Marked variation in disease acuity and outcomes on the liver transplant waiting list by sociodemographic characteristics.

Understanding the association of social determinants of health (SDOH) with liver transplant listing and wait list outcomes can inform healthcare policy and interventions aimed at improving access to care. We analyzed the Scientific Registry of Transplant Recipients database merged with the Social Deprivation Index (SDI) to evaluate if area of residence is associated with Model for End-Stage Liver Disease incorporating sodium (MELD-NA) at time of wait list placement and outcomes following wait listing, and if this varied based on sociodemographic variables. Compared to candidates residing in areas of low SDI), those residing in areas of high SDI (most socioeconomic disadvantage) had 11% higher adjusted likelihood [aOR (95% CI)=1.11(CI 1.05,1.17)] of being listed for transplant with a MELD-NA score ≥30; this was not statistically significant when also adjusted for race/ethnicity [aOR=1.02(0.97,1.08)]. When stratified by race/ethnicity, residing in an area of high SDI was associated with a MELD-NA score ≥30 at time of wait listing among Hispanic White candidates (aOR=1.24, 95% CI: 1.04, 1.49). Candidates residing in areas of high SDI had 8% lower chance [aHR=0.92 (0.88,0.96)] of undergoing a liver transplant, 6% higher risk of death [aHR=1.06(1.002,1.13)], and 20% higher risk [aHR=1.20(1.13,1.28)] of removal on the wait list independent of race, ethnicity, insurance status, or sex. In the US, residence in areas of high socioeconomic disadvantage is significantly associated with higher MELD-NA at the time of wait listing among Hispanic White candidates. In addition, residence in areas of high socioeconomic disadvantage was associated with a higher risk of death or removal from the wait list and lower chances of receiving a liver transplant after wait list placement, particularly among Non-Hispanic White candidates and older candidates.

Area-Level Social Deprivation and Cytomegalovirus Seropositivity at the Time of Solid Organ Transplant.

Importance: Cytomegalovirus (CMV) is associated with significant morbidity and mortality in solid organ transplant (SOT) recipients. The risk factors for CMV seropositivity in SOT recipients, including area-level social deprivation in the US, have not been fully characterized. Objective: To (1) evaluate CMV seroprevalence, (2) assess the recipient characteristics associated with CMV seropositivity, and (3) assess the association of area-level social deprivation index (SDI) scores with pretransplant CMV serostatus. Design, Setting, and Participants: This retrospective cross-sectional analysis of the Scientific Registry of Transplant Recipients database included all adult (aged ≥18 years) SOT recipients from January 1, 2008, to May 31, 2022. Data were analyzed from April 10 to October 25, 2023. Exposure: Recipient characteristics and area-level SDI. Main Outcomes and Measures: Multivariable generalized linear models were used to evaluate the association between (1) patient characteristics and CMV and (2) social deprivation (measured by SDI scores, which were assessed in quintiles, from lowest to highest) and CMV seropositivity. In addition, differences based on patient demographics and the transplanted organ(s) were evaluated. Results: Among the 389 288 SOT recipients included in the analysis, mean (SD) age was 53.3 (13.0) years; 63.0% were male, 21.4% were Black, 15.2% were Hispanic White, 56.2% were non-Hispanic White, and 62.7% were CMV seropositive. The mean (SD) age was higher among CMV seropositive (54.0 [12.7] years) compared with CMV seronegative (52.0 [13.5] years) patients. Seropositivity for CMV was higher among women (69.9%) than men (58.5%) and among Black (74.8%) and Hispanic White (80.2%) patients compared with non-Hispanic White patients (50.4%). Seropositivity for CMV was highest among kidney (64.5%), liver (63.6%), and kidney and liver (66.2%) recipients. Greater SDI scores were associated with greater CMV seropositivity, ranging from 51.7% for the least deprived to 75.5% for the most deprived quintiles (P < .001), independent of age, sex, or race. Conclusions and Relevance: In this cross-sectional study, an association between SDI and CMV seropositivity was observed among SOT recipients, independent of age, sex, or race and ethnicity. To optimize posttransplant outcomes in CMV seropositive recipients, efforts targeting prevention of CMV reactivation need to be prioritized in these higher-risk populations.

Changing Landscape of Open Offers in Liver Transplantation in the Machine Perfusion Era: Exposure, Equity, and Economics.

BACKGROUND: Open offers (OOs) in liver transplantation (LT) result from bypassing the traditional allocation system. Little is known about the trends of OOs or the differences in donor/recipient characteristics compared to traditionally placed organs. We aim to quantify modern practices regarding OOs and understand NMP's impact, focusing on social determinants of health (SDH), cost, and graft-associated risk. METHODS: LTs from 1/1/2018 to 12/31/2023 at a single center were included. NMP was implemented on 10/1/2022. The CDC (centers for disease control)-validated social vulnerability index (SVI) and donor risk index (DRI) were calculated. Comprehensive complications index (CCI), Clavien-Dindo grades, patient and graft survival, and costs of transplantation were included. RESULTS: 1162 LTs were performed; 193 (16.8%) from OOs. OOs were more common in the post-NMP era (26.5% vs. 13.3%, p < 0.001). Pre-NMP, patients receiving OOs had longer waitlist times (118 vs. 69 days, p < 0.001), lower MELDs (17 vs. 25 points, p < 0.001), and riskier grafts (DRI = 1.8 vs. 1.6, p = 0.004) compared to standard offers. Post-NMP, recipients receiving OOs demonstrated no difference in waitlist time (27 vs. 20 days, p = 0.21) or graft risk (DRI = 2.03 vs. 2.23, p = 0.17). OO recipient MELD remained lower (16 vs. 22, p < 0.001). OO recipients were more socially vulnerable (SVI), pre-NMP (0.41 vs. 0.36, p = 0.004), but less vulnerable after NMP (0.23 vs. 0.36, p = 0.019). Despite increased graft risk, pre-NMP OO-LTs were less expensive in the 90-day global period ($154 939 vs. $178 970, p = 0.002) and the 180-days pre-/post-LT ($208 807 vs. $228 091, p = 0.021). Cost trends remained similar with NMP. CONCLUSION: OOs are increasingly utilized and may be appealing due to demonstrated cost reductions even with NMP. Although most OO-related metrics in our center remain similar before and after machine perfusion, programs should take caution that increasing use does not worsen organ access for socially vulnerable populations.

Impact of graft type on outcomes following liver transplantation for primary sclerosing cholangitis.

BACKGROUND: Limited data exists regarding impact of graft type on outcomes following liver transplantation (LT) in Primary Sclerosing Cholangitis (PSC). Our goal was to evaluate the impact of graft type on outcomes following LT in PSC and determine predictors of outcomes. METHODS: Using the Scientific registry of transplant recipients (SRTR), retrospective cohorts were constructed of recipients with PSC over the time period 2010-2020, divided into 2 eras: 2010-2014, 2015-2020, stratified by graft type: living donor (LDLT), donation after circulatory death (DCD) and donation after brain death (DBD). Outcome measures evaluated were graft and patient survival. Survival comparison was performed using Kaplan-Meier method and multivariable analysis using Cox proportional hazard models. RESULTS: 2966 recipients underwent LT for PSC over the study period: LDLT-PSC 153 (5.2%), DCD-PSC 131 (4.4%) and DBD-PSC 2682 (90.4%). While LDLT utilization was higher in PSC (5.2% vs. 1.3%; p < 0.001), DCD use was lower (4.4% vs. 7.2%; p < 0.001) but increased over time (era 1 vs. era 2: 3.3% vs. 5.2%; p = 0.02). Outcomes following DCD-PSC were comparable to DBD and improved over time. Compared to DBD-PSC, there was a trend toward lower short-term graft survival following LDLT-PSC (1 Yr. 85.3 vs. 91.9; p = 0.07) with higher retransplant rate (LDLT-PSC vs. DCD-PSC vs. DBD-PSC: 15% vs 11% vs 7%; p < 0.001). Compared to recipients without PSC, long-term patient survival was superior in LDLT-PSC (5 Yr. 90.1 vs. 83.7%; p = 0.05) and DCD-PSC (93.3 vs. 79.7%, p = 0.01). On multivariable analysis, LDLT but not DCD graft type, was associated with inferior graft survival in PSC (adjusted hazard Ratio = 1.65 (1.16-2.34); p = 0.005). CONCLUSIONS: In PSC, utilization of LDLT is higher, while DCD use is lower but increased over time. Outcomes following DCD LT in PSC are comparable to DBD and superior to recipients without PSC. Reduced graft survival and higher re-transplant rate following LDLT in PSC warrants further study. Consideration of DCD could help expand the donor pool in PSC.

Racial Equity in Family Approach for Patients Medically Suitable for Deceased Organ Donation.

OBJECTIVES: To conduct a contemporary analysis of the association between family approach of medically suitable potential organ donors and race/ethnicity. DESIGN: Retrospective review of data collected prospectively by Organ Procurement Organizations (OPOs). SETTING: Ten OPOs representing eight regions of the Organ Procurement and Transplantation Network and 26% of all deceased donor organs recovered in the United States. SUBJECTS: All hospitalized patients on mechanical ventilation and referred to OPOs as potential donors from January 1, 2018, to December 31, 2022. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: OPOs provided data on referral year, race, sex, donor registration status, screening determination, donation medical suitability, donation type (brain death, circulatory death), and family approach. We evaluated factors associated with family approach to discuss donation using descriptive statistics and multivariable logistic models. Of 255,429 total cases, 138,622 (54%) were screened-in for further evaluation, with variation by race/ethnicity (50% White, 60% Black, 69% Hispanic, and 60% Asian). Among those screened-in, 31,253 (23%) were medically suitable for donation, with modest variation by race/ethnicity (22% White, 26% Black, 23% Hispanic, and 21% Asian). Family approach rate by OPOs of medically suitable cases was 94% ( n = 29,315), which did not vary by race/ethnicity (94% White, 93% Black, 95% Hispanic, and 95% Asian). Family approach by OPOs was lower for circulatory death (95%) vs. brain death (97%) cases but showed minimal differences in approach rate based on race/ethnicity between medically suitable patients with different death pathways. In contrast, donor registration status of medically suitable potential donors was highly variable by race/ethnicity (37% overall; 45% White, 21% Black, 29% Hispanic, and 25% Asian). Multivariable models indicated no significant difference of family approach between White and Black (odds ratio [OR], 1.09; 95% CI, 0.95-1.24) or Asian (OR, 1.23; 95% CI, 0.95-1.60) patients. CONCLUSIONS: Findings indicate racial equity in OPO family approach rates among patients who were medically suitable for organ donation.

The dangerous precedent of censoring scientific dissemination.

The American Transplant Congress (ATC) is the largest national transplant meeting in the United States jointly sponsored by the American Society of Transplantation and the American Society of Transplant Surgeons. The 2024 ATC was held in Philadelphia, Pennsylvania during which a number of peer-reviewed scientific abstracts were censored from the program by the Health Resources and Services Administration. These abstract presentations were redacted from the program for perceived conflict with current government policy effectively restricting dissemination of highly rated findings and discussion in a scientific forum. In this viewpoint, we describe the content of the abstracts that were withdrawn from the annual ATC meeting and the implications of this censorship by the Health Resources and Services Administration. We further consider the ramifications of this action for the prospective evaluation of government policy and the relationship of the contract agency with the transplant community in the context of ongoing discussions of modernizing the transplant system which has previously been critiqued for lack of transparency.

Virtual Nephron: Evaluation of a Novel Virtual Reality Educational Tool.

Introduction: Recent technological advancements allowed the development of engaging technological tools. Using ASN funding from the ASN, we developed a 3D Virtual Reality (VR) physiology course entitled DiAL-Neph (Diuretic Action and eLectrolyte transport in the Nephron). We hereby present its evaluation. Methods: The study consisted of 2 parts: evaluation of knowledge gain, and qualitative evaluation of platform reception. Internal medicine PGY1 residents were randomly assigned into 2 groups: a VR group and a conventional group. Knowledge acquisition was assessed with a post-test administered at the end of the course and repeated within 6 to 12 weeks. Independent t-tests were used to compare the number of correct answers between the groups. A survey and focus groups composed of medicine residents evaluated the platform. Sessions were recorded and transcribed verbatim. Data was analyzed through the content analysis approach by two independent reviewers. Results: Of 117 PGY1 resident participants, 64 were randomized to the VR group and 53 were randomized to the traditional group. Initial test results showed higher scores among VR compared to the traditional group (76.5% correct vs. 68.8%). Seventy-eight PGY1s participated in the follow up testing (46 VR group vs. 32 traditional group) and results showed no significant difference in test results. Greater than 90% of the residents rated the platform positively and 77% preferred it as a teaching method. Conclusion: The DiAL-Neph VR platform appeared to improve short-term learning but not long-term retention. Further studies are needed to investigate the impact of such teaching platforms on overall interest in nephrology.

Crossing national borders for transplantation: A focused evaluation of deceased donor lung exports from the United States.

Organ transplantation is a life-saving treatment for end-stage organ failure patients, but the United States (US) faces a shortage of available organs. US policies incentivize identifying recipients for all recovered organs. Technological advancements have extended donor organ viability, creating new opportunities for long-distance transport and international sharing. We aimed to assess organ exports from deceased US donors to candidates abroad, a component of allocation policy allowed without suitable domestic candidates. Based on the national Scientific Registry of Transplant Recipients data from January 2014 to September 2023, 388 342 organs were recovered for transplantation, with 511 (0.13%) exported. Most exported organs were lungs (80%). Exported lung donors were older (41 vs 34 years, P < .001), more likely hepatitis C positive (22% vs 4%, P < .001), and more likely donors after circulatory death (20% vs 7%, P < .001). Lungs that were eventually exported were offered to more US potential transplant recipients (median = 65) than those kept in the US (median = 21 and 41 for lungs recovered by nonexporting and exporting organ procurement organizations, respectively; P < .001). Our study highlights the necessity for further research and clear policy initiatives to balance the benefits of cross-border sharing while considering potential opportunities for more aggressive organ allocation within the US.

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.

Individual-level social determinants of health and disparities in access to kidney transplant and waitlist mortality.

BACKGROUND: Comprehensive, individual-level social determinants of health (SDOH) are not collected in national transplant registries, limiting research aimed at understanding the relationship between SDOH and waitlist outcomes among kidney transplant candidates. METHODS: We merged Organ Procurement and Transplantation Network data with individual-level SDOH data from LexisNexis, a commercial data vendor, and conducted a competing risk analysis to determine the association between individual-level SDOH and the cumulative incidence of living donor kidney transplant (LDKT), deceased donor kidney transplant (DDKT), and waitlist mortality. We included adult kidney transplant candidates placed on the waiting list in 2020, followed through December 2023. RESULTS: In multivariable analysis, having public insurance (Medicare or Medicaid), less than a college degree, and any type of derogatory record (liens, history of eviction, bankruptcy and/ felonies) were associated with lower likelihood of LDKT. Compared with patients with estimated individual annual incomes ≤ $30,000, patients with incomes ≥ $120,000 were more likely to receive a LDKT (sub distribution hazard ratio (sHR), 2.52; 95% confidence interval (CI), 2.03-3.12). Being on Medicare (sHR, 1.49; 95% CI, 1.42-1.57), having some college or technical school, or at most a high school diploma were associated with a higher likelihood of DDKT. Compared with patients with incomes ≤ $30,000, patients with incomes ≥ $120,000 were less likely to receive a DDKT (sHR, 0.60; 95% CI, 0.51-0.71). Lower individual annual income, having public insurance, at most a high school diploma, and a record of liens or eviction were associated with higher waitlist mortality. CONCLUSIONS: Patients with adverse individual-level SDOH were less likely to receive LDKT, more likely to receive DDKT, and had higher risk of waitlist mortality. Differential relationships between SDOH, access to LDKT, DDKT, and waitlist mortality suggest the need for targeted interventions aimed at decreasing waitlist mortality and increasing access to LDKT among patients with adverse SDOH.

Racial, Ethnic, and Regional Disparities of Post-Acute Service Utilization After Stroke in the United States.

Background and Objectives: Post-acute care is critical for patient functional recovery and successful community transition. This study aimed to understand the current racial, ethnic, and regional disparities in post-acute service utilization after stroke. Methods: This retrospective cross-sectional study included patients hospitalized for ischemic stroke and intracerebral hemorrhage in 2017-2018 using the National Inpatient Sample. Discharge destinations were classified as follows: (1) facility including inpatient rehabilitation, skilled nursing facility, and facility hospice; (2) home health care (HHC), including home health and home hospice; and (3) home without HHC. Multinomial logistic regression was used to study the odds of discharge to a facility over home and HHC over home without HHC by race, ethnicity, insurance, and census division, adjusting for clinical factors and survey design. Results: Among the 1,000,980 weighted ischemic stroke admissions, 66.9% were White, 17.6% Black, 9.5% Hispanic, 3.1% Asian American/Pacific Islander, and 0.4% Native American. Relative to private insurance, uninsured patients had the lowest adjusted odds of facility over home discharge (0.44; 95% CI 0.40-0.48) and HHC discharge over home without HHC (0.79; 95% CI 0.71-0.88). Compared with White patients, only Hispanic patients with Medicare/Medicaid insurance or self-pay had lower odds of facility over home discharge (adjusted OR 0.80 and 0.75, respectively; 95% CI 0.76-0.84 and 0.63-0.93). Uninsured Hispanic patients also had lower odds of HHC discharge over home without HHC than White patients (0.74; 95% CI 0.57-0.97). Facility discharge rate was the highest in East North Central (39.2%) and lowest in Pacific (31.2%). HHC discharge rate was the highest in New England (20.2%) and lowest in West North Central (10.3%), which had the highest home without HHC discharge (46.1%). Compared with New England, other census divisions had lower odds of facility over any home discharge with Pacific being the lowest (adjusted OR, 0.66; 95% CI 0.60-0.71) and HHC over home without HHC discharge with West North Central being the lowest (adjusted OR, 0.33; 95% CI 0.29-0.38). Similar patterns were observed in intracerebral hemorrhage. Discussion: Significant insurance-dependent racial and ethnic disparities and regional variations were evident in post-acute service utilization after stroke. Targeted efforts are needed to improve post-acute service access for uninsured patients especially Hispanic patients and people in certain regions.

Pragmatic strategies to address health disparities along the continuum of care in chronic liver disease.

Racial, ethnic, and socioeconomic disparities exist in the prevalence and natural history of chronic liver disease, access to care, and clinical outcomes. Solutions to improve health equity range widely, from digital health tools to policy changes. The current review outlines the disparities along the chronic liver disease health care continuum from screening and diagnosis to the management of cirrhosis and considerations of pre-liver and post-liver transplantation. Using a health equity research and implementation science framework, we offer pragmatic strategies to address barriers to implementing high-quality equitable care for patients with chronic liver disease.

Geospatial Modeling Methods in Epidemiological Kidney Research: An Overview and Practical Example.

Geospatial modeling methods in population-level kidney research have not been used to full potential because few studies have completed associative spatial analyses between risk factors and exposures and kidney conditions and outcomes. Spatial modeling has several advantages over traditional modeling, including improved estimation of statistical variation and more accurate and unbiased estimation of coefficient effect direction or magnitudes by accounting for spatial data structure. Because most population-level kidney research data are geographically referenced, there is a need for better understanding of geospatial modeling for evaluating associations of individual geolocation with processes of care and clinical outcomes. In this review, we describe common spatial models, provide details to execute these analyses, and perform a case-study to display how results differ when integrating geographic structure. In our case-study, we used U.S. nationwide 2019 chronic kidney disease (CKD) data from Centers for Disease Control and Prevention's Kidney Disease Surveillance System and 2006 to 2010 U.S. Environmental Protection Agency environmental quality index (EQI) data and fit a nonspatial count model along with global spatial models (spatially lagged model [SLM]/pseudo-spatial error model [PSEM]) and a local spatial model (geographically weighted quasi-Poisson regression [GWQPR]). We found the SLM, PSEM, and GWQPR improved model fit in comparison to the nonspatial regression, and the PSEM model decreased the positive relationship between EQI and CKD prevalence. The GWQPR also revealed spatial heterogeneity in the EQI-CKD relationship. To summarize, spatial modeling has promise as a clinical and public health translational tool, and our case-study example is an exhibition of how these analyses may be performed to improve the accuracy and utility of findings.

Socioeconomic deprivation is associated with worse patient and graft survival following adult liver transplantation.

The impact of social determinants of health on adult liver transplant recipient outcomes is not clear at a national level. Further understanding of the impact of social determinants of health on patient outcomes can inform effective, equitable health care delivery. Unadjusted and multivariable models were used to analyze the Scientific Registry of Transplant Recipients to evaluate the association between the Social Deprivation Index (SDI) based on the liver transplant recipient's residential location and patient and graft survival. We included adult recipients between January 1, 2008 and December 1, 2021. Patient and graft survival were lower in adults living in areas with deprivation scores above the median. Five-year patient and graft survival were 78.7% and 76.5%, respectively, in the cohort above median SDI compared to 80.5% and 78.3% below median SDI. Compared to the recipients in low-deprivation residential areas, recipients residing in the highest deprivation (SDI quintile = 5) cohort had 6% higher adjusted risk of mortality (adjusted hazard ratio = 1.06, 95% CI: 1.01-1.13) and 6% higher risk of graft failure (adjusted hazard ratio = 1.06, 95% CI: 1.001-1.11). The increased risks for recipients residing in more vulnerable residential areas were higher (adjusted hazard ratio = 1.11, 95% CI: 1.03-1.20 for both death and graft loss) following the first year after transplantation. Importantly, the overall risk for graft loss associated with SDI was not linear but instead accelerated above the median level of deprivation. In the United States, social determinants of health, as reflected by residential distress, significantly impacts 5-year patient and graft survival. The overall effect of residential deprivation modest, and importantly, results illustrate they are more strongly associated with longer-term follow-up and accelerate at higher deprivation levels. Further research is needed to evaluate effective interventions and policies to attenuate disparities in outcomes among recipients in highly disadvantaged areas.

Incomplete reporting of clinically significant acute rejection episodes in the national kidney transplant registry.

Administrative claims data could provide a unique opportunity to identify acute rejection (AR) events using specific antirejection medications and to validate rejected data reported to the Organ Procurement and Transplantation Network. This retrospective cohort study examined differences in registry-reported events and those identified using claims data among adult kidney transplant recipients from 2012 to 2017 using Standard Analysis Files from the US Renal Data System. Rejection rates, survival estimates, and center-level differences were assessed using each approach. Among 45 880 first-time kidney transplant recipients, we identified 3841 AR events within 12 months of transplant reported by centers in the registry; claims data yielded 2945 events. Of all events occurring within 12 months of transplant, 48.5% were reported using registry only, 32.9% were identified using claims only, and 18.6% were identified using both approaches. A 3-year death-censored graft survival probability was 90.0%, 88.4%, and 81.2% (P < .001) for ARs identified using registry only, claims data only, and both approaches, respectively. The large discordance between registry-reported and claims-based events suggests incomplete and potentially inaccurate reporting of events in the Organ Procurement Transplant Network registry. These findings have important implications for analyses that use AR data and underscore the need for improved capture of clinically meaningful events.

Cold Ischemia Time and Delayed Graft Function in Kidney Transplantation: A Paired Kidney Analysis.

BACKGROUND: We aimed to understand the association between cold ischemia time (CIT) and delayed graft function (DGF) after kidney transplantation and the impact of organ pumping on that association. METHODS: Retrospective cohort study using US registry data. We identified kidney pairs from the same donor where both kidneys were transplanted but had a CIT difference >0 and ≤20 h. We determined the frequency of concordant (both kidneys with/without DGF) or discordant (only 1 kidney DGF) DGF outcomes. Among discordant pairs, we computed unadjusted and adjusted relative risk of DGF associated with longer-CIT status, when then repeated this analysis restricted to pairs where only the longer-CIT kidney was pumped. RESULTS: Among 25 831 kidney pairs included, 71% had concordant DGF outcomes, 16% had only the longer-CIT kidney with DGF, and 13% had only the shorter-CIT kidney with DGF. Among discordant pairs, longer-CIT status was associated with a higher risk of DGF in unadjusted and adjusted models. Among pairs where only the longer-CIT kidney was pumped, longer-CIT kidneys that were pumped had a lower risk of DGF than their contralateral shorter-CIT kidneys that were not pumped regardless of the size of the CIT difference. CONCLUSIONS: Most kidney pairs have concordant DGF outcomes regardless of CIT difference, but even small increases in CIT raise the risk of DGF. Organ pumping may mitigate and even overcome the adverse consequences of prolonged CIT on the risk of DGF, but prospective studies are needed to better understand this relationship.