Addressing geographic disparities in liver transplantation through redistricting

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.

Financial Impact of Liver Sharing and Organ Procurement Organizations' Experience With Share 35: Implications for National Broader Sharing

The Share 35 policy for organ allocation, which was adopted in June 2013, allocates livers regionally for candidates with Model for End-Stage Liver Disease scores of 35 or greater. The authors analyzed the costs resulting from the increased movement of allografts related to this new policy. Using a sample of nine organ procurement organizations, representing 17% of the US population and 19% of the deceased donors in 2013, data were obtained on import and export costs before Share 35 implementation (June 15, 2012, to June 14, 2013) and after Share 35 implementation (June 15, 2013, to June 14, 2014). Results showed that liver import rates increased 42%, with an increased cost of 51%, while export rates increased 112%, with an increased cost of 127%. When the costs of importing and exporting allografts were combined, the total change in costs for all nine organ procurement organizations was $11 011 321 after Share 35 implementation. Extrapolating these costs nationally resulted in an increased yearly cost of $68 820 756 by population or $55 056 605 by number of organ donors. Any alternative allocation proposal needs to account for the financial implications to the transplant infrastructure.

Direct costs of care for hepatocellular carcinoma in patients with hepatitis C cirrhosis

BACKGROUND

Hepatitis C virus (HCV) is the commonest cause of hepatocellular carcinoma (HCC) in the United States. The benefits of HCV therapy may be measured in part by the prevention of HCC and other complications of cirrhosis. The true cost of care of the HCV patient with HCC is unknown.

METHODS

One hundred patients were randomly selected from a cohort of all HCC patients with HCV at a US transplant center between 2003 and 2013. Patients were categorized by the primary treatment modality, Barcelona class, and ultimate transplant status. Costs included the unit costs of procedures, imaging, hospitalizations, medications, and all subsequent care of the HCC patient until either death or the end of follow-up. Associations with survival and cost were assessed in multivariate regression models.

RESULTS

Overall costs included a median of $176,456 (interquartile range [IQR], $84,489-$292,192) per patient or $6279 (IQR, $4043-$9720) per patient-month of observation. The median costs per patient-month were $7492 (IQR, $5137-$11,057) for transplant patients and $4830 for nontransplant patients. The highest median monthly costs were for transplant patients with Barcelona A4 disease ($11,349) and patients who received chemoembolization whether they underwent transplantation ($10,244) or not ($8853). Transarterial chemoembolization and radiofrequency ablation were independently associated with a 28% increase and a 22% decrease in costs, respectively, with adjustments for the severity of liver disease and Barcelona class.

CONCLUSIONS

These data represent real-world estimates of the cost of HCC care provided at a transplant center and should inform economic studies of HCV therapy.

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.

Impact of geography on organ allocation: Beyond the distance to the transplantation center

AIM

To illustrate the application and utility of Geographic Information System (GIS) in exploring patterns of liver transplantation. Specifically, we aim to describe the geographic distribution of transplant registrations and identify disparities in access to liver transplantation across United Network of Organ Sharing (UNOS) region 1.

METHODS

Based on UNOS data, the number of listed transplant candidates by ZIP code from 2003 to 2012 for Region 1 was obtained. Choropleth (color-coded) maps were used to visualize the geographic distribution of transplant registrations across the region. Spatial interaction analysis was used to analyze the geographic pattern of total transplant registrations by ZIP code. Factors tested included ZIP code log population and log distance from each ZIP code to the nearest transplant center; ZIP code population density; distance from the nearest city over 50000; and dummy variables for state residence and location in the southern portion of the region.

RESULTS

Visualization of transplant registrations revealed geographic disparities in organ allocation across Region 1. The total number of registrations was highest in the southern portion of the region. Spatial interaction analysis, after adjusting for the size of the underlying population, revealed statistically significant clustering of high and low rates in several geographic areas could not be predicted based solely on distance to the transplant center or density of population.

CONCLUSION

GIS represents a new method to evaluate the access to liver transplantation within one region and can be used to identify the presence of disparities and reasons for their existence in order to alleviate them.

Model for end-stage liver disease score and MELD exceptions: 15 years later

The model for end-stage liver disease (MELD) score has been used as an objective scale of disease severity for management of patients with end-stage liver disease; it currently serves as the basis of an urgency-based organ-allocation policy in several countries. Implementation of the MELD score led to a reduction in waiting-list registration and waiting-list mortality and an increase in the number of deceased-donor transplants without adversely affecting long-term outcomes after liver transplantation (LT). The MELD score has been used for management of non-transplant patients with chronic liver disease. MELD exceptions serve as a mechanism to advance the needs of subsets of patients with liver disease not adequately addressed by MELD-based organ allocation. Several models have been proposed to refine and improve the MELD score as the environment within which it operates continues to evolve toward transplantation for sicker patients. The MELD score continues to serve and be used as a template to improve upon as an objective gauge of disease severity and as a metric enabling optimization of allocation of scarce donor organs for LT.

Regional disparities in interferon therapy for chronic hepatitis C in Japan: a nationwide retrospective cohort study

Background

Many patients with chronic hepatitis C have been treated with interferon (IFN) therapy in Japan, especially after the introduction of subsidies for medical expenses in 2008. However, its performance and outcome have never been evaluated. Therefore, a nationwide, mail-based, retrospective cohort study was conducted.

Methods

Regional disparities in the demographic features, treatment performance, and virological response were evaluated using an intent-to-treat design. The participating prefectures were classified into nine regions from north to south (Hokkaido/Tohoku, Kanto, Shin-etsu, Hokuriku, Tokai, Kinki, Chugoku, Shikoku, and Kyushu). Multivariate logistic regression analysis was performed to select predictive factors for treatment performance and outcome.

Results

From December 2009 to May 2013, 16,854 patients with chronic hepatitis C were registered from 37 prefectures in Japan (median age: 60 years; 50.4 % male; 74.8 % IFN-naïve; HCV genotype [1 or 2]/viral load [high (≥5 log IU/mL) or low (<5 log IU/mL)]: 1/high = 58.2 %, 1/low = 5.2 %, 2/high = 27.3 %, 2/low = 7.5 %; 83.4 % treated with peginterferon-α and ribavirin). Mean age, proportion of elderly patients (≥65 years), male sex, IFN-experienced, and HCV genotype were significantly different among the nine regions (all P < 0.001). Regional disparities were independently selected as one of the predictive factors for treatment performance and outcome in patients treated with peginterferon-α and ribavirin, which revealed two regions that required further investigation.

Conclusions

Regional disparities still exist in IFN therapy, and are strongly associated with treatment performance and outcome. Since the accessibility to medical resources for individual patients seemed to be different among the nine regions, public health actions should be focused on how to construct and properly manage consultation networks between base hospitals and local clinics, especially in those regions with low population density.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-1891-2) contains supplementary material, which is available to authorized users.

Gender-based disparities in access to and outcomes of liver transplantation

Despite comprising 35% of transplants, the number of female transplant recipients has continued to decline. Accordingly, there is a growing attention to the issue of access to and outcomes of liver transplantation in women. The purpose of this review is to critically evaluate the published literature on etiologies contributing to gender-based disparities in liver transplantation focusing on the steps from chronic liver disease through transplantation including disparities in liver disease prevalence, access to liver transplant centers and transplant waiting list, receipt of liver transplantation once listed and disparities in post-liver transplantation outcomes. Our review finds factors contributing to this disparity may include gender differences in the etiology of underlying liver disease and patient and physician referral patterns, lifestyle and health care, but also utilization of an imperfect organ allocation system based on the model for end stage liver disease score and donor-recipient liver size matching. The review also highlights the need for further research in the area of gender disparity in order to develop appropriate approaches to address it and to improve allocation of this precious resource in the future.

The impact of proposed changes in liver allocation policy on cold ischemia times and organ transportation costs

Changes to the liver allocation system have been proposed to decrease regional variation in access to liver transplant. It is unclear what impact these changes will have on cold ischemia times (CITs) and donor transportation costs. Therefore, we performed a retrospective single center study (2008-2012) measuring liver procurement CIT and transportation costs. Four groups were defined: Local-within driving distance (Local-D, n = 262), Local-flight (Local-F, n = 105), Regional-flight <3 h (Regional <3 h, n = 61) and Regional-Flight >3 h (Regional >3 h, n = 53). The median travel distance increased in each group, varying from zero miles (Local-D), 196 miles (Local-F), 384 miles (Regional <3 h), to 1647 miles (Regional >3 h). Increasing travel distances did not significantly increase CIT until the flight time was >3 h. The average CIT ranged from 5.0 to 6.0 h for Local-D, Local-F and Regional <3 h, but increased to 10 h for Regional >3 h (p < 0.0001). Transportation costs increased with greater distance traveled: Local-D $101, Local-F $1993, Regional <3 h $8324 and Regional >3 h $27 810 (p < 0.0001). With proposed redistricting, local financial modeling suggests that the average liver donor procurement transportation variable direct costs will increase from $2415 to $7547/liver donor, an increase of 313%. These findings suggest that further discussion among transplant centers and insurance providers is needed prior to policy implementation.

The race to liver transplantation: a comparison of patients with and without hepatocellular carcinoma from listing to post-transplantation

BACKGROUND

There are geographic and disease-specific inequities in liver allograft distribution. We examined differences between hepatocellular carcinoma (HCC) and non-HCC liver transplantation (LT) candidates from listing through LT in a region with prolonged wait times.

STUDY DESIGN

We performed a single-center retrospective study, from 2005 to 2013, of adult, primary, nonstatus 1 candidates who were listed and subsequently underwent LT (n=270), or were removed because of death or clinical deterioration (n=277).

RESULTS

Of the HCC candidates removed from the waitlist (n=184), 5.5% died waiting, 25.5% deteriorated clinically, and 69% had LT. Of the non-HCC candidates (n=363), 38.8% died waiting, 21.8% clinically deteriorated, and 39.4% had LT. Of the LT recipients, 127 (47%) had HCC. When compared with non-HCC transplant recipients, HCC recipients spent more time on the waitlist (435±475 vs 301±604 days, p=0.045) and from listing until LT had higher total pre-transplant hospital admissions per patient (1.1±1.2 vs 0.8±1.8, p<0.001). These admissions were more often planned (0.65±0.88 vs 0.17±0.52 planned admissions per patient, p<0.001) and of shorter duration (2.7±2.8 vs 5.2±4.6 days, p<0.001). The HCC and non-HCC recipients demonstrated similar overall post-transplant survival (5 year 80% vs. 83%, respectively; p=0.84).

CONCLUSIONS

Despite a shorter wait to have LT, non-HCC candidates at our center have inferior waitlist outcomes. National reprioritization of liver allocation to improve access for non-HCC candidates may lead to increased wait time and resource use for the HCC population; however, a mortality benefit may exist for the non-HCC candidate lacking the benefit of time.

Impact of broader sharing on the transport time for deceased donor livers

Recent allocation policy changes have increased the sharing of deceased donor livers across local boundaries, and sharing even broader than this has been proposed as a remedy for persistent geographic disparities in liver transplantation. It is possible that broader sharing may increase cold ischemia times (CITs) and thus harm recipients. We constructed a detailed model of transport modes (car, helicopter, and fixed-wing aircraft) and transport times between all hospitals, and we investigated the relationship between the transport time and the CIT for deceased donor liver transplants. The median estimated transport time was 2.0 hours for regionally shared livers and 1.0 hour for locally allocated livers. The model-predicted transport mode was flying for 90% of regionally shared livers but for only 22% of locally allocated livers. The median CIT was 7.0 hours for regionally shared livers and 6.0 hours for locally allocated livers. Variation in the transport time accounted for only 14.7% of the variation in the CIT, and the transport time on average composed only 21% of the CIT. In conclusion, nontransport factors play a substantially larger role in the CIT than the transport time. Broader sharing will have only a marginal impact on the CIT but will significantly increase the fraction of transplants that are transported by flying rather than driving.

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.

Geographic determinants of access to pediatric deceased donor kidney transplantation

Children receive priority in the allocation of deceased donor kidneys for transplantation in the United States, but because allocation begins locally, geographic differences in population and organ supply may enable variation in pediatric access to transplantation. We assembled a cohort of 3764 individual listings for pediatric kidney transplantation in 2005-2010. For each donor service area, we assigned a category of short (<180 days), medium (181-270 days), or long (>270 days) median waiting time and calculated the ratio of pediatric-quality kidneys to pediatric candidates and the percentage of these kidneys locally diverted to adults. We used multivariable Cox regression analyses to examine the association between donor service area characteristics and time to deceased donor kidney transplantation. The Kaplan-Meier estimate of median waiting time to transplantation was 284 days (95% confidence interval, 263 to 300 days) and varied from 14 to 1313 days across donor service areas. Overall, 29% of pediatric-quality kidneys were locally diverted to adults. Compared with areas with short waiting times, areas with long waiting times had a lower ratio of pediatric-quality kidneys to candidates (3.1 versus 5.9; P<0.001) and more diversions to adults (31% versus 27%; P<0.001). In multivariable regression, a lower kidney to candidate ratio remained associated with longer waiting time (hazard ratio, 0.56 for areas with <2:1 versus reference areas with ≥5:1 kidneys/candidates; P<0.01). Large geographic variation in waiting time for pediatric deceased donor kidney transplantation exists and is highly associated with local supply and demand factors. Future organ allocation policy should address this geographic inequity.

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.

Meeting report of the 19th Annual International Congress of the International Liver Transplantation Society (Sydney Convention and Exhibition Centre, Sydney, Australia, June 12-15, 2013)

The International Liver Transplantation Society held its annual meeting from June 12 to 15 in Sydney, Australia. More than 800 registrants attended the congress, which opened with a conference celebrating 50 years of liver transplantation (LT). The program included series of featured symposia, focused topic sessions, and oral and poster presentations. This report is by no means all-inclusive and focuses on specific abstracts on key topics in LT. Similarly to previous reports, this one presents data in the context of the published literature and highlights the current direction of LT.