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Sodium-glucose cotransporter-2 inhibitors (SGLT2i) reduce the risk for several adverse outcomes among patients with diabetic kidney disease. Yet, optimal timing for SGLT2i after acute kidney injury (AKI) is uncertain, as are the providers responsible for post-AKI SGLT2i initiation. Using a retrospective cohort of United States Veterans with diabetes mellitus type 2 and proteinuria, we examined encounters by provider specialty before SGLT2i initiation and subsequent all-cause mortality after hospitalization with AKI, defined by a 50% or more rise in serum creatinine. Covariates included recovery, defined by return to a 110% or less of baseline creatinine, and time since AKI hospitalization. Among 21,330 eligible Veterans, 7,798 died (37%) and 6,562 received a SGLT2i (31%) over median follow-up of 2.1 years. Post-AKI SGLT2i use was associated with lower mortality risk [adjusted hazard ratio 0.63 (95% confidence interval 0.58-0.68)]. Compared with neither SGLT2i use nor recovery, mortality risk was similar with recovery without SGLT2i use [0.97 (0.91-1.02)] but was lower without recovery prior to SGLT2i use [0.62 (0.55-0.71)] and with SGLT2i use after recovery [0.60 (0.54-0.67)]. Finally, the effect of SGLT2i was stable over time (P for time-interaction 0.19). Thus, we observed reduced mortality with SGLT2i use after AKI among Veterans with diabetic kidney disease whether started earlier or later or before or after observed recovery. Hence, patients with diabetic kidney disease who receive a SGLT2i earlier after AKI experience no significant harm impacting mortality and experience a lower mortality risk than those who do not., (Copyright © 2024 International Society of Nephrology. All rights reserved.)

Significance Statement: The Advancing American Kidney Health Initiative aims to increase rates of utilization of peritoneal dialysis (PD) in the United States. One of the first steps to PD is successful catheter placement, which can be performed by surgeons, interventional radiologists, or nephrologists. We examined the association between operator subspecialty and risk of needing a follow-up procedure in the first 90 days after initial PD catheter implantation. Overall, we found that 15.5% of catheters required revision, removal, or a second catheter placement within 90 days. The odds of requiring a follow-up procedure was 36% higher for interventional radiologists and 86% higher for interventional nephrologists compared with general surgeons. Further research is needed to understand how to optimize the function of catheters across different operator types., Background: The US government has implemented incentives to increase the use of PD. Successful placement of PD catheters is an important step to increasing PD utilization rates. Our objective was to compare initial outcomes after PD catheter placement by different types of operators., Methods: We included PD-naïve patients insured by Medicare who had a PD catheter inserted between 2010 and 2019. We examined the association between specialty of the operator (general surgeon, vascular surgeon, interventional radiologist, or interventional nephrologist) and odds of needing a follow-up procedure, which we defined as catheter removal, replacement, or revision within 90 days of the initial procedure. Mixed logistic regression models clustered by operator were used to examine the association between operator type and outcomes., Results: We included 46,973 patients treated by 5205 operators (71.1% general surgeons, 17.2% vascular surgeons, 9.7% interventional radiologists, 2.0% interventional nephrologists). 15.5% of patients required a follow-up procedure within 90 days of the initial insertion, of whom 2.9% had a second PD catheter implanted, 6.6% underwent PD catheter removal, and 5.9% had a PD catheter revision within 90 days of the initial insertion. In models adjusted for patient and operator characteristics, the odds of requiring a follow-up procedure within 90 days were highest for interventional nephrologists (HR, 1.86; 95% confidence interval [CI], 1.56 to 2.22) and interventional radiologists (odds ratio, 1.36; 95% CI, 1.17 to 1.58) followed by vascular surgeons (odds ratio, 1.06; 95% CI, 0.97 to 1.14) compared with general surgeons., Conclusions: The probability of needing a follow-up procedure after initial PD catheter placement varied by operator specialty and was higher for interventionalists and lowest for general surgeons., (Copyright © 2023 by the American Society of Nephrology.)

Background: Mortality is high within the first few months of starting chronic dialysis. Pre-ESKD trajectory of kidney function has been shown to be predictive of early death after dialysis initiation. We aim to better understand how two key aspects of pre-dialysis kidney function-an abrupt transition pattern and an episode of dialysis-requiring AKI (AKI-D) leading directly to ESKD-are associated with early mortality after dialysis initiation., Methods: We extracted national data from U.S. Veterans Health Administration cross-linked with the United States Renal Data System (USRDS) to identify patients who initiated hemodialysis during 2009-2013. We defined abrupt transition as having a mean outpatient eGFR ≥ 30 ml/min/1.73m 2 within 1 year prior to ESKD. AKI-D was identified using inpatient serum creatinine measurements (serum Cr increase by at least 50% from baseline) along with billing codes for inpatient receipt of dialysis for AKI within 30 days prior to the ESKD start date. We used multivariable proportional hazards models to examine the association between patterns of kidney function prior to ESKD and all-cause mortality within 90 days after ESKD., Results: Twenty-two thousand eight hundred fifteen patients were identified in the final analytic cohort of Veterans who initiated hemodialysis and entered the USRDS. We defined five patterns of kidney function decline. Most (68%) patients (N = 15,484) did not have abrupt transition and did not suffer an episode of AKI-D prior to ESKD (reference group). The remaining groups had abrupt transition, AKI-D, or both. Patients who had an abrupt transition with (N = 503) or without (N = 3611) AKI-D had the highest risk of early mortality after ESKD onset after adjustment for demographics and comorbidities (adjusted HR 2.10, 95% CI 1.66-2.65 for abrupt transition with AKI-D; adjusted HR 2.10, 95% CI 1.90-2.33 for abrupt transition without AKI-D). In contrast, patients who experienced AKI-D without an abrupt transition pattern (N =  2141 had only a modestly higher risk of early death (adjusted HR 1.19, 95% CI 1.01-1.40)., Conclusions: An abrupt decline in kidney function within 1 year prior to ESKD occurred in nearly 1 in 5 incident hemodialysis patients (18%) in this national cohort of Veterans and was strongly associated with higher early mortality after ESKD onset., (© 2023. The Author(s).)

Peritoneal dialysis (PD) use has increased in the United States since 2009, but how this has affected disparities in PD use is unclear. We used data from the United States Renal Data System to identify a cohort of incident dialysis patients from 2009 to 2019. We used logistic regression models to examine how odds of PD use changed by demographic characteristics. The incident PD population increased by 203% from 2009 to 2019, and the odds of PD use increased in every subgroup. PD use increased more among older people because the odds for those aged 75 years or older increased 15% more per 5-year period compared with individuals aged 18-44 years (odds ratio [OR] 1.68, 95% confidence interval [CI], 1.64 to 1.73 versus OR 1.46, 95% CI, 1.42 to 1.50). The odds of PD use increased 5% more per 5-year period among Hispanic people compared with White people (OR 1.58, 95% CI, 1.53 to 1.63 versus OR 1.51, 95% CI, 1.48 to 1.53). There was no difference in odds of PD initiation among people who were Black, Asian, or of another race. The odds of PD use increased 5% more for people living in urban areas compared with people living in nonurban areas (5-year OR 1.54, 95% CI, 1.52 to 1.56 versus 5-year OR 1.46, 95% CI, 1.42 to 1.50). The odds of PD use increased 7% more for people living in socioeconomically advantaged areas compared with people living in more deprived areas (5-year OR 1.60, 95% CI, 1.56 to 1.63 for neighborhoods with lowest Social Deprivation Index versus 5-year OR 1.50, 95% CI, 1.48 to 1.53 in the most deprived areas). Expansion of PD use led to a reduction in disparities for older people and for Hispanic people. Although PD use increased across all strata of socioeconomic deprivation, the gap in PD use between people living in the least deprived areas and those living in the most deprived areas widened., (Copyright © 2023 by the American Society of Nephrology.)

Importance: The Centers for Medicare & Medicaid Services designed a mandatory payment model to incentivize home dialysis use: the End-Stage Renal Disease Treatment Choices (ETC). Outpatient dialysis facilities and health care professionals providing nephrology services were randomly assigned to ETC participation at the hospital referral region level., Objective: To assess the association between ETC and home dialysis use in the incident dialysis population in its first 18 months of implementation., Design, Setting, and Participants: A cohort study with controlled, interrupted time series analysis of the US End-Stage Renal Disease Quality Reporting System database was conducted, using generalized estimating equations. All adults initiating home-based dialysis in the US between January 1, 2016, and June 30, 2022, without a prior kidney transplant were included in the analysis., Exposures: Prior to vs after ETC onset in January 1, 2021, and random assignment to ETC participation of facilities and health care professionals involved in patient care., Main Outcomes and Measures: Percentage of patients started on incident home dialysis and yearly change in percentage initiating home dialysis., Results: A total of 817 177 adults initiated home dialysis during the study period, of whom 750 314 were included in the study cohort. The cohort included 41.4% women; 26.2% of the patients were Black, 17.4% were Hispanic, and 49.1% were White. Approximately half (49.6%) of the patients were aged at least 65 years. A total of 31.2% received care from health care professionals assigned to ETC participation, and 33.6% had Medicare fee-for-service coverage. Overall, home dialysis use increased from 10.0% in January 2016 to 17.4% in June 2022. Home dialysis use increased more in ETC markets than in non-ETC markets after January 2021 (by 1.07%; 95% CI, 0.16%-1.97%). The rate of increase in home dialysis use in the entire cohort nearly doubled after January 2021 to 1.66% per year (95% CI, 1.14%-2.19%) compared with before 2021, when the rate was 0.86% per year (95% CI, 0.75%-0.97%), but the difference in rate of increase in home dialysis use was not significant between ETC and non-ETC markets., Conclusions and Relevance: This study noted that, although the overall rate of dialysis use at home was greater after ETC implementation, the increase occurred more among patients in ETC markets than among those in non-ETC markets. These findings suggest that federal policy and financial incentives affected care for the entire incident dialysis population in the US.

Background: Kidney transplant programs have variable thresholds to accept obese candidates. This study aimed to examine trends and the social context of obesity among United States dialysis patients and implications for kidney transplant access., Methods: We performed a retrospective cohort study of 1 084 816 adults who initiated dialysis between January 2007 and December 2016 using the United States Renal Data System data. We estimated national body mass index (BMI) trends and 1-y cumulative incidence of waitlisting and death without waitlisting by BMI category (<18.5 kg/m 2 , ≥18.5 and <25 kg/m 2 [normal weight], ≥25 and <30 kg/m 2 [overweight], ≥30 and <35 kg/m 2 [class 1 obesity], ≥35 and <40 kg/m 2 [class 2 obesity], and ≥40 kg/m 2 [class 3 obesity]). We then used Fine-Gray subdistribution hazard regression models to examine associations between BMI category and 1-y waitlisting with death as a competing risk and tested for effect modification by End Stage Renal Disease (ESRD) network, patient characteristics, and neighborhood social deprivation index., Results: The median age was 65 (interquartile range 54-75) y, 43% were female, and 27% were non-Hispanic Black. From 2007 to 2016, the adjusted prevalence of class 1 obesity or higher increased from 31.9% to 38.2%. Class 2 and 3 obesity but not class 1 obesity were associated with lower waitlisting rates relative to normal BMI, especially for younger individuals, women, those of Asian race, or those living in less disadvantaged neighborhoods ( pinteraction < 0.001 for all)., Conclusions: Obesity prevalence is rising among US incident dialysis patients. Relative to normal BMI, waitlisting rates with class 2 and 3 obesity were lower and varied substantially by region, patient characteristics, and socioeconomic context., Competing Interests: M.N.H. discloses a consultancy agreement with Nephria Bio. The other authors declare no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

How maintenance dialysis modality, dialysis setting, and residence in a nursing facility have jointly associated with coronavirus disease 2019 (COVID-19)-related outcomes in the United States is relevant to future viral outbreaks. Using Medicare claims, we determined the incidence of COVID-19-related infection, hospitalization, and death between March 15, 2020 and June 5, 2021. The exposure was one of five combinations of dialysis modality and care setting: in-facility hemodialysis without a recent history of skilled nursing facility care, in-facility hemodialysis with a recent history of skilled nursing facility care, hemodialysis in a skilled nursing facility, home hemodialysis, and (home) peritoneal dialysis. Patient-weeks were pooled to estimate the adjusted associations of event incidence with each dialysis modality/setting during four intervals in 2020-2021. Relative to in-facility hemodialysis without a recent history of skilled nursing facility care, home dialysis was associated with 36%-60% lower odds of all events during weeks 12-23 of 2020; 24%-37% lower odds of all events during weeks 24-37 of 2020; 20%-33% lower odds of infection and hospitalization during the winter of 2020-2021; and similar odds of all events thereafter. In contrast, exposure to skilled nursing facilities was associated with 570%-1140% higher odds of all events during spring of 2020, although excess risk attenuated as the pandemic transpired, especially among patients who received hemodialysis in skilled nursing facilities. In conclusion, home dialysis was associated with lower risks of COVID-19 diagnosis, hospitalization, and death until vaccines were available, whereas care in skilled nursing facilities was associated with higher risks., (Copyright © 2022 by the American Society of Nephrology.)

Background and Objectives: Recovery of kidney function after the start of maintenance dialysis can occur, but data on the incidence and risk factors for restarting dialysis after recovery of kidney function in this population are limited., Design, Setting, Participants, & Measurements: We conducted a retrospective study of adult Medicare beneficiaries who started dialysis between 2005 and 2015 according to the United States Renal Data System but who had recovery of kidney function (defined as a ≥90-day dialysis-free interval). We identified risk factors that were associated with the risk for the reinitiation of dialysis within a 3-year time frame following the recovery of kidney function and at any time during follow-up using Cox proportional hazards models., Results: Of the 34,530 individuals previously on dialysis who had recovery of kidney function, 7217 (21%) restarted dialysis (absolute rate of 11.5 per 100 person-years) within 3 years of recovery of kidney function, and 9120 (26%) restarted dialysis during the entire follow-up period (absolute rate of 8.8 per 100 person-years). Among those with CKD stage 1 or 2 after recovery of kidney function, 10% of individuals restarted dialysis within 3 years of their recovery of kidney function, whereas among those with CKD stage 3, 4, or 5, 13%, 27%, and 36% of individuals restarted dialysis within 3 years of recovery of kidney function, respectively. Age at first dialysis, cause of kidney disease, history of CKD or nephrology care prior to starting dialysis, presence of heart failure, CKD stage following recovery of kidney function, and location of first dialysis initiation (inpatient versus outpatient) were some of the risk factors that were strongly associated with the risk of restarting dialysis after the recovery of kidney function., Conclusions: Over one in five patients with recovery of kidney function after kidney failure restarted dialysis within 3 years., (Copyright © 2022 by the American Society of Nephrology.)

There are limited data on the degree of variability in practices surrounding prioritization of referrals for transplant evaluation and criteria for transplant candidacy and their association with transplantation rates. We surveyed transplant programs across the United States between January 2020 and May 2020 to determine current pre-transplantation practices. We examined the relation between these reported practices and the outcomes of waitlisted patients at responding programs between January 2015 and March 2021 using Scientific Registry of Transplant Recipients data. We used adjusted Cox models with random effects to accommodate clustering by program. Primary outcomes included living or deceased donor transplantation. Of 172 surveyed programs, 90 participated. Substantial variations were noted in when the candidacy evaluation began (13% reported when eGFR was <30 mL/min/1.73 m 2 and 17% reported no set policy) and the approach to pre-transplantation cardiac workup (multi-modality [58%], stress echocardiogram [20%]). Using adjusted models, a program policy of using other measures of body habitus to determine transplant candidacy rather than requiring patients to meet a body mass index (BMI) threshold of ≤35 kg/m 2 (reference group) for candidacy was associated with a higher hazard of living donor transplantation (HR 1.83 [95% CI 1.10-3.03]). Pre-transplant practices vary substantially across the United States, and select practices were associated with transplantation rates., (© 2022 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Measures implemented to prevent transmission of severe acute respiratory syndrome coronavirus 2 in outpatient dialysis facilities may also help to prevent catheter-associated bloodstream infections in patients receiving hemodialysis. We used United States Renal Data System data to examine rates of antibiotic administration within dialysis facilities and rates of hospital admission for catheter-associated bloodstream infection from March 2018 through November 2020, and rates of hospitalization for sepsis, to address overall changes in hospitalization during the coronavirus disease 2019 (COVID-19) pandemic. Using logistic regression, we estimated year-over-year adjusted odds ratios of these events in 3-month intervals. During the first 6 months of the pandemic, rates of antibiotic administration were between 20% and 21% lower, and rates of hospitalization for catheter-associated bloodstream infection were between 17% and 24% lower than during corresponding periods in 2019, without significant changes in rates of hospitalization for sepsis. However, rates of catheter-associated events also decreased between 2018 and 2019, driven by reductions in facilities operated by a large dialysis provider. These data suggest that significant reductions in catheter-associated infections occurred during the pandemic, superimposed on nonpandemic-related reductions in some facilities before the pandemic. Even after the pandemic, it may be prudent to continue some COVID-19 mitigation measures to prevent catheter-associated bloodstream infections., (Copyright © 2022 by the American Society of Nephrology.)

Background: The COVID-19 pandemic caused major disruptions to care for patients with advanced CKD., Methods: We investigated the incidence of documented ESKD, ESKD treatment modalities, changes in eGFR at dialysis initiation, and use of incident central venous catheters (CVCs) by epidemiologic week during the first half of 2020 compared with 2017-2019 historical trends, using Centers for Medicare and Medicaid Services data. We used Poisson and logistic regression for analyses of incidence and binary outcomes, respectively., Results: Incidence of documented ESKD dropped dramatically in 2020 compared with the expected incidence, particularly during epidemiologic weeks 15-18 (April, incidence rate ratio [IRR], 0.75; 95% CI, 0.73 to 0.78). The decrease was most pronounced for individuals aged ≥75 years (IRR, 0.69; 95% CI, 0.66 to 0.73). Pre-emptive kidney transplantation decreased markedly during weeks 15-18 (IRR, 0.56; 95% CI, 0.46 to 0.67). Mean eGFR at dialysis initiation decreased by 0.33 ml/min per 1.73 m 2 in weeks 19-22; non-Hispanic Black patients exhibited the largest decrease, at 0.61 ml/min per 1.73 m 2 . The odds of initiating dialysis with eGFR <10 ml/min per 1.73 m 2 were highest during weeks 19-22 (May, OR, 1.14; 95% CI, 1.05 to 1.17), corresponding to an absolute increase of 2.9%. The odds of initiating peritoneal dialysis (versus hemodialysis) were 24% higher (OR, 1.24; 95% CI, 1.14 to 1.34) in weeks 11-14, an absolute increase of 2.3%. Initiation with a CVC increased by 3.3% (OR, 1.30; 95% CI, 1.20 to 1.41)., Conclusions: During the first wave of the COVID-19 pandemic, the number of patients starting treatment for ESKD fell to a level not observed since 2011. Changes in documented ESKD incidence and other aspects of ESKD-related care may reflect differential access to care early in the pandemic., (Copyright © 2021 by the American Society of Nephrology.)

Background: Reports from around the world have indicated a fatality rate of patients with coronavirus disease 2019 (COVID-19) in the range of 20%-30% among patients with ESKD. Population-level effects of COVID-19 on patients with ESKD in the United States are uncertain., Methods: We identified patients with ESKD from Centers for Medicare and Medicaid Services data during epidemiologic weeks 3-27 of 2017-2020 and corresponding weeks of 2017-2019, stratifying them by kidney replacement therapy. Outcomes comprised hospitalization for COVID-19, all-cause death, and hospitalization for reasons other than COVID-19. We estimated adjusted relative rates (ARRs) of death and non-COVID-19 hospitalization during epidemiologic weeks 13-27 of 2020 (March 22 to July 4) versus corresponding weeks in 2017-2019., Results: Among patients on dialysis, the rate of COVID-19 hospitalization peaked between March 22 and April 25 2020. Non-Hispanic Black race and Hispanic ethnicity associated with higher rates of COVID-19 hospitalization, whereas peritoneal dialysis was associated with lower rates. During weeks 13-27, ARRs of death in 2020 versus 2017-2019 were 1.17 (95% confidence interval [95% CI], 1.16 to 1.19) and 1.30 (95% CI, 1.24 to 1.36) among patients undergoing dialysis or with a functioning transplant, respectively. Excess mortality was higher among non-Hispanic Black, Hispanic, and Asian patients. Among patients on dialysis, the rate of non-COVID-19 hospitalization during weeks 13-27 in 2020 was 17% lower versus hospitalization rates for corresponding weeks in 2017-2019., Conclusions: During the first half of 2020, the clinical outcomes of patients with ESKD were greatly affected by COVID-19, and racial and ethnic disparities were apparent. These findings should be considered in prioritizing administration of COVID-19 vaccination., (Copyright © 2021 by the American Society of Nephrology.)

Background: Transplant candidates may gain an advantage by traveling to receive care at a transplant center that may have more favorable characteristics than their local center. Factors associated with longer travel distance for transplant care and whether the excess travel distance (ETD) is associated with access to transplantation or with graft failure are unknown., Methods: This study of adults in the United States wait-listed for kidney transplantation in 1995-2015 used ETD, defined as distance a patient traveled beyond the nearest transplant center for initial waiting list registration. We used linear regression to examine patient and center characteristics associated with ETD and Fine-Gray models to examine the association between ETD (modeled as a spline) and time to deceased or living donor transplantation or graft failure., Results: Of 373,365 patients, 11% had an ETD≥50 miles. Traveling excess distance was more likely among patients who were of non-Black race or those whose nearest transplant center had lower annual living donor transplant volume. At an ETD of 50 miles, we observed a lower likelihood of deceased donor transplantation (subhazard ratio [SHR], 0.85; 95% confidence interval [95% CI], 0.84 to 0.87) but higher likelihood of living donor transplantation (SHR, 1.14; 95% CI, 1.12 to 1.16) compared with those who received care at their nearest center. ETD was weakly associated with higher risk of graft failure., Conclusions: Patients who travel excess distances for transplant care have better access to living donor but not deceased donor transplantation and slightly higher risk of graft failure. Traveling excess distances is not clearly associated with better outcomes, especially if living donors are unavailable., (Copyright © 2021 by the American Society of Nephrology.)

Background: Kidney replacement therapy is controversial for patients with hepatorenal syndrome who may not be liver transplant candidates. Data surrounding the likelihood of recovery of kidney function and mortality after outpatient dialysis initiation in patients with dialysis-requiring hepatorenal syndrome could inform discussions between patients and providers., Methods: We performed a retrospective cohort study of patients with hepatorenal syndrome who were registered in the United States Renal Data System between 1996 and 2015 ( n =7830) as receiving maintenance dialysis. We characterized patients with hepatorenal syndrome by recovery of kidney function using Fine and Gray models. We also examined hazard of recovery of kidney function and death among those with hepatorenal syndrome versus those with acute tubular necrosis ( n =48,861) using adjusted Fine-Gray and Cox models, respectively., Results: Of the patients with hepatorenal syndrome, 11% recovered kidney function. Those with higher likelihood of recovery were younger, non-Hispanic White, and had a history of alcohol use. Compared with patients with acute tubular necrosis, patients with hepatorenal syndrome as the attributed cause of kidney disease had a lower hazard of recovery (HR, 0.22; 95% CI, 0.21 to 0.24) and higher hazard of death within 1 year (HR, 3.10; 95% CI, 2.99 to 3.23) in fully adjusted models., Conclusions: Patients with hepatorenal syndrome receiving chronic maintenance dialysis had a lower likelihood of recovery of kidney function and higher mortality risk compared with patients with acute tubular necrosis. Among patients with hepatorenal syndrome, those most likely to recover kidney function were younger, had a history of alcohol use, and lacked comorbid conditions. These data may inform prognosis and discussions surrounding treatment options when patients with hepatorenal syndrome need chronic maintenance dialysis therapy., Competing Interests: K.L. Johansen reports serving as a member of the steering committee for the GlaxoSmithKline prolyl hydroxylase inhibitor clinical trials program, and being an associate editor for JASN. E. Ku reports receiving research funding from CareDX. J.C. Lai reports being a scientific advisor for, or member of, the American Association for the Study of Liver Diseases, American Journal of Transplantation, American Society of Transplantation, and Liver Transplantation; and receiving research funding from Axcella Health, Inc., Genentech, and Vir Biotechnology. All remaining authors have nothing to disclose., (Copyright © 2021 by the American Society of Nephrology.)

Background: Patients may accrue wait time for kidney transplantation when their eGFR is ≤20 ml/min. However, Black patients have faster progression of their kidney disease compared with White patients, which may lead to disparities in accruable time on the kidney transplant waitlist before dialysis initiation., Methods: We compared differences in accruable wait time and transplant preparation by CKD-EPI estimating equations in Chronic Renal Insufficiency Cohort participants, on the basis of estimates of kidney function by creatinine (eGFR cr ), cystatin C (eGFR cys ), or both (eGFR cr-cys ). We used Weibull accelerated failure time models to determine the association between race (non-Hispanic Black or non-Hispanic White) and time to ESKD from an eGFR of ≤20 ml/min per 1.73 m 2 . We then estimated how much higher the eGFR threshold for waitlisting would be required to achieve equity in accruable preemptive wait time for the two groups., Results: By eGFR cr , 444 CRIC participants were eligible for waitlist registration, but the potential time between eGFR ≤20 ml/min per 1.73 m 2 and ESKD was 32% shorter for Blacks versus Whites. By eGFR cys , 435 participants were eligible, and Blacks had 35% shorter potential wait time compared with Whites. By the eGFR cr-cys equation, 461 participants were eligible, and Blacks had a 31% shorter potential wait time than Whites. We estimated that registering Blacks on the waitlist as early as an eGFR of 24-25 ml/min per 1.73 m 2 might improve racial equity in accruable wait time before ESKD onset., Conclusions: Policies allowing for waitlist registration at higher GFR levels for Black patients compared with White patients could theoretically attenuate disparities in accruable wait time and improve racial equity in transplant access., (Copyright © 2021 by the American Society of Nephrology.)

Background: Little is known about factors associated with recovery of kidney function-and return to dialysis independence-or temporal trends in recovery after starting outpatient dialysis in the United States. Understanding the characteristics of individuals who may have the potential to recover kidney function may promote better recognition of such events. The goal of this study was to determine factors associated with recovery of kidney function in children compared with adults starting dialysis in the US., Methods and Findings: We determined factors associated with recovery of kidney function-defined as survival and discontinuation of dialysis for ≥90-day period-in children versus adults who started maintenance dialysis between 1996 and 2015 according to the United States Renal Data System (USRDS) followed through 2016 in a retrospective cohort study. We also examined temporal trends in recovery rates over the last 2 decades in this cohort. Among 1,968,253 individuals included for study, the mean age was 62.6 ± 15.8 years, and 44% were female. Overall, 4% of adults (83,302/1,953,881) and 4% of children (547/14,372) starting dialysis in the outpatient setting recovered kidney function within 1 year. Among those who recovered, the median time to recovery was 73 days (interquartile range [IQR] 43-131) in adults and 100 days (IQR 56-189) in children. Accounting for the competing risk of death, children were less likely to recover kidney function compared with adults (sub-hazard ratio [sub-HR] 0.81; 95% CI 0.74-0.89, p-value <0.001; point estimates <1 indicating increased risk for a negative outcome). Non-Hispanic black (NHB) adults were less likely to recover compared with non-Hispanic white (NHW) adults, but these racial differences were not observed in children. Of note, a steady increase in the incidence of recovery of kidney function was noted initially in adults and children between 1996 and 2010, but this trend declined thereafter. The diagnoses associated with the highest recovery rates of recovery were acute tubular necrosis (ATN) and acute interstitial nephritis (AIN) in both adults and children, where 25%-40% of patients recovered kidney function depending on the calendar year of dialysis initiation. Limitations to our study include the potential for residual confounding to be present given the observational nature of our data., Conclusions: In this study, we observed that discontinuation of outpatient dialysis due to recovery occurred in 4% of patients with end-stage kidney disease (ESKD) and was more common among those with ATN or AIN as the cause of their kidney disease. While recovery rates rose initially, they declined starting in 2010. Additional studies are needed to understand how to best recognize and promote recovery in patients whose potential to discontinue dialysis is high in the outpatient setting., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing risks: KLJ reports membership on the Steering Committee for the GSK ASCEND clinical trials program. KDL received funding from the National Institutes of Health on acute kidney injury and is a member of the ASN and the AKI!Now workgroup.

Background and Objectives: Women with kidney failure have lower access to kidney transplantation compared with men, but the magnitude of this disparity may not be uniform across all kidney diseases. We hypothesized that the attributed cause of kidney failure may modify the magnitude of the disparities in transplant access by sex., Design, Setting, Participants, & Measurements: We performed a retrospective cohort study of adults who developed kidney failure between 2005 and 2017 according to the United States Renal Data System. We used adjusted Cox models to examine the association between sex and either access to waitlist registration or deceased-donor kidney transplantation, and tested for interaction between sex and the attributed cause of kidney failure using adjusted models., Results: Among a total of 1,478,037 patients, 271,111 were registered on the waitlist and 89,574 underwent deceased-donor transplantation. The rate of waitlisting was 6.5 per 100 person-years in women and 8.3 per 100 person-years for men. In adjusted analysis, women had lower access to the waitlist (hazard ratio, 0.89; 95% confidence interval, 0.89 to 0.90) and to deceased-donor transplantation after waitlisting (hazard ratio, 0.96; 95% confidence interval, 0.94 to 0.98). However, there was an interaction between sex and attributed cause of kidney disease in adjusted models ( P <0.001). Women with kidney failure due to type 2 diabetes had 27% lower access to the kidney transplant waitlist (hazard ratio, 0.73; 95% confidence interval, 0.72 to 0.74) and 11% lower access to deceased-donor transplantation after waitlisting compared with men (hazard ratio, 0.89; 95% confidence interval, 0.86 to 0.92). In contrast, sex disparities in access to either the waitlist or transplantation were not observed in kidney failure secondary to cystic disease., Conclusions: The disparity in transplant access by sex is not consistent across all causes of kidney failure. Lower deceased-donor transplantation rates in women compared with men are especially notable among patients with kidney failure attributed to diabetes., (Copyright © 2021 by the American Society of Nephrology.)

Background: Non-Hispanic black (NHB) and Hispanic patients have lower access to kidney transplantation compared to non-Hispanic whites (NHWs). We examined whether differences in the prevalence of comorbidities that affect eligibility for transplant contribute to disparities in receipt of transplantation., Methods: We performed a retrospective study of 986 019 adults who started dialysis between 2005 and 2014, according to the United States Renal Data System. We compared prevalence of comorbidities that could influence transplant eligibility by race/ethnicity. We examined time to first transplant by race/ethnicity in this overall cohort and in a very healthy sub-cohort without conditions that could be contraindications to transplantation., Results: During 2.3 years of mean follow-up, 64 892 transplants occurred. NHBs and Hispanics had a lower prevalence of medical barriers to transplantation at the time of dialysis initiation than NHWs, including age >70 years (26% in NHB versus 47% in NHW) and malignancy (4% in Hispanics versus 10% in NHWs). Access to transplant was 65% lower (95% CI, 0.33-0.37) in NHBs and 43% lower (95% CI, 0.54-0.62) in Hispanics (versus NHWs) in the first year after end-stage renal disease, but by Year 4, access to transplantation was not statistically significantly different between Hispanics or NHBs (versus NHWs). In our very healthy cohort, racial and ethnic disparities in access to transplantation persisted up to Year 5 in NHBs and Year 4 in Hispanics after end-stage renal disease onset., Conclusions: Differences in medical eligibility do not appear to explain racial/ethnic disparities in receipt of kidney transplantation and may mask the actual magnitude of the inequities that are present.

Background: Given the potential utility of frailty, a clinical phenotype of decreased physiologic reserve and resistance to stressors, to predict postkidney transplant (KT) outcomes, we sought to understand the perceptions and practices regarding frailty measurement in US KT programs., Methods: Surveys were emailed to American Society of Transplantation Kidney/Pancreas Community of Practice members and 202 US transplant programs (November 2017 to April 2018). Program characteristics were gleaned from Scientific Registry of Transplant Recipients., Results: The 133 responding programs (response rate = 66%) represented 77% of adult KTs and 79% of adult KT candidates in the United States. Respondents considered frailty to be a useful concept in evaluating candidacy (99%) and endorsed a need to develop a frailty measurement specific to KT (92%). Frailty measurement was more common during candidacy evaluation (69%) than during KT admission (28%). Of the 202 programs, 38% performed frailty assessments in all candidates while 23% performed assessments only for older candidates. There was heterogeneity in the frailty assessment method; 18 different tools were utilized to measure frailty. The most common tool was a timed walk test (19%); 67% reported performing >1 tool. Among programs that measure frailty, 53% reported being less likely to list frail patients for KT., Conclusions: Among US KT programs, frailty is recognized as a clinically relevant construct and is commonly measured at evaluation. However, there is considerable heterogeneity in the tools used to measure frailty. Efforts to identify optimal measurement of frailty using either an existing or a novel tool and subsequent standardization of its measurement and application across KT programs should be considered.

Background: Study findings suggest that initiating dialysis at a higher eGFR level in adults with ESRD does not improve survival. It is less clear whether starting dialysis at a higher eGFR is associated with a survival benefit in children with CKD., Methods: To investigate this issue, we performed a retrospective cohort study of pediatric patients aged 1-18 years who, according to the US Renal Data System, started dialysis between 1995 and 2015. The primary predictor was eGFR at the time of dialysis initiation, categorized as higher (eGFR>10 ml/min per 1.73 m 2 ) versus lower eGFR (eGFR≤10 ml/min per 1.73 m 2 )., Results: Of 15,170 children, 4327 (29%) had a higher eGFR (median eGFR, 12.8 ml/min per 1.73 m 2 ) at dialysis initiation. Compared with children with a lower eGFR (median eGFR, 6.5 ml/min per 1.73 m 2 ), those with a higher eGFR at dialysis initiation were more often white, girls, underweight or obese, and more likely to have GN as the cause of ESRD. The risk of death was 1.36 times higher (95% confidence interval, 1.24 to 1.50) among children with a higher (versus lower) eGFR at dialysis initiation. The association between timing of dialysis and survival differed by treatment modality-hemodialysis versus peritoneal dialysis ( P <0.001 for interaction)-and was stronger among children initially treated with hemodialysis (hazard ratio, 1.56, 95% confidence interval, 1.39 to 1.75; versus hazard ratio, 1.07, 95% confidence interval, 0.91 to 1.25; respectively)., Conclusions: In children with ESRD, a higher eGFR at dialysis initiation is associated with lower survival, particularly among children whose initial treatment modality is hemodialysis., (Copyright © 2019 by the American Society of Nephrology.)

Acid retention associated with reduced glomerular filtration rate (GFR) exacerbates nephropathy progression in partial nephrectomy models of chronic kidney disease (CKD) and might be reflected in patients with CKD with reduced estimated GFR (eGFR) by increased anion gap (AG). We explored the presence of AG and its association with CKD in 14,924 adults aged ≥20 yr with eGFR ≥ 15 ml·min -1 ·1.73 m -2 enrolled in the National Health and Nutrition Examination Survey III, 1988-1994, using multivariable regression analysis. The model was adjusted for sociodemographic characteristics, diabetes, and hypertension. We further examined the association between AG and incident end-stage renal disease (ESRD) using frailty models, adjusting for demographics, clinical factors, body mass index, serum albumin, bicarbonate, eGFR, and urinary albumin-to-creatinine ratio by following 558 adults with moderate CKD for 12 yr via the United States Renal Data System. Laboratory measures determined AG using the traditional, albumin-corrected, and full AG definitions. Individuals with moderate CKD (eGFR: 30-59 ml·min -1 ·1.73 m -2 ) had a greater AG than those with eGFR ≥ 60 ml·min -1 ·1.73 m -2 in multivariable regression analysis with adjustment for covariates. We found a graded relationship between the adjusted mean for all three definitions of AG and eGFR categories ( P trend < 0.0001). During followup, 9.2% of adults with moderate CKD developed ESRD. Those with AG in the highest tertile had a higher risk of ESRD after adjusting for covariates in a frailty model [relative hazard (95% confidence interval) for traditional AG: 1.76 (1.16-2.32)] compared with those in the middle tertile. The data suggest that high AG, even after adjusting for serum bicarbonate, is a contributing acid-base mechanism to CKD progression in adults with moderate chronic kidney disease.

Background: Despite the high prevalence of frailty among patients receiving hemodialysis, few preventable or treatable contributing causes have been identified. Hypogonadism is also common in this population and low serum testosterone concentrations share several clinical phenotypes with frailty. We hypothesized that low serum testosterone concentrations would be associated with frailty and several of its individual components., Methods: We used data from 440 men from A Cohort Study To Investigate the Value of Exercise in ESRD/Analysis Designed to Investigate the Paradox of Obesity and Survival in ESRD, a longitudinal study that recruited participants from 14 dialysis centers in Atlanta, GA and the San Francisco, CA Bay Area from 2009 to 2011. We assessed frailty using the Fried Frailty Phenotype. We examined the association between free testosterone (as a continuous and dichotomous variable) and frailty, individual frailty components, sarcopenia, lower extremity function and muscle mass estimation by creatinine and body impedance spectroscopy over 12 months using generalized estimating equations., Results: The mean age was 56.1 ± 14.2 years and 27% were white. A 50% lower concentration of free testosterone was associated with 1.40-fold higher odds of being frail [95% confidence interval (CI) 1.05-1.53] and 1.40-fold higher odds of becoming frail over 12 months (95% CI 1.07-1.73). This association was mainly due to an association with two components of frailty: grip strength and gait speed. In addition, 50% lower free testosterone concentration was associated with a 1.55-fold higher odds of having sarcopenia (95% CI 1.09-2.02) and 1.72-fold higher odds for developing sarcopenia (95% CI 1.13-2.33) as well as with lower muscle mass and a decrease in muscle mass over 12 months as estimated by serum creatinine and by bioelectrical impedance spectroscopy., Conclusion: Serum free testosterone concentration was associated with frailty, physical function, sarcopenia and muscle mass as well as with changes in these outcomes over 12 months. Testosterone replacement may be a feasible therapeutic target toward prevention of frailty, although clinical trials are needed to test this possibility., (© The Author(s) 2018. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.)

Background: Guidelines recommend avoidance of several psychoactive medications such as hypnotics in older adults due to their adverse effects. Older patients on hemodialysis may be particularly vulnerable to complications related to use of these agents, but only limited data are available about the risks in this population., Objectives: To evaluate the association between the use of psychoactive medications and time to first emergency department visit or hospitalization for altered mental status, fall, and fracture among older patients receiving hemodialysis., Design: Observational cohort study., Setting: National registry of patients receiving hemodialysis (US Renal Data System)., Participants: A total of 60 007 adults 65 years or older receiving hemodialysis with Medicare Part D coverage in 2011., Measurements: The predictors were use of sedative-hypnotics and anticholinergic antidepressants (modeled as separate time-varying exposures). The outcomes were time to first emergency department visit or hospitalization for altered mental status, fall, and fracture (modeled separately)., Results: Overall, 17% and 6% used sedative-hypnotics and anticholinergic antidepressants, respectively, in 2011. In multivariable-adjusted Cox regression, anticholinergic antidepressant use was associated with a 25%, 27%, and 39% higher hazard of altered mental status, fall, and fracture, respectively, compared with no use. Use of sedative-hypnotics was not associated with adverse outcomes., Conclusion: Anticholinergic antidepressants were associated with adverse outcomes in older hemodialysis patients, and alternative treatments should be considered. Sedative-hypnotics were not associated with the risks evaluated in this study, but further investigation of the harms of this class of agents is warranted before their recommendation as a treatment option for insomnia in this population. J Am Geriatr Soc 67:449-454, 2019., (© 2019 The American Geriatrics Society.)

Rationale & Objective: In the general population, girls have lower mortality risk compared with boys. However, few studies have focused on sex differences in survival and in access to kidney transplantation among children with end-stage kidney disease., Study Design: Retrospective cohort study., Setting & Participants: Children aged 2 to 19 years registered in the US Renal Data System who started renal replacement therapy (RRT) between 1995 and 2011., Predictor: Study participant sex., Outcome: Time to death and time to kidney transplantation., Analytical Approach: We used adjusted Cox models to examine the association between sex and all-cause mortality. We used Fine-Gray models to examine the association between sex and kidney transplantation accounting for the competing risk for death., Results: We included 14,024 children, of whom 1,880 died during a median 7.1 years of follow-up. In adjusted analyses, the HR for death was higher for girls (HR, 1.36; 95% CI, 1.25-1.50) than boys. When we further adjusted our survival models for transplantation as a time-dependent covariate, the hazard rate of death in girls was partially attenuated but remained statistically significantly higher than that for boys (HR, 1.28; 95% CI, 1.17-1.41). Girls were also less likely to receive a kidney transplant than boys (adjusted subdistribution HR, 0.91; 95% CI, 0.88-0.95) in analyses treating death as a competing risk., Limitations: Lack of data for disease course before the onset of RRT and observational study data., Conclusions: The mortality rate was substantially higher for girls than for boys treated with RRT. Access to transplantation was lower for girls than boys, but differences in transplantation access accounted for only a small proportion of the survival differences by sex., (Copyright © 2018 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Background Gabapentin and pregabalin are used to manage neuropathic pain, pruritus, and restless legs syndrome in patients on hemodialysis. These patients may be especially predisposed to complications related to these agents, which are renally cleared, but data regarding the risk thereof are lacking. Methods From the US Renal Data System, we identified 140,899 Medicare-covered adults receiving hemodialysis with Part D coverage in 2011. Using Cox regression models in which we adjusted for demographics, comorbidities, duration of exposure, number of medications, and use of potentially confounding concomitant medications, we investigated the association between gabapentin and pregabalin, modeled as separate time-varying exposures, and time to first emergency room visit or hospitalization for altered mental status, fall, and fracture. We evaluated risk according to daily dose categories: gabapentin (>0-100, >100-200, >200-300, and >300 mg) and pregabalin (>0-100 and >100 mg). Results In 2011, 19% and 4% of patients received gabapentin and pregabalin, respectively. Sixty-eight percent of gabapentin or pregabalin users had a diagnosis of neuropathic pain, pruritus, or restless legs syndrome. Gabapentin was associated with 50%, 55%, and 38% higher hazards of altered mental status, fall, and fracture, respectively, in the highest dose category, but even lower dosing was associated with a higher hazard of altered mental status (31%-41%) and fall (26%-30%). Pregabalin was associated with up to 51% and 68% higher hazards of altered mental status and fall, respectively. Conclusions Gabapentin and pregabalin should be used judiciously in patients on hemodialysis, and research to identify the most optimal dosing is warranted., (Copyright © 2018 by the American Society of Nephrology.)

Background and Objectives: Poor linear growth is common in children with CKD and has been associated with higher mortality. However, recent data in adult dialysis patients have suggested a higher risk of death in persons of tall stature. In this study, we aimed to examine the risk of all-cause and cause-specific mortality in children at both extremes of height at the time of first RRT., Design, Setting, Participants, & Measurements: Using the US Renal Data System, we performed a retrospective analysis of 13,218 children aged 2-19 years, who received their first RRT (dialysis or transplant) during 1995-2011. We used adjusted Cox models to examine the association between short (<3rd percentile) and tall (>3rd percentile) stature and risk of death, compared with less extreme heights., Results: Over a median follow-up of 7.1 years, there were 1721 deaths. Risk of death was higher in children with short (hazard ratio, 1.49; 95% confidence interval, 1.33 to 1.66) and tall stature (hazard ratio, 1.32; 95% confidence interval, 1.03 to 1.69) in adjusted analysis. In secondary analyses, there was a statistically significant interaction between height and body mass index categories (P=0.04), such that the association of tall stature with higher mortality was limited to children with elevated body mass index (defined as ≥95th percentile for age and sex). Children with short stature had a higher risk of cardiac- and infection-related death, whereas children with tall stature had a higher risk of cancer-related death., Conclusions: Children with short and tall stature are at higher mortality risk, although this association was modified by body mass index at time of first RRT. Studies to further explore the reasons behind the higher risk of mortality in children with extremes of height at the time of first RRT are warranted., (Copyright © 2016 by the American Society of Nephrology.)

Background: Use of serum creatinine to estimate GFR may lead to underestimation of the association between self-reported frailty and kidney function. Our objectives were to evaluate the association of measured GFR (mGFR) with self-reported frailty among patients with CKD and to determine whether self-reported frailty was associated with death after adjusting for mGFR., Methods: Participants in the Modification of Diet in Renal Disease study (1989-1993) had GFR measured using iothalamate clearance (mGFR), and GFR was estimated based on the CKD-EPI creatinine (eGFRcr) and cystatin C (eGFRcys) equations. We defined self-reported frailty as three or more of: exhaustion, poor physical function, low physical activity, and low body weight. Death was ascertained through 2007 using the National Death Index and the United States Renal Data System., Results: Eight hundred twelve MDRD participants (97 %) had complete data on self-reported frailty (16 % prevalence, N = 130) and mGFR (mean (SD) 33.1 ± 11.7 ml/min/1.73 m(2)). Higher GFR was associated with lower odds of self-reported frailty based on mGFR, (OR 0.71, 95 % CI 0.60-0.86 per 10 ml/min/1.73 m(2)), eGFRcr (OR 0.80, 95 % CI 0.67-0.94 per 10 ml/min/1.73 m(2)), and eGFRcys (OR 0.75, 95 % CI 0.62-0.90 per 10 ml/min/1.73 m(2)). Median follow-up was 17 (IQR 11-18) years, with 371 deaths. Self-reported frailty was associated with a higher risk of death (HR 1.71, 95 % CI 1.26-2.30), which was attenuated to a similar degree when mGFR (HR 1.48, 95 % CI 1.08-2.00), eGFRcr (HR 1.57, 95 % CI 1.15-2.10), or eGFRcys (HR 1.51, 95 % CI 1.10-2.10) was included as an indicator of kidney function., Conclusions: We found an inverse association between kidney function and self-reported frailty that was similar for mGFR, eGFR and eGFRcys. In this relatively healthy cohort of clinical trial participants with CKD, using serum creatinine to estimate GFR did not substantially alter the association of GFR with self-reported frailty or of self-reported frailty with death.

Background and Objectives: Infection-related hospitalizations have increased dramatically over the last 10 years in patients receiving in-center hemodialysis. Patient and dialysis facility characteristics associated with the rate of infection-related hospitalization were examined, with consideration of the region of care, rural-urban residence, and socioeconomic status., Design, Setting, Participants, & Measurements: The US Renal Data System linked to the American Community Survey and Rural-Urban Commuting Area codes was used to examine factors associated with hospitalization for infection among Medicare beneficiaries starting in-center hemodialysis between 2005 and 2008. A Poisson mixed effects model was used to examine the associations among patient and dialysis facility characteristics and the rate of infection-related hospitalization., Results: Among 135,545 Medicare beneficiaries, 38,475 (28%) had at least one infection-related hospitalization. The overall rate of infection-related hospitalization was 40.2 per 100 person-years. Age ≥ 85 years old, cancer, chronic obstructive pulmonary disease, inability to ambulate or transfer, drug dependence, residence in a care facility, serum albumin <3.5 g/dl at dialysis initiation, and dialysis initiation with an access other than a fistula were associated with a ≥ 20% increase in the rate of infection-related hospitalization. Patients residing in isolated small rural compared with urban areas had lower rates of hospitalization for infection (rate ratio, 0.91; 95% confidence interval, 0.86 to 0.97), and rates of hospitalization for infection varied across the ESRD networks. Measures of socioeconomic status (at the zip code level), total facility staffing, and the composition of staff (percentage of nurses) were not associated with the rate of hospitalization for infection., Conclusions: Patient and facility factors associated with higher rates of infection-related hospitalization were identified. The findings from this study can be used to identify patients at higher risk for infection and inform the design of infection prevention strategies., (Copyright © 2015 by the American Society of Nephrology.)

Background and Objectives: Anemia guidelines for CKD recommend withholding intravenous iron in the setting of active infection, although no data specifically support this recommendation. This study aimed to examine the association between intravenous iron and clinical outcomes among hemodialysis patients hospitalized for infection., Design, Setting, Participants, & Measurements: This was a retrospective observational cohort study using data from the US Renal Data System of 22,820 adult Medicare beneficiaries on in-center hemodialysis who had received intravenous iron in the 14 days preceding their first hospitalization for bacterial infection in 2010. In multivariable analyses, the association between receipt of intravenous iron at any point from the day of hospital admission to discharge and all-cause 30-day mortality, mortality in 2010, length of hospital stay, and readmission for infection or death within 30 days of discharge was evaluated., Results: There were 2463 patients (10.8%) who received intravenous iron at any point from the day of admission to discharge. Receipt of intravenous iron was not associated with age, dialysis vintage, or comorbidities. There were 2618 deaths within 30 days of admission and 6921 deaths in 2010 (median follow-up 173 days; 25th and 75th percentiles, 78-271 days). The median length of stay was 7 days (25th and 75th percentiles, 5-12 days). Receipt of intravenous iron was not associated with higher 30-day mortality (odds ratio, 0.86; 95% confidence interval [95% CI], 0.74 to 1.00), higher mortality in 2010 (hazard ratio, 0.92; 95% CI, 0.85 to 1.00), longer mean length of stay (10.1 days [95% CI, 9.7 to 10.5] versus 10.5 days [95% CI, 10.3 to 10.7]; P=0.05), or readmission for infection or death within 30 days of discharge (odds ratio, 1.08; 95% CI, 0.96 to 1.22) compared with no receipt of intravenous iron., Conclusions: This analysis does not support withholding intravenous iron upon admission for bacterial infection in hemodialysis patients, although clinical trials are required to make definitive recommendations., (Copyright © 2015 by the American Society of Nephrology.)

There is controversy regarding whether strict blood pressure control is indicated in chronic kidney disease (CKD) since the primary results of randomized controlled trials failed to show any impact on progression of kidney disease with this strategy. However, strict blood pressure control may have other beneficial effects beyond reducing the risk of end-stage renal disease (ESRD), such as lowering mortality after ESRD onset. The Modification of Diet in Renal Disease (MDRD) trial randomized 840 patients with CKD to strict (mean arterial pressure under 92 mm Hg) versus usual (mean arterial pressure under 107 mm Hg) blood pressure control between 1989 and 1993. Here we extended follow-up of study enrollees by linkage with United States Renal Data System and National Death Index to ascertain ESRD and vital status through 2010. Overall, 627 patients developed ESRD through 2010 with a median follow-up of 19.3 years. After ESRD onset, there were 142 deaths in the strict blood pressure arm and 182 deaths in the usual blood pressure arm (significant unadjusted hazard ratio for death was 0.72 (95% CI 0.58-0.89)). Overall, there were 212 deaths in the strict blood pressure control arm and 233 deaths in the usual arm (significant unadjusted hazard ratio for death 0.82 (95% CI 0.68-0.98)). Thus, although strict blood pressure control did not delay progression of CKD to ESRD, this strategy was associated with a lower risk of death after ESRD. Hence, long-term post-ESRD outcomes should be considered when formulating blood pressure targets for CKD.

Background: Although frailty has been linked to higher risk of falls and fracture in the general population, only few studies have examined the extent to which frailty is associated with these outcomes among patients with end-stage renal disease, who are at particularly high risk for these events., Methods: A total of 1,646 patients who were beginning maintenance hemodialysis in 297 dialysis units throughout the United States from September 2005 to June 2007 were enrolled in the Comprehensive Dialysis Study, and 1,053 Medicare beneficiaries were included in this study. Self-reported frailty was defined by the patients endorsing 2 or more of the following: poor physical functioning, exhaustion or low physical activity. Falls and fractures requiring medical attention were identified through Medicare claims data. We examined the association between frailty and the time to first fall or fracture using the Fine-Gray modification of Cox proportional hazards regression, adjusted for demographics, Quételet's body mass index, diabetes mellitus, heart failure and atherosclerosis., Results: Seventy-seven percent of patients were frail by self-report. The median length of follow-up was 2.5 (1.0-3.9) years. Crude rates of first medically urgent falls or fractures were 66 and 126 per 1,000 person-years in non-frail and self-reported frail participants, respectively. After accounting for demographic factors, comorbidities and the competing risk of death, self-reported frailty was associated with a higher risk of falls or fractures requiring medical attention (hazards ratio 1.60, 95% CI 1.16-2.20)., Conclusion: Participants reporting frailty experienced nearly twice the risk of medically urgent falls or fractures compared to those who did not report frailty., (© 2015 S. Karger AG, Basel.)

Background: A well-accepted definition of frailty includes measurements of physical performance, which may limit its clinical utility., Study Design: In a cross-sectional study, we compared prevalence and patient characteristics based on a frailty definition that uses self-reported function to the classic performance-based definition and developed a modified self-report-based definition., Setting & Participants: Prevalent adult patients receiving hemodialysis in 14 centers around San Francisco and Atlanta in 2009-2011., Index Tests: Self-report-based frailty definition in which a score lower than 75 on the Physical Function scale of the 36-Item Short Form Health Survey (SF-36) was substituted for gait speed and grip strength in the classic definition; modified self-report definition with optimized Physical Function score cutoff points derived in a development (one-half) cohort and validated in the other half., Reference Test: Performance-based frailty defined as 3 of the following: weight loss, weakness, exhaustion, low physical activity, and slow gait speed., Results: 387 (53%) patients were frail based on self-reported function, of whom 209 (29% of the cohort) met the performance-based definition. Only 23 (3%) met the performance-based definition of frailty only. The self-report definition had 90% sensitivity, 64% specificity, 54% positive predictive value, 93% negative predictive value, and 72.5% overall accuracy. Intracellular water per kilogram of body weight and serum albumin, prealbumin, and creatinine levels were highest among nonfrail individuals, intermediate among those who were frail by self-report, and lowest among those who also were frail by performance. Age, percentage of body fat, and C-reactive protein level followed an opposite pattern. The modified self-report definition had better accuracy (84%; 95% CI, 79%-89%) and superior specificity (88%) and positive predictive value (67%)., Limitations: Our study did not address prediction of outcomes., Conclusions: Patients who meet the self-report-based but not the performance-based definition of frailty may represent an intermediate phenotype. A modified self-report definition can improve the accuracy of a questionnaire-based method of defining frailty., (Published by Elsevier Inc.)

Objective: Estimating dietary intake is challenging in patients with chronic diseases. The aim of this study was to calibrate the Block Brief 2000 food frequency questionnaire (BFFQ) using 3-day food diary records among patients on dialysis., Methods: Data from 3-day food diary records from 146 patients new to dialysis were reviewed and entered into National Cancer Institute self-administered 24-hour dietary recall (ASA24), a web-based dietary interview system. The information was then re-entered omitting foods reported in the diaries that were not in the BFFQ to generate a "BFFQ-restricted" set of intakes. We modeled each major dietary component (i.e., energy [total calories], protein, carbohydrate, fat) separately using linear regression. The main independent variables were BFFQ-restricted food diary estimates computed as the average of the 3 days of diaries, restricted to items included in the BFFQ, with the unrestricted 3-day food diary averages as dependent variables., Results: The BFFQ-restricted diary energy estimate of 1,325 ± 545 kcal was 87% of the energy intake in the full food diary (1,510.3 ± 510.4, P < .0001). The BFFQ-restricted diary carbohydrate intake was 83% of the full food diary (156.7 ± 78.7 g vs. 190.4 ± 72.7, P < .0001). The BFFQ-restricted fat intake was 90% of the full-diary-reported fat intake (50.1 ± 24.1 g vs. 56.4 ± 21.6 g, P < .0001). Daily protein intake assessments were not statistically different by BFFQ-restricted diary and full diary assessment (63.1 ± 28.5 vs. 64.1 ± 21.4 g, P = .60). The associations between BFFQ-restricted diary intake and unrestricted intake were linear. Three-day diary-reported intake could be estimated from BFFQ-restricted intake with r2 ranging from 0.36 to 0.56 (P < .0001 for energy [total calories], protein, carbohydrate, and fat). Final equations did not include adjustments for age, sex, or race because the patterns of associations were not significantly different., Conclusion: Energy and macronutrient estimates by BFFQ are lower than estimates from 3-day food diaries, but simple calibration equations can be used to approximate total intake from BFFQ responses., (Published by Elsevier Inc.)

Studies of frailty among patients on hemodialysis have relied on definitions that substitute self-reported functioning for measures of physical performance and omit weight loss or substitute alternate criteria. We examined the association between body composition and a definition of frailty that includes measured physical performance and weight loss in a cross-sectional analysis of 638 adult patients receiving maintenance hemodialysis at 14 centers. Frailty was defined as having three of following characteristics: weight loss, weakness, exhaustion, low physical activity, and slow gait speed. We performed logistic regression with body mass index (BMI) and bioelectrical impedance spectroscopy (BIS)-derived estimates of intracellular water (ICW), fat mass, and extracellular water (ECW) as the main predictors, and age, sex, race, and comorbidity as covariates. Overall, 30% of participants were frail. Older age (odds ratio [OR], 1.31 per 10 years; 95% confidence interval [95% CI], 1.14 to 1.50), diabetes (OR, 1.65; 95% CI, 1.13 to 2.40), higher fat mass (OR, 1.18; 95% CI, 1.02 to 1.37), and higher ECW (OR, 1.33; 95% CI, 1.20 to 1.47) associated with higher odds of frailty. Higher ICW associated with lower odds of frailty (OR, 0.80 per kg; 95% CI, 0.73 to 0.87). The addition of BMI data did not change the area under the receiver operating characteristics curve (AUC; AUC=0.66 versus 0.66; P=0.71), but the addition of BIS data did change the AUC (AUC=0.72; P<0.001). Thus, individual components of body composition but not BMI associate strongly with frailty in this cohort of patients receiving hemodialysis.

Background and Objectives: The vast majority of US dialysis facilities are for-profit and profit status has been associated with processes of care and outcomes in patients on dialysis. This study examined whether dialysis facility profit status was associated with the rate of hospitalization in patients starting dialysis., Design, Setting, Participants, & Methods: This was a retrospective cohort study of Medicare beneficiaries starting dialysis between 2005 and 2008 using data from the US Renal Data System. All-cause hospitalization was examined and compared between for-profit and nonprofit dialysis facilities through 2009 using Poisson regression. Companion analyses of cause-specific hospitalization that are likely to be influenced by dialysis facility practices including hospitalizations for heart failure and volume overload, access complications, or hyperkalemia were conducted., Results: The cohort included 150,642 patients. Of these, 12,985 (9%) were receiving care in nonprofit dialysis facilities. In adjusted models, patients receiving hemodialysis in for-profit facilities had a 15% (95% confidence interval [95% CI], 13% to 18%) higher relative rate of hospitalization compared with those in nonprofit facilities. Among patients receiving peritoneal dialysis, the rate of hospitalization in for-profit versus nonprofit facilities was not significantly different (relative rate, 1.07; 95% CI, 0.97 to 1.17). Patients on hemodialysis receiving care in for-profit dialysis facilities had a 37% (95% CI, 31% to 44%) higher rate of hospitalization for heart failure or volume overload and a 15% (95% CI, 11% to 20%) higher rate of hospitalization for vascular access complications., Conclusions: Hospitalization rates were significantly higher for patients receiving hemodialysis in for-profit compared with nonprofit dialysis facilities.

Symptoms of sleep and mood disturbances are common among patients on dialysis and are associated with significant decrements in survival and health-related quality of life. We used data from the Comprehensive Dialysis Study (CDS) to examine the association of self-reported physical activity with self-reported symptoms of insomnia, restless legs syndrome (RLS), and depression in patients new to dialysis. The CDS collected data on physical activity, functional status, and health-related quality of life from 1678 patients on either peritoneal (n = 169) or hemodialysis (n = 1509). The Human Activity Profile was used to measure self-reported physical activity. Symptoms were elicited in the following manner: insomnia using three questions designed to capture difficulty in initiating or maintaining sleep, RLS using three questions based on the National Institutes of Health workshop, and depression using the two-item Patient Health Questionnaire. We obtained data on symptoms of insomnia and depression for 1636, and on symptoms of RLS for 1622 (>98%) patients. Of these, 863 (53%) reported one of three insomnia symptoms as occurring at a persistent frequency. Symptoms of RLS and depression occurred in 477 (29%) and 451 (28%) of patients, respectively. The Adjusted Activity Score of the Human Activity Profile was inversely correlated with all three conditions in models adjusting for demographics, comorbid conditions, and laboratory variables. Sleep and mood disturbances were commonly reported in our large, diverse cohort of patients new to dialysis. Patients who reported lower levels of physical activity were more likely to report symptoms of insomnia, RLS, and depression., (© 2012 The Authors. Hemodialysis International © 2012 International Society for Hemodialysis.)

Background and Objectives: The extent to which racial and socioeconomic disparities in access to kidney transplantation are related to not being assessed for transplant suitability before or shortly after the time of initiation of dialysis is not known. The aims of this study were to determine whether there were disparities based on race, ethnicity, or type of insurance in delayed assessment for transplantation and whether delayed assessment was associated with lower likelihood of waitlisting and kidney transplantation., Design, Setting, Participants, & Measurements: This retrospective cohort study used data from the US Renal Data System and included 426,489 adult patients beginning dialysis in the United States between January 1, 2005 and September 30, 2009 without prior kidney transplant., Results: Overall, 12.5% of patients had reportedly not been assessed for transplantation. Patients without private insurance were more likely to be reported as not assessed (multivariable adjusted odds ratio=1.33, 95% confidence interval=1.28-1.40 for Medicaid), with a pronounced racial disparity but no ethnic disparity among patients aged 18 to <35 years (odds ratio=1.27, 95% confidence interval=1.13-1.43; P<0.001 for interaction with age). Not being assessed for transplant around the time of dialysis initiation was associated with lower likelihood of waitlisting in multivariable analysis (hazard ratio=0.59, 95% confidence interval=0.57-0.62 in the first year) and transplantation (hazard ratio=0.46, 95% confidence interval=0.41-0.51 in the first year), especially within the first 2 years., Conclusions: Racial and insurance-related disparities in transplant assessment potentially delay transplantation, particularly among younger patients.

Background: In light of the recent trend toward earlier dialysis initiation and its association with mortality among patients with end-stage renal disease, we hypothesized that frailty is associated with higher estimated glomerular filtration rate (eGFR) at dialysis start and may confound the relation between earlier dialysis initiation and mortality., Methods: We examined frailty among participants of the Comprehensive Dialysis Study (CDS), a special study of the US Renal Data System, which enrolled incident patients from September 1, 2005, through June 1, 2007. Patients were followed for vital status through September 30, 2009, and for time to first hospitalization through December 31, 2008. We used multivariate logistic regression to model the association of frailty with eGFR at dialysis start and proportional hazards regression to assess the outcomes of death or hospitalization., Results: Among 1576 CDS participants included, the prevalence of frailty was 73%. In multivariate analysis, higher eGFR at dialysis initiation was associated with higher odds of frailty (odds ratio [OR], 1.44 [95% CI, 1.23-1.68] per 5 mL/min/1.73 m(2); P < .001). Frailty was independently associated with mortality (hazard ratio [HR], 1.57 [95% CI, 1.25-1.97]; P < .001) and time to first hospitalization (HR, 1.26 [95% CI, 1.09-1.45]; P < .001). While higher eGFR at dialysis initiation was associated with mortality (HR, 1.12 [95% CI, 1.02-1.23] per 5 mL/min/1.73 m(2); P = .02), the association was no longer statistically significant after frailty was accounted for (HR, 1.08 [95% CI, 0.98-1.19] per 5 mL/min/1.73 m(2); P = .11)., Conclusions: Frailty is extremely common among patients starting dialysis in the United States and is associated with higher eGFR at dialysis initiation. Recognition of signs and symptoms of frailty by clinicians may prompt earlier initiation of dialysis and may explain, at least in part, the well-described association between eGFR at dialysis initiation and mortality.

Background: Socioeconomic disparities are associated with the prevalence of disability in the general population; however, it is unknown whether a similar association exists between socioeconomic status and disability from chronic kidney disease (CKD, defined as albuminuria or an estimated glomerular filtration rate of 15-59 mL/min/1.73 m(2))., Methods: A total of 4,257 US adults aged 20 years or older with CKD who participated in the National Health and Nutrition Examination Survey 1999-2008 completed standardized questionnaires assessing self-reported difficulties in activities of daily living (ADL), instrumental ADL (IADL), lower-extremity mobility (LEM), and leisure and social activities (LSA). We used multivariable logistic regression with population-based weighting to obtain adjusted prevalence estimates of disability by demographic, socioeconomic, health care access, and clinical characteristics., Results: Participants with less education had more disability (age- and sex-adjusted prevalence of disability by lowest vs highest level of education: ADL, 24.5% vs 16.9%; IADL, 34.0% vs 20.3%; LEM, 56.9% vs 44.6%; LSA, 26.2% vs 16.8%; P < .001 for all). We observed similar trends for income. After further adjustment for other sociodemographic factors, health care access, and comorbid conditions, education and income both remained significantly associated, by any measure, with lower prevalence of disability., Conclusion: Among people with CKD in the United States, lower socioeconomic status is associated with greater risk of disability, independent of race/ethnicity, health care access, and comorbid conditions. Our findings suggest that people with CKD and limited education or lower income should be targeted for early intervention to limit disability and further loss of income, both of which could worsen outcomes in CKD.

Background/aims: US registry data have consistently shown that blacks are less likely than whites to be wait-listed before beginning dialysis., Methods: The Comprehensive Dialysis Study (CDS) was a special study conducted by the US Renal Data System (USRDS) in which a national cohort of patients who began maintenance dialysis therapy in 2005-2007 were asked whether kidney transplantation (KT) had been discussed with them before they started dialysis. Using responses from black and white CDS participants and information from the USRDS, we investigated preemptive wait-listing as a function of patient-reported predialysis KT discussion., Results: Among those reporting early KT discussion, 31.0% of patients preemptively wait-listed were black, compared to 27.5% of those not preemptively wait-listed. Two thirds of preemptively wait-listed patients had received nephrology care more than 12 months before starting dialysis and reported that KT was discussed with them 12 months or more before dialysis. Early KT discussion and higher serum albumin and hemoglobin levels remained significant predictors of preemptive wait-listing in an adjusted logistic regression analysis. Among those preemptively wait-listed, 33% of blacks and 60% of whites had received a transplant by September 30, 2009 (study end date)., Conclusion: Early KT discussion appeared to reduce barriers to black patients' waiting list placement before the start of dialysis, which in turn may facilitate earlier access to a deceased donor organ transplant., (Copyright © 2012 S. Karger AG, Basel.)