Hepatitis C infection is very rarely treated among hemodialysis patients

BACKGROUND

Hepatitis C virus (HCV) infection is associated with increased mortality among hemodialysis (HD) patients. Guidelines from Kidney Disease: Improving Global Outcomes recommend that infected HD patients awaiting renal transplantation be treated for HCV and that clinicians decide whether to treat other infected patients on a case-by-case basis. We evaluated the extent and outcome of HCV therapy among HD patients.

METHODS

The Dialysis Outcomes and Practice Patterns Study is an observational study; 49,762 HD patients in 12 nations enrolled between 1996 and 2011. We reviewed HCV status, use of interferon or ribavirin, and survival over a median 1.4 years per study phase.

RESULTS

4,735 patients (9.5%) were HCV+. Only 48 (1.0%) of the 4,589 HCV+ patients with prescription data were receiving antiviral medication. Among the subset of 617 HCV+ patients also known to be on a waiting list for renal transplantation, only 3.7% were receiving treatment. After restricting to HCV+ patients with overlapping propensity for antiviral treatment, 4 (9.5%) of 42 treated patients and 638 (21.0%) of 3,037 untreated patients died. The hazard ratio for adjusted mortality comparing treated patients with untreated patients was 0.47 (95% CI, 0.17-1.26).

CONCLUSIONS

HD patients with hepatitis C infection very rarely receive antiviral therapy. Increased intervention might prolong survival for some patients and in particular might improve the prospects for those awaiting renal transplantation.

Mortality, Hospitalization, and Quality of Life among Patients with Hepatitis C Infection on Hemodialysis

BACKGROUND AND OBJECTIVES

Hepatitis C virus (HCV) infection is widely prevalent among patients on hemodialysis (HD), but very rarely treated. The aim of our study is to evaluate the burdens of HCV suffered by patients on HD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Dialysis Outcomes and Practice Patterns Study is an international, prospective, cohort study of patients on HD. We reviewed the HCV status of 76,689 adults enrolled between 1996 and 2015. We compared HCV-positive (HCV+) with HCV-negative (HCV-) patients for risk of mortality, hospitalization, decline in hemoglobin concentration <8.5 g/dl, and red blood cell transfusion. We also compared health-related quality of life scores using the Kidney Disease Quality of Life instrument and the Center for Epidemiologic Studies Short Depression Scale. We adjusted for age, sex, race, years on dialysis, 14 comorbid conditions (including hepatitis B infection), and serum albumin, phosphorus, and creatinine concentrations.

RESULTS

A total of 7.5% of patients were HCV+ at enrollment. Serum concentrations of alanine aminotransferase and aspartate aminotransferase were not markedly elevated in HCV+ patients on HD; the mean concentrations were only 22.6 and 21.8 U/L, respectively. Median follow-up was 1.4 years. Case-mix adjusted hazard ratios (95% confidence intervals) for HCV+ versus HCV- patients were 1.12 (1.05 to 1.20) for all-cause mortality, 5.90 (3.67 to 9.50) for hepatic-related mortality, 1.09 (1.04 to 1.13) for all-cause hospitalization, and 4.40 (3.14 to 6.15) for hepatic-related hospitalization. Quality of life measures indicated significantly worse scores for physical function, pain, vitality, mental health, depression, pruritus, and anorexia among HCV+ patients. The adjusted hazard ratio for transfusion was 1.36 (95% CI, 1.20 to 1.55) and incidence of hemoglobin concentration <8.5 g/dl was 1.12 (95% CI, 1.03 to 1.21). Only 1.5% of HCV+ patients received antiviral medication.

CONCLUSIONS

HCV infection among patients on HD is associated with higher risk of death, hospitalization, and anemic complications, and worse quality of life scores. Internationally, HCV infection is almost never treated in patients on HD. Our data provide a rationale for more frequent treatment of HCV in this population.

C-reactive protein and prediction of 1-year mortality in prevalent hemodialysis patients

BACKGROUND AND OBJECTIVES

Measurement of C-reactive protein (CRP) levels remains uncommon in North America, although it is now routine in many countries. Using Dialysis Outcomes and Practice Patterns Study data, our primary aim was to evaluate the value of CRP for predicting mortality when measured along with other common inflammatory biomarkers.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We studied 5061 prevalent hemodialysis patients from 2005 to 2008 in 140 facilities routinely measuring CRP in 10 countries. The association of CRP with mortality was evaluated using Cox regression. Prediction of 1-year mortality was assessed in logistic regression models with differing adjustment variables.

RESULTS

Median baseline CRP was lower in Japan (1.0 mg/L) than other countries (6.0 mg/L). CRP was positively, monotonically associated with mortality. No threshold below which mortality rate leveled off was identified. In prediction models, CRP performance was comparable with albumin and exceeded ferritin and white blood cell (WBC) count based on measures of model discrimination (c-statistics, net reclassification improvement [NRI]) and global model fit (generalized R(2)). The primary analysis included age, gender, diabetes, catheter use, and the four inflammatory markers (omitting one at a time). Specifying NRI ≥5% as appropriate reclassification of predicted mortality risk, NRI for CRP was 12.8% compared with 10.3% for albumin, 0.8% for ferritin, and <0.1% for WBC.

CONCLUSIONS

These findings demonstrate the value of measuring CRP in addition to standard inflammatory biomarkers to improve mortality prediction in hemodialysis patients. Future studies are indicated to identify interventions that lower CRP and to identify whether they improve clinical outcomes.

Burden of Kidney Disease, Health-Related Quality of Life, and Employment Among Patients Receiving Peritoneal Dialysis and In-Center Hemodialysis: Findings From the DOPPS Program

RATIONALE & OBJECTIVE

Individuals faced with decisions regarding kidney replacement therapy options need information on how dialysis treatments might affect daily activities and quality of life, and what factors might influence the evolution over time of the impact of dialysis on daily activities and quality of life.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

7,771 hemodialysis (HD) and peritoneal dialysis (PD) participants from 6 countries participating in the Peritoneal and Dialysis Outcomes and Practice Patterns Studies (PDOPPS/DOPPS).

PREDICTORS

Patient-reported functional status (based on daily living activities), country, demographic and clinical characteristics, and comorbidities.

OUTCOME

Employment status and patient-reported outcomes (PROs) including Kidney Disease Quality of Life (KDQOL) instrument physical and mental component summary scores (PCS, MCS), kidney disease burden score, and depression symptoms (Center for Epidemiologic Studies Depression Scale [CES-D] score > 10).

ANALYTICAL APPROACH

Linear regression (PCS, MCS, kidney disease burden score), logistic regression (depression symptoms), adjusted for predictors plus 12 additional comorbidities.

RESULTS

In both dialysis modalities, patients in Japan had the highest PCS and employment (55% for HD and 68% for PD), whereas those in the United States had the highest MCS score, lowest kidney disease burden, and lowest employment (20% in HD and 42% in PD). After covariate adjustment, the association of age, sex, dialysis vintage, diabetes, and functional status with PROs was similar in both modalities, with women having lower PCS and kidney disease burden scores. Lower functional status (score <11) was strongly associated with lower PCS and MCS scores, a much greater burden of kidney disease, and greater likelihood of depression symptoms (CES-D, >10). The median change in KDQOL-based PROs was negligible over 1 year in participants who completed at least 2 annual questionnaires.

LIMITATIONS

Selection bias due to incomplete survey responses. Generalizability was limited to the dialysis populations of the included countries.

CONCLUSIONS

Variation exists in quality of life, burden of kidney disease, and depression across countries but did not appreciably change over time. Functional status remained one of the strongest predictors of all PROs. Routine assessment of functional status may provide valuable insights for patients and providers in anticipating outcomes and support needs for patients receiving either PD or HD.

Variation in intravenous iron use internationally and over time: the Dialysis Outcomes and Practice Patterns Study (DOPPS)

BACKGROUND

To examine patterns of intravenous (IV) iron use across 12 countries from 1999 to 2011.

METHODS

Trends in iron use are described among 32 192 hemodialysis (HD) patients in the Dialysis Outcomes and Practice Patterns Study. Adjusted associations of IV iron dose with serum ferritin and transferrin saturation (TSAT) values were also studied.

RESULTS

IV iron was administered to 50% of patients over 4 months in 1999, increasing to 71% during 2009-11, with increasing use in most countries. Among patients receiving IV iron, the mean monthly dose increased from 232 ± 167 to 281 ± 211 mg. Most countries used 3 to 4 doses/month, but Canada used about 2 doses/month, Italy increased from 3 to almost 6 doses/month and Germany used 5 to 6 doses/month. The USA and most European countries predominantly used iron sucrose and sodium ferric gluconate. A significant use of iron dextran was limited to Canada and France; iron polymaltose was used in Australia and New Zealand; and Japan used ferric oxide saccharate, chondroitin polysulfate iron complex and cideferron. Ferritin values rose in most countries: 22% of patients had ≥ 800 ng/mL in the recent years of study. TSAT levels increased to a lesser degree over time. Japan had much lower IV iron dosing and ferritin levels, but similar TSAT levels. In adjusted analyses, serum ferritin and TSAT levels increased signifcantly by 14 ng/mL and 0.16%, respectively, for every 100 mg/month higher mean monthly iron dose.

CONCLUSIONS

IV iron prescription patterns varied between countries and changed over time from 1999 to 2011. IV iron use and dose increased in most countries, with notable increases in ferritin but not TSAT levels. With rising cumulative IV iron doses, studies of the effects of changing IV iron dosing and other anemia management practices on clinical outcomes should be a high priority.

Two-times weekly hemodialysis in China: frequency, associated patient and treatment characteristics and Quality of Life in the China Dialysis Outcomes and Practice Patterns study

BACKGROUND

Renal replacement therapy is rapidly expanding in China, and two-times weekly dialysis is common, but detailed data on practice patterns are currently limited. Using cross-sectional data from the China Dialysis Outcomes and Practice Patterns Study (DOPPS), we describe the hemodialysis practice in China compared with other DOPPS countries, examining demographic, social and clinical characteristics of patients on two-times weekly dialysis.

METHODS

The DOPPS protocol was implemented in 2011 among a cross-section of 1379 patients in 45 facilities in Beijing, Guangzhou and Shanghai. Data from China were compared with a cross section of 11 054 patients from the core DOPPS countries (collected 2009-11). Among China DOPPS patients, logistic and linear regression were used to describe the association of dialysis frequency with patient and treatment characteristics and quality of life.

RESULTS

A total of 26% of the patients in China were dialyzing two times weekly, compared with < 5% in other DOPPS regions. Standardized Kt/V was lowest in China (2.01) compared with other regions (2.12-2.27). Female sex, shorter dialysis vintage, lower socioeconomic status, less health insurance coverage, and lack of diabetes and hypertension were associated with dialyzing two times weekly (versus three times weekly). Patients dialyzing two times per week had longer treatment times and lower standardized Kt/V, but similar quality of life scores.

CONCLUSIONS

Two-times weekly dialysis is common in China, particularly among patients, who started dialysis more recently, have a lower comorbidity burden and have financial constraints. Quality of life scores do not differ between the two-times and three-times weekly groups. The effect on clinical outcomes merits further study.

Associations between Hemodialysis Facility Practices to Manage Fluid Volume and Intradialytic Hypotension and Patient Outcomes

BACKGROUND AND OBJECTIVES

Fluid overload and intradialytic hypotension are associated with cardiovascular events and mortality in patients on hemodialysis. We investigated associations between hemodialysis facility practices related to fluid volume and intradialytic hypotension and patient outcomes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data were analyzed from 10,250 patients in 273 facilities across 12 countries, from phase 4 of the Dialysis Outcomes and Practice Patterns Study (DOPPS; 2009-2012). Cox regression models (shared frailty) were used to estimate associations between facility practices reported by medical directors in response to the DOPPS Medical Directors Survey and all-cause and cardiovascular mortality and hospitalization, and cardiovascular events, adjusting for country, age, sex, dialysis vintage, predialysis systolic BP, cardiovascular comorbidities, diabetes, body mass index, smoking, residual kidney function, dialysis adequacy, and vascular access type.

RESULTS

Of ten facility practices tested (chosen a priori), having a protocol that specifies how often to assess dry weight in most patients was associated with lower all-cause (hazard ratio [HR], 0.78; 99% confidence interval [99% CI], 0.64 to 0.94) and cardiovascular mortality (HR, 0.72; 99% CI, 0.55 to 0.95). Routine orthostatic BP measurement to assess dry weight was associated with lower all-cause hospitalization (HR, 0.86; 99% CI, 0.77 to 0.97) and cardiovascular events (HR, 0.85; 99% CI, 0.73 to 0.98). Routine use of lower dialysate temperature to limit or prevent intradialytic hypotension was associated with lower cardiovascular mortality (HR, 0.76; 99% CI, 0.58 to 0.98). Routine use of an online volume indicator to assess dry weight was associated with higher all-cause hospitalization (HR, 1.19; 99% CI, 1.02 to 1.38). Routine use of sodium modeling/profiling to limit or prevent intradialytic hypotension was associated with higher all-cause mortality (HR, 1.36; 99% CI, 1.14 to 1.63), cardiovascular mortality (HR, 1.34; 99% CI, 1.04 to 1.73), and cardiovascular events (HR, 1.21; 99% CI, 1.03 to 1.43).

CONCLUSIONS

Hemodialysis facility practices relating to the management of fluid volume and intradialytic hypotension are associated with patient outcomes.

Prescription of renin-angiotensin-aldosterone system inhibitors (RAASi) and its determinants in patients with advanced CKD under nephrologist care

Renin-angiotensin-aldosterone system inhibitors (RAASi) are recommended for chronic kidney disease (CKD) patients. In this study, we describe RAASi prescription patterns in the Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps) in Brazil, Germany, France, and the United States (US). 5870 patients (mean age 66-72 years; congestive heart failure [CHF] in 11%-19%; diabetes in 43%-54%; serum potassium ≥5 in 20%-35%) were included. RAASi prescription was more common in Germany (80%) and France (77%) than Brazil (66%) and the United States (52%), where the prevalence of prescription decreases particularly in patients with CKD stage 5. In the multivariable regression model, RAASi prescription was least common in the United States and more common in patients who were younger, had diabetes, hypertension, or less advanced CKD. In conclusion, RAASi prescription patterns vary by country, and by demographic and clinical characteristics. RAASi appear to be underused, even among patients with strong class-specific recommendations. Although the reasons for this variation could not be fully identified in this cross-sectional observation, our data indicate that the risk of hyperkalemia may contribute to the underuse of this class of agents in moderate to advanced CKD.

Serum Biomarkers of Iron Stores Are Associated with Increased Risk of All-Cause Mortality and Cardiovascular Events in Nondialysis CKD Patients, with or without Anemia

BACKGROUND

Approximately 30%-45% of patients with nondialysis CKD have iron deficiency. Iron therapy in CKD has focused primarily on supporting erythropoiesis. In patients with or without anemia, there has not been a comprehensive approach to estimating the association between serum biomarkers of iron stores, and mortality and cardiovascular event risks.

METHODS

The study included 5145 patients from Brazil, France, the United States, and Germany enrolled in the Chronic Kidney Disease Outcomes and Practice Patterns Study, with first available transferrin saturation (TSAT) and ferritin levels as exposure variables. We used Cox models to estimate hazard ratios (HRs) for all-cause mortality and major adverse cardiovascular events (MACE), with progressive adjustment for potentially confounding variables. We also used linear spline models to further evaluate functional forms of the exposure-outcome associations.

RESULTS

Compared with patients with a TSAT of 26%-35%, those with a TSAT ≤15% had the highest adjusted risks for all-cause mortality and MACE. Spline analysis found the lowest risk at TSAT 40% for all-cause mortality and MACE. Risk of all-cause mortality, but not MACE, was also elevated at TSAT ≥46%. Effect estimates were similar after adjustment for hemoglobin. For ferritin, no directional associations were apparent, except for elevated all-cause mortality at ferritin ≥300 ng/ml.

CONCLUSIONS

Iron deficiency, as captured by TSAT, is associated with higher risk of all-cause mortality and MACE in patients with nondialysis CKD, with or without anemia. Interventional studies evaluating the effect on clinical outcomes of iron supplementation and therapies for alternative targets are needed to better inform strategies for administering exogenous iron.

Low Serum Potassium Levels and Clinical Outcomes in Peritoneal Dialysis-International Results from PDOPPS

Introduction

Hypokalemia, including normal range values <4 mEq/l, has been associated with increased peritonitis and mortality in patients with peritoneal dialysis. This study sought to describe international variation in hypokalemia, potential modifiable hypokalemia risk factors, and the covariate-adjusted relationship of hypokalemia with peritonitis and mortality.

Methods

Baseline serum potassium was determined in 7421 patients from 7 countries in the Peritoneal Dialysis Outcomes and Practice Patterns Study (2014-2017). Association of baseline patient and treatment factors with subsequent serum potassium <4 mEq/l was evaluated by logistic regression, whereas baseline serum potassium levels (4-month average and fraction of 4 months having hypokalemia) on clinical outcomes was assessed by Cox regression.

Results

Hypokalemia was more prevalent in Thailand and among black patients in the United States. Characteristics/treatments associated with potassium <4 mEq/l included protein-energy wasting indicators, lower urine volume, lower blood pressure, higher dialysis dose, greater diuretic use, and not being prescribed a renin-angiotensin system inhibitor. Persistent hypokalemia (all 4 months vs. 0 months over the 4-month exposure period) was associated with 80% higher subsequent peritonitis rates (at K <3.5 mEq/l) and 40% higher mortality (at K <4.0 mEq/l) after extensive case mix/potential confounding adjustments. Furthermore, adjusted peritonitis rates were higher if having mean serum K over 4 months <3.5 mEq/l versus 4.0-4.4 mEq/l (hazard ratio, 1.15 [95% confidence interval, 0.96-1.37]), largely because of Gram-positive/culture-negative infections.

Conclusions

Persistent hypokalemia is associated with higher mortality and peritonitis even after extensive adjustment for patient factors. Further studies are needed to elucidate mechanisms of these poorer outcomes and modifiable risk factors for persistent hypokalemia.

International Anemia Prevalence and Management in Peritoneal Dialysis Patients

Background:The optimal treatment for managing anemia in peritoneal dialysis (PD) patients and best clinical practices are not completely understood. We sought to characterize international variations in anemia measures and management among PD patients.Methods:The Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) enrolled adult PD patients from 6 countries from 2014 to 2017. Hemoglobin (Hb), ferritin levels, and transferrin saturation (TSAT), as well as erythropoiesis stimulating agents (ESAs) and iron use were compared cross-sectionally at study enrollment in Australia and New Zealand (A/NZ), Canada, Japan, the United Kingdom (UK), and the United States (US).Results:Among 3,603 PD patients from 193 facilities, mean Hb ranged from 11.0 - 11.3 g/dL across countries. The majority of patients (range 53% - 59%) had Hb 10 - 11.9 g/dL, with 4% - 12% patients ≥ 13 g/dL and 16% - 23% < 10 g/dL. Use of ESAs was higher in Japan (94% of patients) than elsewhere (66% - 79% of patients). In the US, 63% of patients had a ferritin level > 500 ng/mL, compared with 5% - 38% in other countries. In the US and Japan, 87% - 89% of PD patients had TSAT ≥ 20%, compared with 73% - 76% in other countries. Intravenous (IV) iron use within 4 months of enrollment was higher in the US (55% of patients) than elsewhere (6% - 17% patients).Conclusions:In this largest international observational study of anemia and anemia management in patients receiving PD, comparable Hb levels across countries were observed but with notable differences in ESA and iron use. Peritoneal dialysis patients in the US have higher ferritin levels and higher IV iron use than other countries.

Sex-Specific Differences in Mortality and Incident Dialysis in the Chronic Kidney Disease Outcomes and Practice Patterns Study

Introduction

More men than women start kidney replacement therapy (KRT) although the prevalence of chronic kidney disease (CKD) is higher in women than men. We therefore aimed at analyzing sex-specific differences in clinical outcomes among 8237 individuals with CKD in stages 3 to 5 from Brazil, France, Germany, and the United States participating in the Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps).

Methods

Fine and Gray models, evaluating the effect of sex on time to events, were adjusted for age, Black race (model A); plus diabetes, cardiovascular disease, albuminuria (model B); plus estimated glomerular filtration rate (eGFR) slope during the first 12 months after enrollment and first eGFR after enrollment (model C).

Results

There were more men than women at baseline (58% vs. 42%), men were younger than women, and men had higher eGFR (28.9 ± 11.5 vs. 27.0 ± 10.8 ml/min per 1.73 m²). Over a median follow-up of 2.7 and 2.5 years for men and women, respectively, the crude dialysis initiation and pre-emptive transplantation rates were higher in men whereas that of pre-KRT death was more similar. The adjusted subdistribution hazard ratios (SHRs) between men versus women for dialysis were 1.51 (1.27–1.80) (model A), 1.32 (1.10–1.59) (model B), and 1.50 (1.25–1.80) (model C); for pre-KRT death, were 1.25 (1.02–1.54) (model A), 1.14 (0.92–1.40) (model B), and 1.15 (0.93–1.42) (model C); for transplantation, were 1.31 (0.73–2.36) (model A), 1.44 (0.76–2.74) (model B), and 1.53 (0.79–2.94) (model C).

Conclusion

Men had a higher probability of commencing dialysis before death, unexplained by CKD progression alone. Although the causal mechanisms are uncertain, this finding helps interpret the preponderance of men in the dialysis population.

Anemia Management in the China Dialysis Outcomes and Practice Patterns Study

BACKGROUND

As the utilization of hemodialysis increases in China, it is critical to examine anemia management.

METHODS

Using data from the China Dialysis Outcomes and Practice Patterns Study (DOPPS), we describe hemoglobin (Hgb) distribution and anemia-related therapies.

RESULTS

Twenty one percent of China's DOPPS patients had Hgb <9 g/dl, compared with ≤10% in Japan and North America. A majority of medical directors targeted Hgb ≥11. Patients who were female, younger, or recently hospitalized had higher odds of Hgb <9; those with insurance coverage or on twice weekly dialysis had lower odds of Hgb <9. Iron use and erythropoietin-stimulating agents (ESAs) dose were modestly higher for patients with Hgb <9 compared with Hgb in the range 10-12.

CONCLUSION

A large proportion of hemodialysis patients in China's DOPPS do not meet the expressed Hgb targets. Less frequent hemodialysis, patient financial contribution, and lack of a substantial increase in ESA dose at lower Hgb concentrations may partially explain this gap. Video Journal Club 'Cappuccino with Claudio Ronco' at http://www.karger.com/?doi=442741.

Initiation of Sevelamer and Mortality among Hemodialysis Patients Treated with Calcium-Based Phosphate Binders

BACKGROUND AND OBJECTIVES

Prior studies have shown that sevelamer attenuates progression of arterial calcification and may reduce the risk of death compared with calcium-based phosphate binders. In clinical practice, however, sevelamer is used not only as an alternative but also as an add-on therapy in patients already being treated with calcium-based phosphate binders. We analyzed the Dialysis Outcomes and Practice Patterns Study (DOPPS) data to test the hypothesis that the initiation of sevelamer is associated with improved survival in patients on hemodialysis treated with calcium-based phosphate binders.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We included 12,564 patients from DOPPS phase 3 and phase 4 (2005-2011) who were prescribed calcium-based phosphate binders at baseline or before sevelamer treatment. Mortality risk was assessed using a sequential stratification method to identify as-yet-untreated patients who were appropriately matched to the newly treated patients on the basis of their risk of death.

RESULTS

Of 12,564 patients, 2606 were subsequently treated with sevelamer hydrochloride or sevelamer carbonate. After beginning sevelamer therapy, mean serum phosphorus levels decreased by 0.3 mg/dl in the first 4 months and gradually decreased thereafter. We matched 2501 treated patients with at least one as-yet-untreated patient. Patients treated with sevelamer had a 14% lower risk for mortality compared with as-yet-untreated patients (hazard ratio, 0.86; 95% confidence interval, 0.76 to 0.97). Similar results were observed in the sensitivity analyses when changing the matching calipers or the treated and as-yet-untreated ratios, and by using propensity score matching.

CONCLUSIONS

The use of sevelamer as an add-on or alternative therapy to calcium-based phosphate binders is associated with improved survival in patients on maintenance hemodialysis.

Impact of longer term phosphorus control on cardiovascular mortality in hemodialysis patients using an area under the curve approach: results from the DOPPS

BACKGROUND

Serial assessment of phosphorus is currently recommended by the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines, but its additional value versus a single measurement is uncertain.

METHODS

We studied data from 17 414 HD patients in the Dialysis Outcomes and Practice Patterns Study, a prospective cohort study, and calculated the area under the curve (AUC) by multiplying the time spent with serum phosphorus >4.5 mg/dL over a 6-month run-in period by the extent to which this threshold was exceeded. We estimated the association between the monthly average AUC and cardiovascular (CV) mortality using Cox regression. We formally assessed whether AUC was a better predictor of CV mortality than other measures of phosphorus control according to the Akaike information criterion.

RESULTS

Compared with the reference group of AUC = 0, the adjusted hazard ratio (HR) of CV mortality was 1.12 [95% confidence interval (CI) 0.90-1.40] for AUC > 0-0.5, 1.26 (95% CI 0.99-1.62) for AUC > 0.5-1, 1.44 (95% CI 1.11-1.86) for AUC > 1-2 and 2.03 (95% CI 1.53-2.69) for AUC > 2. The AUC was predictive of CV mortality within strata of the most recent phosphorus level and had a better model fit than other serial measures of phosphorus control (mean phosphorus, months out of target).

CONCLUSIONS

We conclude that worse phosphorus control over a 6-month period was strongly associated with CV mortality. The more phosphorus values do not exceed 4.5 mg/dL the better is survival. Phosphorus AUC is a better predictor of CV death than the single most recent phosphorus level, supporting with real-world data KDIGO's recommendation of serial assessment of phosphorus to guide clinical decisions.

The COVID-19 Pandemic Identifies Significant Global Inequities in Hemodialysis Care in Low and Lower-Middle Income Countries-An ISN/DOPPS Survey

Introduction

It is unknown how the COVID-19 pandemic has affected the care of vulnerable chronic hemodialysis (HD) patients across regions, particularly in low and lower-middle income countries (LLMICs). We aimed to identify global inequities in HD care delivery during the COVID-19 pandemic.

Methods

The ISN and the Dialysis Outcomes and Practice Patterns Study (DOPPS) conducted a global online survey of HD units between March and November, 2020, to ascertain practice patterns and access to resources relevant to HD care during the COVID-19 pandemic. Responses were categorized according to World Bank income classification for comparisons.

Results

Surveys were returned from 412 facilities in 78 countries: 15 (4%) in low-income countries (LICs), 111 (27%) in lower-middle income countries (LMICs), 145 (35%) in upper-middle income countries (UMICs), and 141 (34%) in high-income countries (HICs). Respondents reported that diagnostic tests for SARS-CoV-2 were unavailable or of limited availability in LICs (72%) and LMICs (68%) as compared with UMICs (33%) and HICs (20%). The number of patients who missed HD treatments was reported to have increased during the COVID-19 pandemic in LICs (64%) and LMICs (67%) as compared with UMICs (31%) and HICs (6%). Limited access to HD, intensive care unit (ICU) care, and mechanical ventilation among hospitalized patients on chronic dialysis with COVID-19 were also reportedly higher in LICs and LMICs as compared with UMICs and HICs. Staff in LLMICs reported less routine testing for SARS-CoV-2 when asymptomatic as compared with UMICs and HICs-14% in LICs and 11% in LMICs, compared with 26% and 28% in UMICs and HICs, respectively. Severe shortages of personal protective equipment (PPE) were reported by the respondents from LICs and LMICs compared with UMICs and HICs, especially with respect to the use of the N95 particulate-air respirator masks.

Conclusion

Striking global inequities were identified in the care of chronic HD patients during the pandemic. Urgent action is required to address these inequities which disproportionately affect LLMIC settings thereby exacerbating pre-existing vulnerabilities that may contribute to poorer outcomes.

Patient-reported advantages and disadvantages of peritoneal dialysis: results from the PDOPPS

BACKGROUND

Patient-reported measures are increasingly recognized as important predictors of clinical outcomes in peritoneal dialysis (PD). We sought to understand associations between patient-reported perceptions of the advantages and disadvantages of PD and clinical outcomes.

METHODS

In this cohort study, 2760 PD patients in the Peritoneal Dialysis Outcomes and Practice Patterns Study (PDOPPS) completed a questionnaire on their PD experience, between 2014 and 2017. In this questionnaire, PDOPPS patients rated 17 aspects of their PD experience on a 5-category ordinal scale, with responses scored from - 2 (major disadvantage) to + 2 (major advantage). An advantage/disadvantage score (ADS) was computed for each patient by averaging their response scores. The ADS, along with each of these 17 aspects, were used as exposures. Outcomes included mortality, transition to hemodialysis (HD), patient-reported quality of life (QOL), and depression. Cox regression was used to estimate associations between ADS and mortality, transition to HD, and a composite of the two. Logistic regression with generalized estimating equations was used to estimate cross-sectional associations of ADS with QOL and depression.

RESULTS

While 7% of PD patients had an ADS < 0 (negative perception of PD), 59% had an ADS between 0 and < 1 (positive perception), and 34% had an ADS ≥1 (very positive perception). Minimal association was observed between mortality and the ADS. Compared with a very positive perception, patients with a negative perception had a higher transition rate to HD (hazard ratio [HR] = 1.67; 95% confidence interval [CI]: 1.21, 2.30). Among individual items, "space taken up by PD supplies" was commonly rated as a disadvantage and had the strongest association with transition to HD (HR = 1.28; 95% CI 1.07, 1.53). Lower ADS was strongly associated with worse QOL rating and greater depressive symptoms.

CONCLUSIONS

Although patients reported a generally favorable perception of PD, patient-reported disadvantages were associated with transition to HD, lower QOL, and depression. Strategies addressing these disadvantages, in particular reducing solution storage space, may improve patient outcomes and the experience of PD.

Geographical Variations in Blood Pressure Level and Seasonality in Hemodialysis Patients

Seasons and climate influence the regulation of blood pressure (BP) in the general population and in hemodialysis patients. It is unknown whether this phenomenon varies across the world. Our objective was to estimate BP seasonality in hemodialysis patients from different geographical locations. Patients from 7 European countries (Spain, Italy, France, Belgium, Germany, United Kingdom, and Sweden) participating in the DOPPS (Dialysis Outcomes and Practice Patterns Study) on years 2005 to 2011 were studied. Factors influencing pre- and postdialysis systolic BP and diastolic BP levels were analyzed by mixed models. There were 9655 patients (median age, 68; 59% male) from 263 facilities, seen every 4 months during a median duration of 1.3 years. Pre- and postdialysis systolic BP increased by a mean estimate of 5.1 mm Hg (95% confidence interval [CI], 3.7-6.4 mm Hg) and 4.4 mm Hg (95% CI, 2.9-5.9 mm Hg) for each 10° increase in latitude (1111 km to the North). In the longitudinal analysis, predialysis systolic BP was lower in summer and higher in winter (difference, 1.7 mm Hg; 95% CI, 1.3-2.2 mm Hg), with greater differences in southern locations (P_interaction=0.04). Predialysis systolic BP was inversely associated with outdoor temperature (-0.8 mm Hg/7.2°C; 95% CI, -1.0 to -0.5 mm Hg/7.2°C), with steeper slopes in southern locations (P_interaction=0.005). Results were similar for predialysis diastolic BP. In conclusion, there is a geographical and seasonal gradient of BP in European hemodialysis patients. There is a need to consider these effects when evaluating and treating BP in this population and potentially in others.

Kt/V: achievement, predictors and relationship to mortality in hemodialysis patients in the Gulf Cooperation Council countries: results from DOPPS (2012-18)

BACKGROUND

Dialysis adequacy, as measured by single pool Kt/V, is an important parameter for assessing hemodialysis (HD) patients' health. Guidelines have recommended Kt/V of 1.2 as the minimum dose for thrice-weekly HD. We describe Kt/V achievement, its predictors and its relationship with mortality in the Gulf Cooperation Council (GCC) (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates).

METHODS

We analyzed data (2012-18) from the prospective cohort Dialysis Outcomes and Practice Patterns Study for 1544 GCC patients ≥18 years old and on dialysis >180 days.

RESULTS

Thirty-four percent of GCC HD patients had low Kt/V (<1.2) versus 5%-17% in Canada, Europe, Japan and the USA. Across the GCC countries, low Kt/V prevalence ranged from 10% to 54%. In multivariable logistic regression, low Kt/V was more common (P < 0.05) with larger body weight and height, being male, shorter treatment time (TT), lower blood flow rate (BFR), greater comorbidity burden and using HD versus hemodiafiltration. In adjusted Cox models, low Kt/V was strongly related to higher mortality in women [hazard ratio (HR) = 1.91, 95% confidence interval (CI) 1.09-3.34] but not in men (HR = 1.16, 95% CI 0.70-1.92). Low BFR (<350 mL/min) and TT (<4 h) were common; 41% of low Kt/V cases were attributable to low BFR or TT (52% for women and 36% for men).

CONCLUSION

Relatively large proportions of GCC HD patients have low Kt/V. Increasing BFR to ≥350 mL/min and TT to ≥4 h thrice weekly will reduce low Kt/V prevalence and may improve survival in GCC HD patients-particularly among women.

The association between longer haemodialysis treatment times and hospitalization and mortality after the two-day break in individuals receiving three times a week haemodialysis

BACKGROUND

On the first haemodialysis (HD) day after the 2-day break in three times a week (3×W) in-centre HD, mortality and hospitalization are higher. If longer HD sessions prescribed 3×W is associated with a reduction in these events is unknown.

METHODS

HD session length in 19 557 prevalent European in-centre 3×W HD patients participating in the Dialysis Outcomes and Practice Patterns Study (1998-2011) were categorized into <200, 200-225, 226-250 or >250 min. Standardized event rates on the first (HD1) versus the second (HD2) HD day after the 2-day break, with supporting Cox proportional hazards models adjusted for patient and dialysis characteristics, were generated for all-cause mortality, all-cause hospitalization, out-of-hospital death and fluid overload hospitalization.

RESULTS

By comparing HD1 with HD2, increased rates of all endpoints were observed (all P < 0.002). As HD session lengthened across the four groups, all-cause mortality per 100 patient-years on the HD1 (23.0, 20.4, 16.4 and 14.6) and HD2 (26.1, 13.3, 13.4 and 12.1) reduced. Similar improvements were observed for out-of-hospital death but were less marked for hospitalization endpoints. However, even patients dialysing >250 min were at significantly greater risk on HD1 when compared with their HD2 for out-of-hospital death [hazard ratio (HR) = 2.1, 95% CI 1.0-4.3], all-cause hospitalization (HR = 1.3, 95% CI 1.2-1.4) and fluid overload hospitalization (HR = 3.2, 95% CI 1.8-6.0).

CONCLUSIONS

Despite the association between reduced mortality across all dialysis days in patients performing longer sessions, elevated risk on the first dialysis day relative to the second persists even in patients dialysing 4.5 h 3×W.