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Peritoneal dialysis (PD)-related peritonitis carries high morbidity for PD patients. Understanding the characteristics and risk factors for peritonitis can guide regional development of prevention strategies. We describe peritonitis rates and the associations of selected facility practices with peritonitis risk among countries participating in the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS).Observational prospective cohort study.7,051 adult PD patients in 209 facilities across 7 countries (Australia, New Zealand, Canada, Japan, Thailand, United Kingdom, United States).Facility characteristics (census count, facility age, nurse to patient ratio) and selected facility practices (use of automated PD, use of icodextrin or biocompatible PD solutions, antibiotic prophylaxis strategies, duration of PD training).Peritonitis rate (by country, overall and variation across facilities), microbiology patterns.Poisson rate estimation, proportional rate models adjusted for selected patient case-mix variables.2,272 peritonitis episodes were identified in 7,051 patients (crude rate, 0.28 episodes/patient-year). Facility peritonitis rates were variable within each country and exceeded 0.50/patient-year in 10% of facilities. Overall peritonitis rates, in episodes per patient-year, were 0.40 (95% CI, 0.36-0.46) in Thailand, 0.38 (95% CI, 0.32-0.46) in the United Kingdom, 0.35 (95% CI, 0.30-0.40) in Australia/New Zealand, 0.29 (95% CI, 0.26-0.32) in Canada, 0.27 (95% CI, 0.25-0.30) in Japan, and 0.26 (95% CI, 0.24-0.27) in the United States. The microbiology of peritonitis was similar across countries, except in Thailand, where Gram-negative infections and culture-negative peritonitis were more common. Facility size was positively associated with risk for peritonitis in Japan (rate ratio [RR] per 10 patients, 1.07; 95% CI, 1.04-1.09). Lower peritonitis risk was observed in facilities that had higher automated PD use (RR per 10 percentage points greater, 0.95; 95% CI, 0.91-1.00), facilities that used antibiotics at catheter insertion (RR, 0.83; 95% CI, 0.69-0.99), and facilities with PD training duration of 6 or more (vs 6) days (RR, 0.81; 95% CI, 0.68-0.96). Lower peritonitis risk was seen in facilities that used topical exit-site mupirocin or aminoglycoside ointment, but this association did not achieve conventional levels of statistical significance (RR, 0.79; 95% CI, 0.62-1.01).Sampling variation, selection bias (rate estimates), and residual confounding (associations).Important international differences exist in the risk for peritonitis that may result from varied and potentially modifiable treatment practices. These findings may inform future guidelines in potentially setting lower maximally acceptable peritonitis rates.

In the US DPM sample, median PTH levels increased 32%, from August 2010 through April 2011 and have remained relatively stable since then. Black patients carry a disproportionate burden of PTH levels above 600 pg/ml (29%; vs. 17% among nonblacks). This finding warrants particular attention, since such high PTH levels have consistently been associated with adverse outcomes6–14 and the association between severe hyperparathyroidism and mortality appeared consistent in both racial groups. While we had postulated that the PPS may have led to lower utilization of MBD-related intravenous drugs, vitamin D prescription remained stable over time. Rather, the increase in PTH levels seem to have been driven mainly by adoption of more liberal PTH targets, as reported in the medical director survey. However, PTH levels >600 are above any currently recommended guidelines and likely represent a modifiable risk factor for adverse outcomes. Clinicians should take this into account especially when treating black patients, since nearly a third of them presented such high levels in the US DOPPS sample.

Background Since the bundled end-stage renal disease prospective payment system began in 2011 in the United States, some hemodialysis practices have changed substantially, raising the question of whether vascular access practice also has changed. We describe monthly US vascular access use from August 2010 to August 2013 with international comparisons, and other aspects of US vascular access practice. Study Design Prospective observational cohort study of vascular access. Setting & Participants Maintenance hemodialysis patients in the Dialysis Outcomes and Practice Patterns Study (DOPPS) Practice Monitor (DPM) in the United States (N=3,442; US patients) and 19 other nations (N=8,478). Predictors Country, patient demographics, time period. Outcomes Vascular access use, pre–end-stage renal disease access timing of first nephrologist care and arteriovenous access placement, patient self-reported vascular access preferences (United States only), treatment practices as stated by medical directors. Results In the United States from August 2010 to August 2013, arteriovenous fistula (AVF) use increased from 63% to 68%, while catheter use declined from 19% to 15%. Although AVF use did not differ greatly across age groups, arteriovenous graft use was 2-fold higher among black (26%) versus nonblack US patients (13%) in 2013. Across 20 countries in 2013, AVF use ranged from 49% to 92%, whereas catheter use ranged from 1% to 45%. Patient-reported vascular access preferences differed by sex and race, with 16% to 20% of patients feeling uninformed regarding benefits/risks of different vascular access types. Among new (incident) US hemodialysis patients, AVF use remains low, with ∼70% initiating hemodialysis therapy with a catheter (60% starting with catheter when having ≥4 months of predialysis nephrology care). In the United States, longer typical times to first AVF cannulation were reported. Limitations Noncompletion of surveys may affect the generalizability of findings to the wider hemodialysis population. Conclusions AVF use has increased, with catheter use decreasing among prevalent US hemodialysis patients since the introduction of the prospective payment system. However, AVF use at dialysis therapy initiation remains low, suggesting that reforms affecting predialysis care may be necessary to incentivize improvements in fistula rates at dialysis therapy initiation as achieved for prevalent hemodialysis patients.

Background Most hemodialysis patients worldwide are treated with bicarbonate dialysis using sodium bicarbonate as the base. Few studies have assessed outcomes of patients treated with different dialysate bicarbonate levels, and the optimal concentration remains uncertain. Study Design The Dialysis Outcomes and Practice Patterns Study (DOPPS) is an international prospective cohort study. Setting & Participants This study included 17,031 patients receiving thrice-weekly in-center hemodialysis from 11 DOPPS countries (2002-2011). Predictor Dialysate bicarbonate concentration. Outcomes All-cause and cause-specific mortality and first hospitalization, using Cox regression to estimate the effects of dialysate bicarbonate concentration, adjusting for potential confounders. Measurements Demographics, comorbid conditions, laboratory values, and prescriptions were abstracted from medical records. Results Mean dialysate bicarbonate concentration was 35.5 ± 2.7 (SD) mEq/L, ranging from 32.2 ± 2.3 mEq/L in Germany to 37.0 ± 2.6 mEq/L in the United States. Prescription of high dialysate bicarbonate concentration (≥38 mEq/L) was most common in the United States (45% of patients). Approximately 50% of DOPPS facilities used a single dialysate bicarbonate concentration. 3,913 patients (23%) died during follow-up. Dialysate bicarbonate concentration was associated positively with mortality (adjusted HR, 1.08 per 4 mEq/L higher [95% CI, 1.01-1.15]; HR for dialysate bicarbonate ≥38 vs 33-37 mEq/L, 1.07 [95% CI, 0.97-1.19]). Results were consistent across levels of pre–dialysis session serum bicarbonate and between facilities that used a single dialysate bicarbonate concentration and those that prescribed different concentrations to individual patients. The association of dialysis bicarbonate concentration with mortality was stronger in patients with longer dialysis vintage. Limitations Due to the observational nature of the present study, we cannot rule out that the reported associations may be biased by unmeasured confounders. Conclusions High dialysate bicarbonate concentrations, especially prolonged exposure, may contribute to adverse outcomes, likely through the development of postdialysis metabolic alkalosis. Additional studies are warranted to identify the optimal dialysate bicarbonate concentration.

Background Sudden death is a leading cause of death in patients on maintenance hemodialysis therapy. During hemodialysis sessions, the gradient between serum and dialysate levels results in rapid electrolyte shifts, which may contribute to arrhythmias and sudden death. Controversies exist about the optimal electrolyte concentration in the dialysate; specifically, it is unclear whether patient outcomes differ among those treated with a dialysate potassium concentration of 3 mEq/L compared to 2 mEq/L. Study Design Prospective cohort study. Setting & Participants 55,183 patients from 20 countries in the Dialysis Outcomes and Practice Patterns Study (DOPPS) phases 1 to 5 (1996-2015). Predictor Dialysate potassium concentration at study entry. Outcomes Cox regression was used to estimate the association between dialysate potassium concentration and both all-cause mortality and an arrhythmia composite outcome (arrhythmia-related hospitalization or sudden death), adjusting for potential confounders. Results During a median follow-up of 16.5 months, 24% of patients died and 7% had an arrhythmia composite outcome. No meaningful difference in clinical outcomes was observed for patients treated with a dialysate potassium concentration of 3 versus 2 mEq/L (adjusted HRs were 0.96 [95% CI, 0.91-1.01] for mortality and 0.98 [95% CI, 0.88-1.08] for arrhythmia composite). Results were similar across predialysis serum potassium levels. As in prior studies, higher serum potassium level was associated with adverse outcomes. However, dialysate potassium concentration had only minimal impact on serum potassium level measured predialysis (+0.09 [95% CI, 0.05-0.14] mEq/L serum potassium per 1 mEq/L greater dialysate potassium concentration). Limitations Data were not available for delivered (vs prescribed) dialysate potassium concentration and postdialysis serum potassium level; possible unmeasured confounding. Conclusions In combination, these results suggest that approaches other than altering dialysate potassium concentration (eg, education on dietary potassium sources and prescription of potassium-binding medications) may merit further attention to reduce risks associated with high serum potassium levels.

BackgroundHigh interdialytic weight gain (IDWG) is associated with adverse outcomes in hemodialysis (HD) patients. We identified temporal and regional trends in IDWG, predictors of IDWG, and associations of IDWG with clinical outcomes.Study DesignAnalysis 1: sequential cross-sections to identify facility- and patient-level predictors of IDWG and their temporal trends. Analysis 2: prospective cohort study to assess associations between IDWG and mortality and hospitalization risk.Setting & Participants21,919 participants on HD therapy for 1 year or longer in the Dialysis Outcomes and Practice Patterns Study (DOPPS) phases 2 to 5 (2002-2014).PredictorsAnalysis 1: study phase, patient demographics and comorbid conditions, HD facility practices. Analysis 2: relative IDWG, expressed as percentage of post-HD weight (

More than 380,000 people receive maintenance dialysis for the treatment of end-stage kidney failure in the United States. In 2008, Medicare expenditures for dialysis patients totaled $22 billion, or 4.8% of the total Medicare budget. The new endstage renal disease prospective payment system (PPS), a program begun by the US Centers for Medicare & Medicaid Services in January 2011, is intended to control dialysis costs through bundled payments (that is, fewer dialysis-related medications and services are now separately billable). The Quality Incentive Program, beginning in 2012 with the evaluation of dialysis unit clinical data collected in 2010, is the first Medicare program that ties provider or facility payments to performance, as defined by meeting particular quality measures. The Dialysis Outcomes and Practice Patterns Study (DOPPS) Practice Monitor (DPM) is an initiative of the DOPPS. It is based on a national sample of US hemodialysis patients that provides the first nationally representative data, publicly available on the DPM website, to report trends in dialysis care from before to after implementation of this new bundled PPS. DPM reports comprise more than 800 regularly updated charts, figures, and data tables that can be viewed at the DPM website (www.dopps.org/DPM). The DPM sample provides comparisons and trends over time for the United States as a whole and examines patient subgroups and facility types. An article describing DPM methods has been published recently. In this first overview of DPM findings for AJKD, which covers data through April 2011, we summarize preliminary trends overall and additionally focus on specific patient groups. Data reflect an average of 3,502 hemodialysis patients in 93 facilities per month and are weighted estimates based on the full study sample; generally comparable trends have been found when restricted to facilities participating at all times, when the data are not weighted, and under a variety of other assumptions.

Background Poor nutritional status and both hyper- and hypophosphatemia are associated with increased mortality in maintenance hemodialysis (HD) patients. We assessed associations of phosphate binder prescription with survival and indicators of nutritional status in maintenance HD patients. Study Design Prospective cohort study (DOPPS [Dialysis Outcomes and Practice Patterns Study]), 1996-2008. Setting & Participants 23,898 maintenance HD patients at 923 facilities in 12 countries. Predictors Patient-level phosphate binder prescription and case-mix–adjusted facility percentage of phosphate binder prescription using an instrumental-variable analysis. Outcome All-cause mortality. Results Overall, 88% of patients were prescribed phosphate binders. Distributions of age, comorbid conditions, and other characteristics showed small differences between facilities with higher and lower percentages of phosphate binder prescription. Patient-level phosphate binder prescription was associated strongly at baseline with indicators of better nutrition, ie, higher values for serum creatinine, albumin, normalized protein catabolic rate, and body mass index and absence of cachectic appearance. Overall, patients prescribed phosphate binders had 25% lower mortality (HR, 0.75; 95% CI, 0.68-0.83) when adjusted for serum phosphorus level and other covariates; further adjustment for nutritional indicators attenuated this association (HR, 0.88; 95% CI, 0.80-0.97). However, this inverse association was observed for only patients with serum phosphorus levels ≥3.5 mg/dL. In the instrumental-variable analysis, case-mix–adjusted facility percentage of phosphate binder prescription (range, 23%-100%) was associated positively with better nutritional status and inversely with mortality (HR for 10% more phosphate binders, 0.93; 95% CI, 0.89-0.96). Further adjustment for nutritional indicators reduced this association to an HR of 0.95 (95% CI, 0.92-0.99). Limitations Results were based on phosphate binder prescription; phosphate binder and nutritional data were cross-sectional; dietary restriction was not assessed; observational design limits causal inference due to possible residual confounding. Conclusions Longer survival and better nutritional status were observed for maintenance HD patients prescribed phosphate binders and in facilities with a greater percentage of phosphate binder prescription. Understanding the mechanisms for explaining this effect and ruling out possible residual confounding require additional research.

Predialysis serum sodium concentrations recently have been linked to patient characteristics and outcomes in hemodialysis patients and may have implications for the dialysate sodium prescription.Prospective cohort study.11,555 patients from 12 countries in the Dialysis Outcomes and Practice Patterns Study (DOPPS), phases I (1996-2001) and III (2005-2008).Demographics, comorbid conditions, laboratory measurements (model 1); mean serum sodium level, dialysate sodium concentration (model 2).Serum sodium level, using adjusted linear mixed models (model 1); all-cause mortality, using Cox proportional hazards models (model 2).Median follow-up was 12 months, with 1,727 deaths (15%) occurring during the study period (12,274 patient-years). Mean serum sodium level in the DOPPS countries was 138.5 ± 2.8 mEq/L. Japan had the highest (139.1 ± 2.6 mEq/L) and Australia/New Zealand had the lowest mean serum sodium level (137.4 ± 2.8 mEq/L). Serum sodium level was associated positively with male sex, black race, body mass index, serum albumin level, and creatinine level and negatively with neurologic and psychiatric disease, white blood cell count, and intradialytic weight loss (0.16 mEq/L lower per 1% loss). Higher serum sodium level was associated with lower adjusted all-cause mortality in a continuous model (HR, 0.95 per 1 mEq/L higher; 95% CI, 0.93-0.97). Dialysate sodium prescription was not associated with serum sodium level. Mortality analyses restricted to the serum sodium tertile with the highest mortality (serum sodium137 mEq/L) showed lower mortality risk in patients with dialysate sodium prescriptions140 mEq/L.Causality cannot be established in this observational study, which does not consider potential effects of dialysate sodium level on postdialysis thirst, dietary salt and water intake, interdialytic weight gain, and cardiovascular stability.Lower serum sodium levels are associated with certain hemodialysis patient characteristics and higher adjusted risk of death. The lower mortality observed in our adjusted analyses in patients with serum sodium levels137 mEq/L dialyzed against dialysate sodium prescriptions140 mEq/L is intriguing, may be related to intradialytic cardiovascular stability, and deserves further study.

Background Hemodialysis patients with larger hemoglobin level fluctuations have higher mortality rates. We describe facility-level interpatient hemoglobin variability, its relation to patient mortality, and factors associated with facility-level hemoglobin variability or achieving hemoglobin levels of 10.5-12.0 g/dL. Facility-level hemoglobin variability may reflect within-patient hemoglobin variability and facility-level anemia-control practices. Study Design Prospective cohort study. Setting & Participants Data from the Dialysis Outcomes and Practice Patterns Study (DOPPS; 26,510 hemodialysis patients, 930 facilities, 12 countries, 1996-2008) and from the Centers for Medicare & Medicaid Services (CMS; 193,291 hemodialysis patients, 3,741 US facilities, 2002). Predictors Standard deviation (SD) in single-measurement hemoglobin levels in hemodialysis patients in facility cross-sections (facility-level hemoglobin SD); patient characteristics; facility practices. Outcomes Patient-level mortality; additionally, facility practices correlated with facility-level hemoglobin SD or patient hemoglobin levels of 10.5-12.0 g/dL. Results Facility-level hemoglobin SD varied more than 5-fold across DOPPS facilities (range, 0.5-2.7 g/dL; mean, 1.3 g/dL) and by country (range, 1.1 in Japan-DOPPS [2005/2006] to 1.7 g/dL in Spain-DOPPS [1998/1999]), with substantial decreases seen in many countries from 1998 to 2007. Facility-level hemoglobin SD was related inversely to patient age, but was associated minimally with more than 30 other patient characteristics and facility mean hemoglobin levels. Several anemia management practices were associated strongly with facility-level hemoglobin SD and having a hemoglobin level of 10.5-12.0 g/dL. When examined in CMS data, facility-level hemoglobin SD was positively associated with within-patient hemoglobin SD during the prior 6 months. Patient mortality rates were higher with greater facility-level hemoglobin SD (DOPPS: HR, 1.08 per 0.5-g/dL greater facility-level hemoglobin SD [95% CI, 1.02-1.15; P = 0.006]; CMS: HR, 1.16 per 0.5-g/dL greater facility-level hemoglobin SD [95% CI, 1.11-1.21; P Limitations Residual confounding. Conclusions Facility-level hemoglobin SD was associated strongly and positively with patient mortality, not tightly linked to numerous patient characteristics, but related strongly to facility anemia management practices. Facility-level hemoglobin variability may be modifiable and its optimization may improve hemodialysis patient survival.