Faculty Bibliography

The perception of living kidney donation-related financial burden affects willingness to donate and the experience of donation, yet no existing tools identify donors who are at higher risk of perceived financial burden. We sought to identify characteristics that predicted higher risk of perceived financial burden. We surveyed 51 living kidney donors (LKDs) who donated from 01/2015 to 3/2016 about socioeconomic characteristics, predonation cost concerns, and perceived financial burden. We tested associations between both self-reported and ZIP code-level characteristics and perceived burden using Fisher's exact test and bivariate modified Poisson regression. Donors who perceived donation-related financial burden were less likely to have an income above their ZIP code median (14% vs. 72%, P = .006); however, they were more likely than donors who did not perceive burden to rent their home (57% vs. 16%, P = .03), have an income <$60 000 (86% vs. 20%, P = .002), or have had predonation cost concerns (43% vs. 7%, P = .03). Perceived financial burden was 3.6-fold as likely among those with predonation cost concerns and 10.6-fold as likely for those with incomes <$60 000. Collecting socioeconomic characteristics and asking about donation-related cost concerns prior to donation might allow transplant centers to target financial support interventions toward potential donors at higher risk of perceiving donation-related financial burden.

BACKGROUND:The Organ Procurement and Transplantation Network has implemented medical criteria to determine which candidates are most appropriate for simultaneous liver-kidney (SLK) transplantation in comparison to liver-alone transplantation. We investigated prepolicy center-level variation among SLK listing practice, in light of such criteria. METHODS:We identified 4736 SLK-eligible candidates after Share-35 in the United States. We calculated the proportion of candidates at each center who were listed for SLK transplantation within 6 months of eligibility. Multilevel logistic regression and parametric survival model was used to estimate the center-specific probability of SLK listing, adjusting for patient and center-level characteristics. RESULTS:Among 4736 SLK-eligible candidates, 64.8% were listed for SLK within 6 months of eligibility. However, the percentage of SLK listing ranged from 0% to 100% across centers. African American race, male sex, transplant history, diabetes, and hypertension were associated with a higher likelihood of SLK listing. Conversely, older age was associated with a lower likelihood of SLK listing. After adjusting for candidate characteristics, the percentage of SLK listing still ranged from 3.8% to 80.2% across centers; this wide variation persisted even after further adjusting for center-level characteristics. CONCLUSIONS:There was significant prepolicy center-level variation in SLK listing for SLK-eligible candidates. Implementation of standardized SLK listing practices may reduce center-level variation and equalize access for SLK candidates across the United States.

Transplant candidates who accept a kidney labeled increased risk for disease transmission (IRD) accept a low risk of window period infection, yet those who decline must wait for another offer that might harbor other risks or never even come. To characterize survival benefit of accepting IRD kidneys, we used 2010-2014 Scientific Registry of Transplant Recipients data to identify 104 998 adult transplant candidates who were offered IRD kidneys that were eventually accepted by someone; the median (interquartile range) Kidney Donor Profile Index (KDPI) of these kidneys was 30 (16-49). We followed patients from the offer decision until death or end-of-study. After 5 years, only 31.0% of candidates who declined IRDs later received non-IRD deceased donor kidney transplants; the median KDPI of these non-IRD kidneys was 52, compared to 21 of the IRDs they had declined. After a brief risk period in the first 30 days following IRD acceptance (adjusted hazard ratio [aHR] accept vs decline: _1.22 2.06_3.49 , P = .008) (absolute mortality 0.8% vs. 0.4%), those who accepted IRDs were at 33% lower risk of death 1-6 months postdecision (aHR _0.50 0.67_0.90 , P = .006), and at 48% lower risk of death beyond 6 months postdecision (aHR _0.46 0.52_0.58 , P < .001). Accepting an IRD kidney was associated with substantial long-term survival benefit; providers should consider this benefit when counseling patients on IRD offer acceptance.

Kidney paired donation (KPD) is an important tool to facilitate living donor kidney transplantation (LDKT). Concerns remain over prolonged cold ischemia times (CIT) associated with shipping kidneys long distances through KPD. We examined the association between CIT and delayed graft function (DGF), allograft survival, and patient survival for 1267 shipped and 205 nonshipped/internal KPD LDKTs facilitated by the National Kidney Registry in the United States from 2008 to 2015, compared to 4800 unrelated, nonshipped, non-KPD LDKTs. Shipped KPD recipients had a median CIT of 9.3 hours (range = 0.25-23.9 hours), compared to 1.0 hour for internal KPD transplants and 0.93 hours for non-KPD LDKTs. Each hour of CIT was associated with a 5% increased odds of DGF (adjusted odds ratio: 1.05, 95% confidence interval [CI], 1.02-1.09, P < .01). However, there was not a significant association between CIT and all-cause graft failure (adjusted hazard ratio [aHR]: 1.01, 95% CI: 0.98-1.04, P = .4), death-censored graft failure ( [aHR]: 1.02, 95% CI, 0.98-1.06, P = .4), or mortality (aHR 1.00, 95% CI, 0.96-1.04, P > .9). This study of KPD-facilitated LDKTs found no evidence that long CIT is a concern for reduced graft or patient survival. Studies with longer follow-up are needed to refine our understanding of the safety of shipping donor kidneys through KPD.

The Kidney Allocation System fundamentally altered kidney allocation, causing a substantial increase in regional and national sharing that we hypothesized might impact geographic disparities. We measured geographic disparity in deceased donor kidney transplant (DDKT) rate under KAS (6/1/2015-12/1/2016), and compared that with pre-KAS (6/1/2013-12/3/2014). We modeled DSA-level DDKT rates with multilevel Poisson regression, adjusting for allocation factors under KAS. Using the model we calculated a novel, improved metric of geographic disparity: the median incidence rate ratio (MIRR) of transplant rate, a measure of DSA-level variation that accounts for patient casemix and is robust to outlier values. Under KAS, MIRR was _1.75 1.81_1.86 for adults, meaning that similar candidates across different DSAs have a median 1.81-fold difference in DDKT rate. The impact of geography was greater than the impact of factors emphasized by KAS: having an EPTS score ≤20% was associated with a 1.40-fold increase (IRR = _1.35 1.40_1.45 , P < .01) and a three-year dialysis vintage was associated with a 1.57-fold increase (IRR = _1.56 1.57_1.59 , P < .001) in transplant rate. For pediatric candidates, MIRR was even more pronounced, at _1.66 1.92_2.27 . There was no change in geographic disparities with KAS (P = .3). Despite extensive changes to kidney allocation under KAS, geography remains a primary determinant of access to DDKT.

Importance:Over the past 2 decades, there has been increased attention and effort to reduce disparities in live donor kidney transplantation (LDKT) for black, Hispanic, and Asian patients with end-stage kidney disease. The goal of this study was to investigate whether these efforts have been successful. Objective:To estimate changes over time in racial/ethnic disparities in LDKT in the United States, accounting for differences in death and deceased donor kidney transplantation. Design, Setting, and Participants:A secondary analysis of a prospectively maintained cohort study conducted in the United States of 453 162 adult first-time kidney transplantation candidates included in the Scientific Registry of Transplant Recipients between January 1, 1995, and December 31, 2014, with follow-up through December 31, 2016. Exposures:Race/ethnicity. Main Outcomes and Measures:The primary study outcome was time to LDKT. Multivariable Cox proportional hazards and competing risk models were constructed to assess changes in racial/ethnic disparities in LDKT among adults on the deceased donor kidney transplantation waiting list and interaction terms were used to test the statistical significance of temporal changes in racial/ethnic differences in receipt of LDKT. The adjusted subhazard ratios are estimates derived from the multivariable competing risk models. Data were categorized into 5-year increments (1995-1999, 2000-2004, 2005-2009, 2010-2014) to allow for an adequate sample size in each analytical cell. Results:Among 453 162 adult kidney transplantation candidates (mean [SD] age, 50.9 [13.1] years; 39% were women; 48% were white; 30%, black; 16%, Hispanic; and 6%, Asian), 59 516 (13.1%) received LDKT. Overall, there were 39 509 LDKTs among white patients, 8926 among black patients, 8357 among Hispanic patients, and 2724 among Asian patients. In 1995, the cumulative incidence of LDKT at 2 years after appearing on the waiting list was 7.0% among white patients, 3.4% among black patients, 6.8% among Hispanic patients, and 5.1% among Asian patients. In 2014, the cumulative incidence of LDKT was 11.4% among white patients, 2.9% among black patients, 5.9% among Hispanic patients, and 5.6% among Asian patients. From 1995-1999 to 2010-2014, racial/ethnic disparities in the receipt of LDKT increased (P < .001 for all statistical interaction terms in adjusted models comparing white patients vs black, Hispanic, and Asian patients). In 1995-1999, compared with receipt of LDKT among white patients, the adjusted subhazard ratio was 0.45 (95% CI, 0.42-0.48) among black patients, 0.83 (95% CI, 0.77-0.88) among Hispanic patients, and 0.56 (95% CI, 0.50-0.63) among Asian patients. In 2010-2014, compared with receipt of LDKT among white patients, the adjusted subhazard ratio was 0.27 (95% CI, 0.26-0.28) among black patients, 0.52 (95% CI, 0.50-0.54) among Hispanic patients, and 0.42 (95% CI, 0.39-0.45) among Asian patients. Conclusions and Relevance:Among adult first-time kidney transplantation candidates in the United States who were added to the deceased donor kidney transplantation waiting list between 1995 and 2014, disparities in the receipt of live donor kidney transplantation increased from 1995-1999 to 2010-2014. These findings suggest that national strategies for addressing disparities in receipt of live donor kidney transplantation should be revisited.

OBJECTIVE:To evaluate changes in patient and graft survival for pediatric liver transplant recipients since 2002, and to determine if these outcomes vary by graft type (whole liver transplant, split liver transplant [SLT], and living donor liver transplant [LDLT]). STUDY DESIGN:We evaluated patient and graft survival among pediatric liver-only transplant recipients the PELD/MELD system was implemented using the Scientific Registry of Transplant Recipients. RESULTS:). CONCLUSIONS:In recent years, outcomes after the use of technical variant grafts are comparable with whole grafts, and may be superior for LDLT. Greater use of technical variant grafts might provide an opportunity to increase organ supply without compromising post-transplant outcomes.

Currently, there is debate among the liver transplant community regarding the most appropriate mechanism for organ allocation: urgency-based (MELD) versus utility-based (survival benefit). We hypothesize that MELD and survival benefit are closely associated, and therefore, our current MELD-based allocation already reflects utility-based allocation. We used generalized gamma parametric models to quantify survival benefit of LT across MELD categories among 74 196 adult liver-only active candidates between 2006 and 2016 in the United States. We calculated time ratios (TR) of relative life expectancy with transplantation versus without and calculated expected life years gained after LT. LT extended life expectancy (TR > 1) for patients with MELD > 10. The highest MELD was associated with the longest relative life expectancy (TR = _1.05 1.20_1.37 for MELD 11-15, _2.29 2.49_2.70 for MELD 16-20, _5.30 5.72_6.16 for MELD 21-25, _15.12 16.35_17.67 for MELD 26-30; _39.26 43.21_47.55 for MELD 31-34; _120.04 128.25_137.02 for MELD 35-40). As a result, candidates with the highest MELD gained the most life years after LT: 0.2, 1.5, 3.5, 5.8, 6.9, 7.2 years for MELD 11-15, 16-20, 21-25, 26-30, 31-34, 35-40, respectively. Therefore, prioritizing candidates by MELD remains a simple, effective strategy for prioritizing candidates with a higher transplant survival benefit over those with lower survival benefit.

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.

Kidney paired donation (KPD) can facilitate living donor transplantation for candidates with an incompatible donor, but requires waiting for a match while experiencing the morbidity of dialysis. The balance between waiting for KPD vs desensitization or deceased donor transplantation relies on the ability to estimate KPD wait times. We studied donor/candidate pairs in the National Kidney Registry (NKR), a large multicenter KPD clearinghouse, between October 2011 and September 2015 using a competing-risk framework. Among 1894 candidates, 52% were male, median age was 50 years, 66% were white, 59% had blood type O, 42% had panel reactive antibody (PRA)>80, and 50% obtained KPD through NKR. Median times to KPD ranged from 2 months for candidates with ABO-A and PRA 0, to over a year for candidates with ABO-O or PRA 98+. Candidates with PRA 80-97 and 98+ were 23% (95% confidence interval , 6%-37%) and 83% (78%-87%) less likely to be matched than PRA 0 candidates. ABO-O candidates were 67% (61%-73%) less likely to be matched than ABO-A candidates. Candidates with ABO-B or ABO-O donors were 31% (10%-56%) and 118% (82%-162%) more likely to match than those with ABO-A donors. Providers should counsel candidates about realistic, individualized expectations for KPD, especially in the context of their alternative treatment options.