderate MELD recipient.

Association between liver transplant center performance evaluations and transplant volume

There has been increased oversight of transplant centers and stagnation in liver transplantation nationally in recent years. We hypothesized that centers that received low performance (LP) evaluations were more likely to alter protocols, resulting in reduced rates of transplants and patients placed on the waiting list. We evaluated the association of LP evaluations and transplant activity among liver transplant centers in the United States using national Scientific Registry of Transplant Recipients data (January 2007 to July 2012). We compared the average change in recipient and candidate volume and donor and patient characteristics based on whether the centers received LP evaluations. Of 92 eligible centers, 27 (29%) received at least one LP evaluation. Centers without an LP evaluation (n = 65) had an average increase of 9.3 transplants and 14.9 candidates while LP centers had an average decrease of 39.9 transplants (p < 0.01) and 67.3 candidates (p < 0.01). LP centers reduced the use of older donors, donations with longer cold ischemia, and donations after cardiac death (p-values < 0.01). There was no association between the change in transplant volume and measured performance (R(2)  = 0.002, p = 0.91). Findings indicate a strong association between performance evaluations and changes in candidate listings and transplants among liver transplant centers, with no measurable improvement in outcomes associated with reduction in transplant volume.

The extent and predictors of waiting time geographic disparity in kidney transplantation in the United States

BACKGROUND

Waiting time to deceased donor kidney transplant varies greatly across the United States. This variation violates the final rule, a federal mandate, which demands geographic equity in organ allocation for transplantation.

METHODS

Retrospective analysis of the United States Renal Data System and United Network for Organ Sharing database from 2000 to 2009. Median waiting time was calculated for each of the 58 donor service areas (DSA) in the United States. Multivariate regression was performed to identify DSA predictors for long waiting times to kidney transplantation.

RESULTS

The median waiting time varied between the 58 DSAs from 0.61 to 4.57 years, ranging from 0.59 to 5.17 years for standard criteria donor kidneys and 0.41 to 4.69 years for expanded criteria donor kidneys. The disparity in waiting time between the DSAs grew from 3.26 years (range, 0.41-3.67) in 2000 to 4.72 years (range, 0.50-5.22) in 2009. In DSAs with longer waiting times, there were significantly more patients suffering from end-stage renal disease and more patients listed for kidney transplant, lower kidney procurement rates, and higher transplant center competition. Patients were more likely black, sensitized, with lower educational attainment and less likely to waitlist outside of their DSA of residence. Donor organs used in DSAs with long waiting times were more likely hepatitis C positive and had a higher kidney donor profile index. Graft and patient survival at 5 years was worse for deceased donor kidney transplant, but rates for living donor kidney transplant were higher.

CONCLUSION

Our analysis demonstrates significant and worsening geographic disparity in waiting time for kidney transplant across the DSAs. Increase in living donor kidney transplant and use of marginal organs has not mitigated the disparity. Changes to the kidney allocation system might be required to resolve this extensive geographic disparity in kidney allocation.

Multiple listings as a reflection of geographic disparity in liver transplantation

BACKGROUND

Geographic disparity in access to liver transplantation (LT) exists. This study sought to examine Model for End-Stage Liver Disease-era multiply listed (ML) LT candidate (ie, candidates who list at 2 or more LT centers to receive a liver transplant).

STUDY DESIGN

Data on adult, primary, non-status 1 LT candidates (n = 59,557) listed from January 1, 2005 to December 31, 2011 were extracted from the United Network for Organ Sharing's Standard Transplant Analysis and Research files. Comparisons of ML vs singly listed LT candidates were performed, with additional analysis performed at the donor service area (DSA) and regional level, as well as assessment of the donor population used.

RESULTS

There were 1,358 (2.3%) ML candidates during the 7-year study period. Multiply listed candidates compared with singly listed candidates were more often male, white, blood type O, nondiabetic, college educated, and privately insured. The odds of pursuing ML increased considerably as time on the waitlist increased. Of the ML candidates, 918 (67.6%) went on to receive a liver transplant (ML-LT), 767 (83.6%) at the secondary listing DSA, which was a median of 588 miles (range 229 to 1095 miles) from the primary listing DSA. When compared with the primary listing DSA, the secondary listing DSA had significantly lower match Model for End-Stage Liver Disease scores, as well as shorter wait times. Regional analysis demonstrated significantly higher odds for pursuing ML from LT candidates located within regions 1, 5, and 9.

CONCLUSIONS

A small and distinctive cohort of LT candidates pursue ML, indicating willingness and means to travel to receive a liver transplant. Efforts toward equalizing LT access across regional disparities are warranted, and can help obviate the need for ML.

[Deceased donor liver transplantation]

Deceased donor liver transplantation is nowadays a routine procedure for the treatment of terminal liver failure and often represents the only chance of a cure. Under given optimal conditions excellent long-term results can be obtained with 15-year survival rates of well above 60 %.In Germany the outcome after liver transplantation has deteriorated since the introduction of an allocation policy, which is based on the medical urgency. At present 25 % of liver graft recipients die within the first year after transplantation. In contrast 1-year survival in most other countries, e.g. in the USA or the United Kingdom is around 90 % and therefore significantly better. Reasons for the inferior results in Germany are on the one hand an increasing number of critically ill recipients and on the other hand an unfavorable situation for organ donation. In comparison with other countries the organ donation rate is low and moreover the risk profile of these donors is above average. This combination of organ shortage and organ allocation represents a big challenge for the future orientation of liver transplantation and creates the potential for conflict. These cannot be solved on a medical basis but require a social consensus.Because of the present inferior results and because of the high expenses of the present system we suggest a discussion on future allocation policies as well as on future centre structures in Germany. In addition to the medical urgency the maximum benefit should also be considered for organ allocation.

Center variation in the use of nonstandardized model for end-stage liver disease exception points

The Model for End-Stage Liver Disease (MELD) score is an imperfect prognosticator of waitlist dropout, so transplant centers may apply for exception points to increase a waitlist candidate's priority on the waitlist. Exception applications are categorized as recognized exceptional diagnoses (REDs; eg, hepatocellular carcinoma) and non-REDs (eg, cholangitis). Although prior work has demonstrated regional variation in the use of exceptions, no work has examined the between-center variability. We analyzed all new waitlist candidates from February 27, 2002 to June 3, 2011 to explore variations in the use of non-REDs, for which no strict exception criteria exist. There were 58,641 new waitlist candidates, and 4356 (7.4%) applied for a non-RED exception. The number of applications increased steadily over time, as did the approval rates for such applications: from <50% in 2002 to nearly 75% in 2010. When we adjusted for patient factors, there was significant variability (P < 0.001) in the use of non-RED exceptions in 8 of 11 United Network for Organ Sharing (UNOS) regions and in the approval of these exceptions in 6 of 11 UNOS regions. The variability in the use and approval of non-REDs was clinically significant: waitlist candidates with approved exceptions were significantly more likely to undergo transplantation (68.3% versus 53.4%, P < 0.001) and were less likely to be removed for death or clinical deterioration (10.4% versus 16.2%, P < 0.001). Increased median MELD score at transplantation within a donor service area was the only center factor associated with increased odds of applying for exceptions, while no center factors were associated with having non-RED exceptions approved. Further work is needed to identify other sources of variation to ensure the appropriate and equitable use of non-RED exceptions.

Decadal analysis of deceased organ donation in Spain and the United States linking an increased donation rate and the utilization of older donors

After the foundation of the National Transplant Organization, Spanish rates of deceased donor donation rapidly outpaced US growth over the decade from 1989 to 1999. An analysis of the following decade, 1999-2009, demonstrated a markedly flattened growth curve for Spanish deceased donor organ procurement, which increased only 2.4% from 33.6 to 34.4 donors per million population (pmp). In comparison, over the same decade in the United States, the rate of deceased donation increased from 20.9 to 26.3 donors pmp (25.8%). An age group comparison demonstrated a much higher donation rate among older donors in Spain. For example, the number of donors older than 70 years increased from 3.8 to 8.8 pmp (a 132% increase), and they now constitute 25.4% of all Spanish organ donors. In contrast, the number of US donors older than 70 years increased from 1.0 to 1.3 pmp, and they constitute only 4.4% of total deceased donors. Over the same decade, the number of younger donors (15-30 years old) decreased from 6.6 to 2.5 pmp (a 62% decrease) in Spain, and this contrasted with a slightly increased US donation rate for the same age subgroup (a 15.5% increase from 5.8 to 6.7 pmp). Although older donors were more rarely used in the United States, growth in donation over the 2 decades (1989-2009) was strongly associated with the utilization of donors aged 65 or older (P < 0.01). United Network for Organ Sharing regions demonstrated significant differences in utilization rates for older donors. In conclusion, strategies aimed toward achieving US donation rates equivalent to the Spanish benchmark should target improved utilization rates for older donors in the United States instead of emulating elements of the Spanish organ procurement system.

Impact of the center on graft failure after liver transplantation

The hospital at which liver transplantation (LT) is performed has a substantial impact on post-LT outcomes. Center-specific outcome data are closely monitored not only by the centers themselves but also by patients and government regulatory agencies. However, the true magnitude of this center effect, apart from the effects of the region and donor service area (DSA) as well as recipient and donor determinants of graft survival, has not been examined. We analyzed data submitted to the Organ Procurement and Transplantation Network for all adult (age ≥ 18 years) primary LT recipients (2005-2008). Using a mixed effects, proportional hazards regression analysis, we modeled graft failure within 1 year after LT on the basis of center (de-identified), region, DSA, and donor and recipient characteristics. At 115 unique centers, 14,654 recipients underwent transplantation. Rates of graft loss within a year varied from 5.9% for the lowest quartile of centers to 20.2% for the highest quartile. Gauged by a comparison of the 75th and 25th percentiles of the data, the magnitude of the center effect on graft survival (1.49-fold change) was similar to that of the recipient Model for End-Stage Liver Disease (MELD) score (1.47) and the donor risk index (DRI; 1.45). The center effect was similar across the DRI and MELD score quartiles and was not associated with a center's annual LT volume. After stratification by region and DSA, the magnitude of the center effect, though decreased, remained significant and substantial (1.30-fold interquartile difference). In conclusion, the LT center is a significant predictor of graft failure that is independent of region and DSA as well as donor and recipient characteristics.

Liver transplantation: past, present and future

The first human liver transplant operation was performed by Thomas Starzl in 1963. The next two decades were marked by difficulties with donor organ quality, recipient selection, operative and perioperative management, immunosuppression and infectious complications. Advances in each of these areas transformed liver transplantation from an experimental procedure to a standard treatment for end-stage liver disease and certain cancers. From the handful of pioneering programmes, liver transplantation has expanded to hundreds of programmes in >80 countries. 1-year patient survival rates have exceeded 80% and outcomes continue to improve. This success has created obstacles. Ongoing challenges of liver transplantation include those concerning donor organ shortages, recipients with more advanced disease at transplant, growing need for retransplantation, toxicities and adverse effects associated with long-term immunosuppression, obesity and NASH epidemics, HCV recurrence and the still inscrutable biology of hepatocellular carcinoma. This Perspectives summarizes this transformation over time and details some of the challenges ahead.