Medical Director Practice of Advising Increased Dietary Protein Intake in Hemodialysis Patients With Hyperphosphatemia: Associations With Mortality in the Dialysis Outcomes and Practice Patterns Study.

OBJECTIVES: Patients undergoing hemodialysis (HD) may have poor nutritional status and hyperphosphatemia. Nephrologists sometimes manage hyperphosphatemia by prescribing phosphate binders and/or recommending restriction of dietary phosphate including protein-rich foods; the later may, however, adversely affect nutritional status. DESIGN AND METHODS: The analysis includes 8805 HD patients on dialysis ≥ 120 days in 12 countries in Dialysis Outcomes and Practice Patterns Study (DOPPS) phase 4 (2009-2011), from 248 facilities. The primary exposure variable was response to the following question: "For patients with serum albumin 3.0 g/dL and phosphate 6.0 mg/dL, do you recommend to (A) increase or (B) decrease/no change in dietary protein intake (DPI)?". The association between medical director's practice of recommending an increase in DPI and all-cause mortality was analyzed with Cox regression adjusted for potential confounders. Linear and logistic regressions were used to model the cross-sectional associations between DPI advice practice and intermediate markers of patient nutrition. RESULTS: Median follow-up was 1.6 years. In the case scenario, 91% of medical directors in North America had a practice of recommending DPI increase compared to 58% in Europe (range = 36%-83% across 7 countries) and 56% in Japan. The practice of advising DPI increase was weakly associated with lower mortality [HR (95% CI): 0.88 (0.76-1.02)]. The association tended to be stronger in patients with age 70+ years [HR (95% CI): 0.82 (0.69-0.97), P = .12 for interaction]. The practice of advising DPI increase was associated with 0.276 mg/dL higher serum creatinine levels (95% CI: 0.033-0.520) after adjustment for case mix. CONCLUSIONS: Medical director's practice of recommending an increase in DPI for HD patients with low albumin and high phosphate levels was associated with higher serum creatinine levels and potentially lower all-cause mortality. To recommend protein intake liberalization in parallel with phosphate management by physicians may be a critical practice for better nutritional status and outcomes in HD patients.

Fibroblast Growth Factor 23 and Mortality Among Prevalent Hemodialysis Patients in the Japan Dialysis Outcomes and Practice Patterns Study.

INTRODUCTION: Elevated fibroblast growth factor 23 (FGF23) levels have been strongly associated with mortality in the predialysis and incident hemodialysis populations, but few studies have examined this relationship in a large cohort of prevalent hemodialysis patients and in particular among persons with high dialysis vintage. To address this, we analyzed data from the Japan Dialysis Outcomes and Practice Patterns Study (J-DOPPS). METHODS: We included 1122 prevalent hemodialysis patients from the J-DOPPS phase 5 (2012-2015) who had FGF23 measurements. We evaluated the association of FGF23 levels with all-cause mortality and cardiovascular composite outcome using Cox regression adjusted for potential confounders. RESULTS: At study enrollment, median dialysis vintage was 5.8 years (interquartile range, 2.7-12.4 years) and median FGF23 level was 2113 pg/ml (interquartile range, 583-6880 pg/ml). During 3-year follow-up, 154 of the 1122 participants died. In adjusted analyses, higher FGF23 was associated with a greater hazard of death (hazard ratio per doubling of FGF23, 1.12; 95% confidence interval, 1.03-1.21); however, the association became weaker as the dialysis vintage increased and finally disappeared in the highest tertile (>9.4 years). Similar patterns of effect modification by dialysis vintage were observed for cardiovascular composite outcome and in time-dependent models. CONCLUSION: Elevated FGF23 was associated with mortality and cardiovascular events in prevalent hemodialysis patients, but the association was attenuated at longer dialysis vintages. This novel finding suggests that long-term hemodialysis patients may be less susceptible to the detrimental effects of FGF23 or correlated biological processes, and additional studies are needed to gain understanding of these possibilities.

Estimating the Fraction of First-Year Hemodialysis Deaths Attributable to Potentially Modifiable Risk Factors: Results from the DOPPS.

PURPOSE: Mortality among first-year hemodialysis (HD) patients remains unacceptably high. To address this problem, we estimate the proportions of early HD deaths that are potentially preventable by modifying known risk factors. METHODS: We included 15,891 HD patients (within 60 days of starting HD) from 21 countries in the Dialysis Outcomes and Practice Patterns Study (1996-2015), a prospective cohort study. Using Cox regression adjusted for potential confounders, we estimated the fraction of first-year deaths attributable to one or more of twelve modifiable risk factors (the population attributable fraction, AF) identified from the published literature by comparing predicted survival based on risk factors observed vs counterfactually set to reference levels. RESULTS: The highest AFs were for catheter use (22%), albumin <3.5 g/dL (19%), and creatinine <6 mg/dL (12%). AFs were 5%-9% for no pre-HD nephrology care, no residual urine volume, systolic blood pressure <130 or ≥160 mm Hg, phosphorus <3.5 or ≥5.5 mg/dL, hemoglobin <10 or ≥12 g/dL, and white blood cell count >10,000/µL. AFs for ferritin, calcium, and PTH were <3%. Overall, 65% (95% CI: 59%-71%) of deaths were attributable to these 12 risk factors. Additionally, the AF for C-reactive protein >10 mg/L was 21% in facilities where it was routinely measured. CONCLUSION: A substantial proportion of first-year HD deaths could be prevented by successfully modifying a few risk factors. Highest priorities should be decreasing catheter use and limiting malnutrition/inflammation whenever possible.

Peritoneal Dialysis-Related Infection Rates and Outcomes: Results From the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS).

RATIONALE & OBJECTIVE: 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). STUDY DESIGN: Observational prospective cohort study. SETTING & PARTICIPANTS: 7,051 adult PD patients in 209 facilities across 7 countries (Australia, New Zealand, Canada, Japan, Thailand, United Kingdom, United States). EXPOSURES: 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). OUTCOMES: Peritonitis rate (by country, overall and variation across facilities), microbiology patterns. ANALYTICAL APPROACH: Poisson rate estimation, proportional rate models adjusted for selected patient case-mix variables. RESULTS: 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). LIMITATIONS: Sampling variation, selection bias (rate estimates), and residual confounding (associations). CONCLUSIONS: 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.

Mineral and bone disorder and management in the China Dialysis Outcomes and Practice Patterns Study.

BACKGROUND: Despite a growing population of patients starting hemodialysis in China, little is known about markers of mineral bone disease (MBD) and their management. We present data on prevalence and correlates of hypocalcemia, hyperphosphatemia, and secondary hyperparathyroidism from the China Dialysis Outcomes and Practice Patterns Study (DOPPS), with evaluation of whether these laboratory markers triggered changes in management. METHODS: We compared the frequency of measurement and prevalence of poor control of MBD markers in China DOPPS with other DOPPS regions. We also used generalized estimating equations to assess correlates of MBD markers, and separate models to assess predictors of vitamin D and phosphate binder prescriptions in the China DOPPS. RESULTS: Severe hyperphosphatemia (>7 mg/dL) and secondary hyperparathyroidism (>600 pg/mL) were common (27% and 21% prevalence, respectively); both were measured infrequently (14.9% and 3.2% of patients received monthly measurements in China). Frequency of dialysis sessions was positively associated with hyperphosphatemia; presence of residual kidney function was negatively associated with both hyperphosphatemia and secondary hyperparathyroidism. Laboratory measures indicating poor control of MBD were not associated with subsequent prescription of active vitamin D or phosphate binder. CONCLUSIONS: There are substantial opportunities for improvement and standardization of MBD management in China. Development of country-specific guidelines may yield realistic targets and standardization of medication use accounting for availability and cost.

Cardiovascular Event Rates Among Hemodialysis Patients Across Geographical Regions-A Snapshot From The Dialysis Outcomes and Practice Patterns Study (DOPPS).

INTRODUCTION: Cardiovascular (CV) morbidity and mortality are excessively high among hemodialysis (HD) patients. Anemia is a common complication of chronic kidney disease (CKD) and a known risk factor for CV events. To understand the impact of the recent regulatory and guideline changes in anemia management, we examined regional CV event rates in high-risk and erythropoiesis-stimulating agent (ESA)-hyporesponsive HD patients. METHODS: A prospective cohort study including 16,560 HD patients, 8660 CV high-risk, and 884 hyporesponsive to ESAs, from the Dialysis Outcomes and Practice Patterns Study (DOPPS) phase 4 (2009-2011) and phase 5 (2012-2015) was conducted to quantify all-cause mortality, major adverse cardiovascular events (MACE), and MACE plus heart failure and thromboembolic events (MACE+). RESULTS: The MACE+ rates (per 100 patient-years) were highest in North America (NA) (19.4; 95% CI = 18.2-20.7), followed by Europe (EU) (17.4; 95% CI = 16.6-18.1) and lowest in Japan (7.5; 95% CI = 6.9-8.1). When restricted to the high CV risk population, rates increased by 36% in NA, 45% in EU, and 72% in Japan. Mortality accounted for >74% of MACE+ events. MACE+ rates in ESA-hyporesponsive patients and high CV risk patients were similar in NA and EU cohorts. There were minimal differences in outcomes between the DOPPS phases 4 and 5. CONCLUSION: Cardiovascular event rates are high in the HD population, vary by geographic region, and are substantially higher in high CV risk patients and ESA-hyporesponsive patients; however, the rates appear not to be affected by anemia guideline changes. The findings from this study will be essential to contextualize the design of future CV anemia-related outcome studies and clinical trials.

Pruritus and Patient Reported Outcomes in Non-Dialysis CKD.

BACKGROUND AND OBJECTIVES: Among patients on hemodialysis, pruritus has been associated with poorer mental and physical quality of life, sleep quality, depression, and mortality. We evaluated patients with nondialysis CKD to describe the prevalence of pruritus, identify associated factors, and investigate associations with patient-reported outcomes. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Using cross-sectional data from patient questionnaires in the CKD Outcomes and Practice Patterns Study (CKDopps), we asked patients with CKD stages 3-5 (nondialysis) from the United States, Brazil, and France to identify how much they were bothered by pruritus. Response options ranged from "not at all" to "extremely." Log-Poisson regression, yielding prevalence ratios, was used to evaluate associations of moderate-to-extreme pruritus with patient characteristics, CKD stage, self-reported depression symptoms, and restless sleep. Mixed linear regression was used to examine associations between pruritus and physical and mental component summary scores, with lower scores indicating poorer quality of life. RESULTS: Of the 5658 CKDopps patients enrolled in the United States, Brazil, and France, 3780 (67%) answered the pruritus question. The prevalence of moderate-to-extreme pruritus was 24%, and more likely in older patients, women, and those with stage 5 CKD, lung disease, diabetes, and physician-diagnosed depression. In adjusted models, patients with moderate pruritus had physical and mental component summary scores 3.5 (95% confidence interval [95% CI], -4.6 to -2.3) and 2.3 (95% CI, -3.2 to -1.5) points lower, respectively, than patients without pruritus, and they also had a higher adjusted prevalence of patient-reported depression (prevalence ratio, 1.83; 95% CI, 1.58 to 2.11) and restless sleep (prevalence ratio, 1.69; 95% CI, 1.49 to 1.91) compared with patients without pruritus. These patient-reported outcomes were progressively worse with increasing severity of pruritus. CONCLUSIONS: Our findings demonstrate high prevalence of pruritus in nondialysis CKD, as well as strong associations of pruritus with poor health-related quality of life, self-reported depression symptoms, and self-reported poor sleep.

Prevalence, incidence, and risk factors for hepatitis C virus infection in hemodialysis patients.

Hepatitis C virus (HCV) infection is common in dialysis patients and is associated with increased morbidity and mortality. We used the Dialysis Outcomes and Practice Patterns Study (DOPPS, 1996-2015) to assess trends in the prevalence, incidence, and risk factors for HCV infection as defined by a documented diagnosis or antibody positivity. Among prevalent hemodialysis patients, HCV prevalence was nearly 10% in 2012-2015. Prevalence ranged from 4% in Belgium to as high as 20% in the Middle East, with intermediate prevalence in China, Japan, Italy, Spain, and Russia. HCV prevalence decreased over time in most countries participating in more than one phase of DOPPS, and prevalence was around 5% among patients who had recently (<4 months) initiated dialysis. The incidence of HCV infection decreased from 2.9 to 1.2 per 100 patient-years in countries participating in the initial phase of DOPPS. Although most units reported no seroconversions, 10% of units experienced 3 or more cases over a median of 1.1 years. High HCV prevalence in the hemodialysis unit was a powerful facility-level risk factor for seroconversion, but the use of isolation stations for HCV-positive patients was not associated with significantly lower seroconversion rates. Overall, despite a trend toward lower HCV prevalence among hemodialysis patients, the prevalence of HCV infection remains higher than in the general population. Combined with a high prevalence of HCV infection among patients with Stage 5 CKD, high rates of HCV seroconversion in a subset of hemodialysis units may contribute to this disparity.

The Association of Functional Status with Mortality and Dialysis Modality Change: Results from the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS).

BACKGROUND: Little is known about the prevalence of functional impairment in peritoneal dialysis (PD) patients, its variation by country, and its association with mortality or transfer to hemodialysis. METHODS: A prospective cohort study was conducted in PD patients from 7 countries in the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) (2014 - 2017). Functional status (FS) was assessed by combining self-reports of 8 instrumental and 5 basic activities of daily living, using the Lawton-Brody and the Katz questionnaires. Summary FS scores, ranging from 1.25 (most dependent) to 13 (independent), were based on the patient's ability to perform each activity with or without assistance. Logistic regression was used to estimate the odds ratio (OR; 95% confidence interval [CI]) of a FS score < 11 comparing each country with the United States (US). Cox regression was used to estimate the hazard ratio (HR; 95% CI) for the effect of a low FS score on mortality and transfer to hemodialysis, adjusting for case mix. RESULTS: Of 2,593 patients with complete data on FS, 48% were fully independent (FS = 13), 32% had a FS score 11 to < 13, 14% had a FS score 8 to < 11, and 6% had a FS score < 8. Relative to the US, low FS scores (< 11; more dependent) were more frequent in Thailand (OR = 10.48, 5.90 - 18.60) and the United Kingdom (UK) (OR = 3.29, 1.77 - 6.08), but similar in other PDOPPS countries. The FS score was inversely and monotonically associated with mortality but not with transfer to hemodialysis; the HR, comparing a FS score < 8 vs 13, was 4.01 (2.44 - 6.61) for mortality and 0.91 (0.58 - 1.43) for transfer to hemodialysis. CONCLUSION: Regional differences in FS scores observed across PDOPPS countries may have been partly due to differences in regional patient selection for PD. Functional impairment was associated with mortality but not with permanent transfer to hemodialysis.