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Objectives: Obesogenic medications are a putative contributor to the obesity epidemic. While 20% of adults take ≥1 obesogenic medication, the proportion in the end‐stage kidney disease (ESKD) population—a group enriched for cardiometabolic complications—is unknown. Obesogenic medications may contribute to obesity and hamper weight loss efforts to achieve transplant listing. Methods: Using 2017–2020 USRDS and Medicare claims, patients were identified as taking obesogenic medications if prescribed anticonvulsants, antidepressants, antidiabetics, anti‐inflammatories, antipsychotics, and/or antihypertensives known to cause weight gain for ≥30 days in their first hemodialysis year. Ordinal logistic and Cox regression with inverse probability of treatment weighting were used to quantify obesogenic medications' association with body mass index (BMI) and listing, respectively. Results: Among 271 401 hemodialysis initiates, 63.5% took ≥1 obesogenic medication. For those in underweight, normal weight, overweight, and class I, II, and III categories, 54.3%, 58.4%, 63.1%, 66.5%, 68.6%, and 68.8% took ≥1, respectively. Number of obesogenic medications was associated with increased BMI; use of one was associated with 13% increased odds of higher BMI (aOR [adjusted odds ratio] 1.14; 95%CI: 1.13–1.16; p < 0.001), use of three was associated with a 55% increase (aOR 1.55; 95%CI: 1.53–1.57; p < 0.001). Any use was associated with 6% lower odds of transplant listing (aHR [adjusted hazard ratio] 0.94; 95%CI: 0.92–0.96; p < 0.001). Within each BMI category, obesogenic medication use was associated with lower listing likelihood. Conclusions: Obesogenic medication use is common in ESKD patients—particularly those with obesity—and is associated with lower listing likelihood. Whenever possible, non‐obesogenic alternatives should be chosen for ESKD patients attempting weight loss to achieve transplant listing. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Dialysis patients incur disproportionately high costs compared with other Medicare beneficiaries. Care for frail individuals may be even more costly. We examined the extent to which frailty contributes to higher costs among dialysis patients. METHODS: We used ACTIVE/ADIPOSE (A Cohort to Investigate the Value of Exercise/Analyses Designed to Investigate the Paradox of Obesity and Survival in ESRD) enrollees (adult hemodialysis patients evaluated from June 2009 to August 2011) in a retrospective cohort analysis. Individuals using Medicare as the primary payer were included. Frieds frailty phenotype was evaluated at baseline, 12, and 24 months. Costs were derived from linkage with the US Renal Data System (USRDS) and Medicare claims data. We used generalized estimating equations (GEEs) incorporating time-updated frailty and costs to evaluate adjusted point estimates and the marginal cost associated with being frail. We also investigated if frail patients who died during the study incurred higher costs than those who survived. RESULTS: Among 771 enrollees in ACTIVE/ADIPOSE, 425 met inclusion criteria. Mean age was 56 ± 13 years, body mass index (BMI) 29.2 ± 7.1 kg/m2, 42.4% were women, and 29.0% were frail at baseline. Over a mean follow-up of 2.3 years, frail individuals incurred 22% (95% confidence interval [CI] 9.6%-35.8%) higher costs compared with nonfrail individuals ($87,600 per patient per year [pppy], 95% CI 76,800-100,000, vs. $71,800 pppy, 95% CI 64,800-79,600), the difference was driven primarily by higher inpatient expenditures. The difference between frail and nonfrail patients inpatient expenditures was even more pronounced among those who died during the study compared with those who survived. CONCLUSIONS: Frail dialysis patients incur a significantly higher cost relative to their nonfrail counterparts, primarily driven by higher inpatient costs. Frail patients near end of life incur even higher costs.

Quantitative metrics are used to develop profiles of health care institutions, including hospitals, nursing homes, and dialysis clinics. These profiles serve as measures of quality of care, which are used to compare institutions and determine reimbursement, as a part of a national effort led by the Center for Medicare and Medicaid Services in the United States. However, there is some concern about how misclassification in case-mix factors, which are typically accounted for in profiling, impacts results. We evaluated the potential effect of misclassification on profiling results, using 20 744 patients from 2740 dialysis facilities in the US Renal Data System. In this case study, we compared 30-day readmission as the profiling outcome measure, using comorbidity data from either the Center for Medicare and Medicaid Services Medical Evidence Report (error-prone) or Medicare claims (more accurate). Although the regression coefficient of the error-prone covariate demonstrated notable bias in simulation, the outcome measure-standardized readmission ratio-and profiling results were quite robust; for example, correlation coefficient of 0.99 in standardized readmission ratio estimates. Thus, we conclude that misclassification on case-mix did not meaningfully impact overall profiling results. We also identified both extreme degree of case-mix factor misclassification and magnitude of between-provider variability as 2 factors that can potentially exert enough influence on profile status to move a clinic from one performance category to another (eg, normal to worse performer).

Rationale & Objective: Treatment with certain QT interval-prolonging antibiotics is associated with a higher risk of sudden cardiac death among individuals with hemodialysis-dependent kidney failure. Concurrent exposure to large serum-to-dialysate potassium gradients, which promote large potassium shifts, may augment the proarrhythmic effects of these medications. The primary objective of this study was to examine whether the serum-to-dialysate gradient modifies the cardiac safety of azithromycin, and separately, levofloxacin/moxifloxacin. Study Design: Retrospective observational cohort study using a new-user study design. Setting & Population: Adult in-center hemodialysis patients with Medicare coverage in the US Renal Data System (2007-2017). Exposure: Initiation of azithromycin (or levofloxacin/moxifloxacin) as compared to amoxicillin-based antibiotics (exposure). Serum-to-dialysate potassium gradient (effect modifier). Individual patients could contribute multiple study antibiotic treatment episodes to the analyses. Outcomes: Sudden cardiac death (14 days). Analytical Approach: Inverse probability of treatment-weighted survival models to estimate HRs and robust 95% CIs. Results: The azithromycin versus amoxicillin-based antibiotic cohort included 89,379 unique patients with 113,516 azithromycin and 103,493 amoxicillin-based treatment episodes. Azithromycin versus amoxicillin-based antibiotic treatment was associated with a higher risk of sudden cardiac death overall, HR, 1.68; 95% CI, 1.31-2.16. The risk was numerically higher when the baseline serum-to-dialysate potassium gradient was ≥3 mEq/L compared with

BackgroundIn hemodialysis (HD) patients, higher lipid levels are associated with lower mortality. Lipid-lowering therapy does not reduce all-cause mortality or cardiovascular (CV) mortality. Lipoproteins play a role in the innate immune system. Our objective was to determine whether protection from infection might counterbalance adverse CV outcomes associated with lipoproteins.MethodsWe examined associations between serum apolipoprotein (Apo) A1, B, C2, C3, high-density lipoprotein and low-density lipoprotein (LDL) cholesterol and triglyceride levels and infectious mortality or hospitalization, CV mortality or hospitalization, and all-cause mortality in 433 prevalent HD patients. Cox models with time-varying apolipoprotein concentrations collected every 6 months for up to 2 years were used for analyses.ResultsMedian follow-up time for all-cause mortality was 2.7 years (25th-75th percentile range: 2.2-3.4 years). One hundred seventy-nine (41%) patients had an infection-related event. In multivariable models, higher Apo B and LDL were associated with lower risks of infection-related outcomes (hazard ratio Apo B 0.92 [95% confidence interval 0.86-0.99 per 10 mg/dL, P = .03]; hazard ratio LDL 0.93 [95% confidence interval 0.87-1.00 per 10 mg/dL, P = .05]). Sixty-three (15%) participants had a CV-related event. No significant associations were observed between lipoproteins and CV outcomes. Eighty-seven (20%) participants died. Higher Apo A1, Apo B, and Apo C3 were associated with lower risks of all-cause mortality. There was no interaction between the use of lipid-lowering medication and any of the outcomes.ConclusionAssociations of lipoproteins with lower risk of serious infection accompanied by no significant association with CV events may help to explain the paradoxical association between lipids and survival and lack of benefit of lipid-lowering therapies in HD.

Background Hypokalemia is a risk factor for drug-induced QT prolongation. Larger serum-to-dialysate potassium gradients during hemodialysis (HD) may augment the proarrhythmic risks of selective serotonin reuptake inhibitors (SSRIs). Methods We conducted a cohort study using 2007–2017 data from the United States Renal Data System and a large dialysis provider to examine if the serum-to-dialysate potassium gradient modifies SSRI cardiac safety. Using a new-user design, we compared 1-year sudden cardiac death (SCD) risk among HD patients newly treated with higher (citalopram, escitalopram) versus lower (fluoxetine, fluvoxamine, paroxetine, sertraline) QT-prolonging potential SSRIs, overall and stratified by baseline potassium gradient (≥4 versus <4 mEq/l). We used inverse probability of treatment-weighted survival models to estimate weighted hazard ratios (HRs) and 95% confidence intervals (CIs) and conducted a confirmatory nested case–control study. Results The study included 25   099 patients: 11   107 (44.3%) higher QT-prolonging potential SSRI new users and 13   992 (55.7%) lower QT-prolonging potential SSRI new users. Overall, higher versus lower QT-prolonging potential SSRI use was not associated with SCD [weighted HR 1.03 (95% CI 0.86–1.24)]. However, a greater risk of SCD was associated with higher versus lower QT-prolonging potential SSRI use among patients with baseline potassium gradients ≥4 mEq/l but not among those with gradients <4 mEq/l [weighted HR 2.17 (95% CI 1.16–4.03) versus 0.95 (0.78–1.16)]. Nested case–control analyses yielded analogous results. Conclusions The serum-to-dialysate potassium gradient may modify the association between higher versus lower QT-prolonging SSRI use and SCD among people receiving HD. Minimizing the potassium gradient in the setting of QT-prolonging medication use may be warranted. [ABSTRACT FROM AUTHOR]

Medicare claims data are commonly used to query comorbidities for case-mix adjustment in research of patients with end-stage renal disease (ESRD) in the United States. These adjustments may affect reimbursement and quality rating through comparative profiling and ranking of dialysis facilities. We studied regional and temporal variations in comorbidity from claims data in the United States Renal Data System. Patients with a previous 1-year Medicare history who initiated dialysis therapy between 2006 and 2009 were examined with a follow-up period until 2012. By linking pre- and post-ESRD Medicare claims with the Dartmouth Atlas, we carried out a longitudinal data analysis with multivariable adjustment to investigate regional and temporal variations in the Liu comorbidity index. We identified 23 336 incident hemodialysis patients who were covered by Medicare the year prior to dialysis initiation and had survived with complete 3 years of follow-up data. With the United States divided into 4 geographic regions, the Western region was found to have the lowest Liu index over all 3 follow-up years, compared with the respective years in the other regions (Midwest, Northeast, and South). In comparison with the first year, the Liu index dropped significantly during the second and third years of follow-up across all 4 regions. Significant regional and temporal variations observed in the comorbidity index cannot be explained by differences in reimbursement (average per state) or predialysis comorbidity. Based on our exploratory study, future studies should focus on identifying the factors and reasons for these variations which have the potential to affect health care policy and research.

BackgroundMedicare is one of the world's largest health insurance programs. It provides health insurance to nearly 44 million beneficiaries whose entitlements are based on age, disability, or end-stage renal disease (ESRD). Data of these ESRD beneficiaries are collected in the US Renal Data System (USRDS), which includes comorbidity information entered at the time of dialysis initiation (medical evidence data), and are used to shape health care policy. One limitation of USRDS data is the lack of validation of these medical evidence comorbidities against other comorbidity data sources, such as medical claims data.MethodsWe examined the potential for discordance between USRDS Medical Evidence and medical claims data for 11 comorbid conditions amongst Medicare beneficiaries in 2011-2013 via sensitivity, specificity, kappa and hierarchical logistic regression.ResultsAmong 61,280 patients, most comorbid conditions recorded on the Medical Evidence forms showed high specificity (>0.9), compared to prior medical claims as reference standard. However, both sensitivity and kappa statistics varied greatly and tended to be low (most

IntroductionDialysis patients aged ≥70 years derive improved life expectancy through kidney transplantation compared to their waitlisted counterparts, but guidelines are not clear about how to identify appropriate transplantation candidates. We developed a clinical prediction score to identify elderly dialysis patients with expected 5-year survival appropriate for kidney transplantation (>5 years).MethodsIncident dialysis patients in 2006-2009 aged ≥70 were identified from the United States Renal Data System database and divided into derivation and validation cohorts. Using the derivation cohort, candidate variables with a significant crude association with 5-year all-cause mortality were included in a multivariable logistic regression model to generate a scoring system. The scoring system was tested in the validation cohort and a cohort of elderly transplant recipients.ResultsCharacteristics most predictive of 5-year mortality included age >80, body mass index (BMI) 90% for the highest risk cohort (42% of the validation cohort).ConclusionThis clinical prediction score could be useful for physicians to identify potentially suitable candidates for kidney transplantation.

IntroductionWhile it has been well documented that in the U.S., black and Hispanic dialysis patients have overall lower risks of death than white dialysis patients, little is known whether their lower risks are observed in cause-specific deaths. Additionally, recent research reported that younger black patients have a higher risk of death, but the source is unclear. Therefore, this study examined cause-specific deaths among US dialysis patients by race/ethnicity and age.MethodsThis national study included 1,255,640 incident dialysis patients between 1995 and 2010 in the United States Renal Data System. Five cause-specific mortality rates, including cardiovascular (CVD), infection, malignancy, other known causes (miscellaneous), and unknown, were compared across blacks, Hispanics, and whites overall and stratified by age groups.FindingsAfter multiple adjustments, Hispanic patients had the lowest risk of mortality for every major cause in almost all ages. Compared with whites, blacks had a lower risk of death from CVD, malignancy and miscellaneous causes in most age groups, but not from infection. In fact, blacks had a higher risk of infection death than whites in ages 18-30 years (HR [95% CI] 1.94 [1.69-2.23]; P

Purpose: Polypharmacy is common in the hemodialysis population and increases the likelihood that patients will be exposed to clinically significant drug–drug interactions. Concurrent use of proton pump inhibitors (PPIs) with citalopram or escitalopram may potentiate the QT‐prolonging effects of these selective serotonin reuptake inhibitors through pharmacodynamic and/or pharmacokinetic interactions. Methods: We conducted a retrospective cohort study using data from the U.S. Renal Data System (2007–2017) and a new‐user design to examine the differential risk of sudden cardiac death (SCD) associated with citalopram/escitalopram initiation vs. sertraline initiation in the presence and absence of PPI use among adults receiving hemodialysis. We studied 72 559 patients:14 983 (21%) citalopram/escitalopram initiators using a PPI; 26 503 (36%) citalopram/escitalopram initiators not using a PPI;10 779 (15%) sertraline initiators using a PPI; and 20 294 (28%) sertraline initiators not using a PPI (referent). The outcome of interest was 1‐year SCD. We used inverse probability of treatment weighted survival models to estimate weighted hazard ratios (HRs) and 95% confidence intervals (CIs). Results: Compared with sertraline initiators not using a PPI, citalopram/escitalopram initiators using a PPI had the numerically highest risk of SCD (HR [95% CI] = 1.31 [1.11–1.54]), followed by citalopram/escitalopram initiators not using a PPI (HR [95% CI] = 1.22 [1.06–1.41]). Sertraline initiators using a PPI had a similar risk of SCD compared with those not using a PPI (HR [95% CI] = 1.03 [0.85–1.26]). Conclusions: Existing PPI use may elevate the risk of SCD associated with citalopram or escitalopram initiation among hemodialysis patients. [ABSTRACT FROM AUTHOR]

BackgroundSystematic analyses about sex differences in wait-listing and kidney transplantation after dialysis initiation are scarce. We aimed at identifying sex-specific disparities along the path of kidney disease treatment, comparing two countries with distinctive health care systems, the US and Austria, over time.MethodsWe analyzed subjects who initiated dialysis from 1979–2018, in observational cohort studies from the US and Austria. We used Cox regression to model male-to-female cause-specific hazard ratios (csHRs, 95% confidence intervals) for transitions along the consecutive states dialysis initiation, wait-listing, kidney transplantation and death, adjusted for age and stratified by country and decade of dialysis initiation.ResultsAmong 3,053,206 US and 36,608 Austrian patients starting dialysis, men had higher chances to enter the wait-list, which however decreased over time [male-to-female csHRs for wait-listing, 1978–1987: US 1.94 (1.71, 2.20), AUT 1.61 (1.20, 2.17); 2008–2018: US 1.35 (1.32, 1.38), AUT 1.11 (0.94, 1.32)]. Once wait-listed, the advantage of the men became smaller, but persisted in the US [male-to-female csHR for transplantation after wait-listing, 2008–2018: 1.08 (1.05, 1.11)]. The greatest disparity between men and women occurred in older age groups in both countries [male-to-female csHR for wait-listing after dialysis, adjusted to 75% age quantile, 2008–2018: US 1.83 (1.74, 1.92), AUT 1.48 (1.02, 2.13)]. Male-to-female csHRs for death were close to one, but higher after transplantation than after dialysis.ConclusionsWe found evidence for sex disparities in both countries. Historically, men in the US and Austria had 90%, respectively, 60% higher chances of being wait-listed for kidney transplantation, although these gaps decreased over time. Efforts should be continued to render kidney transplantation equally accessible for both sexes, especially for older women.

Erythropoietin (EPO) is the primary regulator of bone marrow erythropoiesis. Mouse models have provided evidence that EPO also promotes bone remodeling and that EPO‐stimulated erythropoiesis is accompanied by bone loss independent of increased red blood cell production. EPO has been used clinically for three decades to treat anemia in end‐stage renal disease, and notably, although the incidence of hip fractures decreased in the United States generally after 1990, it rose among hemodialysis patients coincident with the introduction and subsequent dose escalation of EPO treatment. Given this clinical paradox and findings from studies in mice that elevated EPO affects bone health, we examined EPO treatment as a risk factor for fractures in hemodialysis patients. Relationships between EPO treatment and hip fractures were analyzed using United States Renal Data System (USRDS) datasets from 1997 to 2013 and Consolidated Renal Operations in a Web‐enabled Network (CROWNWeb) datasets for 2013. Fracture risks for patients treated with <50 units of EPO/kg/week were compared to those receiving higher doses by multivariable Cox regression. Hip fracture rates for 747,832 patients in USRDS datasets (1997–2013) increased from 12.0 per 1000 patient years in 1997 to 18.9 in 2004, then decreased to 13.1 by 2013. Concomitantly, average EPO doses increased from 11,900 units/week in 1997 to 18,300 in 2004, then decreased to 8,800 by 2013. During this time, adjusted hazard ratios for hip fractures with EPO doses of 50–149, 150–299, and ≥ 300 units/kg/week compared to <50 units/kg/week were 1.08 (95% confidence interval [CI], 1.01–1.15), 1.22 (95% CI, 1.14–1.31), and 1.41 (95% CI, 1.31–1.52), respectively. Multivariable analyses of 128,941 patients in CROWNWeb datasets (2013) replicated these findings. This study implicates EPO treatment as an independent risk factor for hip fractures in hemodialysis patients and supports the conclusion that EPO treatment may have contributed to changing trends in fracture incidence for these patients during recent decades. Published 2021. This article is a U.S. Government work and is in the public domain in the USA. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR). [ABSTRACT FROM AUTHOR]

Abstract Background Objective of the study is to assess prevalence and survival among end stage renal disease patients with restless legs syndrome (RLS) within a national database (USRDS). Methods A case-control, retrospective analysis was performed. Differences in characteristics between the groups, RLS and those with no sleep disorder (NSD), were determined using χ2 tests. Cox proportional hazard regression was used to assess survival between those with RLS and propensity score matched controls. Results Cases of restless legs syndrome were defined as patients that had received an ICD-9 code of 333.94 at any point during their treatment (n = 372). RLS group demonstrated a significantly higher proportion of patients with major depressive disorder, dysthymic disorder, anxiety, depression, minor depressive disorder, and psychological disorder. The difference between the survival was not statistically significant in those without sleep disorder as compared to those with RLS (HR =1.16±0.14, p = 0.3). Conclusions True prevalence of RLS in dialysis patients can only be estimated if knowledge gap for care providers in diagnosis of RLS is addressed. RLS patients also have increased incidence of certain psychological disorders which needs to be addressed.

Dialysis patients aged ≥70 years derive improved life expectancy through kidney transplantation compared with their waitlisted counterparts, but guidelines are not clear about how to identify appropriate transplantation candidates. We developed a clinical prediction score to identify elderly dialysis patients with expected 5-year survival appropriate for kidney transplantation (>5 years). Methods: Incident dialysis patients in 2006–2009 aged ≥70 were identified from the United States Renal Data System database and divided into derivation and validation cohorts. Using the derivation cohort, candidate variables with a significant crude association with 5-year all-cause mortality were included in a multivariable logistic regression model to generate a scoring system. The scoring system was tested in the validation cohort and a cohort of elderly transplant recipients. Results: Characteristics most predictive of 5-year mortality included age >80, body mass index 90% for the highest risk cohort (42% of the validation cohort). Discussion: This clinical prediction score could be useful for physicians to identify potentially suitable candidates for kidney transplantation.

Abstract Background Basic and translational research supports beneficial effects of statins on bone metabolism. Clinical studies suggest that statin use may reduce the risk of hip fractures in the general population. Whether statin use is associated with hip fracture risk in kidney transplant recipients, a particularly high-risk group for this outcome, is unknown. Methods From the U.S. Renal Data System (2007–2011), we identified all hip fracture events recorded in Medicare billing claims of first-time kidney transplant recipients. We then matched all cases to an unlimited number of controls on age (±3 years), sex, race (black vs. non-black), and time since transplant. Cases and controls were required to have >1 year of Medicare Parts A + B + D coverage and be without a recorded history of hip fracture. We ascertained any statin use in the previous year and defined adherent statin use as those who had filled prescriptions for statins to cover >80% of days in that year (proportion of days covered, PDC). We ascertained several potential confounders (demographics, comorbidities, BMI, transplant-related factors) and applied conditional logistic regression with multiple imputation for missing data to estimate odds ratios (OR) and 95% confidence intervals (CI). Results We identified 231 hip fracture cases (mean age 51.8 years; 53% female; 11.3% black; 6.9 years from transplant, and 9.9 years from ESRD) and 15,575 matched controls. Any prior statin use was present in 64.1% of cases and 60.3% of controls with 37.2% of cases and 33.9% of controls being found adherent. Unadjusted conditional logistic regression showed an OR of 1.17 (0.89-1.54) for any statin use, and a fully-adjusted OR of 0.89 (0.67-1.19). Compared with statin non-users, the adjusted OR for patients with lesser adherence (PDC ≤80%) and those with greater adherence (PDC >80%) were 0.93 (0.66-1.31) and 0.87 (0.63-1.20), respectively. Conclusion Statin use was not associated with hip fracture risk in first-time kidney transplant recipients.

Introduction: 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., Methods: 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., Results: 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., Conclusion: 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., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

The association of race, ethnicity, and socioeconomic factors with survival rates of nursing home (NH) residents with treated end-stage renal disease (ESRD) is unclear. We examined whether race/ethnicity, ZIP code–level, and individual-level indicators of poverty relate to mortality of NH residents on dialysis. Retrospective cohort study. Using the United States Renal Data System database, we identified 56,194 nursing home residents initiated on maintenance dialysis from January 1, 2007 through December 31, 2013, followed until May 31, 2014. We evaluated baseline characteristics of the NH cohort on dialysis, including race and ethnicity. We assessed the Medicare-Medicaid dual eligibility status as an indicator of individual-level poverty and ZIP code–level median household income (MHI) data. We conducted Cox regression analyses with all-cause mortality as the outcome variable, adjusted for clinical and sociodemographic factors including end-of-life preferences. Adjusted Cox analysis showed a significantly lower risk of death among black vs nonblack NH residents [adjusted hazard ratio (AHR) 0.91, 95% confidence interval (CI) 0.89, 0.94]. Dual-eligibility status was significantly associated with lower risk of death compared to those with Medicare alone (AHR 0.80, 95% CI 0.78, 0.82). Compared to those in higher MHI quintile levels, NH ESRD patients in the lowest quintile were significantly associated with higher risk of death (AHR 1.09, 95% CI 1.06, 1.13). Black and Hispanic NH residents on dialysis had an apparent survival advantage. This "survival paradox" occurs despite well-documented racial/ethnic disparities in ESRD and NH care and warrants further exploration that could generate new insights into means of improving survival of all NH residents on dialysis. Area-level indicator of poverty was independently associated with mortality, whereas dual-eligibility status for Medicare and Medicaid was associated with lower risk of death, which could be partly explained by improved access to care. [ABSTRACT FROM AUTHOR]

Background Medicare is one of the world’s largest health insurance programs. It provides health insurance to nearly 44 million beneficiaries whose entitlements are based on age, disability, or end-stage renal disease (ESRD). Data of these ESRD beneficiaries are collected in the US Renal Data System (USRDS), which includes comorbidity information entered at the time of dialysis initiation (medical evidence data), and are used to shape health care policy. One limitation of USRDS data is the lack of validation of these medical evidence comorbidities against other comorbidity data sources, such as medical claims data. Methods We examined the potential for discordance between USRDS Medical Evidence and medical claims data for 11 comorbid conditions amongst Medicare beneficiaries in 2011–2013 via sensitivity, specificity, kappa and hierarchical logistic regression. Results Among 61,280 patients, most comorbid conditions recorded on the Medical Evidence forms showed high specificity (>0.9), compared to prior medical claims as reference standard. However, both sensitivity and kappa statistics varied greatly and tended to be low (most

Background: Objective of the study is to assess prevalence and survival among end stage renal disease patients with restless legs syndrome (RLS) within a national database (USRDS).Methods: A case-control, retrospective analysis was performed. Differences in characteristics between the groups, RLS and those with no sleep disorder (NSD), were determined using χ2 tests. Cox proportional hazard regression was used to assess survival between those with RLS and propensity score matched controls.Results: Cases of restless legs syndrome were defined as patients that had received an ICD-9 code of 333.94 at any point during their treatment (n = 372). RLS group demonstrated a significantly higher proportion of patients with major depressive disorder, dysthymic disorder, anxiety, depression, minor depressive disorder, and psychological disorder. The difference between the survival was not statistically significant in those without sleep disorder as compared to those with RLS (HR =1.16±0.14, p = 0.3).Conclusions: True prevalence of RLS in dialysis patients can only be estimated if knowledge gap for care providers in diagnosis of RLS is addressed. RLS patients also have increased incidence of certain psychological disorders which needs to be addressed. [ABSTRACT FROM AUTHOR]

Background: Basic and translational research supports beneficial effects of statins on bone metabolism. Clinical studies suggest that statin use may reduce the risk of hip fractures in the general population. Whether statin use is associated with hip fracture risk in kidney transplant recipients, a particularly high-risk group for this outcome, is unknown.Methods: From the U.S. Renal Data System (2007-2011), we identified all hip fracture events recorded in Medicare billing claims of first-time kidney transplant recipients. We then matched all cases to an unlimited number of controls on age (±3 years), sex, race (black vs. non-black), and time since transplant. Cases and controls were required to have >1 year of Medicare Parts A + B + D coverage and be without a recorded history of hip fracture. We ascertained any statin use in the previous year and defined adherent statin use as those who had filled prescriptions for statins to cover >80% of days in that year (proportion of days covered, PDC). We ascertained several potential confounders (demographics, comorbidities, BMI, transplant-related factors) and applied conditional logistic regression with multiple imputation for missing data to estimate odds ratios (OR) and 95% confidence intervals (CI).Results: We identified 231 hip fracture cases (mean age 51.8 years; 53% female; 11.3% black; 6.9 years from transplant, and 9.9 years from ESRD) and 15,575 matched controls. Any prior statin use was present in 64.1% of cases and 60.3% of controls with 37.2% of cases and 33.9% of controls being found adherent. Unadjusted conditional logistic regression showed an OR of 1.17 (0.89-1.54) for any statin use, and a fully-adjusted OR of 0.89 (0.67-1.19). Compared with statin non-users, the adjusted OR for patients with lesser adherence (PDC ≤80%) and those with greater adherence (PDC >80%) were 0.93 (0.66-1.31) and 0.87 (0.63-1.20), respectively.Conclusion: Statin use was not associated with hip fracture risk in first-time kidney transplant recipients. [ABSTRACT FROM AUTHOR]

Background: Although patients treated with maintenance hemodialysis are at an increased risk of colorectal cancer compared with the general population, national practices for colorectal cancer screening have not been reported in this population. We assessed the performance of colorectal cancer screening in the US end-stage renal disease program in comparison with the US Medicare population. Methods: We studied the United States Renal Data System for US prevalent hemodialysis patients between 2002 and 2011 who had Medicare as their primary insurer. We assessed procedure codes for performance of common colorectal cancer screening tests, including fecal occult blood testing, sigmoidoscopy and colonoscopy. We assessed screening sigmoidoscopy and screening colonoscopy only and excluded patients who had preexisting colon cancer or gastrointestinal hemorrhage. Because colorectal cancer screening recommendations are established for hemodialysis patients who have been listed for kidney transplantation, but no general recommendations exist for patients who are not wait-listed, we assessed colorectal cancer screening separately for the two groups. Results: We found that 1-year performance of colonoscopy in wait-listed hemodialysis patients was similar to or higher than that in general Medicare patients of the same age, while performance of colonoscopy in non-wait-listed patients was significantly lower than among general Medicare patients of the same age. Conclusions: Given improved survival among hemodialysis patients in the last decade, the utility of colorectal cancer screening even among non-wait-listed hemodialysis patients should be reassessed. [ABSTRACT FROM AUTHOR]

Background: Little is known about the effect of multiple, or subsequent, ischemic strokes in patients receiving hemodialysis. Methods: We undertook a retrospective cohort study of incident hemodialysis patients with Medicare coverage who had experienced a first ischemic stroke. Factors associated with either a subsequent ischemic stroke or death following a first new stroke were modeled. A multistate model with Cox proportional hazards was used to predict transition probabilities from first ischemic stroke to either subsequent stroke or to death, and the demographic and clinical factors associated with the respective transition probabilities were determined. Effect of a subsequent ischemic stroke on survival was quantified. Results: Overall, 12,054 individuals (mean age 69.7 years, 41.3 % male, 53.0 % Caucasian and 34.0 % African-American) experienced a first new ischemic stroke. Female sex was associated with an increased risk of having a subsequent ischemic stroke (adjusted hazard ratio 1.37, 95 % confidence intervals 1.20 - 1.56, P < 0.0001); African-Americans, as compared to Caucasians, had lower likelihood of dying after a first new ischemic stroke (0.81, 0.77 - 0.85, P < 0.0001). A subsequent stroke trended towards having a higher likelihood of transitioning to death compared to a first new ischemic stroke on dialysis (1.72, 0.96 - 3.09, P = 0.071). When a subsequent ischemic stroke occurs at 24 months, probability of survival dropped >15 %, in absolute terms, from 0.254 to 0.096, with substantial drops observed at subsequent time points such that the probability of survival was more than halved. Conclusions: Likelihood of subsequent ischemic stroke and of survival in hemodialysis patients appears to vary by sex and race: females are more likely than males to experience a subsequent ischemic stroke, and Caucasians are more likely than African-Americans to die after a first new ischemic stroke. The risk of a transitioning to a subsequent stroke (after having had a first) increases until about 1 year, then decreases. Subsequent strokes are associated with decreased probability of survival, an effect which increases as time since first stroke elapses. This information may be of assistance to clinicians when counseling hemodialysis patients about the implications of recurrent ischemic stroke. [ABSTRACT FROM AUTHOR]

Introduction Cross-sectional and longitudinal studies in the general population have shown that a physically active lifestyle may have anti-inflammatory properties, but evidence from studies conducted with maintenance hemodialysis (HD) patients is limited. Methods A multicenter prospective cohort of 755 HD participants aged 20-92 was evaluated in a USRDS special study 2009-2013. Kilocalories/week (kcal/week) of leisure time physical activity (LTPA) was estimated from the Minnesota Leisure Time Activity questionnaire. Predialysis serum samples were obtained concurrent with LTPA report date. Generalized estimating equations (GEE) examined association of participants' LTPA and log-normalized CRP across 24 months. Cox proportional hazards models investigated LTPA and survival over a median follow-up of 718 days. Findings Baseline median CRP concentration was lower for participants with 500+ kcal/week LTPA vs. those with <500 kcal/week LTPA (3.4 mg/L vs. 4.6 mg/L; P = 0.03). Participants who reported lower LTPA (<500 kcal/week) at both baseline and 12 months had a borderline significant increase in CRP concentration (within-group change 4.8 [1.9-10.4] to 5.8 [1.6-15.7]; P = 0.08). Lower LTPA was associated with higher log CRP over 24 months in adjusted GEE analyses (β coefficient = 0.16 [95% CI 0.02-0.31]; P = 0.03). 67/364 (18%) and 43/391 (11%) deaths occurred, respectively, among participants reporting <500 vs. 500+ kcal/week LTPA [adjusted mortality hazard ratio 1.63 (CI, 1.07, 2.47)]. Discussion The data suggest that increased estimated levels of LTPA, a physical activity/exercise opportunity widely applicable to HD patients, may be associated with lower CRP concentration as well as better survival outcome. [ABSTRACT FROM AUTHOR]

Background: Maintaining tight glycemic control is important for prevention of diabetes-related outcomes in end-stage renal disease patients with diabetes, especially in light of their poor prognosis. This study aimed to determine factors associated with poor glycemic control among U.S. patients with diabetes mellitus initiating hemodialysis for end-stage renal disease.Methods: Using data from the U.S. Renal Data System, electronic health records of a large national dialysis provider, and U.S. Census data, we performed a cross-sectional multivariable Poisson regression analysis to characterize risk factors associated with poor glycemic control, defined as glycated hemoglobin (HbA1c) > 7 vs. ≤ 7 %, in adult patients with diabetes who initiated hemodialysis at an outpatient facility between 2006 and 2011.Results: Of 16,297 patients with diabetes, 21.2 % had HbA1c >7 %. In multivariable analysis, younger patients, patients of Native American race, and those of Hispanic ethnicity had higher prevalence of poor glycemic control. Independent correlates of poor glycemic control further included higher platelet count, white blood cell count, and ferritin; higher body mass index, systolic blood pressure, total cholesterol and triglyceride concentrations; lower HDL and albumin concentrations; lower normalized protein catabolic rate; and higher estimated glomerular filtration rate at initiation of dialysis (all P < 0.05). No independent associations were found with area-level socioeconomic indicators. Occurrence of diabetes in patients < 40 years of age, a proxy for type 1 diabetes, was associated with poor HbA1c control compared with that in patients ≥ 40 years of age, which was classified as type 2 diabetes. These findings were robust to the different outcome definitions of HbA1c > 7.5 % and > 8 %.Conclusion: In this cohort of incident end-stage renal disease patients with diabetes, poor glycemic control was independently associated with younger age, Native American race, Hispanic ethnicity, higher body mass index, and clinical risk factors including atherogenic lipoprotein profile, hypertension, inflammation, and markers indicative of malnutrition and a more serious systemic disease. [ABSTRACT FROM AUTHOR]

Background: The impact of socioeconomic factors on arteriovenous fistula (AVF) creation in hemodialysis (HD) patients is not well understood. We assessed the association of area and individual-level indicators of poverty and health care insurance on AVF use among incident end-stage renal disease (ESRD) patients initiated on HD.Methods: In this retrospective cohort study using the United States Renal Data System database, we identified 669,206 patients initiated on maintenance HD from January 1, 2007 through December 31, 2012. We assessed the Medicare-Medicaid dual-eligibility status as an indicator of individual-level poverty and ZIP code-level median household income (MHI) data obtained from the 2010 United States Census. We conducted logistic regression of AVF use at start of dialysis as the outcome variable.Results: The proportions of dual-eligible and non-dual-eligible patients who initiated HD with an AVF were 12.53 and 16.17%, respectively (p<0.001). Dual eligibility was associated with significantly lower likelihood of AVF use upon initiation of HD (adjusted odds ratio (aOR) 0.91; 95% CI 0.90-0.93). Patients in the lowest area-level MHI quintile had an aOR of 0.97 (95% CI 0.95-0.99) compared to those in higher quintile levels. However, dual eligibility and area-level MHI were not significant in patients with Veterans Affairs (VA) coverage.Conclusions: Individual- and area-level measures of poverty were independently associated with a lower likelihood of AVF use at the start of HD, the only exception being patients with VA health care benefits. Efforts to improve incident AVF use may require focusing on pre-ESRD care to be successful. [ABSTRACT FROM AUTHOR]

Background Falls among patients undergoing maintenance hemodialysis (HD) have significant consequences for quality of life and functional independence, morbidity, healthcare utilization and even mortality, but studies on the etiology of falls within large HD cohorts are limited. Methods Falls during the past 12 months were ascertained for a prevalent multi-center HD cohort (n = 762) aged 20–92 years, and associations with demographic and treatment characteristics, comorbidities, cognitive function, prescribed medications, balance tests, frailty and depressive symptoms were assessed. Results Falls were sustained by 28.4% of participants. In multivariable-adjusted analyses, participants classified as frail were over two times more likely to report falls [odds ratio (OR): 2.39, 95% confidence interval (CI): 1.22–4.71, P = 0.01], and participants with a CES-D score 18+ and/or prescribed antidepressants were over 80% more likely to be fallers (OR: 1.83, 95% CI: 1.23–2.74, P = 0.003) than were participants with a CES-D score <18 and no prescribed antidepressants. Conclusions Frailty and depressed mood, factors that are potentially modifiable, are prominently associated with falls. [ABSTRACT FROM AUTHOR]

Background An analysis of intracranial hemorrhage (ICH) in a national sample of autosomal dominant polycystic kidney disease (ADPKD) patients receiving long-term dialysis has not been reported. It is often assumed that patients with ADPKD are not at increased risk of ICH after starting dialysis. We hypothesized that patients with ADPKD would have a higher subsequent risk of ICH even after the start of chronic dialysis. Methods Retrospective cohort study of Medicare primary patients with and without ADPKD in the United States Renal Data System (USRDS), initiated on chronic dialysis or transplanted between 1 January 1999 and 3 July 2009, and followed until 31 December 2009. Covariates included age, gender, race, prior stroke, diabetes mellitus, dialysis modality, body mass index, serum albumin and other co-morbid conditions from the Medical Evidence Form. Primary outcome was ICH, based on inpatient and outpatient Medicare claims, and all-cause mortality. Kaplan-Meier analysis was used for unadjusted assessment of time to events. Cox regression was used for assessment of factors associated with ICH and mortality. We performed competing risk regression using kidney transplant and death as competing risks. Kidney transplant was also modeled as a time-dependent covariate in Cox regression. Results Competing risk regression demonstrated that ADPKD had a subhazard ratio 2.97 for ICH (95% CI 2.27-3.89). Adjusted Cox analysis showed that ADPKD patients had an AHR for death of 0.59 vs. non-ADPKD patients (95% CI 0.57-0.61). Conclusions ADPKD is a significant risk factor for ICH among patients on maintenance dialysis. Our Medicare primary cohort was older than in previous studies of intracranial aneurysm rupture among ADPKD patients. There are also limitations inherent to using the USRDS database. [ABSTRACT FROM AUTHOR]

ABSTRACT Purpose Erythropoietin (EPO) improves measures of quality of life and reduces transfusions. Clinical trials have reported higher mortality associated with higher hemoglobin targets in varied clinical settings, making difficult the selection of erythropoiesis stimulation strategies in end-stage kidney disease. Observational studies distinguishing an effect of EPO from underlying conditions are challenging, but promise insights relevant to real-world settings. Methods Using data from the United States Renal Data System, we performed a retrospective cohort study of hemodialysis patients treated between 2000 and 2004. 409 364 Medicare insured patients receiving hemodialysis therapy as of January 2000 or who began dialysis after January 2000 and survived >6 months were studied. We examined the association of EPO dose in any given month with death over subsequent follow-up. Results Within each hematocrit group ( <30%, 30%- < 33%, 33%- < 36%, 36%- < 39% and >39%), the hazard ratios comparing the 80th percentile to the median EPO dose were 0.88 (95% CI: [0.87-0.90]), 0.94 ([0.93-0.94]), 0.98 ([0.98-0.99]), 1.06 ([1.05-1.06]) and 1.08 ([1.07-1.09]), respectively. Within the highest hematocrit group, the association of a high EPO dose with elevated mortality was attenuated over time. Among patients with malignancy or indications of EPO resistance, the association of higher EPO dose with lower mortality was attenuated when hematocrit was low, while its association with higher mortality was stronger when hematocrit was high. Conclusions These analyses demonstrate a complex relationship between EPO dosing and mortality, suggesting a possible beneficial effect among severely anemic hemodialysis patients, but possible harm when administered to individuals with higher hematocrit levels. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This manuscript is remarkable for revealing a striking difference in the annual mortality rate between patients from Beijing compared to those in the United States.Background The raw annual mortality rate reported in Chinese patients on maintenance hemodialysis (MHD) was around 10% between 2005 to 2010, and it was around 20% in the US as reported by the United States Renal Data System (USRDS). Our hypothesis was that the large survival difference was caused by differences in race and practice pattern between nations in addition to differences in patient characteristics. Methods Annual mortality in Beijing prevalent MHD patients per year in 2007, 2008, 2009 and 2010 was reported and relative risks of death were compared with the corresponding mortality of USRDS prevalent MHD patients (in whites, African-Americans and Asian-Americans) after age, gender and primary cause of end-stage renal disease (ESRD) were adjusted. A total of 11 675 MHD patients from 104 dialysis facilities under control of Beijing Blood Purification Quality Control and Improvement Center (BJBPQCIC) from 31 December 2006 to 31 December 2010 were included. A total of 1 937 819 MHD patients (only white, African-American and Asian-American were eligible for inclusion) were subtracted from the USRDS No-60-Day prevalent dataset from the year 2004 to 2009, using the RenDER system. Raw annual mortality for each race was reported as a number per 1000 MHD patients at risk for each year. Age, gender and primary cause of ESRD, adjusted annual mortality and relative risk race of death were reported comparing the Beijing patients and each race of the USRDS. Results The raw annual mortality for the Beijing cohort increased gradually from 47.8 per 1000 patient-years in 2007 to 76.8 in 2010. The raw annual mortality for the white cohort in 2007 was 250.7 per 1000 patient-years, and gradually decreased to 236.3 in 2009. The raw annual mortality for African-Americans (167.8 and 156.7 per 1000 patient-years in 2007 and 2009, respectively) was much lower than that for whites. The annual mortality for Asian-Americans was slightly lower than that for African-Americans. After adjustment, Beijing MHD still had a survival benefit compared with each of the examined USRDS race. The annual mortality rates were 99.4, 80.6 and 94.3 per 1000 patient-years when adjusted to whites, African-Americans and Asian-Americans, respectively, in cohort 2009. Conclusions The annual mortality for the Beijing MHD patients was lower than that for their USRDS counterparts, and this difference existed after baseline demographics were adjusted. This survival difference between the Beijing and the USRDS MHD cohorts could be attributed to differences in race or practice pattern. More studies are needed to validate our hypothesis. [ABSTRACT FROM PUBLISHER]

Azithromycin is an antibiotic with QT-prolonging potential commonly prescribed to individuals receiving hemodialysis. Hemodialysis patients have a high prevalence of clinical conditions, such as structural heart disease, that can enhance the pro-arrhythmic effects azithromycin, but were excluded from prior investigations evaluating the cardiac safety of azithromycin. Using data from the United States Renal Data System (2007-2017), we conducted two cohort studies to examine the cardiac safety of azithromycin relative to amoxicillin-based antibiotics (amoxicillin, amoxicillin/clavulanic acid) and levofloxacin (a fluoroquinolone antibiotic known to prolong the QT-interval) in the hemodialysis population. The primary outcome was five-day sudden cardiac death. Using inverse probability of treatment weighted survival models, we estimated hazard ratios, risk differences, and 95% confidence intervals. The azithromycin vs. amoxicillin-based antibiotic cohort included 282,899 patients and 725,431 treatment episodes (381,306 azithromycin and 344,125 amoxicillin-based episodes). Azithromycin vs. amoxicillin-based antibiotic treatment was associated with higher relative and absolute risks of sudden cardiac death, weighted hazard ratio of 1.70 (95% Confidence Interval, 1.36 to 2.11) and weighted risk difference per 100,000 treatment episodes of 25.0 (15.5 to 36.5). The azithromycin vs. levofloxacin cohort included 245,143 patients and 554,557 treatment episodes (387,382 azithromycin and 167,175 levofloxacin episodes). Azithromycin vs. levofloxacin treatment was associated with lower relative and absolute risks of sudden cardiac death, weighted hazard ratio of 0.79 (0.64 to 0.96) and weighted risk difference per 100,000 treatment episodes of -18.9 (-35.5 to -3.8). Thus, when selecting among azithromycin, levofloxacin, and amoxicillin-based antibiotics, clinicians should weigh the relative antimicrobial benefits of these drugs against their potential cardiac risks., (Copyright © 2022 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)

Background: Hurricanes are severe weather events that can disrupt power, water, and transportation systems. These disruptions may be deadly for patients requiring maintenance dialysis. We hypothesized that the mortality risk among patients requiring maintenance dialysis would be increased in the 30 days after a hurricane., Methods: Patients registered as requiring maintenance dialysis in the United States Renal Data System who initiated treatment between January 1, 1997 and December 31, 2017 in one of 108 hurricane-afflicted counties were followed from dialysis initiation until transplantation, dialysis discontinuation, a move to a nonafflicted county, or death. Hurricane exposure was determined as a tropical cyclone event with peak local wind speeds ≥64 knots in the county of a patient's residence. The risk of death after the hurricane was estimated using time-varying Cox proportional hazards models., Results: The median age of the 187,388 patients was 65 years (IQR, 53-75) and 43.7% were female. There were 27 hurricanes and 105,398 deaths in 529,339 person-years of follow-up on dialysis. In total, 29,849 patients were exposed to at least one hurricane. Hurricane exposure was associated with a significantly higher mortality after adjusting for demographic and socioeconomic covariates (hazard ratio, 1.13; 95% confidence interval, 1.05 to 1.22). The association persisted when adjusting for seasonality., Conclusions: Patients requiring maintenance dialysis have a higher mortality risk in the 30 days after a hurricane., (Copyright © 2022 by the American Society of Nephrology.)

Background. Altitude is associated with all-cause mortality in US dialysis patients, but its association with cardiovascular outcomes has not been assessed. We hypothesized that higher altitude would be associated with lower rates of cardiovascular events due to an altered physiological response of dialysis patients to altitude induced hypoxia. Methods. We studied 984 265 patients who initiated dialysis from 1995 to 2006. Patients were stratified by the mean elevation of their residential zip codes and were followed from the start of dialysis to the occurrence of several validated cardiovascular endpoints: myocardial infarction, stroke, cardiovascular death and a composite of these end points. Incidence rate ratios across altitude strata were estimated using proportional hazards regression. Results. All outcomes occurred less frequently among patients living at higher altitude compared with patients living at or near sea level, and the association appeared monotonic for all outcomes except for stroke, which was most incident in the 250–1999 ft group. Compared with otherwise similar patients residing at or near sea level, patients living at ≥6000 ft had 31% [95% confidence interval (CI): 21–41%] lower rates of myocardial infarction, 27% (95% CI: 15–37%) lower rates of stroke and 19% (95% CI: 14–24%) lower rates of cardiovascular death. Additional adjustment for biometric information did not materially change these findings. Effect modification between race and altitude was only consistently significant for Native Americans. Altitude did not significantly alter the rates of non-cardiovascular death. Conclusion. We conclude that dialysis patients at higher altitude experience lower rates of cardiovascular events compared to otherwise similar patients at lower altitude. [ABSTRACT FROM PUBLISHER]

We sought to determine the association between living at high altitudes and the estimated glomerular filtration rate (eGFR) and also to determine the prevalence of end-stage renal disease (ESRD) at various altitudes. In the first part of the study, we used data from the National Health and Nutrition Examination Survey III to examine the association between altitude of residence and eGFR. In the second part, we used the United States Renal Data System to study the association between altitude and prevalence of ESRD. The query revealed an ESRD prevalence of 485 012 for the year 2005. The prevalence rates were merged with the zip codes dataset. The mean eGFR was significantly increased at higher altitudes (78.4 ± 21.6 vs 85.4 ± 26.8 mL/min for categories 1 and 5, respectively; P < 0.05). In the analysis of the United States Renal Data System data for prevalence of ESRD, we found a significantly lower prevalence at the altitude of 523 feet and higher. Using a population-based approach, our study demonstrates an association between altitude and renal function. This association is independent of all factors studied and is reached at approximately 250 feet. There is also a negative association between the prevalence of ESRD and altitude of residence. Further studies are needed to elucidate the pathophysiological basis of these epidemiological findings. This is an interesting paper suggesting the negative association between the prevalence of end-stage renal disease and altitude of residence. Pathophysiological basis of this observation needs to be proved by future research. Significance of hypoxic stimulus and the protective effects of erythropoietin are interesting hypotheses. [ABSTRACT FROM AUTHOR]

Background. There are several case reports of rhabdomyolysis (RM) in renal transplant recipients, but the actual incidence of this complication is not known. Most of the reported cases have been attributed to drug–drug interactions with calcineurin inhibitors, with the majority of interactions reported between cyclosporine and 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins). Pharmacokinetic studies have demonstrated that cyclosporine increases statin drug levels, presumably via competitive inhibition of cytochrome P450 3A4. [ABSTRACT FROM PUBLISHER]

We estimated the survival and hospitalization among frequent hemodialysis users in comparison to those patients undergoing thrice-weekly conventional hemodialysis. All patients had similar characteristics and medical histories. In this cohort study of frequent hemodialysis users and propensity score–matched controls, the collaborating clinicians identified 94 patients who used nocturnal hermodialysis (NHD) and 43 patients who used short-duration daily hemodialysis (SDHD) for a minimum of 60 days. Ten propensity score–matched control patients for each NHD and SDHD patient were identified from the United States Renal Data System database. Primary outcomes were risk for all-cause mortality and risk for the composite outcome of mortality or major morbid event (acute myocardial infarction or stroke) estimated using Cox proportional hazards models. Risks for all-cause, cardiovascular-related, infection-related, and vascular access–related hospital admissions were also studied. Nocturnal hemodialysis was associated with significant reductions in mortality risk and risk for mortality or major morbid event when compared to conventional hemodialysis. There was a reduced but non-significant risk of death for patients using SDHD compared to controls. All-cause and specific hospitalizations did not differ significantly between NHD and SDHD patients and their matched control cohorts. Our study suggests that NHD may improve patient survival. [ABSTRACT FROM AUTHOR]

To investigate whether Hurricane Katrina's landfall in August 2005 resulted in excess mortality, we conducted a cohort study of patients who started dialysis between January 2003 and late August 2005 and who received treatment at 94 Katrina-affected clinics in the area. Survival, regardless of patient location after the storm, was followed through February 2006. In adjusted Cox proportional hazards models, Hurricane Katrina (time-varying indicator) was not significantly associated with mortality risk for patients from regions of the Gulf Coast affected by Katrina or those from a subset of 40 New Orleans clinics. Subgroup analyses indicated no significant increased mortality risk by race, income status, or dialysis modality. Sensitivity analyses indicated no significant increased mortality risk for patients from clinics closed for 10 days or longer, patients in their first 90 days of dialysis, or patients not evacuated from the affected areas. Patients remaining in the New Orleans area may have been more vulnerable due to age and comorbidities; however, the change in their mortality risk in the month following the storm was not statistically significant. We suggest that disaster-related education for patients must be ongoing, and that each disaster may present a different set of circumstances and challenges that will require unanticipated response efforts. [ABSTRACT FROM AUTHOR]

The impact of hepatitis C virus (HCV) and other comorbid conditions upon survival is not well quantified in patients on dialysis. We identified HCV-infected and uninfected persons in the USRDS using claims data in 1997–1998 and followed until September 22, 2002 or death. We used Gray's time-varying coefficients model to examine factors associated with survival. Subjects with a renal transplant were excluded. A total of 5737 HCV-infected and 11 228 HCV-uninfected persons were identified. HCV-infected subjects were younger (mean age 57.8 vs 65.3 years), more likely to be male (57.6% vs 49.6%) and black (54.0% vs 36.4%). They were more likely to have a diagnosis of drug (16.5% vs 4.6%) and alcohol use (14.0% vs 3.1%), and to be human immunodeficiency virus (HIV) co-infected (7.4% vs 1.8%) (all comparisons, P < 0.0005). In an adjusted Gray's time-varying coefficient model, HCV was associated with an increased risk of mortality ( P < 0.0005). The hazards were highest at the time of HCV diagnosis and decreased to a stable level 2 years after diagnosis. Other factors associated with increased risk of mortality were ( P < 0.0005 unless stated) HIV coinfection; diagnosis of drug use ( P = 0.001); coronary artery disease ( P = 0.006); stroke; diabetes as the primary cause for renal failure; peripheral vascular disease; depression and presence of anaemia. HCV was associated with higher risk of death in patients on dialysis, even after adjusting for concurrent comorbidities. The risk was highest at the time of HCV diagnosis and stabilized over time. Clinical trials of HCV screening and treatment to reduce mortality in this population are warranted. [ABSTRACT FROM AUTHOR]

Purpose: Previous studies suggest the association of recipient hepatitis C seropositivity (HCV+) and use of tacrolimus (TAC) with post-transplant diabetes mellitus (PTDM) may differ by manifestations of type I or type II diabetes, but this has not been assessed in the era of current immunosuppression. Methods: We performed a retrospective cohort study of 10,342 Medicare primary renal transplantation recipients without evidence of diabetes at the time of listing in the United States Renal Data System between January 1, 1998 and July 31, 2000, followed until December 31, 2000. Outcomes were hospitalizations for a primary diagnosis of diabetic ketoacidosis (DKA) or hyperglycemic hyperosmolar syndrome (HHS). Cox regression analysis was used to calculate adjusted hazard ratios (AHR) for time to DKA or HHS, stratified by diabetes status at the time of transplant. Results: In Cox regression analysis, use of TAC at discharge was independently associated with shorter time to DKA (AHR, 1.88; 95% CI, 1.05–3.37, p =0.034) but not HHS. In contrast, recipient HCV+ was independently associated with shorter time to HHS (AHR, 3.90; 1.59–9.60, p =.003), but not DKA. There was no interaction between TAC and HCV+ for either outcome. Conclusion: These results confirm earlier findings that TAC and HCV+ may mediate the risk of PTDM through different mechanisms, even in the modern era. [Copyright &y& Elsevier]

Objective: To examine the outcomes of geriatric ESRD patients selected for kidney transplantation. Design: Data were extracted from the USRDS Standard Analysis Files (SAF). All persons ages 75 and over who received a kidney transplant from 1994 to 2000 were compared with those remaining on dialysis or on a transplant waiting list. Data on mortality or removal from the waiting list were obtained from the United Network for Organ Sharing (UNOS). The main outcome measure was patient and kidney transplant survival. Results: Superior five year survival after kidney transplantation was attained by the geriatric cohort given a live donor transplant (59.9%), compared with recipients of deceased donor kidneys (40.3%), dialysis patients waiting for transplant (29.7%), and those who were not selected for kidney transplantation and remained on dialysis (12.5%). The likelihood of being removed from the waiting list for any reason was higher in this group (over 75) (30.3%) than in the 66–75 age group (26.8%). Their average annual mortality rate on the waiting list was 7.9, compared to 6.6% for those 66–75. Conclusion: Even after the age of 75 years, kidney transplantation provides substantial life prolongation and excellent graft survival. [ABSTRACT FROM AUTHOR]

Epidemic of end-stage renal disease in people with diabetes in the United States population: Do we know the cause? Background. The number of individuals initiating renal replacement therapy in the United States population grew exponentially over the past two decades. Cases of end-stage renal diseae (ESRD) attributed to diabetes accounted for most of this increase. In this report we examined factors that may account for the increase to determine whether it truly represents an epidemic of ESRD due to diabetes. Methods. We reviewed time trends in data of the United States Renal Data system, the Diabetes Surveillance Program of the Centers for Disease Control and Prevention, and diabetes literature. Results. Recent growth of the number of individuals with diabetes accounted for less than 10% of the increase in the number of diabetes-related ESRD. Instead, most of it was due to a threefold increase in risk of ESRD in people with diabetes and, therefore, qualifies as an epidemic. Curiously, this epidemic occurred despite widening implementation of effective renoprotective therapies. Individuals with type 2 diabetes, regardless of gender, age, or race, experienced the greatest increase in risk. There is no evidence that diabetic patients have been surviving longer, so the increased risk was not attributable to the high risk associated with long duration diabetes. Conclusion. We hypothesize that an epidemic of ESRD has occurred in people with diabetes in the United States population over the last two decades. The nature of the factor responsible for the epidemic and the reasons it affects patients with type 2 diabetes particularly are unknown. Research efforts to identify the putative factor deserve high priority, as does a commitment of resources to provide care for the burgeoning number of patients with ESRD and type 2 diabetes. [ABSTRACT FROM AUTHOR]

Renal cell carcinoma as a cause of end-stage renal disease in the United States: Patient characteristics and survival. Background. The patient characteristics and mortality associated with renal cell carcinoma (RCC) as a cause of end-stage renal disease (ESRD) have not been characterized for a national population. Methods. An historical cohort study of renal cell carcinoma (RCC) was conducted from April 1, 1995, to December 31, 1999. Included were 360,651 patients in the United States Renal Data System (USRDS) who were initiated on ESRD therapy with valid causes of ESRD. Results. Of the study population, 1646 patients (0.5%) had RCC. The mean age of patients with RCC was 66.8 ± 14.6 years versus 61.3 ± 16.4 years for patients with other causes of ESRD (P < 0.01 by Student t test). The unadjusted 3-year survival (censored at the date of renal transplantation) of patients with RCC during the study period was 23% versus 36% in all other patients [adjusted hazard ratio (AHR), 1.10, 95% confidence interval (CI) 1.02–1.19, P = 0.019 by Cox regression]. However, patients with RCC who underwent nephrectomy (bilateral or unilateral) had significantly better survival compared to RCC patients who did not (AHR, 0.73, 95% CI, 0.63–0.85, P < 0.01), and their survival was not significantly different in comparison with nondiabetic ESRD patients. Bilateral nephrectomy (vs. unilateral) was not associated with any difference in adjusted mortality. Conclusion. Among patients with ESRD, the demographics of those with RCC were similar to those of patients with RCC in the general population. Overall, patients with RCC had decreased survival compared to patients with other causes of ESRD; those who underwent nephrectomy had significantly better survival than those who did not, with survival comparable to patients with nondiabetic ESRD. [ABSTRACT FROM AUTHOR]

PURPOSE: In contrast to its role in the general population, obesity, defined as body mass index (BMI) &ges; 30 kg/m2, has been associated with improved survival in patients with end stage renal disease (ESRD). This apparent benefit has not been explained.METHODS: Using the United States Renal Data System (USRDS), we performed an historical cohort study on 151,027 patients initiated on ESRD therapy between January 1, 1995 and June 30, 1997, who never received renal transplants, and who had information sufficient to calculate BMI. We explored the association of various comorbidities present at the time of dialysis initiation (from HCFA Form 2728) with the presence of obesity by logistic regression, and the association of obesity with patient survival, including specific causes of death, by Cox regression adjusting for factors known to be associated with survival in this population.RESULTS: Obese patients had an unadjusted two-year survival of 68% compared with 58% for non obese patients. Obesity was independently associated with a reduced risk of mortality among chronic dialysis patients (adjusted hazard ratio (AHR) 0.75, 95% confidence interval, 0.72–0.78), after controlling for all comorbidities and risk factors. However, there were significantly adverse interactions among whites (AHR 1.22, 1.14–1.30, across all causes of death) and females (AHR 1.12, 1.04–1.20, entirely due to an increased risk of infectious death).CONCLUSIONS: Obesity in patients presenting with ESRD is associated independently with reduced all cause mortality; however, the relationship is complex and is stronger in African Americans. In addition, subgroup analysis suggests that obesity is associated with increased risk of infectious death in females. [Copyright &y& Elsevier]