United States Renal Data System Research Articles

Comparing Medicare Fee-for-Service Beneficiaries with ESKD who Switched to Medicare Advantage versus Remained in Traditional Medicare.

Patients choosing Medicare Advantage vs. Medicare fee-for-service (FFS) differ with respect to race, socioeconomic status, and burden of disease. However, it is unclear whether these differences also occur among patients with kidney failure, who were newly allowed to switch to Medicare Advantage after the 21st Century Cares Act. We used data from the United States Renal Data System (USRDS) to examine differences in characteristics of dialysis patients and kidney transplant recipients who switched from FFS to Medicare Advantage compared with those who stayed with FFS in 2021, the first year such switching was allowed. We used unadjusted and adjusted logistic regression to compare odds of switching among demographic and geographic subgroups. Among 411,513 patients with FFS coverage in 2020, 10.1% switched to Medicare Advantage in 2021. Switchers constituted 12% of the dialysis population and 5% of the kidney transplant population. In the dialysis population, patients of Black race and Hispanic ethnicity were more likely to switch than patients of White race (adjusted OR 1.69, 95% Confidence Interval [CI] 1.64, 1.73 and OR 1.42, 95% CI 1.40, 1.47, respectively), as were patients with dual eligibility for Medicaid (adjusted OR 1.12, 95% CI 1.09, 1.15). Patients living in the South were also more likely to switch to Medicare Advantage than those living in the West (adjusted OR 1.48, 95% CI 1.43, 1.52). Similar differences were observed among kidney transplant recipients. Patients who switched from FFS to Medicare Advantage were disproportionately from historically marginalized groups, including Black, Hispanic, and low income individuals. They were also more likely to live in the South. These differences may threaten the generalizability of USRDS data that relies on FFS insurance claims and suggest that comparisons of outcomes between FFS and MA beneficiaries with kidney failure should be adjusted for key patient characteristics.

Waitlist Time, Age, and Social Vulnerability: Impact on the Survival Benefit of Deceased Donor Kidney Transplantation Versus Long-term Dialysis Among Patients With End-stage Renal Disease.

We sought to define the survival benefit of kidney transplantation versus long-term dialysis relative to waitlist time on dialysis, social vulnerability, and age among end-stage renal transplant candidates. End-stage renal disease patients who were candidates for their first deceased donor kidney transplantation between 2008 and 2020 were identified using the US Renal Data System. Survival probabilities for patient survival were compared using the restricted mean survival times (RMSTs) across different age and social vulnerability index (SVI) ranges. Among 149 923 patients, 68 795 (45.9%) patients underwent a kidney transplant and 81 128 (54.1%) remained on dialysis. After propensity-score matching (n = 58 035 in each cohort), the 5-y RMST difference between kidney transplant and dialysis demonstrated an increasing trend in mean life-years gained within 5 y of follow-up relative to advancing age (<30 y: 0.40 y, 95% confidence interval, 0.36-0.44 y versus >70 y: 0.75 y, 95% confidence interval, 0.70-0.80 y). Conversely, disparities in 5-y RMSTs remained consistent relative to social vulnerability (median 5-y RMST difference: 0.62 y comparing low versus high SVI). When considering waitlist duration, stratified analyses demonstrated increasing trends across different age groups with the largest RMST differences observed among older patients aged ≥70 y. Notably, longer waitlist durations (>3 y) yielded more pronounced RMST differences compared with shorter durations (<1 y). These data underscore the survival benefit associated with kidney transplantation over long-term dialysis across various age and SVI ranges. Transplantation demonstrated a greater advantage among older patients who had a longer waitlist duration.

Evaluation of the Current Status of Home Hemodialysis in the Middle East Then Perspectives and Possibilities of Home Hemodialysis in Egypt

Abstract Background Chronic kidney disease (CKD) is a growing worldwide epidemic. The incidence and prevalence of end-stage renal disease (ESRD) are expected to continue to increase. The most recent United States Renal Data System (USRDS) reports indicate that the incident dialysis population has grown older, has more comorbid conditions than previous years, and is starting dialysis with higher levels of residual kidney function (RKF). Aim of the Work This study was done to evaluate the current status of home hemodialysis in the Middle East, then to study the perspectives and future possibilities of home hemodialysis in Egypt. It was carried out during the last 2 years; 2019 and 2020. It included 2 parts: Patients and Methods A retrospective and prospective study on 100 patients that was randomly selection and was adult ESRD patients (age &amp;gt; 18 years) either were treated and maintained on home hemodialysis during the last 5 years or will be treated and maintained on home hemodialysis during the period from march 2019 to march 2020. Results HD patients with volume overload or those with cardio-renal syndrome were found to better tolerate excessive UF with the use of home HD machines than that with the usual in-center machines. SLED and SCUF modes were very effectively managed with the use of these simple HD machines. It was noticed that the loss of residual renal functions in new HD patients, was significantly less with the use of home HD than with the usual in-center HD. This was related to less dialysate exposure other than the use of ultrapure dialysate. Conclusion The psychological status was significantly improved in those patients with having their sessions at their homes without any added stressors related to in-center HD. Even new ESRD patients who are too reluctant to start HD, were better convinced to start home HD. Home HD is a gentle and benign mode of HD with less reported intra-dialytic complications; attributed to the use of ultrapure dialysate solutions other than the treated tap/well water used in center HD.

Sleep Disorders and Dementia Risk in Older Patients with Kidney Failure: A Retrospective Cohort Study.

Community-dwelling older adults with sleep disorders are at higher risk of developing dementia. Greater than 50% of older patients with kidney failure experience sleep disorders, which may explain their high burden of dementia. Among 216,158 patients (age ≥66 years) with kidney failure (United States Renal Data System; 2008-2019), we estimated the risk of dementia (including subtypes) associated with sleep disorders using Cox proportional-hazard models with propensity score weighting. We tested whether positive airway pressure (PAP) therapy was associated with reduced dementia risk among patients with obstructive sleep apnea (OSA). 26.3% of patients were diagnosed with sleep disorders; these patients had a higher five-year unadjusted cumulative incidence for any type of dementia (36.2% vs. 32.3%; P<0.001), vascular dementia (4.4% vs. 3.7%; P<0.001), and other/mixed dementia (29.3% vs. 25.8%; P<0.001). Higher risk of any type of dementia was identified in patients with insomnia (aHR=1.42; 95%CI: 1.34-1.51), sleep-related breathing disorders (SRBDs) (aHR=1.20; 95%CI: 1.17-1.23), and other sleep disorders (aHR=1.24; 95%CI: 1.11-1.39). Higher vascular dementia risk was observed in patients with insomnia (aHR=1.43; 95%CI: 1.19-1.73), SRBDs (aHR=1.15; 95%CI: 1.07-1.24). Patients with SRBDs (aHR=1.07; 95%CI: 1.00-1.15) were at higher risk of Alzheimer's disease. Among patients with OSA, PAP therapy was associated with lower risk for any type of dementia (aHR=0.82; 95%CI: 0.76-0.90), and vascular dementia (aHR=0.65; 95%CI: 0.50-0.85). Older patients with kidney failure and sleep disorders are at a higher risk of dementia. Sleep is an important modifiable factor that should be considered for targeted interventions to mitigate dementia risk in patients with kidney failure. For patients with OSA, PAP therapy is associated with lower dementia risk.

Trends and Inequalities in Diabetes-Related Complications Among U.S. Adults, 2000-2020.

We examined national trends in diabetes-related complications (heart failure [HF], myocardial infarction [MI], stroke, end-stage renal disease [ESRD], nontraumatic lower-extremity amputation [NLEA], and hyperglycemic crisis) among U.S. adults with diagnosed diabetes during 2000-2020 by age-group, race and ethnicity, and sex. We also assessed trends in inequalities among those subgroups. Hospitalization rates for diabetes-related complications among adults (≥18 years) were estimated using the 2000-2020 National (Nationwide) Inpatient Sample. The incidence of diabetes-related ESRD was estimated using the United States Renal Data System. The number of U.S. adults with diagnosed diabetes was estimated from the National Health Interview Survey. Annual percent change (APC) was estimated for assessment of trends. After declines in the early 2000s, hospitalization rates increased for HF (2012-2020 APC 3.9%, P < 0.001), stroke (2009-2020 APC 2.8%, P < 0.001), and NLEA (2009-2020 APC 5.9%, P < 0.001), while ESRD incidence increased (2010-2020 APC 1.0%, P = 0.044). Hyperglycemic crisis increased from 2000 to 2020 (APC 2.2%, P < 0.001). MI hospitalizations declined during 2000-2008 (APC -6.0%, P < 0.001) and were flat thereafter. On average, age inequalities declined for hospitalizations for HF, MI, stroke, and ESRD incidence but increased for hyperglycemic crisis. Sex inequalities increased on average for hospitalizations for stroke and NLEA and for ESRD incidence. Racial and ethnic inequalities declined during 2012-2020 for ESRD incidence but increased for HF, stroke, and hyperglycemic crisis. There was a continued increase of several complications in the past decade. Age, sex, and racial and ethnic inequalities have worsened for some complications.

#83 Cardiovascular outcomes in home hemodialysis and peritoneal dialysis patients

Abstract Background and Aims Cardiovascular disease is the leading cause of morbidity and mortality in patients with end-stage kidney disease. Little is known about differences in cardiovascular outcomes between home hemodialysis (HHD) and peritoneal dialysis (PD). Methods We evaluated 68 645 patients who initiated home dialysis between 1/1/2005 and 12/31/2018 using the United States Renal Data System with linked Medicare claims. Rates for incident cardiovascular events of acute coronary syndrome, heart failure, and stroke hospitalizations were determined. Using adjusted time-to-event models, the associations of type of home dialysis modality with the outcomes of incident cardiovascular events, cardiovascular death, and all-cause death were examined. Results The mean age of patients in the study cohort was 64 ± 15 years, and 42.3% were women. Mean time of follow up was 1.8 ± 1.6 years. The unadjusted cardiovascular event rate was 95.1 per thousand person-years [PTPY] (95% CI, 93.6-96.8), with a higher rate in patients on HHD than on PD (127.8 PTPY; 95% CI, 118.9-137.2 vs. 93.3 PTPY; 95% CI, 91.5-95.1). However, HHD was associated with a slightly lower adjusted risk of cardiovascular events than PD (HR, 0.92; 95% CI, 0.85 to 0.997). Compared to PD patients, HHD patients had 42% lower adjusted risk of stroke (HR, 0.58; 95% CI, 0.48-0.71), 17% lower adjusted risk of acute coronary syndrome (HR, 0.83; 95% CI, 0.72-0.95), and no difference in risk of heart failure (HR, 1.05; 95% CI, 0.94-1.16). HHD was associated with 22% lower adjusted risk of cardiovascular death (HR, 0.78; 95% CI, 0.71-0.86) and 8% lower adjusted risk of all-cause death (HR, 0.92; 95% CI, 0.87-0.97) as compared to PD. Conclusion Relative to PD, HHD is associated with decreased risk of stroke, acute coronary syndrome, cardiovascular death, and all-cause death. Further studies are needed to better understand the factors associated with differences in cardiovascular outcomes by type of home dialysis modality in patients with kidney failure.

#541 Secular trends in CKD and ESKD mortality rates in the United States, 2011–2021

Abstract Background and Aims Patients with chronic kidney disease (CKD) and end-stage kidney disease (ESKD) have a considerably higher mortality than the general population. Nevertheless, in the United States, mortality rates in the CKD and ESKD populations have declined steadily over the last decade until the onset of the COVID-19 pandemic [1]. Through a quantitative analysis of the age- and time-dependence of mortality rates in renal patient populations in the US, we aimed at quantifying trends in life expectancy between 2011 and 2021. Method We analysed CKD and ESKD mortality rates as reported in the US Renal Data System's (USRDS) Annual Data Report 2023 for the years 2011–2021 [1]. There, CKD mortality rates were determined from a Medicare 5% random sample (CKD stages 4 and 5) for patients aged 65 and above (“CKD 65+”). ESKD mortality rates were obtained from the USRDS database; we analysed data for patients aged 45 and above (“ESKD 45+”). We used fits of analytical functions to the data to hosphorzed their dependence on age and time. This technique enables us to extract quantitative trends in time by tracking fit parameters. Results We found that for each year between 2011 and 2021, mortality rates in the adult CKD and ESKD populations in the US largely conformed to an exponential dependence on patient age, $m = {{m}_0}( t ){{2}^{a/{{\Delta }}a}}$, that is, mortality rates doubled over constant age increments ${{\Delta }}a$. While overall, mortality rates were declining between 2011 and 2019, the age increments over which mortality rates doubled were nearly identical for each year (CKD 65+: ${{\Delta }}a$ = 10.5 ± 0.4 y, ESKD 45+: ${{\Delta }}a$ = 15.1 ± 0.9 y; mean ± SD). Exploiting this simple relationship, we found that the changes in mortality rates over time could largely be reduced to a steady right-shift of an otherwise unchanged mortality curve over time (shown for the ESKD 45+ group in Fig. 1a). By quantifying this right-shift over time, we estimated the gain in 1-year survival probability for different ages (Fig. 1b,c). This gain in survival does not necessarily imply a prolonged time on renal replacement therapy (RRT), e.g., when patients concomitantly start RRT at a later age. The onset of the COVID-19 pandemic in 2020 coincides with an abrupt cessation of these positive trends, reflected by a setback of mortality curves close to those in the year 2016 for the CKD population and to before 2011 for the ESKD population. Conclusion Public health data on CKD and ESKD show systematic dependencies of mortality rates on age and time, which can be revealed using analytical parameterisations of the data. Using this technique, we can capture trends in mortality rates and 1-year survival probability in adult kidney patient populations in the US during the years 2011–2019 and can quantify the abrupt cessation of these trends during the onset of the COVID-19 pandemic. In the CKD population we observed a setback of mortality rates close to those in the year 2016 with the onset of the pandemic. Changes in mortality rates in the ESKD population were more distinct. Specifically in elderly patients (aged 65 and above) 1-year survival dropped abruptly to levels lower than those observed in the previous decade.

Differences in Racial and Ethnic Disparities Between First and Repeat Kidney Transplantation.

Recent data suggest patients with graft failure had better access to repeat kidney transplantation (re-KT) than transplant-naive dialysis accessing first KT. This was postulated to be because of better familiarity with the transplant process and healthcare system; whether this advantage is equitably distributed is not known. We compared the magnitude of racial/ethnic disparities in access to re-KT versus first KT. Using United States Renal Data System, we identified 104 454 White, Black, and Hispanic patients with a history of graft failure from 1995 to 2018, and 2 357 753 transplant-naive dialysis patients. We used adjusted Cox regression to estimate disparities in access to first and re-KT and whether the magnitude of these disparities differed between first and re-KT using a Wald test. Black patients had inferior access to both waitlisting and receiving first KT and re-KT. However, the racial/ethnic disparities in waitlisting for (adjusted hazard ratio [aHR] = 0.77; 95% confidence interval [CI], 0.74-0.80) and receiving re-KT (aHR = 0.61; 95% CI, 0.58-0.64) was greater than the racial/ethnic disparities in first KT (waitlisting: aHR = 0.91; 95% CI, 0.90-0.93; Pinteraction = 0.001; KT: aHR = 0.68; 95% CI, 0.64-0.72; Pinteraction < 0.001). For Hispanic patients, ethnic disparities in waitlisting for re-KT (aHR = 0.83; 95% CI, 0.79-0.88) were greater than for first KT (aHR = 1.14; 95% CI, 1.11-1.16; Pinteraction < 0.001). However, the disparity in receiving re-KT (aHR = 0.76; 95% CI, 0.72-0.80) was similar to that for first KT (aHR = 0.73; 95% CI, 0.68-0.79; Pinteraction = 0.55). Inferences were similar when restricting the cohorts to the Kidney Allocation System era. Unlike White patients, Black and Hispanic patients with graft failure do not experience improved access to re-KT. This suggests that structural and systemic barriers likely persist for racialized patients accessing re-KT, and systemic changes are needed to achieve transplant equity.

Effect of End-Stage Renal Disease Prospective Payment System on Utilization of Peritoneal Dialysis in Patients with Kidney Allograft Failure.

The Center for Medicare and Medicaid Services (CMS) introduced an End Stage Renal Disease (ESRD) Prospective Payment System (PPS) in 2011 to increase the utilization of home dialysis modalities, including peritoneal dialysis (PD). Several studies have shown a significant increase in PD utilization after PPS implementation. However, its impact on patients with kidney allograft failure remains unknown. We conducted an interrupted time series (ITS) analysis using data from the United States Renal Data System (USRDS) that include all adult kidney transplant recipients with allograft failure who started dialysis between 2005 and 2019. We compared the PD utilization in the pre-PPS period (2005-2010) to the fully implemented post-PPS period (2014 - 2019) for early (within 90 days) and late (91-365 days) PD experience. 27507 adult recipients with allograft failure started dialysis during the study period. There was no difference in early PD utilization between the pre-PPS and the post-PPS period in either immediate change (0.3% increase; 95%CI: -1.95%, 2.54%; p=0.79) or rate of change over time (0.28% increase per year; 95%CI: -0.16%, 0.72%; p=0.18). Subgroup analyses revealed a trend toward higher PD utilization post-PPS in for-profit and large-volume dialysis units. There was a significant increase in PD utilization in the post-PPS period in units with low PD experience in the pre-PPS period. Similar findings were seen for the late PD experience. PPS did not significantly increase the overall utilization of PD in patients initiating dialysis after allograft failure.

Evaluating site-of-care-related racial disparities in kidney graft failure using a novel federated learning framework.

Racial disparities in kidney transplant access and posttransplant outcomes exist between non-Hispanic Black (NHB) and non-Hispanic White (NHW) patients in the United States, with the site of care being a key contributor. Using multi-site data to examine the effect of site of care on racial disparities, the key challenge is the dilemma in sharing patient-level data due to regulations for protecting patients' privacy. We developed a federated learning framework, named dGEM-disparity (decentralized algorithm for Generalized linear mixed Effect Model for disparity quantification). Consisting of 2 modules, dGEM-disparity first provides accurately estimated common effects and calibrated hospital-specific effects by requiring only aggregated data from each center and then adopts a counterfactual modeling approach to assess whether the graft failure rates differ if NHB patients had been admitted at transplant centers in the same distribution as NHW patients were admitted. Utilizing United States Renal Data System data from 39043 adult patients across 73 transplant centers over 10 years, we found that if NHB patients had followed the distribution of NHW patients in admissions, there would be 38 fewer deaths or graft failures per 10000 NHB patients (95% CI, 35-40) within 1year of receiving a kidney transplant on average. The proposed framework facilitates efficient collaborations in clinical research networks. Additionally, the framework, by using counterfactual modeling to calculate the event rate, allows us to investigate contributions to racial disparities that may occur at the level of site of care. Our framework is broadly applicable to other decentralized datasets and disparities research related to differential access to care. Ultimately, our proposed framework will advance equity in human health by identifying and addressing hospital-level racial disparities.

Sex Differences in Cardiovascular Outcomes in Patients With Kidney Failure.

Cardiovascular disease is the leading cause of mortality in patients with kidney failure, and their risk of cardiovascular events is 10 to 20 times higher as compared with the general population. We evaluated 508 822 patients who initiated dialysis between January 1, 2005 and December 31, 2014 using the United States Renal Data System with linked Medicare claims. We determined hospitalization rates for cardiovascular events, defined by acute coronary syndrome, heart failure, and stroke. We examined the association of sex with outcome of cardiovascular events, cardiovascular death, and all-cause death using adjusted time-to-event models. The mean age was 70±12 years and 44.7% were women. The cardiovascular event rate was 232 per thousand person-years (95% CI, 231-233), with a higher rate in women than in men (248 per thousand person-years [95% CI, 247-250] versus 219 per thousand person-years [95% CI, 217-220]). Women had a 14% higher risk of cardiovascular events than men (hazard ratio [HR], 1.14 [95% CI, 1.13-1.16]). Women had a 16% higher risk of heart failure (HR, 1.16 [95% CI, 1.15-1.18]), a 31% higher risk of stroke (HR, 1.31 [95% CI, 1.28-1.34]), and no difference in risk of acute coronary syndrome (HR, 1.01 [95% CI, 0.99-1.03]). Women had a lower risk of cardiovascular death (HR, 0.89 [95% CI, 0.88-0.90]) and a lower risk of all-cause death than men (HR, 0.96 [95% CI, 0.95-0.97]). Among patients undergoing dialysis, women have a higher risk of cardiovascular events of heart failure and stroke than men. Women have a lower adjusted risk of cardiovascular mortality and all-cause mortality.

Neighborhood Racial and Ethnic Segregation and the Risk of Dementia in Older Adults Living with Kidney Failure.

Dementia disproportionately impacts older minoritized adults with kidney failure. To better understand the mechanism of this disparity, we studied the role of racial and ethnic segregation (segregation hereafter), a form of structural racism recently identified as a mechanism in numerous other health disparities. We identified 901,065 older adults (age ≥55) with kidney failure from 2003 to 2019 using the United States Renal Data System (USRDS). We quantified dementia risk across tertiles of residential neighborhood segregation score using cause-specific hazard models, adjusting for individual and neighborhood-level factors. We included an interaction term to quantify the differential effect of segregation on dementia diagnosis by race and ethnicity. We identified 79,851 older adults with kidney failure diagnosed with dementia between 2003 and 2019 (median follow-up: 2.2 years). Compared to those in low-segregation neighborhoods, older adults with kidney failure in high-segregation neighborhoods had a 1.63-fold (95% confidence interval (CI):1.60-1.66) higher risk of dementia diagnosis, an association that differed by race and ethnicity (Asian: adjusted hazard ratio [aHR]=1.26, 95%CI:1.15-1.38; Black: aHR=1.66, 95%CI:1.61-1.71; Hispanic: aHR=2.05, 95%CI:1.93-2.18; White: aHR=1.59, 95%CI:1.55-1.64;Pinteraction<0.001). Notably, older Asian (aHR=1.76, 95%CI:1.64-1.89), Black (aHR=2.65, 95%CI:2.54-2.77), Hispanic (aHR=2.15, 95%CI:2.04-2.26), and White (aHR=2.20, 95%CI:2.09-2.31) adults with kidney failure residing in minority-predominant high-segregation neighborhoods had a higher risk of dementia diagnosis compared to older White adults with kidney failure in White-predominant high-segregation neighborhoods. Moreover, older adults with kidney failure receiving care at dialysis facilities located in high-segregation neighborhoods also experienced a higher risk of dementia diagnosis (aHR=1.53, 95%CI:1.50-1.56); this association differed by race and ethnicity (Pinteraction<0.001). Residing in or receiving care at dialysis facilities located in high-segregation neighborhoods was associated with a higher risk of dementia diagnosis among older individuals with kidney failure, particularly minoritized individuals.

Comparative Safety of Long-Acting vs. Short-Acting Erythropoiesis-Stimulating Agents Among Patients Undergoing Hemodialysis.

Both short-acting (epoetin alfa or beta) and long-acting (darbepoetin alfa or PEG-epoetin) erythropoiesis-stimulating agents (ESAs) are commonly prescribed for patients with kidney failure undergoing maintenance hemodialysis. We compared the risks of major adverse cardiovascular events (MACE) and of all-cause mortality associated with receipt of short- vs. long-acting ESAs. This retrospective cohort analysis included Medicare hemodialysis beneficiaries aged ≥ 18 years in the United States Renal Data System from January 2015 to December 2017. We included adults who survived > 90 days after initiating hemodialysis and received either short- or long-acting ESAs. Outcomes were MACE (first occurrence of stroke, acute myocardial infarction, or cardiovascular-related mortality) and all-cause mortality. After stabilized inverse probability of treatment weighting, Cox proportional hazards regression models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for each outcome. Of 68,607 patients (mean age: 65 years, 45% females), 33,658 (49%) received long-acting ESAs and 34,949 (51%) received short-acting ESAs. There was no difference in the risk of MACE associated with receipt of short- vs. long-acting ESAs (HR: 1.02 (95% CI: 0.98-1.08)). However, long-acting (vs. short-acting) ESA receipt was associated with a lower risk of all-cause mortality (HR: 0.91 (95% CI: 0.87-0.96)). Compared with short-acting ESAs, long-acting ESAs were associated with a lower risk of all-cause mortality, with no difference in the risk of MACE. Future studies with a longer follow-up are needed to confirm these findings.

A clinical score to predict recovery in end-stage kidney disease due to acute kidney injury.

Acute kidney injury (AKI) is a major contributor to end-stage kidney disease (ESKD). About one-third of patients with ESKD due to AKI recover kidney function. However, the inability to accurately predict recovery leads to improper triage of clinical monitoring and impacts the quality of care in ESKD. Using data from the United States Renal Data System from 2005 to 2014 (n=22922), we developed a clinical score to predict kidney recovery within 90 days and within 12 months after dialysis initiation in patients with ESKD due to AKI. Multivariable logistic regressions were used to examine the effect of various covariates on the primary outcome of kidney recovery to develop the scoring system. The resulting logistic parameter estimates were transformed into integer point totals by doubling and rounding the estimates. Internal validation was performed. Twenty-four percent and 34% of patients with ESKD due to AKI recovered kidney function within 90 days and 12 months, respectively. Factors contributing to points in the two scoring systems were similar but not identical, and included age, race/ethnicity, body mass index, congestive heart failure, cancer, amputation, functional status, hemoglobin and prior nephrology care. Three score categories of increasing recovery were formed: low score (0-6), medium score (7-9) and high score (10-12), which exhibited 90-day recovery rates of 12%, 26% and 57%. For the 12-month scores, the low, medium and high groups consisted of scores 0-5, 6-8 and 9-11, with 12-month recovery rates of 16%, 33% and 62%, respectively. The internal validation assessment showed no overfitting of the models. A clinical score derived from information available at incident dialysis predicts renal recovery at 90 days and 12 months in patients with presumed ESKD due to AKI. The score can help triage appropriate monitoring to facilitate recovery and begin planning long-term dialysis care for others.

Sex/Gender Disparities in Preemptive Referrals for Kidney Transplantation

BackgroundSex/gender inequities persist in access to kidney transplantation. Whether differences in preemptive referral (i.e., referral prior to dialysis start) explain this inequity remains unknown. MethodsAll adults (18-79 years; N = 44,204) initiating kidney replacement therapy (KRT; dialysis or transplant) in Georgia, North Carolina, or South Carolina between 2015 and 2019 were identified from the United States Renal Data System. Individuals were linked to the Early Steps to Transplant Access Registry to obtain data on preemptive referral and followed through November 13, 2020 for outcomes of waitlisting and living donor transplant. Logistic regression assessed the association between sex/gender and likelihood of preemptive referral among all KRT patients. Cox-proportional hazards assessed the association between sex/gender and waitlisting or living donor among preemptively referred patients. ResultsOverall, men and women were similarly likely to be preemptively referred (OR: 0.99 [0.95-1.04]). Preemptively referred women (vs. men) were, on average, younger and with fewer comorbidities. There were no sex/gender differences in waitlisting once patients were preemptively referred (HR: 0.97 [0.91-1.03]), but women (vs. men) who were preemptively referred remained 25% (HR: 0.75 [0.66-0.86]) less likely to receive a living donor transplant. ConclusionIn the Southeast US, men and women initiating KRT are similarly likely to be preemptively referred for a kidney transplant, and this appears, at least in part, to mitigate known sex/gender inequities in access to waitlisting, but not living donor transplant. Despite this, preemptively referred women, on average, had a more favorable medical profile relative to preemptively referred men.

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.

Association of Sevelamer Initiation with Gastrointestinal Bleeding Hospitalization in Individuals Requiring Hemodialysis

Introduction: Case reports have suggested a causative role between sevelamer use and subsequent gastrointestinal bleeding (GIB), but no large observational studies have evaluated this association. Methods: Using the United States Renal Data System database from 2015 to 2019, we examined the association between initiation of sevelamer (vs. non-sevelamer containing phosphate binders) and GIB hospitalization as well as all-cause mortality among individuals on hemodialysis. We emulated a target trial using Cox regression models and inverse probability of treatment weights to estimate the adjusted hazard ratios (HR) across outcomes and subgroups. Results: Among 21,354 new users of phosphate binders (11,276 sevelamer and 10,078 non-sevelamer) with baseline lab data (calcium, phosphorus, hemoglobin, and albumin), there were 2,811 GIB hospitalizations and 5,920 deaths after a median follow-up of 1.3 years. Compared with the initiation of non-sevelamer binders, sevelamer was not associated with an increased risk of GIB hospitalization (89 vs. 90 events per 1,000 person-years; IPTW-HR: 0.98, 95% CI: 0.91–1.06) or all-cause mortality (220 vs. 224 events per 1,000 person-years; IPTW-HR: 0.98, 95% CI: 0.93–1.03). Subgroup analyses (such as diabetes and anti-coagulation use) were generally consistent, and there was no association between sevelamer dose and GIB hospitalization. Conclusion: Among patients requiring hemodialysis, sevelamer (vs. non-sevelamer) containing phosphate binders was not associated with increased risk of GIB hospitalization.

Incidental AVF creation during unrelated hospitalization is associated with worse outcomes compared with outpatient AVF creation.

Arteriovenous fistula (AVF) creation during an inpatient hospitalization is often performed for patient convenience and to ensure compliance. We sought to evaluate whether this approach has comparable outcomes to outpatient AVF creation. We identified patients undergoing index AVF creation from the United States Renal Data System dataset (2012-2017). Patients were grouped into outpatient and inpatient. Outpatient included patients that were operated in either an outpatient setting, ambulatory surgical center or were admitted inpatient on the day of AVF creation. Inpatient included only patients with claims for an inpatient visit before access creation. Multiple safety outcomes were compared between groups using unadjusted and adjusted logistic regression methods generating odds ratios and 95% confidence intervals (95% CI). One-year maturation rates were compared using competing-risks regression methods generating sub-hazard ratios (sHR) and 95% CI. Outcomes were also compared after 1:1 propensity score matching. We identified 68,872 patients undergoing AVF creation, 4855 (7.1%) of which were created during inpatient hospitalization. Patients in the inpatient group were older (65.8 ± 13.8 vs 65.2 ± 13.8, p = 0.002), more likely to be of Black race (28.1% vs 26.8%, p = 0.02), and have cardiovascular comorbidities (all p < 0.05). Patients in the inpatient groups were more likely to be dialyzed at for-profit (88.1% vs 85.9%, p < 0.01) and freestanding (94.8% vs 92.9%, p < 0.01) dialysis centers. On both unadjusted and adjusted analysis, inpatient group was more likely to experience 30-day adverse events (e.g. pneumonia, COPD exacerbation, stroke, myocardial infarction), any complication, and all-cause mortality. On competing risks analysis, successful two-needle cannulation at 1 year was significantly less likely in the inpatient group (68.1% vs 76.8%, p < 0.01; sHR = 0.68 [95% CI, 0.65-0.71], p < 0.01). These trends were robust on 1:1 propensity matching. Incidental AVF creation in hospitalized patients is associated with worse outcomes, ranging from mortality to postoperative complications to fistula maturation, compared with outpatient AVF creation.

Abstract P415: Validation of an Algorithm to Identify End-Stage Kidney Disease Cases in Electronic Health Record Data

Introduction: End-stage kidney disease (ESKD) is an important clinical outcome. However, there is limited work on validating algorithms to detect ESKD cases within electronic health record (EHR) data. Hypothesis: Algorithms using diagnostic and procedure codes in EHR data can accurately identify ESKD cases. Methods: Using data from Geisinger linked to the United States Renal Data System (USRDS), we developed algorithms to identify individuals with ESKD (either dialysis or kidney transplant, whichever occurred first) and validated them against ESKD cases ascertained from the USRDS data from January 1, 1996, through June 28, 2018 (gold standard). We calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Results: To identify dialysis cases, we required 1) diagnosis codes of stage 5 chronic kidney disease or ESKD with dialysis codes within seven days or 2) three dialysis codes lasted longer than a month with any two consecutive codes occurring within 3 months. To identify kidney transplant cases, we required 1) one procedure code of kidney transplant or 2) one diagnosis code of kidney transplant in inpatients or problem list. Among 572,574 individuals (mean age, 41.6 years; female, 55.4%; White, 92.9%), the algorithms identified 4,187 ESKD cases (3,875 dialysis and 792 kidney transplant cases), while there were 4,529 ESKD cases (4,368 dialysis and 772 kidney transplant cases) by USRDS data. Our ESKD identifying algorithms’ sensitivity, specificity, PPV, and NPV were 71.1%, 99.8%, 76.9%, and 99.8%, respectively. Median (interquartile range) duration between incident dates by the algorithm and by the USRDS was -2 (-21, 86) days ( Table ). Conclusions: The algorithms developed by diagnostic and procedure codes accurately identified ESKD cases with high specificity in EHR data. Further validation is required in different health systems. Table The validity of the algorithms to identify ESKD cases IQR: interquartile range

Patient Care Technician Staffing and Outcomes Among US Patients Receiving In-Center Hemodialysis

Dialysis patient care technicians (PCTs) play a critical role in US in-center hemodialysis (HD) care, but little is known about the association of PCT staffing with patient outcomes at US HD facilities. To estimate the associations of in-center HD patient outcomes with facility-level PCT staffing. This was a retrospective cohort study, with data analysis performed from March 2023 to January 2024. Data on US patients with end-stage kidney disease and their treatment facilities were obtained from the US Renal Data System. Participants included patients (aged 18-100 years) initiating in-center HD between January 1, 2016, and December 31, 2018, who continued receiving in-center HD for 90 days or more and had data on PCT staffing at their initial treating HD facility. Facility-level patient-to-PCT ratios (number of HD patients divided by the number of PCTs reported by the treating facility in the prior year), categorized into quartiles (highest quartile denotes the highest PCT burden). Patient-level outcomes included 1-year patient mortality, hospitalization, and transplantation. Associations of outcomes with quartile of patient-to-PCT ratio were estimated using incidence rate ratios (IRRs) from mixed-effects Poisson regression, with adjustment for patient demographics and clinical and facility factors. A total of 236 126 patients (mean [SD] age, 63.1 [14.4] years; 135 952 [57.6%] male; 65 945 [27.9%] Black; 37 777 [16.0%] Hispanic; 153 637 [65.1%] White; 16 544 [7.0%] other race; 146 107 [61.9%] with diabetes) were included. After full adjustment, the highest vs lowest quartile of facility-level patient-to-PCT ratio was associated with a 7% higher rate of patient mortality (IRR, 1.07; 95% CI, 1.02-1.12), a 5% higher rate of hospitalization (IRR, 1.05; 95% CI, 1.02-1.08), an 8% lower rate of waitlisting (IRR, 0.92; 95% CI, 0.85-0.98), and a 20% lower rate of transplant (IRR, 0.80; 95% CI, 0.71-0.91). The highest vs lowest quartile of patient-to-PCT ratio was also associated with an 8% higher rate of sepsis-related hospitalization (IRR, 1.08; 95% CI, 1.03-1.14) and a 15% higher rate of vascular access-related hospitalization (IRR, 1.15; 95% CI, 1.03-1.28). These findings suggest that initiation of treatment in facilities with the highest patient-to-PCT ratios may be associated with worse early mortality, hospitalization, and transplantation outcomes. These results support further investigation of the impact of US PCT staffing on patient safety and quality of US in-center HD care.