Faculty Bibliography

The newest kidney allocation policy kidney allocation system 250 (KAS250) broadened geographic distribution while increasing allocation system complexity. We studied the volume of kidney offers received by transplant centers and the efficiency of kidney placement since KAS250. We identified deceased-donor kidney offers (N = 907,848; N = 36,226 donors) to 185 US transplant centers from January 1, 2019, to December 31, 2021 (policy implemented March 15, 2021). Each unique donor offered to a center was considered a single offer. We compared the monthly volume of offers received by centers and the number of centers offered before the first acceptance using an interrupted time series approach (pre-/post-KAS250). Post-KAS250, transplant centers received more kidney offers (level change: 32.5 offers/center/mo, P < .001; slope change: 3.9 offers/center/mo, P = .003). The median monthly offer volume post-/pre-KAS250 was 195 (interquartile range 137-253) vs. 115 (76-151). There was no significant increase in deceased-donor transplant volume at the center level after KAS250, and center-specific changes in offer volume did not correlate with changes in transplant volume (r = -0.001). Post-KAS250, the number of centers to whom a kidney was offered before acceptance increased significantly (level change: 1.7 centers/donor, P < .001; slope change: 0.1 centers/donor/mo, P = .014). These findings demonstrate the logistical burden of broader organ sharing, and future allocation policy changes will need to balance equity in transplant access with the operational efficiency of the allocation system.

IMPORTANCE:Insurance coverage for patients with end-stage kidney disease has shifted toward more commercially insured patients at dialysis facilities. The associations among insurance status, facility-level payer mix, and access to kidney transplantation are unclear. OBJECTIVE:To determine the association of dialysis facility commercial payer mix and 1-year incidence of wait-listing for kidney transplantation, and to delineate the association of commercial insurance at the patient vs facility level. DESIGN, SETTING, AND PARTICIPANTS:This retrospective population-based cohort study used data from the United States Renal Data System from 2013 to 2018. Participants included patients aged 18 to 75 years initiating chronic dialysis between 2013 and 2017, excluding patients with a prior kidney transplant or with major contraindications to kidney transplant. Data were analyzed from August 2021 and May 2023. EXPOSURE:Dialysis facility commercial payer mix, calculated as the proportion of patients with commercial insurance per facility. MAIN OUTCOMES AND MEASURES:The primary outcome was patients added to a waiting list for kidney transplant within 1 year of dialysis initiation. Multivariable Cox regression, censoring for death, was used to adjust for patient-level (demographic, socioeconomic, and medical) and facility-level factors. RESULTS:A total of 233 003 patients (97 617 [41.9%] female patients; mean [SD] age, 58.0 [12.1] years) across 6565 facilities met inclusion criteria. Participants included 70 062 Black patients (30.1%), 42 820 Hispanic patients (18.4%), 105 368 White patients (45.2%), and 14 753 patients (6.3%) who identified as another race or ethnicity (eg, American Indian or Alaskan Native, Asian, Native Hawaiian or Pacific Islander, and multiracial). Of 6565 dialysis facilities, the mean (SD) commercial payer mix was 21.2% (15.6 percentage points). Patient-level commercial insurance was associated with increased incidence of wait-listing (adjusted hazard ratio [aHR], 1.86; 95% CI, 1.80-1.93; P < .001). At the facility-level and before covariate adjustment, higher commercial payer mix was associated with increased wait-listing (fourth vs first payer mix quartile [Q]: HR, 1.79; 95% CI, 1.67-1.91; P < .001). However, after covariate-adjustment, including adjusting for patient-level insurance status, commercial payer mix was not significantly associated with outcome (Q4 vs Q1: aHR, 1.02; 95% CI, 0.95-1.09; P = .60). CONCLUSIONS AND RELEVANCE:In this national cohort study of patients newly initiated on chronic dialysis, although patient-level commercial insurance was associated with higher access to the kidney transplant waiting lists, there was no independent association of facility-level commercial payer mix with patients being added to waiting lists for transplant. As the landscape of insurance coverage for dialysis evolves, the potential downstream impact on access to kidney transplant should be monitored.

IMPORTANCE:Allocation of deceased donor kidneys is meant to follow a ranked match-run list of eligible candidates, but transplant centers with a 1-to-1 relationship with their local organ procurement organization have full discretion to decline offers for higher-priority candidates and accept them for lower-ranked candidates at their center. OBJECTIVE:To describe the practice and frequency of transplant centers placing deceased donor kidneys with candidates who are not the highest rank at their center according to the allocation algorithm. DESIGN, SETTING, AND PARTICIPANTS:This retrospective cohort study used 2015 to 2019 organ offer data from US transplant centers with a 1-to-1 relationship with their local organ procurement organization, following candidates for transplant events from January 2015 to December 2019. Participants were deceased kidney donors with a single match-run and at least 1 kidney transplanted locally and adult, first-time, kidney-only transplant candidates receiving at least 1 offer for a locally transplanted deceased donor kidney. Data were analyzed from March 1, 2022 to March 28, 2023. EXPOSURE:Demographic and clinical characteristics of donors and recipients. MAIN OUTCOMES AND MEASURES:The outcome of interest was kidney transplantation into the highest-priority candidate (defined as transplanted after zero declines for local candidates in the match-run) vs a lower-ranked candidate. RESULTS:This study assessed 26 579 organ offers from 3136 donors (median [IQR] age, 38 [25-51] years; 2903 [62%] men) to 4668 recipients. Transplant centers skipped their highest-ranked candidate to place kidneys further down the match-run for 3169 kidneys (68%). These kidneys went to a median (IQR) of the fourth- (third- to eighth-) ranked candidate. Higher kidney donor profile index (KDPI; higher score indicates lower quality) kidneys were less likely to go to the highest-ranked candidate, with 24% of kidneys with KDPI of at least 85% going to the top-ranked candidate vs 44% of KDPI 0% to 20% kidneys. When comparing estimated posttransplant survival (EPTS) scores between the skipped candidates and the ultimate recipients, kidneys were placed with recipients with both better and worse EPTS than the skipped candidates, across all KDPI risk groups. CONCLUSIONS AND RELEVANCE:In this cohort study of local kidney allocation at isolated transplant centers, we found that centers frequently skipped their highest-priority candidates to place kidneys further down the allocation prioritization list, often citing organ quality concerns but placing kidneys with recipients with both better and worse EPTS with nearly equal frequency. This occurred with limited transparency and highlights the opportunity to improve the matching and offer algorithm to improve allocation efficiency.

INTRODUCTION/UNASSIGNED:The use of race coefficients in equations for estimated glomerular filtration rate (eGFR) may have contributed to racial disparities in access to preemptive (without dialysis exposure) kidney transplantation (Ktx). METHODS/UNASSIGNED:In this retrospective national cohort study of incident kidney transplant candidates in the United States from 2001 to 2019, we describe temporal trends and racial disparities in preemptive listing and the distribution of eGFR at listing, using eGFR as reported and after removing the race coefficient for Black candidates. RESULTS/UNASSIGNED:). After adjusting for candidate characteristics, including listing eGFR without the race coefficient, preemptive Black candidates still had significantly lower odds of preemptive deceased donor (DD) kidney transplantation compared to non-Black candidates (odds ratio 0.87, 95% confidence interval: 0.78-0.98). CONCLUSIONS/UNASSIGNED:Over the last 2 decades, Black patients were consistently less likely to be listed preemptively and were listed at lower eGFR values. Adjusting for listing eGFR with the race coefficient computationally removed did not eliminate the racial disparity, suggesting that additional efforts are needed to achieve equity in preemptive transplantation beyond adopting race-free eGFR equations.

BACKGROUND:The prevalence of obesity among kidney transplant recipients is rising. We sought to determine the association between recipient body mass index (BMI) and post-transplant complications. METHODS:Single-center, retrospective cohort study of all adult kidney transplant recipients from 2004 to 2020. Recipients were stratified into four BMI categories: normal-weight (BMI 18.5-24.9 kg/m2, n = 1020), overweight (BMI 25-29.9 kg/m2, n = 1002), moderately obese (BMI 30-34.9 kg/m2, n = 510) and severely-to-morbidly obese (BMI ≥35 kg/m2, n = 274). Logistic regression was used to estimate the association between BMI category and surgical site infections (SSIs). RESULTS:Recipients with BMI ≥35 kg/m2 had significantly higher rates of SSIs (P < .0001) compared with recipients in all other categories. On multivariable analysis, recipients with BMI ≥35 kg/m2 had increased odds of SSIs compared with normal-weight recipients [odds ratio (OR) 3.34, 95% confidence interval (CI) 1.55-7.22, P = .022). On multivariable and Kaplan-Meier analyses, no BMI groups demonstrated increased odds for death-censored graft failure. CONCLUSION:Severe obesity in kidney transplant recipients is associated with increased SSIs, but not kidney allograft failure.

Delayed graft function (DGF) is a frequent complication of kidney transplantation, but its impact on long- and short-term transplant outcomes is unclear. We conducted a systematic literature search for studies published from 2007 to 2020 investigating the association between DGF and posttransplant outcomes. Forest plots stratified between center studies and registry studies were created with pooled odds ratios. Posttransplant outcomes including graft failure, acute rejection, patient mortality, and kidney function were analyzed. Of the 3422 articles reviewed, 38 papers were included in this meta-analysis. In single-center studies, patients who experienced DGF had increased graft failure (odds ratio [OR] 3.38; 95% confidence interval [CI], 1.85-6.17; P < 0.01), acute allograft rejection (OR 1.84; 95% CI, 1.30-2.61; P < 0.01), and mortality (OR 2.32; 95% CI, 1.53-3.50; P < 0.01) at 1-y posttransplant. Registry studies showed increased graft failure (OR 3.66; 95% CI, 3.04-4.40; P < 0.01) and acute rejection (OR 3.24; 95% CI, 1.88-5.59; P < 0.01) but not mortality (OR 2.27; 95% CI, 0.97-5.34; P = 0.06) at 1-y posttransplant. DGF was associated with increased odds of graft failure, acute rejection, and mortality. These results in this meta-analysis could help inform the selection process, treatment, and monitoring of transplanted kidneys at high risk of DGF.