Following the Organ Supply: Assessing the Benefit of Inter-DSA Travel in Liver Transplantation

Association of a Liver Allocation Policy Change With Domestic Travel for Liver Transplantation

Background

In 2020, liver allocation policy in the United States was changed to allow for broader organ sharing, which was hypothesized to reduce patient incentives to travel for transplant. Our objective was to describe patterns of travel for domestic liver transplant pre- and post-acuity circle (AC) implementation.

Methods

Incident adult liver transplant listings between August 16, 2016, and February 3, 2020 (pre-AC) or June 13, 2020, and December 3, 2023 (post-AC) were obtained from the Scientific Registry of Transplant Recipients. We used previously defined geographic catchment areas to classify patients as (1) no travel, (2) travel to a neighboring region, and (3) travel beyond a neighboring region. We used multinomial logistic regression to identify characteristics associated with travel and cause-specific hazards modeling to estimate the association between travel and time to deceased donor transplant, stratified by model for end-stage liver disease (MELD) score and AC era.

Results

Among 83 033 liver candidates, 76% were listed in their home region. Black race, lower educational attainment, increased neighborhood social deprivation, and Medicaid were significantly associated with decreased odds of traveling beyond a neighboring region. After AC, traveling beyond a neighboring region was associated with an increased hazard of transplant for patients with a MELD score <15 (cause-specific hazard ratio [csHR]: 1.25; 95% confidence interval [CI], 1.11-1.40), MELD score 15-24 (csHR: 1.19; 95% CI, 1.07-1.31), and MELD score 25-34 (csHR: 1.15; 95% CI, 1.01-1.32).

Conclusions

Travel frequency, geographic patterns of travel, and characteristics associated with travel were largely unchanged after AC. Changes to allocation policy alone may not equalize patient means or desire to travel for transplant care.

Liver Transplant Costs and Activity After United Network for Organ Sharing Allocation Policy Changes

Importance

A new liver allocation policy was implemented by United Network for Organ Sharing (UNOS) in February 2020 with the stated intent of improving access to liver transplant (LT). There are growing concerns nationally regarding the implications this new system may have on LT costs, as well as access to a chance for LT, which have not been captured at a multicenter level.

Objective

To characterize LT volume and cost changes across the US and within specific center groups and demographics after the policy implementation.

Design, Setting, and Participants

This cross-sectional study collected and reviewed LT volume from multiple centers across the US and cost data with attention to 8 specific center demographics. Two separate 12-month eras were compared, before and after the new UNOS allocation policy: March 4, 2019, to March 4, 2020, and March 5, 2020, to March 5, 2021. Data analysis was performed from May to December 2022.

Main Outcomes and Measures

Center volume, changes in cost.

Results

A total of 22 of 68 centers responded comparing 1948 LTs before the policy change and 1837 LTs postpolicy, resulting in a 6% volume decrease. Transplants using local donations after brain death decreased 54% (P < .001) while imported donations after brain death increased 133% (P = .003). Imported fly-outs and dry runs increased 163% (median, 19; range, 1-75, vs 50, range, 2-91; P = .009) and 33% (median, 3; range, 0-16, vs 7, range, 0-24; P = .02). Overall hospital costs increased 10.9% to a total of $46 360 176 (P = .94) for participating centers. There was a 77% fly-out cost increase postpolicy ($10 600 234; P = .03). On subanalysis, centers with decreased LT volume postpolicy observed higher overall hospital costs ($41 720 365; P = .048), and specifically, a 122% cost increase for liver imports ($6 508 480; P = .002). Transplant centers from low-income states showed a significant increase in hospital (12%) and import (94%) costs. Centers serving populations with larger proportions of racial and ethnic minority candidates and specifically Black candidates significantly increased costs by more than 90% for imported livers, fly-outs, and dry runs despite lower LT volume. Similarly, costs increased significantly (>100%) for fly-outs and dry runs in centers from worse-performing health systems.

Conclusions and Relevance

Based on this large multicenter effort and contrary to current assumptions, the new liver distribution system appears to place a disproportionate burden on populations of the current LT community who already experience disparities in health care. The continuous allocation policies being promoted by UNOS could make the situation even worse.

Geographic disparities in access to liver transplantation

Since the Final Rule regarding transplantation was published in 1999, organ distribution policies have been implemented to reduce geographic disparity. While a recent change in liver allocation, termed acuity circles, eliminated the donor service area as a unit of distribution to decrease the geographic disparity of waitlisted patients to liver transplantation, recently published results highlight the complexity of addressing geographic disparity. From geographic variation in donor supply, as well as liver disease burden and differing model for end-stage liver disease (MELD) scores of candidates and MELD scores necessary to receive liver transplantation, to the urban-rural disparity in specialty care access, and to neighborhood deprivation (community measure of socioeconomic status) in liver transplant access, addressing disparities of access will require a multipronged approach at the patient, transplant center, and national level. Herein, we review the current knowledge of these disparities-from variation in larger (regional) to smaller (census tract or zip code) levels to the common etiologies of liver disease, which are particularly affected by these geographic boundaries. The geographic disparity in liver transplant access must balance the limited organ supply with the growing demand. We must identify patient-level factors that contribute to their geographic disparity and incorporate these findings at the transplant center level to develop targeted interventions. We must simultaneously work at the national level to standardize and share patient data (including socioeconomic status and geographic social deprivation indices) to better understand the factors that contribute to the geographic disparity. The complex interplay between organ distribution policy, referral patterns, and variable waitlisting practices with the proportion of high MELD patients and differences in potential donor supply must all be considered to create a national policy strategy to address the inequities in the system.

Quantifying Sex-Based Disparities in Liver Allocation

Importance

Differences in local organ supply and demand have introduced geographic inequities in the Model for End-stage Liver Disease (MELD) score-based liver allocation system, prompting national debate and patient-initiated lawsuits. No study to our knowledge has quantified the sex disparities in allocation associated with clinical vs geographic characteristics.

Objective

To estimate the proportion of sex disparity in wait list mortality and deceased donor liver transplant (DDLT) associated with clinical and geographic characteristics.

Design, Setting, and Participants

This retrospective cohort study used adult (age ≥18 years) liver-only transplant listings reported to the Organ Procurement and Transplantation Network from June 18, 2013, through March 1, 2018.

Exposure

Liver transplant waiting list.

Main Outcomes and Measures

Primary outcomes included wait list mortality and DDLT. Multivariate Cox proportional hazards regression models were constructed, and inverse odds ratio weighting was used to estimate the proportion of disparity across geographic location, MELD score, and candidate anthropometric and liver measurements.

Results

Among 81 357 adults wait-listed for liver transplant only, 36.1% were women (mean [SD] age, 54.7 [11.3] years; interquartile range, 49.0-63.0 years) and 63.9% were men (mean [SD] age, 55.7 [10.1] years; interquartile range, 51.0-63.0 years). Compared with men, women were 8.6% more likely to die while on the waiting list (adjusted hazard ratio [aHR], 1.11; 95% CI, 1.04-1.18) and were 14.4% less likely to receive a DDLT (aHR, 0.86; 95% CI, 0.84-0.88). In the geographic domain, organ procurement organization was the only variable that was significantly associated with increased disparity between female sex and wait list mortality (22.1% increase; aHR, 1.22; 95% CI, 1.09-1.30); no measure of the geographic domain was associated with DDLT. Laboratory and allocation MELD scores were associated with increases in disparities in wait list mortality: 1.14 (95% CI, 1.09-1.19; 50.1% increase among women) and DDLT: 0.87 (95% CI, 0.86-0.88; 10.3% increase among women). Candidate anthropometric and liver measurements had the strongest association with disparities between men and women in wait list mortality (125.8% increase among women) and DDLT (49.0% increase among women).

Conclusions and Relevance

Our findings suggest that addressing geographic disparities alone may not mitigate sex-based disparities, which were associated with the inability of the MELD score to accurately estimate disease severity in women and to account for candidate anthropometric and liver measurements in this study.

Lung transplant waitlist outcomes in the United States and patient travel distance

There is a broad range of patient travel distances to reach a lung transplant hospital in the United States. Whether patient travel distance is associated with waitlist outcomes is unknown. We present a cohort study of patients listed between January 1, 2006 and May 31, 2017 using the Scientific Registry of Transplant Recipients. Travel distance was measured from the patient's permanent zip code to the transplant hospital using shared access signature URL access to Google Maps, and assessed using multivariable competing risk regression models. There were 22 958 patients who met inclusion criteria. Median travel distance was 69.7 miles. Among patients who traveled > 60 miles, 41.2% bypassed a closer hospital and sought listing at a more distant hospital. In the adjusted models, when compared to patients who traveled ≤60 miles, patients who traveled >360 miles had a 27% lower subhazard ratio (SHR) for waitlist removal (SHR 0.73, 95% confidence interval [CI]: 0.60, 0.89, P = .002), 16% lower subhazard for waitlist death (SHR 0.84; 95% CI 0.73-0.95, P = .07), and 13% increased likelihood for transplant (SHR 1.13, 95% CI: 1.07, 1.20, P < .001). Many patients bypassed the nearest transplant hospital, and longer patient travel distance was associated with favorable waitlist outcomes.

Racial disparities in patient selection for liver transplantation: An ongoing challenge

Ample evidence suggests continued racial disparities once listed for liver transplantation, though few studies examine disparities in the selection process for listing. The objective of this study, via retrospective chart review, was to determine whether listing for liver transplantation was influenced by socioeconomic status and race/ethnicity. We identified 1968 patients with end-stage liver disease who underwent evaluation at a large, Midwestern center from January 1, 2004 through December 31, 2012 (72.9% white, 19.6% black, and 7.5% other). Over half (54.6%) of evaluated patients were listed; the three most common reasons for not listing were medical contraindications (11.9%), patient expired during evaluation (7.0%), and psychosocial contraindications (5.9%). In multivariable logistic regressions (listed vs not listed), across the three racial categories, the odds of being listed were lower for alcohol-induced hepatitis (±hepatitis C), unmarried, more than one insurance, inadequate insurance, and lower annual household income quartile. Similar factors predicted time to transplant listing, including being identified as black race. Black race, even when adjusting for the above mentioned medical and socioeconomic factors, was associated with 26% lower odds of being listed and a longer time to listing decision compared to all other patients.

Migration of Patients for Liver Transplantation and Waitlist Outcomes

BACKGROUND & AIMS

Patients in need of liver transplantation may travel to improve their chance of receiving an organ. We evaluated factors to determine which transplant candidates travel to other regions to increase their chances of receiving a liver and effects of travel on waitlist outcomes.

METHODS

We performed a retrospective cohort study of all adult patients registered for primary deceased donor liver transplantation in the United States from January 2004 to December 2016. Zip code data were used to calculate the travel distance from a patient's residence to centers at which they were on the waitlist or received a liver transplant. Distant listing and migration were defined as placement on a waitlist and receipt of liver transplantation, respectively, outside the home transplantation region and greater than 500 miles from the home zip code. We assessed the effect of distant listing on outcomes (death and liver transplantation) and predictors of distant listing or migration using multivariable analyses.

RESULTS

There were 104,914 waitlist registrations during the study period; of these, 2930 (2.8%) pursued listing at a distant center. Of waitlist registrants, 60,985 received liver transplants, of whom 1985 (3.3%) had migrated. In a multivariable competing risk analysis in which liver transplantation was considered as a competing event, distant listing was associated with a 22% reduction in the risk of death within 1 year (subhazard ratio, 0.78; 95% CI, 0.70-0.88). Distant listing and migration were associated with non-black race, non-Medicaid payer, residence in a higher income area, and education beyond high school.

CONCLUSIONS

Placement on a liver transplant waitlist outside the home transplantation region is associated with reduced waitlist mortality and an increased probability of receiving a liver transplant. Geographic disparities in access to liver transplantation have disproportionate effects on patients who are minorities, have lower levels of education, or have public insurance.

The landscape of international living kidney donation in the United States

In the United States, kidney donation from international (noncitizen/nonresident) living kidney donors (LKDs) is permitted; however, given the heterogeneity of healthcare systems, concerns remain regarding the international LKD practice and recipient outcomes. We studied a US cohort of 102 315 LKD transplants from 2000-2016, including 2088 international LKDs, as reported to the Organ Procurement and Transplantation Network. International LKDs were more tightly clustered among a small number of centers than domestic LKDs (Gini coefficient 0.76 vs 0.58, P < .001). Compared with domestic LKDs, international LKDs were more often young, male, Hispanic or Asian, and biologically related to their recipient (P < .001). Policy-compliant donor follow-up was substantially lower for international LKDs at 6, 12, and 24 months postnephrectomy (2015 cohort: 45%, 33%, 36% vs 76%, 71%, 70% for domestic LKDs, P < .001). Among international LKDs, Hispanic (aOR = 0.23 0.360.56 , P < .001) and biologically related (aOR = 0.39 0.590.89 , P < .01) donors were more compliant in donor follow-up than white and unrelated donors. Recipients of international living donor kidney transplant (LDKT) had similar graft failure (aHR = 0.78 0.891.02 , P = .1) but lower mortality (aHR = 0.53 0.620.72 , P < .001) compared with the recipients of domestic LDKT after adjusting for recipient, transplant, and donor factors. International LKDs may provide an alternative opportunity for living donation. However, efforts to improve international LKD follow-up and engagement are warranted.

Geographic disparities in liver supply/demand ratio within fixed-distance and fixed-population circles

Recent OPTN proposals to address geographic disparity in liver allocation have involved circular boundaries: the policy selected 12/17 allocated to 150-mile circles in addition to DSAs/regions, and the policy selected 12/18 allocated to 150-mile circles eliminating DSA/region boundaries. However, methods to reduce geographic disparity remain controversial, within the OPTN and the transplant community. To inform ongoing discussions, we studied center-level supply/demand ratios using SRTR data (07/2013-06/2017) for 27 334 transplanted deceased donor livers and 44 652 incident waitlist candidates. Supply was the number of donors from an allocation unit (DSA or circle), allocated proportionally (by waitlist size) to the centers drawing on these donors. We measured geographic disparity as variance in log-transformed supply/demand ratio, comparing allocation based on DSAs, fixed-distance circles (150- or 400-mile radius), and fixed-population (12- or 50-million) circles. The recently proposed 150-mile radius circles (variance = 0.11, P = .9) or 12-million-population circles (variance = 0.08, P = .1) did not reduce the geographic disparity compared to DSA-based allocation (variance = 0.11). However, geographic disparity decreased substantially to 0.02 in both larger fixed-distance (400-mile, P < .001) and larger fixed-population (50-million, P < .001) circles (P = .9 comparing fixed distance and fixed population). For allocation circles to reduce geographic disparities, they must be larger than a 150-mile radius; additionally, fixed-population circles are not superior to fixed-distance circles.

Patients From Appalachia Have Reduced Access to Liver Transplantation After Wait-Listing

BACKGROUND

The Appalachian region is medically underserved and characterized by high morbidity and mortality. We investigated disparities among patients listed for liver transplantation (LT) in wait-list outcomes, according to residence in the Appalachian region.

METHODS

Data on adult patients listed for LT were obtained from the United Network for Organ Sharing for July 2013 to December 2015. Wait-list outcomes were compared using cause-specific hazard models by region of residence (Appalachian vs non-Appalachian) among patients listed at centers serving Appalachia. Posttransplant patient and graft survival were also compared. The study included 1835 LT candidates from Appalachia and 5200 from non-Appalachian regions, of whom 1016 patients experienced wait-list mortality or were delisted; 3505 received liver transplants.

RESULTS

In multivariable analyses, patients from Appalachia were less likely to receive LT (hazard ratio [HR] = 0.86; 95% confidence interval [CI]: 0.79-0.93; P < .001), but Appalachian residence was not associated with wait-list mortality or delisting (HR = 1.03; 95% CI: 0.89-1.18; P = .696). Among liver transplant recipients, patient and graft survival did not differ by Appalachian versus non-Appalachian residence.

CONCLUSION

Appalachian residence was associated with lower access to transplantation after listing for LT. This geographic disparity should be addressed in the current debate over reforming donor liver allocation and patient priority for LT.

Waitlist Outcomes in Liver Transplant Candidates with High MELD and Severe Hepatic Encephalopathy

BACKGROUND

Organ Procurement and Transplantation Network and United Network for Organ Sharing (OPTN/UNOS) implemented the Share 35 policy in June 2013 to prioritize the sickest patients awaiting liver transplantation (LT). However, Model for End-Stage Liver Disease (MELD) score does not incorporate hepatic encephalopathy (HE), an independent predictor of waitlist mortality.

AIM

To evaluate the impact of severe HE (grade 3-4) on waitlist outcomes in MELD ≥ 30 patients.

METHODS

Using the OPTN/UNOS database, we evaluated LT waitlist registrants from 2005-2014. Demographics, comorbidities, and waitlist survival were compared between four cohorts: MELD 30-34 with severe HE, MELD 30-34 without severe HE, MELD ≥ 35 with severe HE, and MELD ≥ 35 without severe HE.

RESULTS

Among 10,003 waitlist registrants studied, 41.6% had MELD score 30-34 and 58.4% had MELD ≥ 35. Patients with severe HE had a higher 90-day waitlist mortality in both MELD 30-34 (severe HE 71.1% vs. no HE 56.6%; p < 0.001) and MELD ≥ 35 subgroups (severe HE 85% versus no HE 74.2%; p < 0.001). MELD 30-34 patients with severe HE had similar 90-day waitlist mortality as MELD ≥ 35 patients without severe HE (71.1 vs. 74.2%, respectively; p = 0.35). On multivariate Cox proportional hazards modeling, MELD ≥ 30 patients had 58% greater risk of 90-day waitlist mortality than those without severe HE (HR 1.58, 95% CI 1.53-1.62; p < 0.001).

CONCLUSION

Patients awaiting LT with MELD score of 30-34 and severe HE should receive priority status for organ allocation with exception MELD ≥ 35.

Pediatric kidney transplantation and mortality: Distance to transplant center matters

Distance from pediatric kidney transplant centers may be a significant barrier in accessing care for patients and families, particularly due to the lower number of pediatric kidney transplant centers compared with the number of adult centers. We performed a retrospective cohort study using data from the Scientific Registry of Transplant Recipients to determine the effect of distance on pediatric kidney transplant waitlist outcomes. We found that distance did not play a role in the likelihood of transplantations for patients who were placed on the waitlist. However, living a greater distance from the transplant center was associated with a greater risk of death while on the waitlist. Larger volume centers attracted patients from greater distances, many of whom had other centers closer to their home. Further investigation on the role of distance to transplant center and the likelihood of being evaluated and listed for a kidney transplant would elucidate whether there are additional barriers these patients face.

Predicting Outcomes on the Liver Transplant Waiting List in the United States: Accounting for Large Regional Variation in Organ Availability and Priority Allocation Points

BACKGROUND

The probability of liver transplant and death on the waiting list in the United States varies greatly by donation service area (DSA) due to geographic differences in availability of organs and allocation of priority points, making it difficult for providers to predict likely outcomes after listing. We aimed to develop an online calculator to report outcomes by region and patient characteristics.

METHODS

Using the Scientific Registry of Transplant Recipients database, we included all prevalent US adults aged 18 years or older waitlisted for liver transplant, examined on 24 days at least 30 days apart over a 2-year period. Outcomes were determined at intervals of 30 to 365 days. Outcomes are reported by transplant program, DSA, region, and the nation for comparison, and can be shown by allocation or by laboratory model for end-stage liver disease (MELD) score (6-14, 15-24, 25-29, 30-34, 35-40), age, and blood type.

RESULTS

Outcomes varied greatly by DSA; for candidates with allocation MELD 25-29, the 25th and 75th percentiles of liver transplant probability were 30% and 67%, respectively, at 90 days. Corresponding percentiles for death or becoming too sick to undergo transplant were 5% and 9%. Outcomes also varied greatly for candidates with and without MELD exception points.

CONCLUSIONS

The waitlist outcome calculator highlights ongoing disparities in access to liver transplant and may assist providers in understanding and counseling their patients about likely outcomes on the waiting list.

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.

The Impact of Redistricting Proposals on Health Care Expenditures for Liver Transplant Candidates and Recipients

Redistricting, which means sharing organs in novel districts developed through mathematical optimization, has been proposed to reduce pervasive geographic disparities in access to liver transplantation. The economic impact of redistricting was evaluated with two distinct data sources, Medicare claims and the University HealthSystem Consortium (UHC). We estimated total Medicare payments under (i) the current allocation system (Share 35), (ii) full regional sharing, (iii) an eight-district plan, and (iv) a four-district plan for a simulated population of patients listed for liver transplant over 5 years, using the liver simulated allocation model. The model predicted 5-year transplant volumes (Share 35, 29,267; regional sharing, 29,005; eight districts, 29,034; four districts, 28,265) and a reduction in overall mortality, including listed and posttransplant patients, of up to 676 lives. Compared with current allocation, the eight-district plan was estimated to reduce payments for pretransplant care ($1638 million to $1506 million, p < 0.001), transplant episode ($5607 million to $5569 million, p < 0.03) and posttransplant care ($479 million to $488 million, p < 0.001). The eight-district plan was estimated to increase per-patient transportation costs for organs ($8988 to $11,874 per patient, p < 0.001) and UHC estimated hospital costs ($4699 per case). In summary, redistricting appears to be potentially cost saving for the health care system but will increase the cost of performing liver transplants for some transplant centers.

One Size Does Not Fit All--Regional Variation in the Impact of the Share 35 Liver Allocation Policy

Allocation policies for liver transplantation underwent significant changes in June 2013 with the introduction of Share 35. We aimed to examine the effect of Share 35 on regional variation in posttransplant outcomes. We examined two patient groups from the United Network for Organ Sharing dataset; a pre-Share 35 group composed of patients transplanted between June 17, 2012, and June 17, 2013 (n = 5523), and a post-Share group composed of patients transplanted between June 18, 2013, and June 18, 2014 (n = 5815). We used Kaplan-Meier and Cox multivariable analyses to compare survival. There were significant increases in allocation Model for End-stage Liver Disease (MELD) scores, laboratory MELD scores, and proportions of patients in the intensive care unit and on mechanical, ventilated, or organ-perfusion support at transplant post-Share 35. We also observed a significant increase in donor risk index in this group. We found no difference on a national level in survival between patients transplanted pre-Share 35 and post-Share 35 (p = 0.987). Regionally, however, posttransplantation survival was significantly worse in the post-Share 35 patients in regions 4 and 10 (p = 0.008 and p = 0.04), with no significant differences in the remaining regions. These results suggest that Share 35 has been associated with transplanting "sicker patients" with higher MELD scores, and although no difference in survival is observed on a national level, outcomes appear to be concerning in some regions.

Patterns and Outcomes Associated with Patient Migration for Liver Transplantation in the United States

Background

Traveling to seek specialized care such as liver transplantation (LT) is a reality in the United States. Patient migration has been attributed to organ availability. The aims of this study were to delineate patterns of patient migration and outcomes after LT.

Study Design

All deceased donor LT between 2008–2013 were extracted from UNOS data. Migrated patients were defined as those patients who underwent LT at a center in a different UNOS region from the region in which they resided and traveled a distance > 100 miles.

Results

Migrated patients comprised 8.2% of 28,700 LT performed. Efflux and influx of patients were observed in all 11 UNOS regions. Regions 1, 5, 6, and 9 had a net efflux, while regions 2, 3, 4, 7, 10, and 11 had a net influx of patients. After multivariate adjustment for donor and recipient factors, graft (p = 0.68) and patient survival (p = 0.52) were similar between migrated and non-migrated patients.

Conclusion

A significant number of patients migrated in patterns that could not be explained alone by regional variations in MELD score and wait time. Migration may be a complex interplay of factors including referral patterns, specialized services at centers of excellence and patient preference.

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.

Liver sharing and organ procurement organization performance under redistricted allocation

Concerns have been raised that optimized redistricting of liver allocation areas might have the unintended result of shifting livers from better-performing to poorer-performing organ procurement organizations (OPOs). We used liver simulated allocation modeling to simulate a 5-year period of liver sharing within either 4 or 8 optimized districts. We investigated whether each OPO's net liver import under redistricting would be correlated with 2 OPO performance metrics (observed to expected liver yield and liver donor conversion ratio), along with 2 other potential correlates (eligible deaths and incident listings above a Model for End-Stage Liver Disease score of 15). We found no evidence that livers would flow from better-performing OPOs to poorer-performing OPOs in either redistricting scenario. Instead, under these optimized redistricting plans, our simulations suggest that livers would flow from OPOs with more-than-expected eligible deaths toward those with fewer-than-expected eligible deaths and that livers would flow from OPOs with fewer-than-expected incident listings to those with more-than-expected incident listings; the latter is a pattern that is already established in the current allocation system. Redistricting liver distribution to reduce geographic inequity is expected to align liver allocation across the country with the distribution of supply and demand rather than transferring livers from better-performing OPOs to poorer-performing OPOs.

Socioeconomic status and ethnicity of deceased donor kidney recipients compared to their donors

Public perception and misperceptions of socioeconomic disparities affect the willingness to donate organs. To improve our understanding of the flow of deceased donor kidneys, we analyzed socioeconomic status (SES) and racial/ethnic gradients between donors and recipients. In a retrospective cohort study, traditional demographic and socioeconomic factors, as well as an SES index, were compared in 56,697 deceased kidney donor and recipient pairs transplanted between 2007 and 2012. Kidneys were more likely to be transplanted in recipients of the same racial/ethnic group as the donor (p < 0.001). Kidneys tended to go to recipients of lower SES index (50.5% of the time, p < 0.001), a relationship that remained after adjusting for other available markers of donor organ quality and SES (p < 0.001). Deceased donor kidneys do not appear to be transplanted from donors of lower SES to recipients of higher SES; this information may be useful in counseling potential donors and their families regarding the distribution of their organ gifts.

Increasing prevalence of nonalcoholic steatohepatitis as an indication for liver transplantation

BACKGROUND

In Ohio, the obesity rate has increased from 21.5% in 2000 to 30.1% in 2012. Nonalcoholic steatohepatitis is believed to be increasing as an indication for orthotopic liver transplantation.

METHODS

We evaluated the diagnosis of nonalcoholic steatohepatitis as an indication for orthotopic liver transplantation and ensuing outcomes relative to other common hepatic diseases requiring orthotopic liver transplantation in Ohio. We queried 2,356 patients with nonalcoholic steatohepatitis, alcoholic cirrhosis (ETOH), and hepatitis C cirrhosis from the Ohio Solid Organ Transplantation Consortium who were listed for and/or received an orthotopic liver transplant from 2000 to 2012.

RESULTS

The proportion of listed patients with nonalcoholic steatohepatitis increased from 0% to 26% and the proportion of transplanted patients increased from 0% to 23.4%. Compared with patients with hepatitis C and ETOH, patients with nonalcoholic steatohepatitis were older, and more likely to be white, and have private insurance (P < .05 for each). There was no difference in median waiting time among patients with nonalcoholic steatohepatitis, hepatitis C, and ETOH (P = .18) and Model for End-Stage Liver Disease scores at orthotopic liver transplantation among patients with nonalcoholic steatohepatitis, hepatitis C (P = .48), and ETOH (P = .27). Patient and graft survival after orthotopic liver transplantation was comparable between patients with nonalcoholic steatohepatitis and ETOH (P = .79 and P = .86, respectively); however, patients with nonalcoholic steatohepatitis had better patient and graft survival compared with patients with hepatitis C after orthotopic liver transplantation (P < .01 and P = .02, respectively). Additionally, body mass index had no influence on overall or graft survival for patients with nonalcoholic steatohepatitis undergoing orthotopic liver transplantation.

CONCLUSION

This study reflects the growing potential for transplantation in patients with fatty liver disease and suggests the outcomes are equivalent or superior to other common indications for orthotopic liver transplantation.

Neighborhood level effects of socioeconomic status on liver transplant selection and recipient survival

BACKGROUND & AIMS

Previous studies have reported that patients of higher socioeconomic status (SES) have increased access to liver transplantation and reduced waitlist mortality than patients of lower SES. However, little is known about the association between SES and outcomes after liver transplantation.

METHODS

By using a link between the University HealthSystem Consortium and the Scientific Registry of Transplant Recipients databases, we identified 12,445 patients who underwent liver transplantation from 2007 through 2011. We used a proportional hazards model to assess the effect of SES on patient survival, controlling for characteristics of recipients, donors, geography, and center.

RESULTS

Compared with liver recipients in the lowest SES quintile, those in the highest quintile were more likely to be male, Caucasian, have private insurance, and undergo transplantation when they had lower Model for End-Stage Liver Disease scores. In proportional hazards model analysis, liver recipients of the lowest SES were at an increased risk for death within a median of 2 years after transplantation (hazard ratio, 1.17; 95% confidence interval, 1.02-1.35).

CONCLUSIONS

Patients of lower SES appear to face barriers to liver transplantation, but perioperative outcomes (length of stay, in-hospital mortality, or 30-day readmission) do not differ significantly from those of patients of higher SES. However, fewer patients of low SES survive for 2 years after transplantation, independent of features of the recipient, donor, surgery center, or location.

Geographic disparity: the dilemma of lower socioeconomic status, multiple listing, and death on the liver transplant waiting list

Due to the current regionally based allocation system, some patients list for and are transplanted away from home in regions with shorter waits and higher transplant rates. Of 147 included patients, 120 died waiting and 27 received transplants at outside centers during the study (32.5 months). Those transplanted elsewhere had higher median incomes than patients dying on the waitlist ($84 946 vs. $55 250, p = 0.0001). Those with median incomes <$60 244 were more likely to die than those with incomes >$60 244 (94% vs. 70%, RR: 1.35, 95% CI: 1.14-1.59). Patients with Medicaid were more likely to die waiting than those with other insurance (100% vs. 77%, RR: 1.30, 95% CI: 1.18-1.44). Our analysis demonstrates that those who died waiting were more likely to have lower incomes and Medicaid compared with those transplanted elsewhere. Even when we controlled for Medicaid status, patients who died waiting had lower incomes compared with those transplanted elsewhere. Increased organ sharing over geographically broader regions, as recommended by the Institute of Medicine in 1999, may reduce incentives for patients to travel to receive a liver and reduce inequities. Current efforts to address this disparity continue to fall short of the Institute of Medicine recommendations, United States Department of Health and Human Services regulations and the Final Rule.

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.

Health services and policy research in hepatology

PURPOSE OF REVIEW

This article examines recent health services and policy research studies in hepatology and liver transplantation.

RECENT FINDINGS

Critical issues include access to medical care, timeliness of referral and consultation, resource utilization in clinical practice, comparative effectiveness research, and the evaluation of care delivery models. Despite policymaking efforts, there continues to be unwarranted variation in access to subspecialty care and liver transplantation services based on race and geographic location. Variations in primary care and specialist awareness of practice guidelines for liver disease contribute to disparities in appropriateness and timeliness of treatments. Defining the cost-effectiveness of increased resource utilization for novel antiviral therapies and liver transplantation continues to stimulate controversy. Few comparative effectiveness studies in hepatology exist to date, yet a growing number of analyses using national datasets will help inform policy in this arena. Identifying care delivery models that demonstrate high value for populations with chronic liver disease is critical in the context of recent healthcare reform efforts.

SUMMARY

Health services and policy research is a growing field of investigation in hepatology and liver transplantation. Further emphasis on research training and workforce development in this area will be critical for understanding and improving patient-centered outcomes for this population.

Assessing variation in the costs of care among patients awaiting liver transplantation

Previous economic analyses of liver transplantation have focused on the cost of the transplant and subsequent care. Accurate characterization of the pretransplant costs, indexed to severity of illness, is needed to assess the economic burden of liver disease. A novel data set linking Medicare claims with transplant registry data for 15,710 liver transplant recipients was used to determine average monthly waitlist spending (N = 249,434 waitlist months) using multivariable linear regression models to adjust for recipient characteristics including Model for End-Stage Liver Disease (MELD) score. Characteristics associated with higher spending included older age, female gender, hepatocellular carcinoma, diabetes, hypertension and increasing MELD score (p < 0.05 for all). Spending increased exponentially with severity of illness: expected monthly spending at a MELD score of 30 was 10 times higher than at MELD of 20 ($22,685 vs. $2030). Monthly spending within MELD strata also varied geographically. For candidates with a MELD score of 35, spending varied from $19,548 (region 10) to $36,099 (region 7). Regional variation in waitlist costs may reflect the impact of longer waiting times on greater pretransplant hospitalization rates among high MELD score patients. Reducing the number of high MELD waitlist patients through improved medical management and novel organ allocation systems could decrease total spending for end-stage liver care.

HCC patients suffer less from geographic differences in organ availability

It has been suggested that the number of exception model for end-stage liver disease (MELD) points for hepatocellular carcinoma (HCC) overestimates mortality risk. Average MELD at transplant, a measure of organ availability, correlates with mortality on an intent-to-treat basis and varies by donation service area (DSA). We analyzed Scientific Registry of Transplant Recipients data from 2005 to 2010, comparing transplant and death parameters for patients transplanted with HCC exception points to patients without HCC diagnosis (non-HCC), to determine whether the two groups were impacted differentially by DSA organ availability. HCC candidates are transplanted at higher rates than non-HCC candidates and are less likely to die on the waitlist. Overall risk of death trends downward by 1% per MELD point (p = 0.65) for HCC, but increases by 7% for non-HCC patients (p < 0.0001). The difference in the change of mortality with MELD is statistically significant between HCC and non-HCC candidates p < 0.0001. Posttransplant risk of death trends downward by 2% per MELD point (p = 0.28) for HCC patients, but increases by 3% per MELD point in non-HCC patients (p = 0.027), with the difference being statistically significant with p < 0.005. In summary, increasing wait time impacts HCC candidates less than non-HCC candidates and under increased competition for donor organs, HCC candidates' advantage increases.