Transfusion Management of Incident Dialysis Patients in Canada: A Prospective Observational Study.

BACKGROUND: Several studies have demonstrated harm associated with using erythropoiesis-stimulating agents (ESA) to achieve higher hemoglobin (Hb) levels. Subsequently, more conservative use of ESAs has changed anemia therapy in patients with chronic renal failure. OBJECTIVE: The objectives were to identify transfusion rates in hemodialysis (HD) patients during the first year of therapy, to identify factors associated with the probability of transfusion, describe reasons for the transfusions, and identify the Hb values associated with each transfusion. An exploratory objective was to describe the age of red blood cell transfusions. DESIGN: This was a multicenter prospective observational cohort study. SETTING: There were 12 study sites in 5 Canadian provinces. The study was performed from 2012 to 2014. METHODS: The study patients were adult incident chronic HD patients in these centers. Patients with acute kidney injury, peritoneal dialysis, and planned transfer to satellite units were excluded. Patients had to receive at least 1 month of chronic HD to be eligible. Data for 3 months prior to HD were obtained by retrospective chart review. Prospectively, charts were reviewed monthly for 12 months for data abstraction. RESULTS: There were 314 patients enrolled and 79.9% completed 12 month follow-up. Ninety-four (29.9%) patients received at least 1 unit of blood. During the first 90 days, the transfusion episode rate was 148.4 per 100 patient-years compared with 62.6 per 100 patient-years post 90 days. The most frequent indication was a low Hb value (92%) with gastrointestinal bleeding, surgical blood loss, and fatigue accounting for 9.9%, 8.6%, and 4.5%, respectively. Some patients had >1 indication. The mean Hb values prior to transfusion episodes ranged from 75.3 to 78.6 g/L. Cox regression analysis on time to first transfusion and time to first hospitalization/death both showed an association with inpatient initiation of HD. Some 37.5% initiated HD as an inpatient and differed from those starting as an outpatient. They had less predialysis care and laboratory data suggested more inflammation. The mean and median ages of the blood units transfused were 24.9 (SD = 10.0) and 23 days (interquartile range = 17-33). CONCLUSIONS: This work reported the blood transfusion rate in incident HD patients in Canada during a period associated with conservative ESA prescription. The major indication for transfusion was a low Hb rather than clinical symptoms. Initiation of HD as an inpatient was independently associated with the probability of receiving a blood transfusion. These findings require further investigation.

CONTEXTE: Plusieurs études ont fait état de lésions associées à l'utilisation d'agents stimulant l'érythropoïèse (ASE) pour hausser le taux d'hémoglobine (Hb). Dès lors, une utilisation plus conservatrice des ASE a modifié le traitement de l'anémie chez les patients atteints d'insuffisance rénale chronique. OBJECTIFS DE L'ÉTUDE: L'étude visait à i) établir les taux de transfusion sanguine chez les patients hémodialysés au cours de la première année de traitement; ii) cerner les facteurs associés à la probabilité de recourir à une transfusion sanguine; iii) connaître les raisons de la transfusion; et iv) caractériser le taux d'hémoglobine au moment de l'intervention. En outre, un objectif exploratoire consistait à déterminer l'âge des érythrocytes transfusés. TYPE D'ÉTUDE: Il s'agit d'une étude de cohorte observationnelle prospective multicentrique. CADRE DE L'ÉTUDE: L'étude s'est tenue entre 2012 et 2014 sur douze sites répartis dans cinq provinces canadiennes. MÉTHODOLOGIE: Les patients adultes hémodialysés des centres participants ont été recrutés pour l'étude. Ont été exclus les patients atteints d'insuffisance rénale aiguë, les patients traités par dialyse péritonéale et les patients à être transférés vers une unité satellite. Pour être admissible, le patient devait recevoir un traitement d'hémodialyse continu pendant au moins un mois. On a rétrospectivement tiré des dossiers médicaux les données des trois mois précédant l'hémodialyse, puis on a extrait les données des dossiers médicaux chaque mois sur un an. RÉSULTATS: Un total de 314 patients a participé à l'étude et 79,9 % d'entre eux ont complété les 12 mois de suivi. Sur cette période, 94 patients (29,9 %) ont reçu au moins une transfusion sanguine. Au cours des 90 premiers jours, le taux d'épisodes transfusionnels était de 148,4 pour 100 années-patients, comparativement à 62,6 pour 100 années-patients pour le reste de l'étude. La raison la plus fréquente de recourir à une transfusion était un faible taux d'Hb (92 % des cas); les cas de saignements gastro-intestinaux, de perte de sang périchirurgicale et de fatigue comptaient quant à eux pour 9,9 %, 8,6 % et 4,5 % respectivement. Certains patients cumulant plus d'une indication. Le taux d'Hb moyen prétransfusion variait de 75,3 à 78,6 g/L. Une analyse de régression de Cox sur le temps écoulé jusqu'à la première transfusion et jusqu'à la première hospitalisation (ou le décès) du patient a montré une corrélation avec l'initiation d'un traitement d'hémodialyse chez les patients hospitalisés. Les sujets qui avaient initié leur traitement d'hémodialyse alors qu'ils étaient hospitalisés (37,5 %) ont reçu moins de soins prédialyse et présentaient davantage d'inflammation que les sujets qui avaient commencé leurs traitements d'hémodialyse en tant que patient externe. Enfin, l'âge moyen et l'âge médian des érythrocytes transfusés étaient de 24,9 jours (ÉT : 10,0) et de 23 jours (EIQ : 17 à 23). CONCLUSION: Notre étude a permis de connaître le taux de transfusions sanguines dans une population de patients hémodialysés canadiens au cours d'une période correspondant à une prescription conservatrice d'ASE. On a observé que la principale raison de transfusion était un faible taux d'Hb et non des symptômes cliniques. Enfin, une hémodialyse amorcée en cours d'hospitalisation a été associée à une probabilité accrue de transfusion sanguine. Nos constatations devraient faire l'objet d'études plus approfondies.

Psychometric properties of the Patient's Perception of Life on Hemodialysis Scale.

BACKGROUND AND PURPOSE: Hemodialysis (HD) is the main form of renal replacement therapy for many patients with end-stage renal disease. The purpose of this research is to assess reliability and validity of the Patient's Perception of Hemodialysis Scale. METHODS: Using a cross-sectional design and a convenient sample (n = 236), psychometric properties of the PPHS were examined. Validity was assessed using factor analysis and Pearson's correlation. Reliability was determined using Cronbach's alpha and test-retest stability (n = 30). RESULTS: Validity and reliability was supported. CONCLUSION: Examination of the PPHS provides evidence that it is a valid and reliable instrument for measuring disease-specific concerns with the HD patients, assessing how people experience life, and identifying ways in which people interpret the meaning of their physical and psychosocial health and adaptation to life on HD.

Responsiveness of the patient's perception of hemodialysis scale.

OBJECTIVES: To assess hemodialysis (HD) patients' physical health, social supports, psychosocial well-being and the interrelationship among patients' experiences, demographics, illness characteristics, and biochemical indicators of health. To determine responsiveness of the Patient's Perception of Hemodialysis Scale (PPHS) to change in health status and critical events. METHODS: Using a longitudinal design HD patients (n = 85) were assessed at two time periods. Data analysis included measures of central tendency and tests of difference to assess interrelationships and responsiveness of the PPHS. RESULTS: There were no significant changes in PPHS's subscales scores between measurement times or groups based on demographic variables. Significant differences were found in the number of co-morbid illnesses, illness severity, albumin, and urea reduction. The Psychosocial Distress subscale varied significantly in relation to time on HD, reason for admission to hospital, and number of admissions. Physical Health scores were significantly different for subgroups divided by illness, illness severity, number of illnesses, age, albumin and reason for admission. PPHS subscale mean scores were responsive to positive events in the predicted direction most of the time and appeared to have had more of an effect on the PPHS scores than negative critical events. CONCLUSION: The PPHS is responsive to a change in physical health and positive critical events, but results were unsubstantiated for patient's reaction to negative critical events. The PPHS is reliable, valid, and responsive to physical changes and positive critical events. This instrument offers health care professionals a viable method for assessing important factors capable of predicting quality outcomes.

The (99m)Tc-DTPA urinary clearance method may be preferable to the plasma disappearance method for assessing glomerular filtration rate in diabetic nephropathy.

BACKGROUND: Isotopic glomerular filtration rate (iGFR) measurement is comparable to the inulin method. In this study, we compared urinary and plasma iGFR methodologies in patients with diabetic nephropathy. METHODS: A total of 147 patients from 3 sites in the Diabetic Intervention with Vitamins to Improve Nephropathy (DIVINe) trial provided 213 sets of urine and blood collections, at baseline, 18 and 36 months. RESULTS: The mean (with standard deviation) plasma iGFR of 60.7 (24.9) ml/min/1.73 m(2) compared to urinary iGFR of 52.0 (28.0) ml/min/1.73 m(2) was statistically significant (p value <0.001). Although plasma and urinary iGFRs were highly related (R(2) = 0.86), plasma iGFR increasingly overestimated urinary iGFRs at lower GFRs. In contrast to the cross-sectional analyses, the two measures of iGFR were weakly related (R(2) = 0.32) in regard to patients' change over 18 months of follow-up. CONCLUSION: Plasma iGFR may not be a suitable method for accurately measuring GFR in patients with advancing degrees of chronic kidney disease from diabetic nephropathy.

Dialysis patients treated with Epoetin α show improved exercise tolerance and physical function: A new analysis of the Canadian Erythropoietin Study Group trial.

The risks/benefits of anemia treatment in dialysis patients have been redefined in the US Epoetin α label. This analysis was carried out to determine if increasing hemoglobin (Hb) levels improve exercise tolerance and physical function in anemic dialysis patients. This is a new analysis of the Canadian Erythropoietin Study Group trial, a double-blind, randomized, placebo-controlled trial in dialysis patients. Subjects were 18 to 75 years old, on hemodialysis for >3 months, and had a baseline Hb <9.0 g/dL. Patients with a history of diabetes mellitus, ischemic heart disease, or severe/uncontrolled hypertension were excluded. Patients were randomized to receive Epoetin α to a target Hb of 9.5 to 11.0 g/dL (n=40) or a target of 11.5 to 13.0 g/dL (n=38), or receive placebo (n=40). Results from patients in the Epoetin-α-treated arms were combined for this analysis. Hb level, exercise tolerance (Treadmill Stress Test and 6-Minute Walk Test) and patient-reported physical function measures (Physical Summary domain from the Kidney Disease Questionnaire, and 4 domains from the Sickness Impact Profile) were reported at baseline and months 2, 4, and 6. Differences in measures were statistically significant for exercise tolerance (Treadmill Stress, P=0.0001) and patient-reported physical function (Kidney Disease Questionnaire Physical, P=0.0001; Sickness Impact Profile Physical, P=0.0015) across all time points for Epoetin-α-treated patients compared with placebo. Improvements were seen at 2 months and were maintained through months 4 and 6. Dialysis patients receiving Epoetin α showed improved exercise tolerance and physical function. These findings should be considered as physicians weigh the risks and benefits of treatment.

Effect of B-vitamin therapy on progression of diabetic nephropathy: a randomized controlled trial.

CONTEXT: Hyperhomocysteinemia is frequently observed in patients with diabetic nephropathy. B-vitamin therapy (folic acid, vitamin B(6), and vitamin B(12)) has been shown to lower the plasma concentration of homocysteine. OBJECTIVE: To determine whether B-vitamin therapy can slow progression of diabetic nephropathy and prevent vascular complications. DESIGN, SETTING, AND PARTICIPANTS: A multicenter, randomized, double-blind, placebo-controlled trial (Diabetic Intervention with Vitamins to Improve Nephropathy [DIVINe]) at 5 university medical centers in Canada conducted between May 2001 and July 2007 of 238 participants who had type 1 or 2 diabetes and a clinical diagnosis of diabetic nephropathy. INTERVENTION: Single tablet of B vitamins containing folic acid (2.5 mg/d), vitamin B(6) (25 mg/d), and vitamin B(12) (1 mg/d), or matching placebo. MAIN OUTCOME MEASURES: Change in radionuclide glomerular filtration rate (GFR) between baseline and 36 months. Secondary outcomes were dialysis and a composite of myocardial infarction, stroke, revascularization, and all-cause mortality. Plasma total homocysteine was also measured. RESULTS: The mean (SD) follow-up during the trial was 31.9 (14.4) months. At 36 months, radionuclide GFR decreased by a mean (SE) of 16.5 (1.7) mL/min/1.73 m(2) in the B-vitamin group compared with 10.7 (1.7) mL/min/1.73 m(2) in the placebo group (mean difference, -5.8; 95% confidence interval [CI], -10.6 to -1.1; P = .02). There was no difference in requirement of dialysis (hazard ratio [HR], 1.1; 95% CI, 0.4-2.6; P = .88). The composite outcome occurred more often in the B-vitamin group (HR, 2.0; 95% CI, 1.0-4.0; P = .04). Plasma total homocysteine decreased by a mean (SE) of 2.2 (0.4) micromol/L at 36 months in the B-vitamin group compared with a mean (SE) increase of 2.6 (0.4) micromol/L in the placebo group (mean difference, -4.8; 95% CI, -6.1 to -3.7; P < .001, in favor of B vitamins). CONCLUSION: Among patients with diabetic nephropathy, high doses of B vitamins compared with placebo resulted in a greater decrease in GFR and an increase in vascular events. TRIAL REGISTRATION: isrctn.org Identifier: ISRCTN41332305.

Dialysis patients treated with Epoetin alfa show improved anemia symptoms: A new analysis of the Canadian Erythropoietin Study Group trial.

The health-related quality of life (HRQOL) claims in the current Epoetin alfa label are based on the reanalyses of the exercise and physical function data from the Canadian Erythropoietin Study Group trial. The reanalysis was done to comply with the Food and Drug Administration's requirement of using statistical methods that are currently standard in evaluating clinical trial data. Presented here are HRQOL results associated with anemia. The Canadian Erythropoietin Study Group trial was a multicenter, double blind, randomized, placebo-controlled trial evaluating the effects of Epoetin alfa on HRQOL in anemic hemodialysis patients. A total of 118 patients who were 18-75 years old, on hemodialysis for >3 months, who had a hemoglobin <9.0 g/dL, and did not have coronary artery disease or diabetes mellitus, were randomized to either receive placebo (n=40), or receive intravenous Epoetin alfa to achieve a target hemoglobin of 9.5-11.0 g/dL (n=40) or a target of 11.5-13.0 g/dL (n=38). Patients were followed for 6 months. The two Epoetin alfa-treatment groups were combined for all analyses performed. This post hoc analysis was conducted using an intent-to-treat repeated measures mixed model analysis of variance using Bonferroni's multiplicity correction. The Epoetin alfa-treated group showed a statistically significant improvement in the Kidney Disease Questionnaire symptom of fatigue in comparison with placebo. Additionally, the change in hemoglobin at 2 months was correlated with change in fatigue, energy, shortness of breath, and weakness, but had minimal effect on depression. These analyses confirm previously reported results, which indicate that treating hemodialysis patients with an erythropoiesis-stimulating agent improves HRQOL.

Costs associated with erythropoiesis-stimulating agent administration to hemodialysis patients.

BACKGROUND: Treatment of anemia in hemodialysis patients usually requires the use of expensive erythropoietic proteins. Cost analyses usually focus on drug acquisition costs. Other costs associated with anemia therapy include resources for anemia monitoring as well as preparation and administration of an erythropoiesis-stimulating agent. METHODS: The nonacquisition costs associated with subcutaneous administration of epoetin alfa were determined in a Canadian hemodialysis unit. A time-and-motion technique was used to determine the nursing time for preparation and administration. Fixed anemia costs were inventory control, monitoring, blood sampling, and laboratory analysis. Variable costs were those which varied with dosing frequency. The costs are expressed in Canadian dollars (2005). RESULTS: The mean time associated with preparation and administration was 3.2 min/injection. The annual nonacquisition per patient cost was CAD 2,290.04. Fixed costs were CAD 1,946.01, while the variable costs were CAD 344.03/year. Sensitivity analysis showed a decrease in cost to CAD 1,611.34, if iron monitoring were decreased from monthly to 3 monthly, and to CAD 2,090.66, if patients were converted to less frequent dosing using darbepoetin alfa. CONCLUSIONS: The nonacquisition costs associated with anemia therapy in hemodialysis patients are considerable. Less frequent monitoring of iron therapy and less frequent dosing could decrease costs by CAD 678.40 and CAD 199.38/patient/year, respectively.

Effect of chronic kidney disease on red blood cell rheology.

BACKGROUND: Anemia of renal failure is primarily a problem of decreased RBC production due to erythropoietin deficiency. RBC survival is also reduced, perhaps due to decreased RBC deformability. This study measured blood viscosity over a range of shear rates in erythropoietin-treated patients on hemodialysis (HD), and compared the findings to matched patients with chronic renal insufficiency (CRI) and healthy controls. METHODS: Four groups (control, CRI, non-diabetic HD, and diabetic HD) of 9 matched subjects were recruited. Blood viscosity was measured using a cone-plate viscometer over a variety of shear rates (11 to 225 s(-1)). RESULTS: Control subjects had lower viscosity values throughout all shear rates when compared to the 3 renal disease groups (P value=0.039). A trend was observed to higher levels of renal function being associated with decreased blood viscosity in patients with CRI. CONCLUSIONS: Patients with kidney disease have increased blood viscosity at all shear rates. This may be related to changes in RBC shape and decreased deformability in patients with kidney disease, independent of HD- or DM-status. This may have implications for strategies to treat anemia in these patients.

Plasma exchange when myeloma presents as acute renal failure: a randomized, controlled trial.

BACKGROUND: Two small, randomized trials provide conflicting evidence about the benefits of plasma exchange for patients with acute renal failure at the onset of multiple myeloma. OBJECTIVE: To assess the effect of 5 to 7 plasma exchanges on a composite outcome in patients with acute renal failure at the onset of multiple myeloma. DESIGN: Randomized, open, controlled trial, stratified by chemotherapy and dialysis dependence, conducted from 1998 to 2004. SETTING: Hospital plasma exchange units in 14 Canadian medical centers. PARTICIPANTS: 104 patients between 18 and 81 years of age with acute renal failure at the onset of myeloma. INTERVENTION: Study participants were randomly assigned to conventional therapy plus 5 to 7 plasma exchanges of 50 mL per kg of body weight of 5% human serum albumin for 10 days or conventional therapy alone. Ninety-seven participants completed the 6-month follow-up. MEASUREMENTS: The primary outcome was a composite measure of death, dialysis dependence, or glomerular filtration rate less than 0.29 mL x s(-2) x m(-2) (<30 mL/min per 1.73 m2). RESULTS: At enrollment, the plasma exchange and control groups were similar for dialysis dependence, chemotherapy, sex, age, hypercalcemia, serum albumin level, 24-hour urine protein level, serum creatinine level, and Durie-Salmon staging. The primary composite end point occurred in 33 of 57 (57.9%) patients in the plasma exchange group and in 27 of 39 (69.2%) patients in the control group (difference between groups, 11.3% [95% CI, -8.3% to 29.1%]; P = 0.36). One third of patients in each group died. LIMITATIONS: The study was small, used a composite outcome, and did not use renal biopsy as an inclusion criterion. Recruiting physicians were blinded to treatment allocation but not to treatment thereafter. CONCLUSIONS: In patients with acute renal failure at the onset of multiple myeloma, there is no conclusive evidence that 5 to 7 plasma exchanges substantially reduce a composite outcome of death, dialysis dependence, or glomerular filtration rate less than 0.29 mL.s(-2).m(-2) (<30 mL/min per 1.73 m2) at 6 months.

Impact of peritoneal dialysis dose guidelines on clinical outcomes.

The objective was to review the rationale for the Kidney Disease Outcomes Quality Initiative (K/DOQI) recommendations for adequacy of peritoneal dialysis and to evaluate the impact of these recommendations on clinical practice and patient survival. The K/DOQI recommendations were based on large observational studies; the target weekly Kt/V value of 2.0 assumed equivalence of peritoneal and renal clearances. This assumption is no longer considered correct. The impact on clinical practice was evaluated by an examination of temporal trends before and after publication of the guidelines in 1997. In the United States and The Netherlands, there had been a trend toward increased delivered total Kt/V prior to 1997, and there was no acceleration in this trend after 1997. Two randomized clinical trials have implemented these guidelines with increased peritoneal Kt/V (or creatinine clearance) used to achieve the K/DOQI target in the intervention group. This was not associated with improved survival, compared to a lower Kt/V, in either of the randomized clinical trials. Among the explanations for the failure to improve outcome are potential adverse effects of increasing the dialysis dose. These include increased intraperitoneal pressure associated with increased exchange volume, failure to increase clearance of middle molecules, and increased exposure to glucose. Strategies that increase peritoneal clearance without exposure to these potential adverse effects include more-frequent exchanges rather than increased exchange volume, and decreased exposure to glucose and glucose degradation products. Pending such studies, current K/DOQI guidelines should be updated in a timely manner.

Regular monitoring of access flow compared with monitoring of venous pressure fails to improve graft survival.

Regular vascular access blood flow (Qa) surveillance is recommended to detect graft stenosis; however, there is little evidence that monitoring and correcting with angioplasty improves graft survival. This blinded, randomized, controlled trial of 112 patients studied time to graft thrombosis and graft loss, comparing monthly Qa plus standard surveillance (dynamic venous pressure and physical examination) (treatment group) to standard surveillance alone (control group). Only the treatment group was referred for angiogram if Qa <650 ml/min or a 20% decrease in Qa from baseline. Percutaneous angioplasty was performed for stenosis >50%. The rate of graft thrombosis per patient-year at risk was 0.41 and 0.51 in the control and treatment groups, respectively. Fifty-one interventions (0.93/patient-years at risk) were performed in the treatment group versus 31 interventions (0.61/patient-years at risk) in the control group. There was no difference in time to graft loss (P = 0.890). In a multivariate analysis, aspirin (ASA) therapy at baseline was associated with an 84% reduction in risk of graft thrombosis (odds ratio [OR], 0.14; P = 0.002). Higher baseline Qa (OR, 0.84; P = 0.05) and longer interval since graft insertion (OR, 0.97; P = 0.07) were associated with a decrease in graft thrombosis. Results reveal that graft surveillance that uses Qa increases the detection of stenosis, compared with standard surveillance; however, intervention with angioplasty does not improve the time to graft thrombosis or time to graft loss.

Survival comparison between hemodialysis and peritoneal dialysis based on matched doses of delivered therapy.

Several studies have recently confirmed that hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) survival is highly associated with delivered therapy Kt/V(urea). A direct comparison of equivalently dosed CAPD and HD has not previously been performed. A total of 968 incident HD patients at the Regional Kidney Disease Program from 1987 to June 1995 were studied, and these results were compared with those of the Canadian-United States prospective trial (CANUSA) consisting of 680 incident CAPD patients from September 1990 to December 31, 1992, with follow-up through December 31, 1993. All patients had quantitation of urea nitrogen for a total delivered dialysis session. On HD, in vivo, 2-pool, pre- and post-blood urea nitrogen kinetic modeling was performed with residual renal function determined every 6 mo. Patients were characterized by age, gender, race, renal diagnosis, and comorbid conditions. A Cox proportional hazards model was used to evaluate the effect of the individual comorbid conditions and the effect of dialysis therapy in the time-dependent method. The mean total Kt/V, both residual renal function and dialytic therapy in the HD patients, was 1.59. The CANUSA-delivered weekly Kt/V was 2.38 at the beginning of the baseline period and 1.99 after 24 mo of follow-up. When the peak concentration hypothesis was used, a Kt/V of 1.59 on HD was equivalent to a weekly CAPD dose of 2.1 to 2.2. A 1-unit increase in Kt/V was associated with 7% lower risk of death on HD and with a similar 8% lower risk of death while on CAPD. Patients with diabetes aged 46 to 60 yr had virtually identical 2-yr survival estimates on HD (83 to 90%), compared with CAPD (83 to 89%), with Kt/V ranges from 0.84 to 1.70 in HD and from 1.6 to 2.2 weekly Kt/V on peritoneal dialysis. Comparisons between HD and CAPD in older patients with diabetes yielded comparable results. Patient survival is highly influenced by delivered dialysis in both HD and peritoneal dialysis. Carefully matching of the therapies with delivered Kt/V demonstrates little differences in the survival outcome of HD and peritoneal dialysis patients, in contrast to some previous reports.

Relative contribution of residual renal function and peritoneal clearance to adequacy of dialysis: a reanalysis of the CANUSA study.

Studies of the adequacy of peritoneal dialysis and recommendations have assumed that renal and peritoneal clearances are comparable and therefore additive. The CANUSA data were reanalyzed in an effort to address this assumption. Among the 680 patients in the original CANUSA study, 601 had all of the variables of interest for this report. Adequacy of dialysis was estimated from GFR (mean of renal urea and creatinine clearance) and from peritoneal creatinine clearance. The Cox proportional-hazards model was used to evaluate the time-dependent association of these independent variables with patient survival. For each 5 L/wk per 1.73 m(2) increment in GFR, there was a 12% decrease in the relative risk (RR) of death (RR, 0.88; 95% confidence interval [CI], 0.83 to 0.94) but no association with peritoneal creatinine clearance (RR, 1.00; 95% CI, 0.90 to 1.10). Estimates of fluid removal (24-h urine volume, net peritoneal ultrafiltration, and total fluid removal) then were added to the Cox model. For a 250-ml increment in urine volume, there was a 36% decrease in the RR of death (RR, 0.64; 95% CI, 0.51 to 0.80). The association of patient survival with GFR disappeared (RR, 0.99; 95% CI, 0.94 to 1.04). However, neither net peritoneal ultrafiltration nor total fluid removal was associated with patient survival. Although these results may be explained partly, statistically, by less variability in peritoneal clearance than in GFR, the latter seems to be physiologically more important than the former. The assumption of equivalence of peritoneal and renal clearances is not supported by these data. Recommendations for adequate peritoneal dialysis need to be reevaluated in light of these observations.