Racial disparities in access to pediatric kidney transplantation since share 35

Dialysis Facility Staffing Ratios and Kidney Transplant Access Among Adolescents and Young Adults

Importance

Patient to staff ratios vary across US dialysis facilities and have been associated with patient outcomes in older adults.

Objective

To determine whether patient to nurse or patient to social worker staff ratios are associated with access to kidney transplant for adolescents and young adults.

Design, Setting, and Participants

Retrospective cohort study including patients aged 12 to 30 years who started dialysis between 2005 and 2019 at 8490 US facilities according to the US Renal Data System, the national end-stage kidney disease registry.

Exposures

Time-updated quartile of patient to nurse and patient to social worker ratios at dialysis facilities.

Main Outcomes and Measures

Fine-Gray models were used to relate the exposure to the incidence of waitlisting and kidney transplant, accounting for the competing risk of death. Subgroup analysis by age at dialysis initiation (<22 vs ≥22 years) was performed. Follow-up was censored in January 2020.

Results

A total of 54 141 participants were included (median age, 25 years [IQR, 21-28]; 54.4% male; 4.3% of Asian race, 35.3% of non-Hispanic Black race). The median patient to staff ratios were 14.4 patients per nurse (IQR, 10.3-18.9) and 91.0 patients per social worker (IQR, 65.2-115.0). During a median follow-up of 2.6 years, 39.9% of patients (n = 21 598) received a transplant. In adjusted analysis, the highest (vs lowest) quartile of patient to nurse ratios was associated with 14% lower incidence of transplant (subhazard ratio [SHR], 0.86 [95% CI, 0.82-0.91]). The highest (vs lowest) quartile of patient to social worker ratios was associated with lower incidence of waitlisting (SHR, 0.95 [95% CI, 0.91-0.99]) and transplant (SHR, 0.85 [95% CI, 0.81-0.89]). For both staff ratios, there was an interaction with age at dialysis initiation, such that the association was more pronounced in patients starting dialysis at younger than 22 years (SHR, 0.71 [95% CI, 0.65-0.78] for the highest vs lowest quartile for nursing; SHR, 0.74 [95% CI, 0.68-0.80] for social work) compared with those 22 years and older (SHR, 1.00 [95% CI, 0.94-1.06] for nursing; SHR, 0.96 [95% CI, 0.91-1.02] for social work) for the outcome of transplant.

Conclusions and Relevance

Adolescents and young adults receiving care at dialysis facilities with higher patient to staff ratios had reduced access to waitlisting and transplant, particularly if they were younger than 22 years of age at dialysis initiation.

Disparities in Access to Timely Waitlisting Among Pediatric Kidney Transplant Candidates

BACKGROUND AND OBJECTIVES

Kidney transplantation with minimal or no dialysis exposure provides optimal outcomes for children with end-stage kidney disease. We sought to understand disparities in timely access to transplant waitlisting.

METHODS

We conducted a retrospective, registry-based cohort study of candidates ages 3 to 17 added to the US kidney transplant waitlist 2015 to 2019. We defined "preemptive waitlisting" as waitlist addition before receiving dialysis and compared demographics of candidates based on preemptive status. We used competing risk regression to determine the association between preemptive waitlisting and transplantation. We then identified waitlist additions age >18 who initiated dialysis as children, thereby missing pediatric allocation prioritization, and evaluated the association between waitlisting with pediatric prioritization and transplantation.

RESULTS

Among 4506 pediatric candidates, 48% were waitlisted preemptively. Female sex, Hispanic ethnicity, Black race, and public insurance were associated with lower adjusted relative risk of preemptive waitlisting. Preemptive listing was not associated with time from waitlist activation to transplantation (adjusted hazard ratio 0.94, 95% confidence interval 0.87-1.02). Among transplant recipients waitlisted preemptively, 68% had no pretransplant dialysis, whereas recipients listed nonpreemptively had median 1.6 years of dialysis at transplant. Among 415 candidates initiating dialysis as children but waitlisted as adults, transplant rate was lower versus nonpreemptive pediatric candidates after waitlist activation (adjusted hazard ratio 0.54, 95% confidence interval 0.44-0.66).

CONCLUSIONS

Disparities in timely waitlisting are associated with differences in pretransplant dialysis exposure despite no difference in time to transplant after waitlist activation. Young adults who experience delays may miss pediatric prioritization, highlighting an area for policy intervention.

Progress made toward equitable transplantation in children and young adults with kidney disease

Racial disparities in pediatric kidney transplantation have been well described over the last two decades and include disparities in preemptive transplantation, waitlisting, time from activation to transplantation, living donation, and graft outcomes. Changes to the organ allocation system including the institution of Share 35 in 2005 and the Kidney Allocation System (KAS) of 2014 have resulted in resolution of some, but not all racial-ethnic disparities. Despite overall improvements in time from waitlist activation to transplant, disparities remain in preemptive transplantation, time to waitlisting, and living donor transplantation. Although improving under the KAS, racial disparities remain in graft survival as well. Racial disparity in kidney transplant access and graft survival is an international problem within pediatric nephrology. Although the racial group affected may differ, various minoritized pediatric groups across the world are affected by transplant disparities. Social determinants of health including financial access, language barriers, and the presence of a healthy living donor play a role in mediating these disparities. Further investigation is needed to better understand and intervene upon modifiable social, biological, and cultural factors driving the remaining disparity in transplant outcomes.

Association Between Dialysis Facility Ownership and Mortality Risk in Children With Kidney Failure

Importance

In adults, treatment at profit dialysis facilities has been associated with a higher risk of death.

Objective

To determine whether profit status of dialysis facilities is associated with the risk of death in children with kidney failure treated with dialysis and whether any such association is mediated by differences in access to transplant.

Design, Setting, and Participants

This retrospective cohort study reviewed US Renal Data System records of 15 359 children who began receiving dialysis for kidney failure between January 1, 2000, and December 31, 2019, in US dialysis facilities. The data analysis was performed between May 2, 2022, and June 15, 2023.

Exposure

Time-updated profit status of dialysis facilities.

Main Outcomes and Measures

Adjusted Fine-Gray models were used to determine the association of time-updated profit status of dialysis facilities with risk of death, treating kidney transplant as a competing risk. Cox proportional hazards regression models were also used to determine time-updated profit status with risk of death regardless of transplant status.

Results

The final cohort included 8465 boys (55.3%) and 6832 girls (44.7%) (median [IQR] age, 12 [3-15] years). During a median follow-up of 1.4 (IQR, 0.6-2.7) years, with censoring at transplant, the incidence of death was higher at profit vs nonprofit facilities (7.03 vs 4.06 per 100 person-years, respectively). Children treated at profit facilities had a 2.07-fold (95% CI, 1.83-2.35) higher risk of death compared with children at nonprofit facilities in adjusted analyses accounting for the competing risk of transplant. When follow-up was extended regardless of transplant status, the risk of death remained higher for children treated in profit facilities (hazard ratio, 1.47; 95% CI, 1.35-1.61). Lower access to transplant in profit facilities mediated 67% of the association between facility profit status and risk of death (95% CI, 45%-100%).

Conclusions and Relevance

Given the higher risk of death associated with profit dialysis facilities that is partially mediated by lower access to transplant, the study's findings indicate a need to identify root causes and targeted interventions that can improve mortality outcomes for children treated in these facilities.

The unfinished journey toward transplant equity: an analysis of racial/ethnic disparities for children after the implementation of the Kidney Allocation System in 2014

BACKGROUND

Disparities in pediatric kidney transplantation (KT) result in reduced access and worse outcomes for minority children. We assessed the impact of recent systems changes on these disparities.

METHODS

This is a retrospective cohort study of pediatric patients utilizing data from the US Renal Data System (n = 7547) and Scientific Registry of Transplant Recipients (n = 6567 waitlisted and n = 6848 transplanted patients). We compared access to transplantation, time to deceased donor kidney transplant (DDKT), and allograft failure (ACGF) in the 5 years preceding implementation of the Kidney Allocation System (KAS) to the 5 years post-KAS implementation 2010-2014 vs. 2015-2019, respectively.

RESULTS

Compared to the pre-KAS era, post-KAS candidates were more likely to be pre-emptively listed (26.8% vs. 38.1%, p < 0.001), pre-emptively transplanted (23.8% vs. 28.0%, p < 0.001), and less likely to have private insurance (35.6% vs. 32.3%, p = 0.01), but these were not uniform across racial groups. Compared to white children, Black and Hispanic children had a lower likelihood of transplant listing within 2 years of first dialysis service (aHR 0.590.670.76 and 0.730.820.92, respectively) in the post-KAS era. Time to DDKT was comparable across all racial groups in the post-KAS era. Compared to white children, Black DDKT recipients have more 5-year ACGF (aHR 1.001.432.06 p = 0.05) while there was no difference in 3- or 5-year ACGF among LDKT recipients.

CONCLUSIONS

After KAS implementation, there is equity in time to DDKT. Pre-KAS increased hazard of ACGF among Black children has decreased in the post-KAS era; however, persistent disparities exist in time to transplant listing among Black and Hispanic children when compared to white children. A higher resolution version of the Graphical abstract is available as Supplementary information.

A systematic review of social determinants of health in pediatric organ transplant outcomes

BACKGROUND

Equitable access to pediatric organ transplantation is critical, although risk factors negatively impacting pre- and post-transplant outcomes remain. No synthesis of the literature on SDoH within the pediatric organ transplant population has been conducted; thus, the current systematic review summarizes findings to date assessing SDoH in the evaluation, listing, and post-transplant periods.

METHODS

Literature searches were conducted in Web of Science, Embase, PubMed, and Cumulative Index to Nursing and Allied Health Literature databases.

RESULTS

Ninety-three studies were included based on pre-established criteria and were reviewed for main findings and study quality. Findings consistently demonstrated disparities in key transplant outcomes based on racial or ethnic identity, including timing and likelihood of transplant, and rates of rejection, graft failure, and mortality. Although less frequently assessed, variations in outcomes based on geography were also noted, while findings related to insurance or SES were inconsistent.

CONCLUSION

This review underscores the persistence of SDoH and disparity in equitable transplant outcomes and discusses the importance of individual and systems-level change to reduce such disparities.

Racial/ethnic differences in receipt of surgery among children in the United States

BACKGROUND

It is unknown whether racial/ethnic disparities exist in surgical utilization for children. The aim, therefore, was to evaluate the odds of surgery among children in the US by race/ethnicity to test the hypothesis that minority children have less surgery.

METHODS

Cross-sectional data were analyzed on children 0-18 years old from the 1999 to 2018 National Health Interview Survey, a large, nationally representative survey. The primary outcome was odds of surgery in the prior 12 months for non Latino African-American, Asian, and Latino children, compared with non Latino White children, after adjustment for relevant covariates. The National Surgical Quality Improvement Program Pediatric Dataset was used to analyze the odds of emergent/urgent surgery by race/ethnicity.

RESULTS

Data for 219,098 children were analyzed, of whom 10,644 (4.9%) received surgery. After adjustment for relevant covariates, African-American (AOR, 0.54; 95% CI, 0.50-0.59), Asian (AOR, 0.39; 95% CI, 0.33-0.46), and Latino (AOR, 0.62; 95% CI, 0.57-0.67) children had lower odds of surgery than White children. Latino children were more likely to require emergent or urgent surgery (AOR, 1.71; 95% CI, 1.68-1.74).

CONCLUSIONS

Latino, African-American, and Asian children have significantly lower adjusted odds of having surgery than White children in America, and Latino children were more likely to have emergent or urgent surgery. These racial/ethnic differences in surgery may reflect disparities in healthcare access which should be addressed through further research, ongoing monitoring, targeted interventions, and quality-improvement efforts.

LEVEL OF EVIDENCE

II.

TYPE OF STUDY

Prognosis study.

Association Between Dialysis Facility Ownership and Access to the Waiting List and Transplant in Pediatric Patients With End-stage Kidney Disease in the US

IMPORTANCE

Care of adults at profit vs nonprofit dialysis facilities has been associated with lower access to transplant. Whether profit status is associated with transplant access for pediatric patients with end-stage kidney disease is unknown.

OBJECTIVE

To determine whether profit status of dialysis facilities is associated with placement on the kidney transplant waiting list or receipt of kidney transplant among pediatric patients receiving maintenance dialysis.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study reviewed the US Renal Data System records of 13 333 patients younger than 18 years who started dialysis from 2000 through 2018 in US dialysis facilities (followed up through June 30, 2019).

EXPOSURES

Time-updated profit status of dialysis facilities.

MAIN OUTCOMES AND MEASURES

Cox models, adjusted for clinical and demographic factors, were used to examine time to wait-listing and receipt of kidney transplant by profit status of dialysis facilities.

RESULTS

A total of 13 333 pediatric patients who started receiving maintenance dialysis were included in the analysis (median age, 12 years [IQR, 3-15 years]; 6054 females [45%]; 3321 non-Hispanic Black patients [25%]; 3695 Hispanic patients [28%]). During a median follow-up of 0.87 years (IQR, 0.39-1.85 years), the incidence of wait-listing was lower at profit facilities than at nonprofit facilities, 36.2 vs 49.8 per 100 person-years, respectively (absolute risk difference, -13.6 (95% CI, -15.4 to -11.8 per 100 person-years; adjusted hazard ratio [HR] for wait-listing at profit vs nonprofit facilities, 0.79; 95% CI, 0.75-0.83). During a median follow-up of 1.52 years (IQR, 0.75-2.87 years), the incidence of kidney transplant (living or deceased donor) was also lower at profit facilities than at nonprofit facilities, 21.5 vs 31.3 per 100 person-years, respectively; absolute risk difference, -9.8 (95% CI, -10.9 to -8.6 per 100 person-years) adjusted HR for kidney transplant at profit vs nonprofit facilities, 0.71 (95% CI, 0.67-0.74).

CONCLUSIONS AND RELEVANCE

Among a cohort of pediatric patients receiving dialysis in the US from 2000 through 2018, profit facility status was associated with longer time to wait-listing and longer time to kidney transplant.

Organ allocation in pediatric abdominal transplant

Pediatric patients constitute an important group within the general transplant population, given the opportunity to significantly extend their lives with successful transplantation. Children have historically received special consideration under the various abdominal solid organ allocation algorithms, but matching patients with size and weight restrictions with appropriate donors remains an ongoing issue. Here, we describe the historical trends in pediatric organ allocation policies for liver, kidney, intestine, and pancreas transplantation. We also review recent changes to these allocation policies, with particular attention to recent amendments to geographical prioritization, with the dissolution of donor service areas and United Network for Organ Sharing (UNOS) regions and the subsequent creation of acuity circles.

Racial Disparities in Pediatric Kidney Transplantation under the New Kidney Allocation System in the United States

BACKGROUND AND OBJECTIVES

In December 2014, the Kidney Allocation System (KAS) was implemented to improve equity in access to transplantation, but preliminary studies in children show mixed results. Thus, we aimed to assess how the 2014 KAS policy change affected racial and ethnic disparities in pediatric kidney transplantation access and related outcomes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a retrospective cohort study of children <18 years of age active on the kidney transplant list from 2008 to 2019 using the Scientific Registry of Transplant Recipients. Log-logistic accelerated failure time models were used to determine the time from first activation on the transplant list and the time on dialysis to deceased donor transplant, each with KAS era or race and ethnicity as the exposure of interest. We used logistic regression to assess odds of delayed graft function. Log-rank tests assessed time to graft loss within racial and ethnic groups across KAS eras.

RESULTS

All children experienced longer wait times from activation to transplantation post-KAS. In univariable analysis, Black and Hispanic children and other children of color experienced longer times from activation to transplant compared with White children in both eras; this finding was largely attenuated after multivariable analysis (time ratio, 1.16; 95% confidence interval, 1.01 to 1.32; time ratio, 1.13; 95% confidence interval, 1.00 to 1.28; and time ratio, 1.17; 95% confidence interval, 0.96 to 1.41 post-KAS, respectively). Multivariable analysis also showed that racial and ethnic disparities in time from dialysis initiation to transplantation in the pre-KAS era were mitigated in the post-KAS era. There were no disparities in odds of delayed graft function. Black and Hispanic children experienced longer times with a functioning graft in the post-KAS era.

CONCLUSIONS

No racial and ethnic disparities from activation to deceased donor transplantation were seen before or after implementation of the KAS in multivariable analysis, whereas time on dialysis to transplantation and odds of short-term graft loss improved in equity after the implementation of the KAS, without compromising disparities in delayed graft function.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2021_12_07_CJN06740521.mp3.

Policy in pediatric nephrology: successes, failures, and the impact on disparities

Pediatric nephrology has a history rooted in pediatric advocacy and has made numerous contributions to child health policy affecting pediatric kidney diseases. Despite this progress, profound social disparities remain for marginalized and socially vulnerable children with kidney disease. Different risk factors, such as genetic predisposition, environmental factors, social risk factors, or health care access influence the emergence and progression of pediatric kidney disease, as well as access to life-saving interventions, leading to disparate outcomes. This review will summarize the breadth of literature on social determinants of health in children with kidney disease worldwide and highlight policy-based initiatives that mitigate the adverse social factors to generate greater equity in pediatric kidney disease.

Resident foreign patients receive adequate dialysis but fewer preemptive transplantations: data from the Italian pediatric dialysis registry

BACKGROUND

Sociocultural issues play a key role in children needing kidney replacement therapy (KRT).

METHODS

Data of incident patients < 18 years treated with chronic dialysis or preemptive kidney transplantation (pTx) between 2007 and 2016 were retrospectively collected from the Italian Pediatric Dialysis Registry; KRT modality and outcome were compared between patients with at least one non-Italian parent ("resident foreign patients," RFPs) and those from native parents ("domestic patients," DPs) and between the quinquennium 2007-2011 (period 1) and 2012-2016 (period 2).

RESULTS

We included 448 children (26.8% RFPs). The percentage of RFPs increased from 23 to 30.3% (p = 0.08) from periods 1 to 2. They were younger (6.7 vs. 9.4 years, p = 0.025) and less often treated with pTx (3.3 vs. 13.4%, p = 0.009) than DPs. The percentage of pTx increased from period 1 to 2 in RFPs only (8.4-18.6%, p = 0.006). Independent predictors of a lower probability of pTx were lower age, belonging to RFPs group, starting KRT in period 1 and focal segmental glomerulosclerosis or glomerulopathy as primary kidney disease. Peritoneal dialysis was the preferred dialysis modality in both groups. Age, primary kidney disease, and center size were independently associated with dialysis modality choice. Patient survival, waiting time to Tx, and dialysis modality survival were not different between the two groups.

CONCLUSIONS

The proportion of patients receiving KRT born from immigrant families increased in recent years in Italy. They were younger and less often treated with pTx than domestic patients. In case of dialysis, the outcome was not different between the two groups. Graphical abstract.

Setting reasonable objectives for improving preemptive kidney transplantation rates in children

BACKGROUND

This study aims to develop a method to estimate the potential of preemptive kidney transplantation (PKT) by identifying patients who were transplanted after a dialysis period (non-preemptive kidney transplantation (NPKT)) despite being medically suitable for PKT.

METHODS

All children (< 18 years old) starting kidney replacement therapy (KRT) in France, between 2010 and 2016 and transplanted before December 31, 2017, were included. A propensity score (PS) of receiving PKT was estimated by multivariate logistic regression based on recipient medical characteristics. Healthcare use during the 24 months prior to KRT initiation was extracted from the French National Health Insurance database, and a pre-KRT follow-up of more than 18 months was considered sufficient to allow preemptive transplantation.

RESULTS

Among 643 patients who started KRT, 149 (23.2%) were preemptively transplanted. Using PS stratification, among 391 NPKT patients, we identified 145 patients (37%) suitable for PKT, according to clinical characteristics. Mean age was 12.3 years, 67% were males, and 56% had urological abnormalities. Among those 145 patients, we identified 79 NPKT patients who started on dialysis despite early referral to a nephrologist (more than 18 months prior to KRT initiation).

CONCLUSIONS

This method estimates a potential of 228 (149 + 79) PKT (35%) among pediatric patients in France. A similar method could be used in adults or in other countries. Estimation of the rate of patients with CKD stage 5 medically suitable for PKT will be of interest for health policy makers when setting up objectives for improvement in preemptive kidney transplant access.

Racial and Ethnic Disparities in Kidney Transplant Access Within a Theoretical Context of Medical Eligibility

BACKGROUND

Non-Hispanic black (NHB) and Hispanic patients have lower access to kidney transplantation compared to non-Hispanic whites (NHWs). We examined whether differences in the prevalence of comorbidities that affect eligibility for transplant contribute to disparities in receipt of transplantation.

METHODS

We performed a retrospective study of 986 019 adults who started dialysis between 2005 and 2014, according to the United States Renal Data System. We compared prevalence of comorbidities that could influence transplant eligibility by race/ethnicity. We examined time to first transplant by race/ethnicity in this overall cohort and in a very healthy sub-cohort without conditions that could be contraindications to transplantation.

RESULTS

During 2.3 years of mean follow-up, 64 892 transplants occurred. NHBs and Hispanics had a lower prevalence of medical barriers to transplantation at the time of dialysis initiation than NHWs, including age >70 years (26% in NHB versus 47% in NHW) and malignancy (4% in Hispanics versus 10% in NHWs). Access to transplant was 65% lower (95% CI, 0.33-0.37) in NHBs and 43% lower (95% CI, 0.54-0.62) in Hispanics (versus NHWs) in the first year after end-stage renal disease, but by Year 4, access to transplantation was not statistically significantly different between Hispanics or NHBs (versus NHWs). In our very healthy cohort, racial and ethnic disparities in access to transplantation persisted up to Year 5 in NHBs and Year 4 in Hispanics after end-stage renal disease onset.

CONCLUSIONS

Differences in medical eligibility do not appear to explain racial/ethnic disparities in receipt of kidney transplantation and may mask the actual magnitude of the inequities that are present.

Trends in Living Donation by Race and Ethnicity Among Children With End-stage Renal Disease in the United States, 1995-2015

BACKGROUND

Living donor kidney transplants have declined among adults with end-stage renal disease (ESRD), with increases in racial/ethnic disparities over time. Secular trends in racial/ethnic disparities in living donor kidney transplantation have not been well studied in children.

METHODS

Using multivariable Cox modeling, we examined changes in living donor kidney transplant rates over time and probability of receiving living donor kidney transplantation within 2 years of incident ESRD by race/ethnicity among 19 772 children in the US Renal Data System, 1995-2015. We also examined racial/ethnic concordance between donors and recipients.

RESULTS

Overall, living donor kidney transplant rates declined by 3% annually since 1995 for all racial/ethnic groups except Asians for whom living donor kidney transplant rates remained stable; however, disparities persist. Compared with non-Hispanic white children, Hispanics were 42% less likely (adjusted hazard ratio: 0.58; 95% confidence interval: 0.49-0.67), Asians 39% less likely (0.61; 0.47-0.79), and blacks 66% less likely (0.34; 0.28-0.42) to receive living kidney donor transplantation within 2 years, even when accounting for deceased donor transplantation as a competing risk. Additionally, while 95% of non-Hispanic white children had non-Hispanic white donors, only 56% of Asian recipients had Asian donors (P < 0.001). Asian recipients were more likely to have nonrelated donors (P < 0.001).

CONCLUSIONS

There are ongoing declines in living donation for children with ESRD for uncertain reasons, and minority populations experience significantly reduced access to timely living donor transplant, even when accounting for changes in deceased donation and donor-recipient relationships.

Temporal Changes in the Impact of HLA Mismatching Among Pediatric Kidney Transplant Recipients

BACKGROUND

Allocation for pediatric deceased-donor kidney transplantation (pDDKT) in the United States now de-emphasizes HLA matching to improve equality in access to transplantation, but other national systems still consider HLA matching due to concerns about graft survival. We hypothesized that the impact of HLA mismatching has decreased over time due to advances including improved immunosuppression.

METHODS

Using Scientific Registry of Transplant Recipient data, we analyzed whether the association between the number of HLA mismatches and outcomes of first-time pDDKTs changed between 2 eras: 1995 to 2004 (N = 2854) and 2005 to 2014 (N = 4643).

RESULTS

Between eras, the median number of mismatches increased from 4 to 5 (P < 0.001). Overall graft failure risk was higher among HLA-mismatched versus HLA-matched transplants (adjusted hazard ratio 1.211.431.69 for 3-6 versus 0-2 mismatches; P < 0.001), and this association was similar pre-2005 and post-2005 (Pinteraction = 0.5). Median panel-reactive antibody change at relisting increased from 79 to 85 (P = 0.01), but the association between number of HLA mismatches and panel-reactive antibody change was similar between eras (Pinteraction = 0.6).

CONCLUSIONS

Our finding that increased HLA mismatching continues to impact graft survival, with 43% higher risk of graft failure, highlights the tradeoff between transplant access equity and outcomes and calls into question the deemphasis on HLA matching in pDDKT allocation in the United States.

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.

Eplet mismatch analysis and allograft outcome across racially diverse groups in a pediatric transplant cohort: a single-center analysis

HLA eplet mismatch load has been suggested as an improvement to HLA antigen mismatch determination for organ selection. Given that eplet mismatches are determined based on amino acid sequence difference among HLA alleles, and that the frequency of HLA alleles varies between racial groups, we investigated the correlation between eplet mismatch load and allograft outcomes in 110 pediatric kidney transplant recipients who received their first organ from a donor of the same race (SRT) versus a donor of a different race (DRT). Adjusted modified Poisson regression was used to assess the interaction between eplet mismatch load and race mismatch and its effect on outcome. Caucasians and living donor recipients had lower eplet mismatched loads against their donors compared with non-Caucasian and deceased donor recipients. Overall, for the entire population, the risk of de novo HLA-DSA development was significantly increased with higher eplet loads (p < 0.001). Compared with the SRT group, the DRT group had higher eplet loads when compared with their donor, for HLA class I but not HLA class II molecules; however, there was no significant difference in the incidence of de novo HLA-DSA between the 2 groups. The risk of rejection increased significantly for DRT compared with SRT, only when class I eplet load was ≥ 70 (p = 0.04). Together this data show that eplet mismatch load analysis is an effective tool for alloimmune risk assessment. If considered for donor selection, acceptable eplet mismatch loads determined from studies in homogenous populations may restrict transplantation across racially diverse donor and patient groups with no evidence of poor outcome. Therefore, an acceptable eplet mismatch load threshold must consider the heterogeneity of the transplant population.

Trends in kidney transplant outcomes in children and young adults with cystinosis

Temporal changes in kidney transplant outcomes for cystinosis are unknown. We used the SRTR to identify all kidney transplants performed for cystinosis in patients younger than 31 years between 1987 and 2017. We divided time into three equal eras (1987-1997, 1998-2007, and 2008-2017) to assess changes in outcomes using Cox proportional and linear regression models. We examined 441 transplants in 362 patients. Age at ESRD progressively increased (12.1 vs 13.3 vs 13.4; P = .046). Eras 2 and 3 had lower risk of acute rejection (aHR 2 vs 1:0.45; P < .001) (aHR 3 vs 1:0.26; P < .001) and higher 5-year mean GFR (difference 2 vs 1:9.2 mL/min/1.73 m² ; P = .005) (difference 3 vs 1:12.9 mL/min/1.73 m² ; P = .002) compared with era 1. Five-year graft survival was similar across eras, but 5-year patient survival was higher for era 2 (aHR: 0.25; P = .01). Seventy-nine patients underwent retransplantation. Five-year patient (94.2% vs 92.5%; P = .57) and graft survival (79.1% vs 74.1%; P = .52) were similar between primary and subsequent transplants. Age at ESRD, acute rejection, GFR at 5 years, and patient survival improved over time. Kidney retransplantation is associated with excellent outcomes in children and young adults with cystinosis.

Race and Mortality in CKD and Dialysis: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study

RATIONALE & OBJECTIVES

Few studies have investigated racial disparities in survival among dialysis patients in a manner that considers risk factors and mortality during the phase of kidney disease before maintenance dialysis. Our objective was to explore racial variations in survival among dialysis patients and relate them to racial differences in comorbid conditions and rates of death in the setting of kidney disease not yet requiring dialysis therapy.

STUDY DESIGN

Retrospective cohort study.

SETTINGS & PARTICIPANTS

3,288 black and white participants in the Chronic Renal Insufficiency Cohort (CRIC), none of whom were receiving dialysis at enrollment.

EXPOSURE

Race.

OUTCOME

Mortality.

ANALYTIC APPROACH

Cox proportional hazards regression was used to examine the association between race and mortality starting at: (1) time of dialysis initiation and (2) entry into the CRIC.

RESULTS

During 7.1 years of median follow-up, 678 CRIC participants started dialysis. Starting from the time of dialysis initiation, blacks had lower risk for death (unadjusted HR, 0.67; 95% CI, 0.51-0.87) compared with whites. Starting from baseline CRIC enrollment, the strength of the association between some risk factors and dialysis was notably stronger for whites than blacks. For example, the HR for dialysis onset in the presence (vs absence) of heart failure at CRIC enrollment was 1.30 (95% CI, 1.01-1.68) for blacks versus 2.78 (95% CI, 1.90-4.50) for whites, suggesting differential severity of these risk factors by race. When we included deaths occurring both before and after dialysis, risk for death was higher among blacks (vs whites) starting from CRIC enrollment (HR, 1.41; 95% CI, 1.22-1.64), but this finding was attenuated in adjusted models (HR, 1.08; 95% CI, 0.91-1.28).

LIMITATIONS

Residual confounding.

CONCLUSIONS

The apparent survival advantage among blacks over whites treated with dialysis may be attributed to selected transition of a subset of whites with more severe comorbid conditions onto dialysis.

Renal allograft loss due to renal vascular thrombosis in the US pediatric renal transplantation

BACKGROUND

Renal vascular thrombosis (RVT) is a major cause of early allograft loss in the first year following pediatric kidney transplantation. We examined recent trends in allograft loss due to RVT and identified associated risk factors.

METHODS

We identified 14,640 kidney-only transplants performed between 1995 and 2014 with follow-up until June 30, 2016, in 13,758 pediatric patients aged < 19 years from the US Renal Data System. We examined the 1-year incidence of allograft loss due to RVT by year of transplant, and plotted the trend over time. Cox proportional hazards models were used to investigate the relationship between year of transplant as well as recipient, donor, and transplant characteristics with allograft loss due to RVT.

RESULTS

The incidence of allograft loss due to RVT consistently declined among pediatric kidney transplant performed between 1995 and 2014. Among transplants performed between 1995 and 2004, 128/7542 (1.7%) allografts were lost due to RVT compared to 53/7098 (0.8%) among transplants performed between 2005 and 2014; average 1-year cumulative incidence was 1.5% (95% CI, 1.3-1.9%) and 0.6% (95% CI, 0.5-0.8%), respectively. Increased risk for allograft loss due to RVT was associated with en bloc kidney transplantation (HR, 3.42; 95% CI 1.38-8.43) and cold ischemia time ≥ 12 h (HR, 1.78; 95% CI, 1.15-2.76). Interestingly, these risk factors were more prevalent in the latter decade.

CONCLUSIONS

The incidence of allograft loss due to RVT significantly and continuously declined among pediatric kidney transplants performed between 1995 and 2014. The causes for this improvement are unclear in the present analysis.

Sex Disparities in Risk of Mortality Among Children With ESRD

RATIONALE & OBJECTIVE

In the general population, girls have lower mortality risk compared with boys. However, few studies have focused on sex differences in survival and in access to kidney transplantation among children with end-stage kidney disease.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Children aged 2 to 19 years registered in the US Renal Data System who started renal replacement therapy (RRT) between 1995 and 2011.

PREDICTOR

Study participant sex.

OUTCOME

Time to death and time to kidney transplantation.

ANALYTICAL APPROACH

We used adjusted Cox models to examine the association between sex and all-cause mortality. We used Fine-Gray models to examine the association between sex and kidney transplantation accounting for the competing risk for death.

RESULTS

We included 14,024 children, of whom 1,880 died during a median 7.1 years of follow-up. In adjusted analyses, the HR for death was higher for girls (HR, 1.36; 95% CI, 1.25-1.50) than boys. When we further adjusted our survival models for transplantation as a time-dependent covariate, the hazard rate of death in girls was partially attenuated but remained statistically significantly higher than that for boys (HR, 1.28; 95% CI, 1.17-1.41). Girls were also less likely to receive a kidney transplant than boys (adjusted subdistribution HR, 0.91; 95% CI, 0.88-0.95) in analyses treating death as a competing risk.

LIMITATIONS

Lack of data for disease course before the onset of RRT and observational study data.

CONCLUSIONS

The mortality rate was substantially higher for girls than for boys treated with RRT. Access to transplantation was lower for girls than boys, but differences in transplantation access accounted for only a small proportion of the survival differences by sex.

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.

Decreasing deceased donor transplant rates among children (≤6 years) under the new kidney allocation system

The Kidney Allocation System (KAS) was implemented in December 2014 with unknown impact on the pediatric waitlist. To understand the effect of KAS on pediatric registrants, deceased donor kidney transplant (DDKT) rate was assessed using interrupted time series analysis and time-to-event analysis. Two allocation eras were defined with an intermediary washout period: Era 1 (01/01/2013-09/01/2014), Era 2 (09/01/2014-03/01/2015), and Era 3(03/01/2015-03/01/2017). When using Cox proportional hazards, there was no significant association between allocation era and DDKT likelihood as compared to Era 1 (Era 3: aHR: 1.07, 95% CI: 0.97-1.18, P = .17). However, this was not consistent across all subgroups. Specifically, while highly sensitized pediatric registrants were consistently less likely to be transplanted than their less sensitized counterparts, this disparity was attenuated in Era 3 (Era 1 aHR: 0.04, 95%CI: 0.01-0.14, P < .001; Era 3 aHR: 0.33, 95% CI: 0.21-0.53, P < .001) whereas the youngest registrants aged 0-6 experienced a 21% decrease in DDKT likelihood in Era 3 as compared to Era 1 (aHR: 0.79, 95% CI: 0.64-0.98, P = .03). Thus, while overall DDKT likelihood remained stable with the introduction of KAS, registrants ≤ 6 years of age were disadvantaged, warranting further study to ensure equitable access to transplantation.

New Kidney Allocation System Associated With Increased Rates Of Transplants Among Black And Hispanic Patients

Before the 2014 implementation of a new kidney allocation system by the United Network for Organ Sharing, white patients were more likely than black or Hispanic patients to receive a kidney transplant. To determine the effect of the new allocation system on these disparities, we examined data for 179,071 transplant waiting list events in the period June 2013-September 2016, and we calculated monthly transplantation rates (34,133 patients actually received transplants). Implementation of the new system was associated with a narrowing of the disparities in the average monthly transplantation rates by 0.29 percentage point for blacks compared to whites and by 0.24 percentage point for Hispanics compared to whites, which resulted in both disparities becoming nonsignificant after implementation of the new system.

The Change in Living Kidney Donation in Women and Men in the United States (2005-2015): A Population-Based Analysis

The factors underlying the decline in living kidney donation in the United States since 2005 must be understood to inform strategies to ensure access to this option for future patients. Population-based estimates provide a better assessment of donation activity than do trends in the number of living donor transplants. Using data from the Scientific Registry of Transplant Recipients and the United States Census, we determined longitudinal changes in living kidney donation between 2005 and 2015, focusing on the effect of sex and income. We used multilevel Poisson models to adjust for differences in age, race, the incidence of ESRD, and geographic factors (including population density, urbanization, and daily commuting). During the study period, the unadjusted rate of donation was 30.1 and 19.3 per million population in women and men, respectively, and the adjusted incidence of donation was 44% higher in women (incidence rate ratio [IRR], 1.44; 95% confidence interval [95% CI], 1.39 to 1.49). The incidence of donation was stable in women (IRR, 0.95; 95% CI, 0.84 to 1.07) but declined in men (IRR, 0.75; 95% CI, 0.68 to 0.83). Income was associated with longitudinal changes in donation in both sexes, yet donation was stable in the highest two population income quartiles in women but only in the highest income quartile in men. In both sexes, living related donations declined, irrespective of income. In conclusion, living donation declined in men but remained stable in women between 2005 and 2015, and income appeared to have a greater effect on living donation in men.

Changes in Excess Mortality from End Stage Renal Disease in the United States from 1995 to 2013

BACKGROUND AND OBJECTIVES

Individuals with ESRD have a very high risk of death. Although mortality rates have decreased over time in ESRD, it is unknown if improvements merely reflect parallel increases in general population survival. We, therefore, examined changes in the excess risk of all-cause mortality-over and above the risk in the general population-among people treated for ESRD in the United States from 1995 to 2013. We hypothesized that the magnitude of change in the excess risk of death would differ by age and RRT modality.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used time-dependent relative survival models including data from persons with incident ESRD as recorded in the US Renal Data System and age-, sex-, race-, and calendar year-specific general population mortality rates from the Centers for Disease Control and Prevention. We calculated relative excess risks (analogous to hazard ratios) to examine the association between advancing calendar time and the primary outcome of all-cause mortality.

RESULTS

We included 1,938,148 children and adults with incident ESRD from 1995 to 2013. Adjusted relative excess risk per 5-year increment in calendar time ranged from 0.73 (95% confidence interval, 0.69 to 0.77) for 0-14 year olds to 0.88 (95% confidence interval, 0.88 to 0.88) for ≥65 year olds, meaning that the excess risk of ESRD-related death decreased by 12%-27% over any 5-year interval between 1995 and 2013. Decreases in excess mortality over time were observed for all ages and both during treatment with dialysis and during time with a functioning kidney transplant (year by age and year by renal replacement modality interactions were both P<0.001), with the largest relative improvements observed for the youngest persons with a functioning kidney transplant. Absolute decreases in excess ESRD-related mortality were greatest for the oldest persons.

CONCLUSIONS

The excess risk of all-cause mortality among people with ESRD, over and above the risk in the general population, decreased significantly between 1995 and 2013 in the United States.

Organ allocation and utilization in pediatric transplantation

Pediatric transplant candidates include heart, lung, liver, pancreas, small intestine, and kidney. The purpose of this article is to review the history and current methods for determining priority of the above-mentioned transplantable organs. The methods used by the authors involved the review of historical and current manuscripts and UNOS policy documents. We summarized the findings in order to create a concise review of the current policies and wait times for transplantation in pediatric transplant patients.

Outcomes of Live Kidney Donors Who Develop End-Stage Renal Disease

BACKGROUND

Kidney donors can develop end-stage renal disease (ESRD) after donation, but the outcomes of those who do remain poorly characterized.

METHODS

Using United States Renal Data System and Scientific Registry for Transplant Research data, we compared access to kidney transplantation (KT), time from ESRD to listing, time from listing to KT, and post-KT graft failure and death between donors and matched nondonors with ESRD.

RESULTS

Among 99 donors between April 1994 and November 2011 who developed ESRD, 78 initially received dialysis (of whom 37 listed for KT, 2 received live donor KT without listing, and 39 never listed for or received a KT), 20 listed preemptively (of whom 19 were subsequently transplanted), and 1 received a preemptive live donor KT without listing or ever receiving dialysis. Donors were listed earlier (median time to listing, 17 months vs 120 for nondonors; P < 0.001), received KT earlier (median waiting time, 2.8 months vs 21.5 for nondonors; P < 0.001), and received 13% live donor, 87% standard criteria, and 0% expanded criteria deceased donor KT (39%, 50%, and 11% in nondonors). Post-KT graft (adjusted hazard ratio, 1.9; 95% confidence interval, 0.9 to 4.1; P = 0.1) and patient (adjusted hazard ratio, 0.7; 95% confidence interval, 0.2 to 2.4; P = 0.5) survival were comparable in donors and nondonors.

CONCLUSIONS

Our finding that 39 of 99 donors who developed ESRD never listed for a transplant warrants further study to ascertain why these donors with ESRD never gained access to the waiting list.

Racial and Ethnic Disparities in Survival of Children with ESRD

Observational studies have reported that black and Hispanic adults receiving maintenance dialysis survive longer than non-Hispanic white counterparts. Whether there are racial disparities in survival of children with ESRD is not clear. We compared mortality risk among non-Hispanic black, Hispanic, and non-Hispanic white children who started RRT between 1995 and 2011 and were followed through 2012. We examined all-cause mortality using adjusted Cox models. Of 12,123 children included for analysis, 1600 died during the median follow-up of 7.1 years. Approximately 25% of children were non-Hispanic black, and 26% of children were of Hispanic ethnicity. Non-Hispanic black children had a 36% higher risk of death (95% confidence interval [95% CI], 1.21 to 1.52) and Hispanic children had a 34% lower risk of death (95% CI, 0.57 to 0.77) than non-Hispanic white children. Adjustment for transplant as a time-dependent covariate abolished the higher risk of death in non-Hispanic black children (hazard ratio, 0.99; 95% CI, 0.88 to 1.12) but did not attenuate the finding of a lower risk of death in Hispanic children (hazard ratio, 0.59; 95% CI, 0.51 to 0.68). In conclusion, Hispanic children had lower mortality than non-Hispanic white children. Non-Hispanic black children had higher mortality than non-Hispanic white children, which was related to differences in access to transplantation by race. Parity in access to transplantation in children and improvements in strategies to prolong graft survival could substantially reduce disparities in mortality risk of non-Hispanic black children treated with RRT.

Racial-ethnic disparities in mortality and kidney transplant outcomes among pediatric dialysis patients

BACKGROUND

Previous studies in adult hemodialysis patients have shown that African-American and Hispanic patients have a lower risk of mortality in addition to a lower likelihood of kidney transplantation. However, studies of the association between race and outcomes in pediatric dialysis are sparse and often do not examine outcomes in Hispanic children. The objective was to determine if racial-ethnic disparities in mortality and kidney transplantation outcomes exist in pediatric dialysis patients.

METHODS

This was a retrospective cohort analysis of 2,697 pediatric dialysis patients (aged 0-20 years) from a large national dialysis organization (entry period 2001-2011) of non-Hispanic white, African-American, and Hispanic race-ethnicity. Associations between race-ethnicity with mortality and kidney transplantation outcomes were examined separately using competing risks methods. Logistic regression analyses were used to examine the association between race-ethnicity, with outcomes within 1 year of dialysis initiation.

RESULTS

Of the 2,697 pediatric patients in this cohort, 895 were African-American, 778 were Hispanic, and 1,024 were non-Hispanic white. After adjusting for baseline demographics, competing risk survival analysis revealed that compared with non-Hispanic whites, African-Americans had a 64 % higher mortality risk (hazards ratio [HR] = 1.64; 95 % CI 1.24-2.17), whereas Hispanics had a 31 % lower mortality risk (HR = 0.69; 95 % CI 0.47-1.01) that did not reach statistical significance. African-Americans also had higher odds of 1-year mortality after starting dialysis (odds ratio [OR] = 2.08; 95 % CI 0.95-4.58), whereas both African-Americans and Hispanics had a lower odds of receiving a transplant within 1 year of starting dialysis (OR = 0.28; 95 % CI 0.19-0.41 and OR = 0.43; 95 % CI 0.31-0.59 respectively).

CONCLUSION

In contrast to adults, African-American pediatric dialysis patients have worse survival than their non-Hispanic white counterparts, whereas Hispanics have a similar to lower mortality risk. Both African-American and Hispanic pediatric dialysis patients had a lower likelihood of kidney transplantation than non-Hispanic whites, similar to observations in the adult dialysis population.

Pediatric kidney transplantation: a historical review

Successful renal transplantation is the optimal treatment for chronic kidney failure, but this was not always so for children. Beginning with the first kidney transplants in the 1950s, children experienced poorer patient and graft survival rates than adult patients. But over the last 6 decades, an improved understanding of the immune system which has steered pediatric multi-center clinical/pharmacokinetic and mechanistic studies that have sculpted our immunosuppression with markedly better patient and graft survivals. In addition, uniquely pediatric issues related to growth, development, neurocognitive maturation, increased complications from primary viral infections, and comorbid congenital/inherited disorders, are now diagnosed and effectively managed in these children. Refined pretransplant preparation (vaccinations for preventable diseases, attention to cognitive delays, effective dialysis and nutrition) improved donor selection, and more potent immunosuppression have all contributed to enhanced outcomes. Similarly, improvements in pediatric surgical techniques, postoperative care and better antiviral prophylaxis have all shortened hospitalizations and reduced morbidity. Today pediatric kidney transplant outcomes are markedly improved and younger children today experience better long-term graft survival than adults! While difficult problems remain, we have made tremendous progress and anticipate even more advances in the future of pediatric kidney transplantation.

Living Donation Has a Greater Impact on Renal Allograft Survival Than HLA Matching in Pediatric Renal Transplant Recipients

BACKGROUND

Living donor (LD) kidney transplantation accounts for around half of all pediatric renal transplant recipients and results in improved renal allograft survival. The aim of this study was to determine the effect of HLA matching on deceased and LD renal allograft outcomes in pediatric recipients.

METHODS

Data were obtained from the UK Transplant Registry held by NHS Blood and Transplant on all children who received a donation after brain death (DBD) or LD kidney-only transplant between 2000 and 2011. HLA-A, HLA-B and HLA-DR mismatches were categorized into 4 levels and 2 groups. Data were fully anonymized.

RESULTS

One thousand three hundred seventy-eight pediatric renal transplant recipients were analyzed; 804 (58%) received a DBD donor kidney, 574 (42%) received an LD kidney. Five-year renal allograft survival was superior for children receiving a poorly HLA-matched LD kidney transplant (88%, 95% confidence interval [95% CI], 84-91%) compared with children receiving a well HLA-matched DBD kidney transplant (83%, 95% CI, 80-86%, log rank test P = 0.03). Five-year renal allograft survival was superior for children receiving an LD kidney with 1 or 2 HLA-DR mismatches (88%, 95% CI, 84-91%) compared with children receiving a DBD kidney with 0 HLA-DR mismatches (83%, 95% CI, 80-86%, log rank test P = 0.03).

CONCLUSIONS

In children, poorly HLA-matched LD renal transplant outcomes are not inferior when compared with well HLA-matched DBD renal transplants. It is difficult to justify preferentially waiting for an improved HLA-matched DBD kidney when a poorer HLA-matched LD kidney transplant is available.

Preemptive kidney transplantation is associated with survival benefits among pediatric patients with end-stage renal disease

Kidney transplantation is the preferred treatment for pediatric end-stage renal disease (ESRD). Preemptive transplantation avoids the increased morbidity and mortality of dialysis. Yet, previous studies have not demonstrated significant graft or patient survival benefits for children undergoing transplantation preemptively versus nonpreemptively. These previous studies were limited by small samples sizes and low rates of adverse events. Here we compared graft failure and mortality rates using Kaplan-Meier methods and Cox regression among a large national cohort of children with ESRD undergoing preemptive versus nonpreemptive kidney transplantation between 2000 and 2012. Among 7527 pediatric kidney transplant recipients in the United States Renal Data System, 1668 underwent preemptive transplantation. Over a median 4.8 years follow-up, 1314 experienced graft failure, and over a median 5.2 years of follow-up, 334 died. Dialysis exposure versus preemptive transplantation conferred a higher risk of graft failure (hazard ratio 1.32; 95% confidence interval: 1.10-1.56) and a higher risk of death (hazard ratio 1.69; 95% confidence interval: 1.22-2.33) in multivariable analysis. Compared with children undergoing preemptive transplantation, children on dialysis for >1 year had a 52% higher risk of graft failure and those on dialysis >18 months had an 89% higher risk of death, regardless of donor source. Thus, preemptive transplantation is associated with substantial benefits in allograft and patient survival among children with ESRD, particularly when compared with children who receive dialysis for >1 year. These findings support policies to promote early access to transplantation and avoidance of dialysis for children with ESRD whenever feasible.

Racial differences in renal replacement therapy initiation among children with a nonglomerular cause of chronic kidney disease

PURPOSE

African American (AA) adults with chronic kidney disease (CKD) have a faster progression to end-stage renal disease and are less likely to receive a kidney transplant. It is unclear whether AA children experience renal replacement therapy (RRT) for end-stage renal disease sooner than non-AA children after accounting for socioeconomic status (SES).

METHODS

Among children with nonglomerular CKD in the Chronic Kidney Disease in Children study, we investigated time to RRT (i.e., first dialysis or transplant) after CKD onset using parametric survival models and accounted for SES differences by inverse probability weights.

RESULTS

Of 110 AA and 493 non-AA children (median age = 10 years), AA children had shorter time to first RRT: median time was 3.2 years earlier than non-AA children (95% CI: -6.1, -0.3). When accounting for SES, this difference was diminished and nonsignificant (-1.6 years; 95% CI: -4.6, +1.5), and its directionality was consistent with faster glomerular filtration rate decline among AA children (-6.2% vs. -4.4% per year, P = .098). When RRT was deconstructed into dialysis or transplant, the time to dialysis was 37.5% shorter for AA children and 53.7% longer for transplant. These inferences were confirmed by the frequency and timing of transplant after initiating dialysis.

CONCLUSIONS

Racial differences in time to RRT were almost fully accounted for by SES, and the remaining difference was congruent with a faster glomerular filtration rate decline among AA children. Access to transplant occurred later, yet times to dialysis were shorter among AA children even when accounting for SES which may be due to a lack of organ availability.

Renal transplantation in infants

Renal transplantation (RTx) has become an accepted mode of therapy in infants with severe renal failure. The major indications are structural abnormalities of the urinary tract, congenital nephrotic syndrome, polycystic diseases, and neonatal kidney injury. Assessment of these infants needs expertise and time as well as active treatment before RTx to ensure optimal growth and development, and to avoid complications that could lead to permanent neurological defects. RTx can be performed already in infants weighing around 5 kg, but most operations occur in infants with a weight of 10 kg or more. Perioperative management focuses on adequate perfusion of the allograft and avoidance of thrombotic and other surgical complications. Important long-term issues include rejections, infections, graft function, growth, bone health, metabolic problems, neurocognitive development, adherence to medication, pubertal maturation, and quality of life. The overall outcome of infant RTx has dramatically improved, with long-term patient and graft survivals of over 90 and 80 %, respectively.

Inequalities in access to pediatric ESRD care: a global health challenge

The increasing attention paid to chronic kidney disease (CKD) as a major cause of mortality and disability, as well as the advances in management of CKD in children, have created a growing demand for pediatric renal replacement therapy (RRT) worldwide. A study by Koch Nogueira and colleagues of children on the transplant waiting list showed large disparities in access to pediatric kidney transplantation between regions in Brazil. This finding raises a wider question about inequalities in access to CKD care in children. Here we review the available data on the global burden of end-stage renal disease in children, the need for pediatric RRT, and its actual provision worldwide. We focus on inequalities in access to renal care for children that currently exist between and within countries. Reduction in worldwide inequalities in access to RRT in children remains a challenge, which requires greater awareness and effective interventions and policies.

Pediatric deceased donor renal transplantation: An approach to decision making I. Pediatric kidney allocation in the USA: The old and the new

Renal transplantation is the treatment of choice for children with end-stage renal disease. More than 50% of children receive a deceased donor renal transplant. Marked disparity between the number of children on the renal transplant wait list and the supply has prompted numerous advances to increase supply as well as maximize the utility of donor organs. Allocation of deceased donor kidneys is based on several criteria. The organ allocation system policy is continually evaluated and changed incrementally to optimize allocation. We, in the United States, are in the process of transitioning into a new kidney allocation system to enhance post-transplant survival benefit, increase utilization of donated kidneys, and increase transplant access for biologically disadvantaged candidates. This review will provide a brief overview of the organ sharing system in the United States, compare the "old" and the "new" allocation system, and discuss the considerations for the pediatric nephrologist while accepting a deceased donor kidney for a particular pediatric patient.

Australian deceased donor kidney allocation protocols: Transplant waiting and graft quality for children and adolescents

DD kidney allocation protocols may influence timing of transplantation and graft quality for pediatric recipients. This study aimed to evaluate the effects of these protocols, including pediatric priority, on waiting time on dialysis, transplant type, donor age, and HLA matching according to state of transplant in Australia. De-identified information on patients <15 yr of age who commenced RRT in NSW, Qld, and Victoria from 2002 to 2011 was retrieved from the ANZDATA. Transplant type, donor age, and HLA mismatching were compared between states, with competing risk regression used to examine the time to transplant. There were significant differences in waiting time to DD transplantation between the three states. Children in NSW and Qld waited a median of 14 and 11 months vs. 21 months in Victoria. The ratio of LD to DD transplants was lower in NSW and Qld. Differences correlated with DD pediatric priority in NSW and Qld. DDs in NSW were older than in the other states. HLA matching did not differ. DD kidney allocation protocols with pediatric priority in Australian states were associated with shorter waiting times and increased DD proportion.

An overview of disparities and interventions in pediatric kidney transplantation worldwide

Despite the stated goals of the transplant community and the majority of organ allocation systems, persistent racial disparities in pediatric kidney transplantation exist throughout the world. These disparities are evident in both living and deceased donor kidney transplantation and are independent of any clinical differences between racial groups. The reasons for these persistent disparities are multifactorial, reflecting both patient and provider barriers to care. In this review, we examine the most current findings regarding disparities in pediatric kidney transplantation and consider interventions which may help reduce those disparities.

Disparities in the burden, outcomes, and care of chronic kidney disease

PURPOSE OF REVIEW

Racial, ethnic and socioeconomic disparities in chronic kidney disease (CKD) have been documented for decades, yet little progress has been made in mitigating them. Several recent studies offer new insights into the root causes of these disparities, point to areas in which future research is warranted, and identify opportunities for changes in policy and clinical practice.

RECENT FINDINGS

Recently published evidence suggests that geographic disparities in CKD prevalence exist and vary by race. CKD progression is more rapid for racial and ethnic minority groups compared with whites and may be largely, but not completely, explained by genetic factors. Stark socioeconomic disparities in outcomes for dialysis patients exist and vary by race, place of residence, and treatment facility. Disparities in access to living kidney donation may be driven primarily by the socioeconomic status of the donor as opposed to recipient factors.

SUMMARY

Recent studies highlight opportunities to eliminate disparities in CKD, including efforts to direct resources to areas and populations where disparities are most prevalent, efforts to understand how to best use emerging information on the contribution of genetic factors to disparities, and continued work to identify modifiable environmental, social, and behavioral factors for targeted interventions among high-risk populations.

The RaDIANT community study protocol: community-based participatory research for reducing disparities in access to kidney transplantation

BACKGROUND

The Southeastern United States has the lowest kidney transplant rates in the nation, and racial disparities in kidney transplant access are concentrated in this region. The Southeastern Kidney Transplant Coalition (SEKTC) of Georgia, North Carolina, and South Carolina is an academic and community partnership that was formed with the mission to improve access to kidney transplantation and reduce disparities among African American (AA) end stage renal disease (ESRD) patients in the Southeastern United States.

METHODS/DESIGN

We describe the community-based participatory research (CBPR) process utilized in planning the Reducing Disparities In Access to kidNey Transplantation (RaDIANT) Community Study, a trial developed by the SEKTC to reduce health disparities in access to kidney transplantation among AA ESRD patients in Georgia, the state with the lowest kidney transplant rates in the nation. The SEKTC Coalition conducted a needs assessment of the ESRD population in the Southeast and used results to develop a multicomponent, dialysis facility-randomized, quality improvement intervention to improve transplant access among dialysis facilities in GA. A total of 134 dialysis facilities are randomized to receive either: (1) standard of care or "usual" transplant education, or (2) the multicomponent intervention consisting of transplant education and engagement activities targeting dialysis facility leadership, staff, and patients within dialysis facilities. The primary outcome is change in facility-level referral for kidney transplantation from baseline to 12 months; the secondary outcome is reduction in racial disparity in transplant referral.

DISCUSSION

The RaDIANT Community Study aims to improve equity in access to kidney transplantation for ESRD patients in the Southeast.

TRIAL REGISTRATION

Clinicaltrials.gov number NCT02092727.

Racial and ethnic disparities in pediatric renal allograft survival in the United States

This study was undertaken to describe the association of patient race/ethnicity and renal allograft survival among the national cohort of pediatric renal allograft recipients. Additionally, we determined whether racial and ethnic differences in graft survival exist among individuals living in low or high poverty neighborhoods and those with private or public insurance. Among 6,216 incident, pediatric End Stage Renal Disease patients in the United States Renal Data System (kidney transplant from 2000 through September, 2011) 14.4% experienced graft failure, with a median follow-up time of 4.5 years. After controlling for multiple covariates, black race, but not Hispanic ethnicity, was significantly associated with a higher rate of graft failure for both deceased and living donor transplant recipients. Disparities were particularly stark by 5 years post-transplant, when black living donor transplant recipients experienced only 63.0% graft survival compared with 82.8% and 80.8% for Hispanics and whites, respectively. These disparities persisted among high and low poverty neighborhoods and among both privately- and publicly-insured patients. Notably profound declines in both deceased and living donor graft survival rates for black, compared to white and Hispanic, children preceded the 3-year mark when transplant Medicare eligibility ends. Further research is needed to identify the unique barriers to long-term graft success among black pediatric transplant recipients.

The mortality risk with graft function has decreased among children receiving a first kidney transplant in the United States

Mortality has decreased in children with end stage kidney disease. Decreases in mortality during dialysis and improved graft survival contributed to this improvement. However, it is unknown if rates of death with graft function have also improved. We measured this in first transplant recipients under 21 years old registered in the USRDS. Cox models were used with a time-dependent renal replacement therapy modality variable to estimate the hazard ratios for death with graft function associated with a 1-year increment in the calendar year of transplant. There were 157,201 person-years of observation among 17,468 recipients with 82.2% of study time during graft function and 17.8% during dialysis after graft failure. There were 2003 deaths (12.7 deaths/1000 person-years) overall of which 985 occurred with graft function (7.6 deaths/1000 person-years) and 1018 occurred during dialysis after graft failure (36.1 deaths/1000 person-years). Each 1-year increment in calendar year of first transplant was associated with a significantly lower risk of death, both over all observation (HR 0.97 [0.96, 0.98]) and focusing on time with graft function (HR 0.98 [0.97, 0.99]). Living donation was significantly associated with better survival while dialysis after graft failure was associated with a much higher mortality risk (HR 4.85 [4.40, 5.35]) compared with graft function. Thus, the risk of death with graft function has decreased in children receiving a first kidney transplant. Increasing living donation and minimizing dialysis may further improve outcomes.

Disparities, race/ethnicity and access to pediatric kidney transplantation

PURPOSE OF REVIEW

Kidney transplantation remains the optimal treatment for children with end-stage renal disease; yet, in the United States, profound differences in access to transplant persist, with black children experiencing significantly reduced access to transplant compared with white children. The reasons for these disparities remain poorly understood. Several recent studies provide new insights into the interplay of socioeconomic status, racial/ethnic disparities and access to pediatric kidney transplantation.

RECENT FINDINGS

New evidence suggests that disparities are more pronounced in access to living vs. deceased donors. National allocation policies have mitigated racial differences in pediatric deceased donor kidney transplant (DDKT) access after waitlisting. However, disparities in access to DDKT are stark for minority emerging adults, who lose pediatric priority allocation. Although absence of health insurance poses an important barrier to transplant, even after adjustment for insurance status and neighborhood poverty, disparities persist. Differential access to care and unjust social structures are posited as important modifiable barriers to achieving equity in pediatric transplant access.

SUMMARY

Future approaches to overcome disparities in pediatric kidney transplant access must focus on the continuum of the transplant process, including equitable health care access. Public health advocacy efforts to promote national policies that address disparate multilevel socioeconomic factors are essential.

Population income and longitudinal trends in living kidney donation in the United States

Living kidney donation is declining in the United States. We examined longitudinal trends in living donation as a function of median household income and donor relation to assess the effect of financial barriers on donation in a changing economic environment. The zip code-level median household income of all 71,882 living donors was determined by linkage to the 2000 US Census. Longitudinal changes in the rate of donation were determined in income quintiles between 1999 and 2004, when donations were increasing, and between 2005 and 2010, when donations were declining. Rates were adjusted for population differences in age, sex, race, and ESRD rate using multilevel linear regression models. Between 1999 and 2004, the rate of growth in living donation per million population was directly related to income, increasing progressively from the lowest to highest income quintile, with annualized changes of 0.55 (95% confidence interval [95% CI], 0.14 to 1.05) for Q1 and 1.77 (95% CI, 0.66 to 2.77) for Q5 (P<0.05). Between 2005 and 2010, donation declined in Q1, Q2, and Q3; was stable in Q4; and continued to grow in Q5. Longitudinal changes varied by donor relationship, and the association of income with longitudinal changes also varied by donor relationship. In conclusion, changes in living donation in the past decade varied by median household income, resulting in increased disparities in donation between low- and high-income populations. These findings may inform public policies to support living donation during periods of economic volatility.