The Impact of the Share 35 Policy on Racial and Ethnic Disparities in Access to Liver Transplantation for Patients with End Stage Liver Disease in the United States: An Analysis from UNOS Database

Mitigating Health Disparities in Transplantation Requires Equity, Not Equality

Despite decades of research and evidence-based mitigation strategies, disparities in access to transplantation persist for all organ types and in all stages of the transplant process. Although some strategies have shown promise for alleviating disparities, others have fallen short of the equity goal by providing the same tools and resources to all rather than tailoring the tools and resources to one's circumstances. Innovative solutions that engage all stakeholders are needed to achieve equity regardless of race, sex, age, socioeconomic status, or geography. Mitigation of disparities is paramount to ensure fair and equitable access for those with end-stage disease and to preserve the trust of the public, upon whom we rely for their willingness to donate organs. In this overview, we present a summary of recent literature demonstrating persistent disparities by stage in the transplant process, along with policies and interventions that have been implemented to combat these disparities and hypotheses for why some strategies have been more effective than others. We conclude with future directions that have been proposed by experts in the field and how these suggested strategies may help us finally arrive at equity in transplantation.

Racial Disparities in Candidates for Hepatocellular Carcinoma Liver Transplant After 6-Month Wait Policy Change

Importance

Racial disparities in liver transplant (LT) for hepatocellular carcinoma (HCC) may be associated with unequal access to life-saving treatment.

Objective

To quantify racial disparities in LT for HCC and mortality after LT, adjusting for demographic, clinical, and socioeconomic factors.

Design, Setting, and Participants

This cohort study was a retrospective analysis of United Network Organ Sharing/Organ Procurement Transplant Network (OPTN) data from 2003 to 2021. Participants were adult patients with HCC on the LT waiting list and those who received LT. Data were analyzed from March 2022 to September 2023.

Exposures

Race and time before and after the 2015 OPTN policy change.

Main Outcomes and Measures

Proportion of LT from wait-listed candidates, the proportion of waiting list removals, and mortality after LT.

Results

Among 12 031 patients wait-listed for LT with HCC (mean [SD] age, 60.8 [7.4] years; 9054 [75.3%] male; 7234 [60.1%] White, 2590 [21.5%] Latinx/o/a, and 1172 [9.7%] Black or African American), this study found that after the 2015 model of end-stage liver disease (MELD) exception policy changes for HCC (era 2), the overall proportion of LT for HCC across all races decreased while the proportion of dropouts on the LT waiting list remained steady compared with patients who did not have HCC. In Kaplan-Meier analysis, Asian patients demonstrated the lowest dropout rates in both era 1 and era 2 (1-year dropout, 16% and 17%, respectively; P < .001). In contrast, Black or African American patients had the highest dropout rates in era 1 (1-year dropout, 24%), but comparable dropout rates (23%) with White patients (23%) and Latinx/o/a patients in era 2 (23%). In both eras, Asian patients had the highest survival after LT (5-year survival, 82% for era 1 and 86% for era 2), while Black or African American patients had the worst survival after LT (5-year survival, 71% for era 1 and 79% for era 2). In the multivariable analysis for HCC LT recipients, Black or African American race was associated with increased risk of mortality in both eras, compared with White race (HR for era 1, 1.17; 95% CI, 1.05-1.35; and HR for era 2, 1.31; 95% CI, 1.10-1.56).

Conclusions and Relevance

This cohort study of LT candidates in the US found that after the 2015 MELD exception policy change for HCC, the proportion of LT for HCC had decreased for all races. Black or African American patients had worse outcomes after LT than other races. Further research is needed to identify the underlying causes of this disparity and develop strategies to improve outcomes for HCC LT candidates.

Tools to Measure the Impact of Structural Racism and Discrimination on Gastrointestinal and Hepatology Disease Outcomes: A Scoping Review

BACKGROUND & AIMS

Structural racism and discrimination (SRD) are important upstream determinants of health perpetuated by discriminatory laws and policies. Therefore, measuring SRD and its impact on health is critical to developing interventions that address resultant health disparities. We aimed to identify gastrointestinal (GI) or liver studies that report measures of SRD or interventions to achieve health equity in these domains by addressing upstream determinants of health.

METHODS

We conducted a scoping review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses scoping reviews guidelines. Studies that used an SRD measure or examined an upstream intervention in GI or liver disease were included. Studies that described health disparities in GI or liver conditions without mentioning SRD were excluded. Study characteristics, findings, and limitations were extracted.

RESULTS

Forty-six articles (19 studies using SRD measures and 27 studies of upstream interventions) were identified. Measures of residential racial segregation were reported most frequently. SRD was associated with poorer health outcomes for racial and ethnic minority populations. Although upstream intervention studies focused primarily on policies related to colon cancer screening and organ graft allocation, racial and ethnic disparities often persisted post-intervention.

CONCLUSIONS

To achieve health equity in GI and liver conditions, there is an urgent need for research that goes beyond describing health disparities to incorporating measures of SRD and implementing interventions that address this understudied determinant of health.

Actionable Solutions to Achieve Health Equity in Chronic Liver Disease

There are well-described racial and ethnic disparities in the burden of chronic liver diseases. Hispanic persons are at highest risk for developing nonalcoholic fatty liver disease, the fastest growing cause of liver disease. Hepatitis B disproportionately affects persons of Asian or African descent. The highest rates of hepatitis C occur in American Indian and Alaskan Native populations. In addition to disparities in disease burden, there are also marked racial and ethnic disparities in access to treatments, including liver transplantation. Disparities also exist by gender and geography, especially in alcohol-related liver disease. To achieve health equity, we must address the root causes that drive these inequities. Understanding the role that social determinants of health play in the disparate health outcomes that are currently observed is critically important. We must forge and/or strengthen collaborations between patients, community members, other key stakeholders, health care providers, health care institutions, professional societies, and legislative bodies. Herein, we provide a high-level review of current disparities in chronic liver disease and describe actionable strategies that have potential to bridge gaps, improve quality, and promote equity in liver care.

Current status of disparity in liver disease

Disparities have emerged as an important issue in many aspects of healthcare in developed countries and may be based on race, ethnicity, sex, geographical location, and socioeconomic status. For liver disease specifically, these potential disparities can affect access to care and outcome in viral hepatitis, chronic liver disease, and hepatocellular carcinoma. Shortages in hepatologists and medical providers versed in liver disease may amplify these disparities by compromising early detection of liver disease, surveillance for hepatocellular carcinoma, and prompt referral to subspecialists and transplant centers. In the United States, continued efforts have been made to address some of these disparities with better education of healthcare providers, use of telehealth to enhance access to specialists, reminders in electronic medical records, and modifying organ allocation systems for liver transplantation. This review will detail the current status of disparities in liver disease and describe current efforts to minimize these disparities.

An Analysis of Free-Text Refusals as an Indicator of Readiness to Accept Organ Offers in Liver Transplantation

Racial/ethnic minorities experience higher rates of wait-list mortality and longer waiting times on the liver transplant wait list. We hypothesized that racial/ethnic minorities may encounter greater logistical barriers to maintaining "readiness" on the wait list, as reflected in offer nonacceptance. We identified all candidates who received an organ offer between 2009 and 2018 and investigated candidates who did not accept an organ offer using a free-text refusal reason associated with refusal code 801. We isolated patients who did not accept an organ offer due to "candidate-related logistical reasons" and evaluated their characteristics. We isolated 94,006 "no 801" patients and 677 "with 801 logistical" patients. Common reasons for offer decline among the 677 were 60% "unable to travel/distance," 22% "cannot be contacted," 13% "not ready/unspecified," and 5% "financial/insurance." Compared to "no 801," "with 801 logistical" patients were more likely to be Hispanic (19% vs. 15%, P < 0.01). Multivariate logistic modeling showed Hispanic (odds ratio [OR] 1.44, 95% confidence interval [CI] 1.17-1.76, P < 0.01) and multiracial/other ethnicity (OR 1.82, 95% CI 1.08-3.05, P = 0.02) were associated with "with 801 logistical" status. The "with 801 logistical" patients were listed with higher allocation (inclusive of exception points) Model for End-Stage Liver Disease scores (16 vs. 15, P < 0.01) and remained longer on the wait list (median 428 days vs. 187 days, P < 0.01). Conclusion: In this analysis of wait-list candidates, we isolated 677 patients who declined an organ offer with a free-text reason consistent with a "candidate-related logistical reason." Compared with non-Hispanic Whites, Hispanics were at 1.44 odds of not accepting organ offers due to logistical reasons. These limited findings motivate further research into interventions that would improve candidates' "readiness" to accept organ offers and may benefit racial/ethnic minorities on the liver-transplantation wait list.

A scoping review of inequities in access to organ transplant in the United States

Background

Organ transplant is the preferred treatment for end-stage organ disease, yet the majority of patients with end-stage organ disease are never placed on the transplant waiting list. Limited access to the transplant waiting list combined with the scarcity of the organ pool result in over 100,000 deaths annually in the United States. Patients face unique barriers to referral and acceptance for organ transplant based on social determinants of health, and patients from disenfranchised groups suffer from disproportionately lower rates of transplantation. Our objective was to review the literature describing disparities in access to organ transplantation based on social determinants of health to integrate the existing knowledge and guide future research.

Methods

We conducted a scoping review of the literature reporting disparities in access to heart, lung, liver, pancreas and kidney transplantation based on social determinants of health (race, income, education, geography, insurance status, health literacy and engagement). Included studies were categorized based on steps along the transplant care continuum: referral for transplant, transplant evaluation and selection, living donor identification/evaluation, and waitlist outcomes.

Results

Our search generated 16,643 studies, of which 227 were included in our final review. Of these, 34 focused on disparities in referral for transplantation among patients with chronic organ disease, 82 on transplant selection processes, 50 on living donors, and 61 on waitlist management. In total, 15 studies involved the thoracic organs (heart, lung), 209 involved the abdominal organs (kidney, liver, pancreas), and three involved multiple organs. Racial and ethnic minorities, women, and patients in lower socioeconomic status groups were less likely to be referred, evaluated, and added to the waiting list for organ transplant. The quality of the data describing these disparities across the transplant literature was variable and overwhelmingly focused on kidney transplant.

Conclusions

This review contextualizes the quality of the data, identifies seminal work by organ, and reports gaps in the literature where future research on disparities in organ transplantation should focus. Future work should investigate the association of social determinants of health with access to the organ transplant waiting list, with a focus on prospective analyses that assess interventions to improve health equity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12939-021-01616-x.

The influence of equitable access policies and socioeconomic factors on post-liver transplant survival

BACKGROUND

Survival following liver transplant (LT) is influenced by a variety of factors, including donor risk factors and recipient disease burden and co-morbidities. It is difficult to separate these effects from those of socioeconomic factors, such as income or insurance. The United Network for Organ Sharing (UNOS) created equitable access policies, such as Share 35, to ensure that organs are distributed to individuals with greatest medical need; however, the effect of Share 35 on disparities in post-LT survival is not clear. This study aimed to (1) characterize associations between post-transplant survival and race and ethnicity, income, insurance, and citizenship status, when adjusted for other clinical and demographic factors that may influence survival, and (2) determine if the direction of associations changed after Share 35.

METHODS

A retrospective, cohort study of adult LT recipients (n = 83,254) from the UNOS database from 2005 to 2019 was conducted. Kaplan-Meier survival graphs and stepwise multivariate cox-regression analyses were performed to characterize the effects of socioeconomic status on post-LT survival, adjusted for recipient and donor characteristics, across the time period and after Share 35.

FINDINGS

Male sex (HR: 0.93 (95% CI: 0.90-0.96)), private insurance (0.91 (0.88-0.94)), income (0.82 (0.79-0.85)), U.S. citizenship, and Asian (0.81 (0.75-0.88)) or Hispanic (0.82 (0.79-0.86)) race and ethnicity were associated with higher post-transplant survival, after adjustment for clinical and demographic factors (Table 3). These associations were found across the entire time period studied and many persisted after the implementation of Share 35 in 2013 (Table 3; male sex (0.84 (0.79-0.90)), private insurance (0.94 (0.89-1.00)), income (0.82 (0.77-0.89)), and Asian (0.87 (0.73-1.02)) or Hispanic (0.88 (0.81-0.96)) race and ethnicity).

INTERPRETATION

Recipients' socioeconomic factors at time of transplant may impact long-term post-transplant survival, and a single policy may not significantly alter these structural health inequalities.

FUNDING

None.

Ethnicity and Insurance-Specific Disparities in the Model for End-Stage Liver Disease Score at Time of Liver Transplant Waitlist Registration and its Impact on Mortality

BACKGROUND AND AIMS

Disparities in timely referral to liver transplantation (LT) evaluation persist. We aim to examine race/ethnicity and insurance-specific differences in the Model for End-Stage Liver Disease (MELD) score at time of waitlist (WL) registration and its impact on WL survival.

METHODS

We retrospectively evaluated U.S. adults listed for LT using 2005-2018 United Network for Organ Sharing LT registry. Multiple linear regression methods examined factors associated with MELD at listing, and Fine-Gray competing risks regression were used to analyze WL mortality.

RESULTS

Among 144,163 WL registrants (median age = 56 years, 65.3% male, 56.4% private insurance, 23.3% Medicare, 15.7% Medicaid), mean WL MELD at listing was higher in African Americans versus non-Hispanic whites (2.57 points higher, 95%CI: 2.40-2.74, P < 0.001). Compared with patients with private insurance, adjusted mean WL MELD was higher among those with no insurance, Medicare, or Medicaid (P < 0.001 for all). After correcting for differences in MELD at listing, Asians had lower risk of WL death versus non-Hispanic whites (subhazard ratio (SHR): 0.92, 95% CI: 0.86-1.00, P = 0.04), but no difference was observed in African Americans or Hispanics. Compared with patients with private insurance, higher risk of WL death was observed in patients with no insurance (SHR: 1.33, 95%CI: 1.14-1.56, P < 0.001), Medicare (SHR: 1.20, 95%CI: 1.16-1.25, P < 0.001), or Medicaid (SHR: 1.22, 95%CI: 1.17-1.27, P < 0.001).

CONCLUSION

Higher MELD scores at listing among African Americans did not translate into increased WL mortality. Patients with Medicare, Medicaid, or uninsured had significantly higher WL mortality than privately insured patients, even after correcting for disparities in MELD scores at listing.

Liver transplant waitlist removal, transplantation rates and post-transplant survival in Hispanics

BACKGROUND AND OBJECTIVES

Hispanics are the fastest growing population in the USA, and our objective was to determine their waitlist mortality rates, liver transplantation (LT) rates and post-LT outcomes.

METHODS

All adults listed for LT with the UNOS from 2002 to 2018 were included. Competing risk analysis was performed to assess the association between ethnic group with waitlist removal due to death/deterioration and transplantation. For sensitivity analysis, Hispanics were matched 1:1 to Non-Hispanics using propensity scores, and outcomes of interest were compared in matched cohort.

RESULTS

During this period, total of 154,818 patients who listed for liver transplant were involved in this study, of them 23,223 (15%) were Hispanics, 109,653 (71%) were Whites, 13,020 (8%) were Blacks, 6,980 (5%) were Asians and 1,942 (1%) were others. After adjusting for differences in clinical characteristics, compared to Whites, Hispanics had higher waitlist removal due to death or deterioration (adjusted cause-specific Hazard Ratio: 1.034, p = 0.01) and lower transplantation rates (adjusted cause-specific Hazard Ratio: 0.90, p<0.001). If Hispanics received liver transplant, they had better patient and graft survival than Non-Hispanics (p<0.001). Compared to Whites, adjusted hazard ratio for Hispanics were 0.88 (95% CI 0.84, 0.92, p<0.001) for patient survival and 0.90 (95% CI 0.86, 0.94, p<0.001) for graft survival. Our analysis in matched cohort showed the consistent results.

CONCLUSIONS

This study showed that Hispanics had higher probability to be removed from the waitlist due to death, and lower probability to be transplanted, however they had better post-LT outcomes when compared to whites.

Racial/Ethnic Disparities in Access and Outcomes of Simultaneous Liver-Kidney Transplant Among Liver Transplant Candidates With Renal Dysfunction in the United States

BACKGROUND

Since the Model for End-stage Liver Disease (MELD) allocation system was implemented, the proportion of simultaneous liver-kidney transplantation (SLKT) has increased significantly. However, whether racial/ethnic disparities exist in access to SLKT and post-SLKT survival remains understudied.

METHODS

A retrospective cohort of patients aged ≥18 years with renal dysfunction on the liver transplant (LT) waiting list was obtained from Organ Procurement and Transplantation Network. Renal dysfunction was defined as estimated glomerular filtration rate <60 mL/min/1.73 m at listing for LT. Multilevel time-to-competing-events regression adjusting for center effect was used to examine the likelihood of receiving SLKT. Inverse probability of treatment weighted survival analyses were used to analyze posttransplant mortality outcomes.

RESULTS

For patients with renal dysfunction at listing for LT, not listed for simultaneous kidney transplant, non-Hispanic black (NHB) and Hispanic patients were more likely to receive SLKT than non-Hispanic white (NHW) patients (NHB: multivariable-adjusted hazard ratio [aHR] 2.57; 95% confidence interval [CI], 1.42-4.65; Hispanic: aHR, 2.03; 95% CI, 1.14-3.60). For post-SLKT outcomes, compared to NHW patients, NHB patients had a lower mortality risk before 24 months (aHR, 0.80; 95% CI, 0.65-0.97) but had a higher mortality risk (aHR, 2.00; 95% CI, 1.59-2.55) afterward; in contrast, Hispanic patients had a lower overall mortality risk than NHW patients (aHR, 0.61; 95% CI, 0.51-0.74).

CONCLUSIONS

In the MELD era, racial/ethnic differences exist in access and survival of SLKT for patients with renal dysfunction at listing for LT. Future studies are warranted to examine whether these differences remain in the post-SLK allocation policy era.

The Impact of Share 35 Policy on Patient Survival in Patients Undergoing Liver Transplantation With Gender- and Race-Mismatched Donors: An Analysis of the United Network for Organ Sharing Registry

INTRODUCTION

The United Network for Organ Sharing (UNOS) instituted the Share 35 policy in June 2013 in order to reduce death on liver transplant waitlist. The effect of this policy on patient survival among patients with gender- and race-mismatched donors has not been examined.

RESEARCH QUESTION

To assess the impact of Share 35 policy on posttransplantation patient survival among patients with end-stage liver disease (ESLD) transplanted with gender- and race-mismatched donors.

DESIGN

A total of 16 467 adult patients with ESLD who underwent liver transplantation between 2012 and 2015 were identified from UNOS. An overall Cox proportional hazards model adjusting for demographic, clinical, and geographic factors and separate models with a dummy variable of pre- and post-Share 35 periods as well as its interaction with other factors were performed to model the effect of gender and race mismatch on posttransplantation patient survival and to compare the patient survival differences between the first 18 months of Share 35 policy to an equivalent time period before.

RESULTS

Comparison of the pre- and post-Share 35 periods did not show significant changes in the numbers of gender- and race-mismatched transplants, or the risk of death for gender-mismatched recipients. However, black recipients with Hispanic donors (hazard ratio: 0.51, 95% confidence interval, 0.29-0.90) had significantly increased patient survival after Share 35 policy took effect.

CONCLUSION

The Share 35 policy had a moderate impact on posttransplantation patient survival among recipients with racially mismatched donors according to the first 18-month experience. Future research is recommended to explore long-term transplantation.