Racial disparities in paediatric kidney transplantation

Background

Transplantation is the preferred treatment for children with end-stage kidney disease (ESKD). Pre-emptive transplants, those from live donors and with few human leukocyte antigen (HLA) mismatches provide the best outcomes. Studies into disparities in paediatric transplantation to date have not adequately disentangled different transplant types.

Methods

We studied a retrospective cohort of 823 patients aged <18 years who started renal replacement therapy (RRT) in Australia 1990–2011, using the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA). The primary outcomes were time to first kidney transplant and kidney donor type (deceased or living), analysed using competing risk regression.

Results

Caucasian patients were most likely to receive any transplant, due largely to disparities in live donor transplantation. No Indigenous patients received a pre-emptive transplant. Indigenous patients were least likely to receive a transplant from a live donor (sub-hazard ratio 0.41, 95 % confidence interval 0.20–0.82, compared to Caucasians). Caucasian recipients had fewer HLA mismatches, were less sensitised and were more likely to have kidney diseases that could be diagnosed early or progress slowly.

Conclusions

Caucasian paediatric patients are more likely to receive optimum treatment—a transplant from a living donor and fewer HLA mismatches. Further work is required to identify and address barriers to live donor transplantation among minority racial groups.     

Racial and ethnic disparities in kidney transplantation

Success of renal transplantation, as a viable alternative to dialysis, has been tempered by long‐standing racial disparities. Ethnic minorities have less access to transplantation, are less likely to be listed for transplantation, and experience a higher rate of graft failure. Reasons for the existing racial disparities at various stages of the transplantation process are complex and multi‐factorial. They include a combination of behavioral, social, environmental, and occupational factors, as well as potential intended or unintended discrimination within the healthcare system. Immunologic factors such as human leukocyte antigen matching, composition of the organ donor pool, and patient immune response, all of which affect post‐transplantation graft rejection rates and patient survival, also contribute to health disparities between ethnic groups.     

Racial disparities in access to pediatric kidney transplantation since share 35

Share 35 was enacted in 2005 to shorten transplant wait times and provide high-quality donors to children with ESRD. To investigate the possible effect of this policy on racial disparities in access to pediatric transplantation, we analyzed data from the US Renal Data System before and after Share 35. Among 4766 pediatric patients with incident ESRD, the probability of receiving a deceased-donor kidney transplant increased 46% after Share 35, with Hispanics experiencing the greatest improvements (increases of 81% for Hispanics, 45% for blacks, and 37% for whites). On average, patients received a deceased-donor kidney transplant earlier after Share 35, but this finding varied by race: 63 days earlier for whites, 90 days earlier for blacks, and 201 days earlier for Hispanics. Furthermore, a shift from living- to deceased-donor sources occurred with Share 35 for all races, with a 25% reduction in living donors for whites compared with 48% and 46% reductions for Hispanics and blacks, respectively. In summary, Share 35 seems to have attenuated racial disparities in the time to and probability of children receiving a deceased-donor kidney transplant. These changes coincided with changes in the rates of living-donor sources, which vary by race. Future studies should explore how these changes may impact racial differences in long-term graft outcomes.     

Racial/ethnic disparities in waitlisting for deceased donor kidney transplantation 1 year after implementation of the new national kidney allocation system

The impact of a new national kidney allocation system (KAS) on access to the national deceased‐donor waiting list (waitlisting) and racial/ethnic disparities in waitlisting among US end‐stage renal disease (ESRD) patients is unknown. We examined waitlisting pre‐ and post‐KAS among incident (N = 1 253 100) and prevalent (N = 1 556 954) ESRD patients from the United States Renal Data System database (2005‐2015) using multivariable time‐dependent Cox and interrupted time‐series models. The adjusted waitlisting rate among incident patients was 9% lower post‐KAS (hazard ratio [HR]: 0.91; 95% confidence interval [CI], 0.90‐0.93), although preemptive waitlisting increased from 30.2% to 35.1% (P < .0001). The waitlisting decrease is largely due to a decline in inactively waitlisted patients. Pre‐KAS, blacks had a 19% lower waitlisting rate vs whites (HR: 0.81; 95% CI, 0.80‐0.82); following KAS, disparity declined to 12% (HR: 0.88; 95% CI, 0.85‐0.90). In adjusted time‐series analyses of prevalent patients, waitlisting rates declined by 3.45/10 000 per month post‐KAS (P < .001), resulting in ≈146 fewer waitlisting events/month. Shorter dialysis vintage was associated with greater decreases in waitlisting post‐KAS (P < .001). Racial disparity reduction was due in part to a steeper decline in inactive waitlisting among minorities and a greater proportion of actively waitlisted minority patients. Waitlisting and racial disparity in waitlisting declined post‐KAS; however, disparity remains.     

A single center experience in preemptive kidney transplantation

Transplantation is recognized as preemptive if it takes place before the initiation of chronic dialysis. This maneuver has the potential to avoid the morbidity and burden of chronic dialysis. From November 2003 to April 2005, 15 (7 male, 8 female) end-stage renal failure patients of mean age 40 +/- 14.8 years received preemptive grafts from 2 living-related and 13 cadaveric donors, constituting 11.5% of all kidney transplantations performed in our center at that time. The period on the waiting list for preemptive recipients, namely, 2 weeks to 6 months (mean, 2.4 months), was significantly shorter than that of other patients (mean, 13.8 months). The mean creatinine clearance calculated from the Cockroft Gault formula and the mean plasma creatinine level in preemptive recipients before transplantation were 12.7 +/- 3.1 mL/min and 6.6 +/- 0.8 mg/dL, respectively. The donors for preemptive and non-preemptive groups of recipients did not differ significantly in respect to age, gender, and renal function. The mean number of mismatches of 3.73 and 3.25 and the mean total ischemic times of 9.53 +/- 5 and 11.2 +/- 5 hours, in preemptive and non-preemptive groups of recipients, respectively. The incidence of delayed graft function (dialysis in the first week after transplantation) was significantly lower among preemptive recipients (20% versus 42%, respectively). The groups did not differ either in respect to the occurrence of acute rejection episodes or graft and patient survivals. In preemptive patients the mean plasma creatinine levels at 3 and 12 months were 1.37 +/- 0.3 and 1.09 +/- 0.3 mg/dL, and in non-preemptive patients 1.7 +/- 0.5 and 1.4 +/- 0.4 mg/dL. In conclusion, these results are promising, confirming the notion that preemptive kidney transplantation is the optimal treatment for end-stage renal disease patients.     

Policies to promote timely referral for kidney transplantation

There are numerous patient, provider, and health system barriers to accessing kidney transplantation. Patient barriers such as sociocultural and clinical characteristics and provider factors such as provider knowledge and awareness of transplantation play important roles in facilitating transplant. Health system factors like misaligned incentives and quality metrics for dialysis facilities and transplant centers also influence transplant access. While numerous studies have documented the impact of these barriers on wait-listing and transplant, few studies have examined referral from a dialysis facility to a transplant center and start of the transplant evaluation process. While the Centers for Medicare and Medicaid Services (CMS) require that dialysis facilities educate patients about transplant, there are no guidelines for the content and objectives for this education. In addition, policies to require timely referral for transplantation have been considered by CMS but are difficult to implement without national data on referral. Federal policies should be amended to mandate transplant center submission of referral data—while decreasing the unfunded mandate to collect other unusable data currently collected as part of regulatory monitoring of transplant centers—to promote timely access to transplant, increased transplant rates, and to better understand the multilevel barriers and facilitators to transplant referral.     

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.     

Racial and ethnic disparities in end-stage kidney failure-survival paradoxes in African-Americans

The risk of death is nearly 45% lower in African-Americans than Caucasians undergoing chronic hemodialysis. In light of the higher mortality rate in African-Americans in the general US population, this paradox requires explanation and further investigation. Factors that may contribute to this survival advantage include a younger age at which African-Americans arrive at end-stage renal disease (ESRD) and the slightly higher body mass index. On the other hand, factors, such as lower residual renal function, lower mean hemoglobin and hematocrit, increased prevalence of hypertension, a higher prevalence of catheter use for initial dialysis, and generally lower dose of dialysis should put African-Americans on dialysis at a higher risk of death. This survival advantage seems to be completely annulled with a successful renal transplant. Finally, it should be noted that ESRD carries with it a very high mortality rate in all racial and ethnic groups. A successful renal transplant improves but does not restore the expected remaining life times. Therefore, aggressive approach is required in investigating the factors that confer such high mortality risk on ESRD patients.     

Clinical outcome of preemptive kidney transplantation in patients with diabetes mellitus

End-stage renal disease (ESRD) caused by diabetic nephropathy is increasing throughout the world. The survival of diabetic patients treated by transplantation has improved nowadays. Although recent studies have demonstrated preemptive kidney transplantation to be associated with better graft survival in CKD patients, the effect of pre-transplantation dialysis on graft outcomes among diabetic ESRD patients is unclear. This analysis summarized our experience with preemptive kidney transplantation in diabetic ESRD patients by retrospectively comparing 70 such patients transplanted between 1995 and 2009. These 70 patients were divided into two groups: 30 patients underwent preemptive and the other 40 transplantation after maintenance hemodialysis or peritoneal dialysis. We compared graft survivals, acute rejection episodes, postoperative complications, and delayed graft function rates. The 10-year patient survival of 100% in the preemptive group was similar to that of the nonpreemptive group (85%, P = .11). But the 10 year graft survival was higher among the preemptive than the nonpreemptive group (100% vs 75%, P = .02). Pre-transplantation modality did not affect graft survival. Therefore, preemptive kidney transplantation should be applied to eligible patients with diabetic ESRD.     

Ethical implications of ethnic disparities in chronic kidney disease and kidney transplantation

Chronic kidney disease (CKD) is a major epidemic in underserved and minority populations largely due to excess rates of hypertensive and diabetic kidney disease. Multiple complex socioeconomic barriers to early diagnosis and optimal therapies as well as delayed referral for kidney transplantation have created disparities in CKD care provided to ethnic minorities. Disparities exist in wait list time and kidney transplant rates for Native Americans and blacks, independent of insurance status. Moreover, independent of genetic matching, long-term transplant outcomes in blacks remain significantly lower than all other ethnic groups, suggesting that poorly understood social factors contribute to these survival differences. The existence of these disparities raises ethical concerns of equity and social justice in terms of the allocation of scarce resources. Although current changes in allocation policies will improve some disparities, more efforts are ultimately needed to improve access to care and the overall health and survival for all individuals at risk for CKD, independent of their race, ethnicity, or socioeconomic status.     

Racial disparities in outcomes after appendectomy for acute appendicitis

BackgroundAlthough black patients with acute appendicitis have been shown to be less likely than whites to undergo laparoscopic appendectomy, it is unknown whether they suffer increased complications after surgical management of acute appendicitis.MethodsA retrospective analysis of all patients undergoing appendectomy for acute appendicitis from 2005 through 2009, using the National Surgical Quality Improvement Program database, was conducted. Rates of serious and overall morbidity were compared between blacks and whites, with adjustment for preoperative risk factors, the severity of appendicitis, and surgical approach.ResultsBlacks were more likely than whites to suffer serious postoperative complications (4.8% vs 3.3%; adjusted odds ratio vs whites, 1.39; 95% confidence interval, 1.16–1.67; P = .0002) or any complication (8.4% vs 6.0%; adjusted odds ratio vs whites, 1.31; 95% confidence interval, 1.14–1.50; P = .0007).ConclusionsRacial disparities in postoperative outcomes exist for even a procedure as ubiquitous as appendectomy. More research is needed to determine the underlying reasons for these disparities.     

Effect of education on racial disparities in access to kidney transplantation

Higher education level might result in reduced disparities in access to renal transplantation. We analyzed two outcomes: (i) being placed on the waiting list or transplanted without listing and (ii) transplantation in patients who were placed on the waiting list. We identified 3224 adult patients with end-stage renal disease (ESRD) in United States Renal Data System with education information available (mean age of ESRD onset of 57.1 ± 16.2 yr old, 54.3% men, 64.2% white, and 50.4% diabetics). Compared to whites, fewer African Americans graduated from college (10% vs. 16.7%) and a higher percentage never graduated from the high school (38.6% vs. 30.8%). African American race was associated with reduced access to transplantation (hazard ratio [HR] 0.70, p < 0.001 for wait-listing/transplantation without listing; HR 0.58, p < 0.001 for transplantation after listing). African American patients were less likely to be wait-listed/transplanted in the three less-educated groups: HR 0.67 (p = 0.005) for those never completed high school, HR 0.76 (p = 0.02) for high school graduates, and HR 0.65 (p = 0.003) for those with partial college education. However, the difference lost statistical significance in those who completed college education (HR 0.75, p = 0.1). In conclusion, in comparing white and African American candidates, racial disparities in access to kidney transplantation do exist. However, they might be alleviated in highly educated individuals.