Mitigating Racial and Sex Disparities in Access to Living Donor Kidney Transplantation: Impact of the Nation's Longest Single-center Kidney Chain

A systematic review of psychosocial and sex-based contributors to gender disparities in the United States across the steps towards kidney transplantation

INTRODUCTION

Persistent findings suggest women and patients identified as "female" are less likely to receive a kidney transplant. Furthermore, the limited research on transplantation among transgender and gender diverse people suggests this population is susceptible to many of the same psychosocial and systemic barriers.

OBJECTIVE

This review sought to 1) highlight terminology used to elucidate gender disparities, 2) identify barriers present along the steps to transplantation, and 3) summarize contributors to gender disparities across the steps to transplantation.

METHODS

A systematic review of gender and sex disparities in the steps towards kidney transplantation was conducted in accordance with PRISMA guidelines across four social science and public health databases from 2005 to 23.

RESULTS

The search yielded 1696 initial results, 33 of which met inclusion criteria. A majority of studies followed a retrospective cohort design (n = 22, 66.7%), inconsistently used gender and sex related terminology (n = 21, 63.6%), and reported significant findings for gender and sex disparities within the steps towards transplantation (n = 28, 84.8%). Gender disparities among the earlier steps were characterized by patient-provider communication and perception of medical suitability whereas disparities in the later steps were characterized by differential outcomes based on older age, an above average BMI, and Black racial identity. Findings for transgender patients pointed to issues computing eGFR and the need for culturally tailored care.

DISCUSSION

Providers should be encouraged to critically examine the diagnostic criteria used to determine transplant eligibility and adopt practices that can be culturally tailored to meet the needs of patients.

Relationships, race/ethnicity, gender, age, and living kidney donation evaluation willingness

Racial/ethnic and gender disparities in living donor kidney transplantation are large and persistent but incompletely explained. One previously unexplored potential contributor to these disparities is differential willingness to donate to recipients in specific relationships such as children, parents, and friends. We collected and analyzed data from an online sample featuring an experimental vignette in which respondents were asked to rate their willingness to donate to a randomly chosen member of their family or social network. Results show very large differences in respondents' willingness to donate to recipients with different relationships to them, favoring children, spouses/partners, siblings, and parents, and disfavoring friends, aunts/uncles, and coworkers. Evidence suggesting an interactive effect between relationship, respondent race/ethnicity, respondent or recipient gender, was limited to a few cases. At the p < 0.05 level, the parent-recipient gender interaction was statistically significant, favoring mothers over fathers, as was other/multiracial respondents' greater willingness to donate to friends compared to Whites. Additionally, other interactions were significant at the p < 0.10 level, such as Hispanics' and women's higher willingness to donate to parents compared to Whites and men respectively, women's lower willingness to donate to friends compared to men, and Blacks' greater willingness to donate to coworkers than Whites. We also examined differences by age and found that older respondents were less willing to donate to recipients other than their parents. Together these results suggest that differential willingness to donate by relationship group may be a moderately important factor in understanding racial/ethnic and gender disparities in living donor kidney transplantation.

Disparities Persist Among Hispanic Patients: Completing Evaluation, Waitlisting, and Receiving a Kidney Transplant

Background

Hispanic patients receive disproportionately fewer kidney transplants (KT) than non-Hispanic White (NHW) patients. In this observational study, we evaluated disparities in completing evaluation steps to KT among Hispanic patients.

Methods

Using medical records of Hispanic and NHW patients initiating evaluation at 4 transplant centers from January 2011 to March 2020, we performed sequential Cox models to compare Hispanic versus NHW patients reaching each step of the evaluation process until receiving a KT.

Results

Among all 5197 patients (Hispanic n = 2473; NHW n = 2724) initiating evaluation, Hispanic patients had 8% lower risk to be approved by the kidney pancreas (KP) committee than NHW patients (adjusted hazard ratio [aHR], 0.92; 95% confidence intervals (CI), 0.86-0.98; P = 0.015). Among 3492 patients approved by the KP committee, Hispanic patients had 13% lower risk to be waitlisted than NHW patients (aHR, 0.87; 95% CI, 0.81-0.94; P = 0.004). Among 3382 patients who were waitlisted, Hispanic patients had 11% lower risk than NHW patients to receive KT (aHR, 0.89; 95% CI, 0.81-0.97; P = 0.011). Among all patients initiating evaluation, Hispanic patients had a 16% lower risk than NHW patients to reach KT (aHR, 0.84; 95% CI, 0.76-0.92; P = 0.0002).

Conclusions

Our study found that disproportionately fewer Hispanic patients were approved by the KP committee, were waitlisted, and received a KT, particularly a living donor kidney transplant, than NHW patients. Closer oversight of the evaluation process may help patients overcome challenges in access to KT.

Act Together and Act Now to Overcome Gender Disparity in Organ Transplantation

Gender disparity refers to the unequal treatment or a perception of individuals based on their gender and arises from differences in socially constructed gender roles. In the field of transplantation, gender inequality arises at different stages, affecting access to medical care, donation practices, and posttransplant followup care. Gender disparity in transplantation is not limited to any geographic region but is thought to be more prevalent in developing nations. An unusually high number of female donations with relatively fewer female recipients is not only attributable to the low economy but a congregation of medical, social, cultural, and psychological factors. Gender disparities can also be shown in transplant-related professional societies. This review highlights the complexities of spousal donation and vulnerability of women, especially in the developing world. There is a growing need to further modify transplant policies to tackle gender disparities, especially in living related donation. Systematic research in the context of gender-related concerns in transplantation will further aid in understanding the complexities and formulating policies for eliminating gender disparities. Gender disparity is a global problem and not merely limited to transplantation.

Addressing sex-based disparities in solid organ transplantation in the United States - a conference report

Solid organ transplantation provides the best treatment for end-stage organ failure, but significant sex-based disparities in transplant access exist. On June 25, 2021, a virtual multidisciplinary conference was convened to address sex-based disparities in transplantation. Common themes contributing to sex-based disparities were noted across kidney, liver, heart, and lung transplantation, specifically the existence of barriers to referral and wait listing for women, the pitfalls of using serum creatinine, the issue of donor/recipient size mismatch, approaches to frailty and a higher prevalence of allosensitization among women. In addition, actionable solutions to improve access to transplantation were identified, including alterations to the current allocation system, surgical interventions on donor organs, and the incorporation of objective frailty metrics into the evaluation process. Key knowledge gaps and high-priority areas for future investigation were also discussed.

Sex and gender disparity in kidney transplantation: Historical and future perspectives

Sex and gender disparity exist in various stages of kidney transplantation. Females were found to be less likely to be referred for kidney transplant, complete pre-transplant evaluation, be placed on the waitlist, and receive a kidney transplant compared to their male counterparts. Interestingly, females comprise the majority of living kidney donors. This review explores the biological and psychosocial factors that contribute to sex and gender disparity in kidney transplantation and proposes ways to address the disparity.

Sex and Gender Differences in Kidney Transplantation

Sex and gender often are used interchangeably, but are two distinct entities, with sex being the biological attribute and gender including the social, psychological, and cultural aspects of one's identity. Kidney transplantation has been proven to be the best treatment for end-stage kidney disease, improving both quality of life and life-expectancy for most patients. However, gender disparities in access to and outcomes of kidney transplantation remain despite the plethora of evidence showing the advantages of kidney transplantation to our patients. Data have shown that women are less likely to be waitlisted for a kidney transplant and to receive a deceased donor or a living donor kidney. On the other hand, women are more likely than men to become living kidney donors. Although some state the latter is the result of the female gender to nurture and care for loved ones, others believe this observation is because women often are incompatible with their spouse or child because pregnancy is a strong sensitizing event, which stems from the biological rather than the social differences between the sexes. Influence of sex and gender is not limited to access to kidney transplantation, but rather exist in other areas of transplant medicine, such as the difference observed in transplant outcomes between the sexes, variability in immunosuppression metabolism, and even in more contemporary areas such as recent data showing sex-based differences in outcomes of kidney transplant recipients with coronavirus disease-2019, with males having an increased incidence of acute kidney injury and death.

The UK Chinese population with kidney failure: Clinical characteristics, management and access to kidney transplantation using 20 years of UK Renal Registry and NHS Blood and Transplant data

Background

Little is known about the clinical demographics of and access to transplantation for Chinese diaspora populations with kidney disease.

Methods

The UK Renal Registry provided data on adults with ethnicity recorded as ‘Chinese’ or ‘White’ starting Kidney Replacement Therapy (KRT) 1/1/97-31/12/17. Baseline characteristics were compared between Chinese and White patients. Multivariable logistic regression models were used to investigate the relationships between Chinese ethnicity and i) being listed for deceased-donor transplantation at start of KRT, ii) being listed 2 years after start of KRT, iii) pre-emptive kidney transplantation, iv) kidney transplantation 3 years after start of KRT, and v) living-donor kidney transplantation (LDKT).

Results

UK Chinese patients were younger at start of KRT (61.6 vs 65.6 years, p <0.001) and had more diabetic kidney disease (29% vs 20%, p<0.001) and glomerulonephritis (21% vs 13%, p<0.001) than White patients. We found evidence of interaction between ethnicity and sex. Compared to UK White men, UK Chinese men had lower odds of pre-emptive transplant (aOR 0.28, 95% CI [0.10–0.76]) and transplant within 3 years of KRT start (aOR 0.65, [95% CI 0.49–0.87], P = 0.004). UK White women and Chinese women had the same likelihood of pre-emptive transplant (aOR 0.78, 95% CI [0.38–1.61]), or transplant within 3 years of KRT start (aOR 0.94, 95% CI [0.60–1.46]). Both UK Chinese men and women had markedly lower odds of LDKT compared to Whites aOR 0.34 [95% CI 0.21–0.53].

Conclusions

UK Chinese are less likely to receive a LDKT. UK Chinese men have lower odds of accessing pre-emptive wait-listing and transplantation. Understanding whether these disparities reflect modifiable barriers will help ensure equitable access to transplantation.

Effectiveness of a culturally competent care intervention in reducing disparities in Hispanic live donor kidney transplantation: A hybrid trial

Hispanic patients receive disproportionately fewer living donor kidney transplants (LDKTs) than non-Hispanic Whites (NHWs). The Northwestern Medicine Hispanic Kidney Transplant Program (HKTP), designed to increase Hispanic LDKTs, was evaluated as a nonrandomized, implementation-effectiveness hybrid trial of patients initiating transplant evaluation at two intervention and two similar control sites. Using a mixed method, observational design, we evaluated the fidelity of the HKTP implementation at the two intervention sites. We tested the impact of the HKTP intervention by evaluating the likelihood of receiving LDKT comparing pre-intervention (January 2011-December 2016) and postintervention (January 2017-March 2020), across ethnicity and centers. The HKTP study included 2063 recipients. Intervention Site A exhibited greater implementation fidelity than intervention Site B. For Hispanic recipients at Site A, the likelihood of receiving LDKTs was significantly higher at postintervention compared with pre-intervention (odds ratio [OR] = 3.17 95% confidence interval [1.04, 9.63]), but not at the paired control Site C (OR = 1.02 [0.61, 1.71]). For Hispanic recipients at Site B, the likelihood of receiving an LDKT did not differ between pre- and postintervention (OR = 0.88 [0.40, 1.94]). The LDKT rate was significantly lower for Hispanics at paired control Site D (OR = 0.45 [0.28, 0.90]). The intervention significantly improved LDKT rates for Hispanic patients at the intervention site that implemented the intervention with greater fidelity. Registration: ClinicalTrials.gov registered (retrospectively) on September 7, 2017 (NCT03276390).

Gender disparities in transplantation

PURPOSE OF REVIEW

Transplantation is the life-saving therapy for patients suffering from end-organ failure, and as such, equitable access to transplantation (ATT) is of paramount importance. Unfortunately, gender/sex-based disparities exist, and despite the transplant community's awareness of this injustice, gender/sex-based disparities have persisted for more than two decades. Importantly, no legislation or allocation policy has addressed inequity in ATT that women disproportionately face. In fact, introduction of the model for end-stage liver disease-based liver allocation system in 2002 widened the gender disparity gap and it continues to be in effect today. Moreover, women suffering from kidney disease are consistently less likely to be referred for transplant evaluation and subsequently less likely to achieve a kidney transplant, yet they comprise the majority of living kidney donors.

RECENT FINDINGS

Acknowledging gender/sex-based disparities in ATT is the first step toward interventions aimed at mitigating this long-standing injustice in healthcare.

SUMMARY

This article provides a background of end-stage liver and kidney disease in women, summarizes the existing literature describing the issue of gender disparity in ATT, and identifies potential areas of intervention and future investigation.

Race, Education, and Gender Disparities in Transplantation of Kidneys From Hepatitis C Viremic Donors

BACKGROUND

Transplantation of kidneys from hepatitis C virus (HCV)-viremic donors into HCV-negative patients followed by direct-acting antiviral therapy was an important breakthrough to increase the number of life-saving kidney transplants. Data suggest that these transplants offer several benefits; however, it is unknown whether adoption of this practice has been shared equitably, especially among disadvantaged groups.

METHODS

We evaluated United Network for Organ Sharing data on HCV-seronegative adult deceased-donor kidney transplant recipients from January 1, 2017, to June 12, 2020. We compared recipients of a kidney from an HCV antibody- (Ab-)/nucleic acid test- (NAT-), HCV Ab+/NAT-, and HCV NAT+ donor. The primary covariates were as follows: (1) race/ethnicity; (2) female sex; and (3) highest level of education. Models included variables associated with being offered an HCV NAT+ kidney. We fit mixed-effects multinomial logistic regression models with the center as a random effect to account for patient clustering.

RESULTS

Of 48 255 adult kidney-alone deceased-donor kidney transplant HCV-seronegative recipients, 1641 (3.4%) donors were HCV NAT+-, increasing from 0.3% (January 2017-June 2017) to 6.9% (January 2020-June 2020). In multivariable models, racial/ethnic minorities, women, and those with less education were significantly less likely to receive a kidney from an HCV NAT+ donor relative to an HCV Ab-/NAT- and HCV Ab+/NAT- donor. The disparities were most pronounced among Hispanic and Asian patients with less educational attainment (grade school, high school, or some college/tech school).

CONCLUSIONS

Despite an increase in transplants from HCV NAT+ donors, we found substantial racial/ethnic disparities in transplantation of these kidneys. These data highlight how the benefits of a scientific breakthrough are often made less available to disadvantaged patients.

Current and Evolving Indications for Simultaneous Liver Kidney Transplantation

This review will discuss the etiologies of kidney disease in liver transplant candidates, provide a historical background of the prior evolution of simultaneous liver-kidney (SLK) transplant indications, discuss the current indications for SLK including Organ Procurement and Transplantation Network policies and Model for End Stage Liver Disease exception points, as well as provide an overview of the safety net kidney transplant policy. Finally, the authors explore unanswered questions and future research needed in SLK transplantation.

New Perspectives on Desensitization in the Current Era - An Overview

Blood group and tissue incompatibilities remain significant barriers to achieving transplantation. Although no patient should be labeled "un-transplantable" due to blood group or tissue incompatibility, all candidates should be provided with individualized and realistic counseling regarding their anticipated wait times for deceased donor or kidney paired donation matching, with early referral to expert centers for desensitization when needed. Vital is the careful selection of patients whose health status is such that desensitizing treatment is less likely to cause serious harm and whose anti-HLA antibody status is such that treatment is likely to accomplish the goal of increasing organ offers with an acceptable final crossmatch. Exciting new developments have re-energized the interest and scope of desensitization in the times ahead.

Asian American Pacific Islander Representation in Outcomes Research: NSQIP Scoping Review

BACKGROUND

If Asian American and Pacific Islanders (AAPIs) are not recognized within patients in health services research, we miss an opportunity to ensure health equity in patient outcomes. However, it is unknown what the rates are of AAPIs inclusion in surgical outcomes research.

STUDY DESIGN

Through a scoping review, we used Covidence to search MEDLINE, EMBASE, PsycINFO, Web of Science, Scopus, and CINAHL for studies published in 2008-2018 using NSQIP data. NSQIP was chosen because of its national scope, widespread use in research, and coding inclusive of AAPI patients. We examined the proportion of studies representing AAPI patients in the demographic characteristics and Methods, Results, or Discussion section. We then performed multivariable logistic regression to examine associations between study characteristics and AAPI inclusion.

RESULTS

In 1,264 studies included for review, 62% included race. Overall, only 22% (n = 278) of studies included AAPI patients. Of studies that included race, 35% represented AAPI patients in some component of the study. We found no association between sample size or publication year and inclusion. Studies were significantly more likely to represent AAPI patients when there was a higher AAPI population in the region of the first author's institution (lowest vs highest tercile; p < 0.001). Studies with a focus on disparities were more likely to include AAPI patients (p = 0.001).

CONCLUSIONS

Our study is the first to examine AAPI representation in surgical outcomes research. We found < 75% of studies examine race, despite availability within NSQIP. Little more than one-third of studies including race reported on AAPI patients as a separate group. To provide the best care, we must include AAPI patients in our research.

UAB-UCSD O'Brien Center for Acute Kidney Injury Research

Acute kidney injury (AKI) remains a significant clinical problem through its diverse etiologies, the challenges of robust measurements of injury and recovery, and its progression to chronic kidney disease (CKD). Bridging the gap in our knowledge of this disorder requires bringing together not only the technical resources for research but also the investigators currently endeavoring to expand our knowledge and those who might bring novel ideas and expertise to this important challenge. The University of Alabama at Birmingham-University of California-San Diego O'Brien Center for Acute Kidney Injury Research brings together technical expertise and programmatic and educational efforts to advance our knowledge in these diverse issues and the required infrastructure to develop areas of novel exploration. Since its inception in 2008, this O'Brien Center has grown its impact by providing state-of-the-art resources in clinical and preclinical modeling of AKI, a bioanalytical core that facilitates measurement of critical biomarkers, including serum creatinine via LC-MS/MS among others, and a biostatistical resource that assists from design to analysis. Through these core resources and with additional educational efforts, our center has grown its investigator base to include >200 members from 51 institutions. Importantly, this center has translated its pilot and catalyst funding program with a $37 return per dollar invested. Over 500 publications have resulted from the support provided with a relative citation ratio of 2.18 ± 0.12 (iCite). Through its efforts, this disease-centric O'Brien Center is providing the infrastructure and focus to help the development of the next generation of researchers in the basic and clinical science of AKI. This center creates the promise of the application at the bedside of the advances in AKI made by current and future investigators.

Kidney Replacement Treatment in South-Western Italy (Campania): Population-Based Study on Gender and Residence Inequalities in Health Care Access

The aim of this study was to investigate the epidemiology of kidney replacement treatment (KRT) in Italy with a focus on gender and residence. As a population-based study using administrative databases from the Campania region of Italy between 2015 and 2018, the study outcomes included diagnoses of haemodialysis, peritoneal dialysis, kidney transplant, and mortality. A total of 11,713 residents in Campania were on KRT from 2015 to 2018. The annual prevalence ranged between 1000 and 1015 patients per million population (pmp) for haemodialysis, between 115 and 133 pmp for peritoneal dialysis, and between 2081 and 2245 pmp for kidney transplant. The annual incidence ranged between 160 and 185 pmp for de novo haemodialysis and between 59 and 191 pmp for kidney transplant. Annual mortality ranged between 12.8% and 14.2% in haemodialysis, between 5.2% and 13.8% in peritoneal dialysis, and between 2.4% and 3.3% in kidney transplant. In Cox regression targeting mortality, significant HRs were found for age (95%CI = 1.05/1.05), kidney transplant (compared to haemodialysis: 0.37/0.47), residence in suburban areas (1.03/1.24), and de novo dialysis incidence in years 2015–2018 (1.01/1.17). The annual rate of kidney transplant was 2.6%. In regression targeting kidney transplant rate, significant HRs were found for female gender (0.67/0.92), age (0.93/0.94), residence in suburban areas (0.65/0.98), and de novo incidence of dialysis in 2015–2018 (0.49/0.71). The existence of socioeconomic inequities in KRT is suggested by the evidence that gender and suburban residence predicted mortality and/or access to kidney transplant.