Sickle trait in African-American hemodialysis patients and higher erythropoiesis-stimulating agent dose.

African Americans require higher doses of erythropoiesis-stimulating agents (ESAs) during dialysis to manage anemia, but the influence of sickle cell trait and other hemoglobinopathy traits on anemia in dialysis patients has not been adequately evaluated. We performed a cross-sectional study of a large cohort of adult African-American hemodialysis patients in the United States to determine the prevalence of hemoglobinopathy traits and quantify their influence on ESA dosing. Laboratory and clinical data were obtained over 6 months in 2011. Among 5319 African-American patients, 542 (10.2%) patients had sickle cell trait, and 129 (2.4%) patients had hemoglobin C trait; no other hemoglobinopathy traits were present. Sickle cell trait was more common in this cohort than the general African-American population (10.2% versus 6.5%-8.7%, respectively, P<0.05). Among 5002 patients (10.3% sickle cell trait and 2.4% hemoglobin C trait) receiving ESAs, demographic and clinical variables were similar across groups, with achieved hemoglobin levels being nearly identical. Patients with hemoglobinopathy traits received higher median doses of ESA than patients with normal hemoglobin (4737.4 versus 4364.1 units/treatment, respectively, P=0.02). In multivariable analyses, hemoglobinopathy traits associated with 13.2% more ESA per treatment (P=0.001). Within subgroups, sickle cell trait patients received 13.2% (P=0.003) higher dose and hemoglobin C trait patients exhibited a similar difference (12.9%, P=0.12). Sensitivity analyses using weight-based dosing definitions and separate logistic regression models showed comparable associations. Our findings suggest that the presence of sickle cell trait and hemoglobin C trait may explain, at least in part, prior observations of greater ESA doses administered to African-American dialysis patients relative to Caucasian patients.

Abandoning peracetic acid-based dialyzer reuse is associated with improved survival.

BACKGROUND AND OBJECTIVES: Higher mortality risk reported with reuse versus single use of dialyzers is potentially related to reuse reagents that modify membrane surface characteristics and the blood-membrane interface. A key mechanism may involve stimulation of an inflammatory response. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In a prospective crossover design, laboratory markers and mortality from 23 hemodialysis facilities abandoning reuse with peracetic acid mixture were tracked. C-reactive protein (CRP), white blood cell (WBC) count, albumin, and prealbumin were measured for 2 consecutive months before abandoning reuse and subsequently within 3 and 6 months on single use. Survival models were utilized to compare the 6-month period before abandoning reuse (baseline) and the 6-month period on single use of dialyzers after a 3-month "washout period." RESULTS: Patients from baseline and single-use periods had a mean age of approximately 63 years; 44% were female, 54% were diabetic, 60% were white, and the mean vintage was approximately 3.2 years. The unadjusted hazard ratio for death was 0.70 and after case-mix adjustment was 0.74 for single use compared with reuse. Patients with CRP≥5 mg/L during reuse (mean CRP=26.6 mg/ml in April) declined on single use to 20.2 mg/L by August and 20.4 mg/L by November. WBC count declined slightly during single use, but nutritional markers were unchanged. CONCLUSIONS: Abandonment of peracetic-acid-based reuse was associated with improved survival and lower levels of inflammatory but not nutritional markers. Further study is needed to evaluate a potential link between dialyzer reuse, inflammation, and mortality.

Change in vascular access and hospitalization risk in long-term hemodialysis patients.

BACKGROUND AND OBJECTIVES: Conversion from central venous catheters to a graft or a fistula is associated with lower mortality risk in long-term hemodialysis (HD) patients; however, a similar association with hospitalization risk remains to be elucidated. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We conducted a prospective observational study all maintenance in-center HD patients who were treated in Fresenius Medical Care, North America legacy facilities; were alive on January 1, 2007; and had baseline laboratory data from December 2006. Access conversion (particularly from a catheter to a fistula or a graft) during the 4-month period from January 1 through April 30, 2007, was linked using Cox models to hospitalization risk during the succeeding 1-year follow-up period (until April 30, 2008). RESULTS: The cohort (N = 79,545) on January 1, 2007 had 43% fistulas, 29% catheters, and 27% grafts. By April 30, 2007, 70,852 patients were still on HD, and among 19,792 catheters initially, only 10.3% (2045 patients) converted to either a graft or a fistula. With catheters as reference, patients who converted to grafts/fistulas had similar adjusted hazard ratios (0.69) as patients on fistulas (0.71), while patients with fistulas/grafts who converted to catheters did worse (1.22), all P < 0.0001. CONCLUSIONS: Catheters remain associated with the greatest hospitalization risk. Conversion from a catheter to either graft or fistula had significantly lower hospitalization risk relative to keeping the catheter. Prospective studies are needed to determine whether programs that reduce catheters will decrease hospitalization risk in HD patients.

Glycemic control and extended hemodialysis survival in patients with diabetes mellitus: comparative results of traditional and time-dependent Cox model analyses.

BACKGROUND AND OBJECTIVES: The benefits and risks of aggressive glycemic control in diabetes mellitus complicated by end-stage kidney failure remain uncertain but have importance because of the large patient population with inferior overall prognosis. Recent large observational studies with differing methodologies reached somewhat contrasting conclusions regarding the association of hemoglobin A1c with survival in diabetic chronic hemodialysis patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This study supplements the authors' previous analysis (which found no correlation) by extending the follow-up period to 3 years and using time-dependent survival models with repeated measures. Among 24,875 nationally distributed study patients, 94.5% had type 2 diabetes, allowing additional analysis in the subset with type 1 diabetes. Data were collected at baseline and every quarter to a maximum of 3 years' follow-up. RESULTS: Adjusted standard and time-dependent Cox models indicated that only extremes of glycemia were associated with inferior survival. There was no effect modification by serum albumin levels, a marker of protein nutrition status, and no trend associated with random glucose measurements in a post hoc analysis. In type 1 diabetic patients, upper extreme hemoglobin A1c values indicated lower survival risk. CONCLUSIONS: Sustained extremes of glycemia were only variably and weakly associated with decreased survival in this population. In the absence of randomized, controlled trials, these results suggest that aggressive glycemic control cannot be routinely recommended for all diabetic hemodialysis patients on the basis of reducing mortality risk. Physicians are encouraged to individualize glycemic targets based on potential risks and benefits in diabetic ESRD patients.

Digoxin associates with mortality in ESRD.

The safety of prescribing digoxin in ESRD is unknown. Hypokalemia, which frequently occurs among dialysis patients, may enhance the toxicity of digoxin. Here, we analyzed the association between digoxin prescription and survival in a retrospective cohort using covariate- and propensity score-adjusted Cox models to minimize the potential for confounding by indication. Among 120,864 incident hemodialysis patients, digoxin use associated with a 28% increased risk for death (hazard ratio [HR] 1.28; 95% confidence interval 1.25 to 1.31). Increasing serum digoxin level was also significantly associated with mortality (HR 1.19 per ng/ml increase; 95% confidence interval 1.05 to 1.35). This increased mortality risk with level was most pronounced in patients with lower predialysis serum potassium (K) levels (HR 2.53 [P = 0.01] for K <4.3 mEq/L versus HR 0.86 [P = 0.35] for K >4.6 mEq/L). In conclusion, digoxin use among patients who are on hemodialysis associates with increased mortality, especially among those with low predialysis K concentrations.

Modeling the 4D Study: statins and cardiovascular outcomes in long-term hemodialysis patients with diabetes.

BACKGROUND AND OBJECTIVES: Randomized, controlled trials (RCTs) are the gold standard for defining causal inferences but are sometimes not feasible because of cost, ethical, or time considerations. We explored the accuracy and potential use of a "simulated trial" through the modeling of a previously published RCT, Die Deutsche Diabetes Dialyse Studie (4D Study), a landmark study that investigated the cardiovascular benefit of atorvastatin use in 1255 patients with ESRD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Using a large historical database of interventions and outcomes in dialysis patients, we conducted an observational model of the 4D Study in dialysis patients who had type 2 diabetes and were prescribed a statin (5144 patients) and matched to a non-statin user (5144 control subjects) before multivariate modeling. Inclusion, exclusion, and outcome parameters of the study, as prespecified by the 4D Study, were strictly modeled in this analysis. RESULTS: In covariate- and propensity-adjusted Cox regression, statin use (versus nonuse) was associated with a decrease in the composite primary outcome of cardiac death, nonfatal myocardial infarction, and stroke. Statin use was also associated with a decrease in cardiovascular mortality and all cardiac events combined. The hazard ratios in this observational model were numerically comparable to the hazard ratios reported in the 4D Study; however, because of the larger number of patients "enrolled," results in this simulated study achieved statistical significance. CONCLUSIONS: Statin use was associated with some cardiovascular benefit in a simulated trial of patients with ESRD; however, the size of benefit was considerably smaller than that seen in the general population. Such simulated trials may represent an exploratory, cost-effective option when RCTs are not immediately feasible.

Outcomes associated with in-center nocturnal hemodialysis from a large multicenter program.

BACKGROUND AND OBJECTIVES: The objective of this study was to evaluate epidemiology and outcomes of a large in-center nocturnal hemodialysis (INHD) program. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This case-control study compared patients who were on thrice-weekly INHD from 56 Fresenius Medical Care, North America facilities with conventional hemodialysis patients from 244 facilities within the surrounding geographic area. All INHD cases and conventional hemodialysis control subjects who were active as of January 1, 2007, were followed until December 31, 2007, for evaluation of mortality and hospitalization. RESULTS: As of January 1, 2007, 655 patients had been on INHD for 51 +/- 73 d. Patients were younger, there were more male and black patients, and vintage was longer, but they had less diabetes compared with 15,334 control subjects. Unadjusted hazard ratio was 0.59 for mortality and 0.76 for hospitalization. After adjustment for case mix and access type, only hospitalization remained significant. Fewer INHD patients were hospitalized (48 versus 59%) with a normalized rate of 9.6 versus 13.5 hospital days per patient-year. INHD patients had greater interdialytic weight gains but lower BP. At baseline, hemoglobin values were similar, whereas albumin and phosphorus values favored INHD. Mean equilibrated Kt/V was higher in INHD patients related to longer treatment time, despite lower blood and dialysate flow rates. CONCLUSIONS: Patients who were on INHD exhibited excellent quality indicators, with better survival and lower hospitalization rates. The relative contributions of patient selection versus effect of therapy on outcomes remain to be elucidated in prospective clinical trials.

A comparison of SF-36 and SF-12 composite scores and subsequent hospitalization and mortality risks in long-term dialysis patients.

BACKGROUND AND OBJECTIVES: The Short Form 12 (SF-12) has not been validated for long-term dialysis patients. The study compared physical and mental component summary (PCS/MCS) scores from the SF-36 with those from the embedded SF-12 in a national cohort of dialysis patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: All 44,395 patients who had scorable SF-36 and SF-12 from January 1, 2006, to December 31, 2006, and were treated at Fresenius Medical Care, North America facilities were included. Death and first hospitalization were followed for up to 1 year from the date of survey. Correlation and agreement were obtained between PCS-36 and PCS-12 and MCS-36 and MCS-12; then Cox models were constructed to compare associated hazard ratios (HRs) between them. RESULTS: Physical and mental dimensions both exhibited excellent intraclass correlation coefficients of 0.94. Each incremental point for both PCS-12 and PCS-36 was associated with a 2.4% lower adjusted HR of death and 0.4% decline in HR for first hospitalization (both P < 0.0001). Corresponding improvement in HR of death for each MCS point was 1.2% for MCS-12 and 1.3% for MCS-36, whereas both had similar 0.6% lower HR for hospitalization per point (all P < 0.0001). CONCLUSIONS: The use of the SF-12 alone or as part of a larger survey is valid in dialysis patients. Composite scores from the SF-12 and SF-36 have similar prognostic association with death and hospitalization risk. Prospective longitudinal studies of SF-12 surveys that consider responsiveness to specific clinical, situational, and interventional changes are needed in this population.

The "right" of passage: surviving the first year of dialysis.

Mortality risk for dialysis patients is highest in the first year. We previously showed a 41% mortality benefit associated with a pilot case management program for incident hemodialysis patients (n = 918). The RightStart Program (RSP) provided prompt medical management and self-management education and was recently expanded to more facilities. We conducted a matched cohort analysis to validate the expanded program's continued effectiveness. Death risk was reduced for RS patients (n = 4308) versus matched controls (C; n = 4308) by 34% (hazard ratio = 0.66, P < 0.0001) at 120 d and 22% at 1 yr (hazard ratio = 0.78, P < 0.0001). RS patients had lower hospitalization during the first year (RS = 15.5 days per patient year versus C = 16.9, P < 0.01). At 120 d, more RS patients achieved hemoglobin 11 to 12 g/dl (RS = 22.4% versus C = 19.7%, P < 0.01), eKt/V > or = 1.2 (RS = 66% versus C = 53.5%, P < 0.01), albumin > or = 4.0 g/dl (RS = 26% versus C = 22%, P < 0.01), and phosphorus 3.5 to 5.5 mg/dl (RS = 52.4% versus C = 45.4%). At 120 d, RS patients had a greater reduction in catheter use (RS = 32% versus C = 25%, P < 0.01) and more vitamin D orders (RS = 60% versus C = 55%, P < 0.01). Expansion of RS to a larger incident patient population results in significant reduction of morbidity and mortality associated with improvement of intermediate outcomes.

Change in vascular access and mortality in maintenance hemodialysis patients.

BACKGROUND: We hypothesized that a change from central venous catheters to a fistula or graft would improve short-term mortality risk in maintenance hemodialysis patients. DESIGN: Prospective observational study. SETTING & PARTICIPANTS: All maintenance in-center hemodialysis patients treated in Fresenius Medical Care, North America legacy facilities alive on January 1, 2007 with baseline laboratory data from December 2006. PREDICTOR: Access type (fistula, catheter, or graft), determined on December 31, 2006, and monthly thereafter. Conversion from a catheter to a fistula or graft during the 4-month period from January 1 to April 30, 2007. OUTCOME: Mortality was tracked from May 1, 2007, to December 31, 2007. Standard and time-dependent Cox models were used to determine hazard risks (HRs) of death with and without adjustment for case-mix and laboratory values. RESULTS: At baseline, 79,545 patients had 43% fistulas, 29% catheters, and 27% grafts. Mean age was 62 +/- 15 years, 54% were men, 51% were white, and 53% had diabetes. Compared with fistulas, unadjusted HRs of death were higher for grafts (1.22) and catheters (1.76; P < 0.001). In adjusted models, overall risk for grafts was decreased to 1.05 (95% limits, 1.003-1.100; P < 0.05) and approached that for fistulas consistently across multiple strata. Compared with patients who continued using a catheter, those who converted to either a graft or fistula had an HR of 0.69, whereas those who converted from a graft or fistula to a catheter had increased HRs to 2.12 (both P < 0.001). Similar trends were observed in the subset of incident patients (vintage < 90 days at study onset). LIMITATIONS: Observational design with residual confounding from unmeasured patient, facility, and treatment-related factors. CONCLUSIONS: Catheters have the worst associated mortality risk. Changing from a catheter to a fistula or graft is associated with significantly improved survival. The risk for grafts approached that of fistulas, providing an alternative to prolonged catheter exposure and potentially less hazardous "bridge" toward a fistula.

Association between achievement of hemodialysis quality-of-care indicators and quality-of-life scores.

BACKGROUND: Incremental achievement of quality indicator goals has been associated with progressive improvement in mortality and hospitalization risk in hemodialysis (HD) patients. STUDY DESIGN: Descriptive cross-sectional study. SETTING & PARTICIPANTS: All 33,879 HD patients treated at Fresenius Medical Care North America facilities for >90 days with scorable 36-Item Short Form Health Survey responses from January 1, 2006, to December 31, 2006. PREDICTOR: We hypothesized that achieving up to 5 HD goals before the survey (albumin >or= 4.0 g/dL, hemoglobin of 11-12 g/dL, equilibrated Kt/V >or= 1.2, phosphorus of 3.5-5.5 mg/L, and absence of HD catheter) results in better self-reported quality of life (QoL). OUTCOMES & MEASUREMENTS: Distributions of Physical and Mental Component Summary (PCS/MCS) scores within and across quality indicator categories determined during the prior 90 days from survey date (compared using analysis of covariance and linear regression models, with adjustment for case-mix and each of the quality indicators). RESULTS: Incremental achievement of up to 5 goals was associated with progressively higher PCS and MCS scores (both P for trend < 0.001). Compared with patients meeting all 5 goals (n = 4,208; reference group), case-mix-adjusted PCS score was lower by 1.8 point with only 4 goals met (n = 11,785), 3.4 points for 3 goals (n = 10,906), 4.9 points for 2 goals (n = 5,119), 5.9 points for 1 goal (n = 1,592), and 7.8 points in the 269 patients who failed to meet any goal (each P < 0.001 vs the reference group). The corresponding decreases in case-mix-adjusted MCS scores were 1.0 point for 4 goals met, 1.7 point for 3 goals, 2.3 points for 2 goals, 3.0 points for 1 goal, and 4.7 points with no goal met, with each P < 0.001 compared with the MCS score from patients who achieved all 5 goals. LIMITATIONS: Potential residual confounding from unmeasured covariates. CONCLUSION: Patients progressively meeting more quality goals report incrementally better QoL. Further studies are needed to determine whether prospective achievement of quality goals will result in improved QoL for HD patients.

Warfarin use associates with increased risk for stroke in hemodialysis patients with atrial fibrillation.

Use of warfarin, clopidogrel, or aspirin associates with mortality among patients with ESRD, but the risk-benefit ratio may depend on underlying comorbidities. Here, we investigated the association between these medications and new stroke, mortality, and hospitalization in a retrospective cohort analysis of 1671 incident hemodialysis patients with preexisting atrial fibrillation. We followed patient outcomes from the time of initiation of dialysis for an average of 1.6 yr. Compared with nonuse, warfarin use associated with a significantly increased risk for new stroke (hazard ratio 1.93; 95% confidence interval 1.29 to 2.90); clopidogrel or aspirin use did not associate with increased risk for new stroke. Analysis using international normalized ratio (INR) suggested a dose-response relationship between the degree of anticoagulation and new stroke in patients on warfarin (P = 0.02 for trend). Warfarin users who received no INR monitoring in the first 90 d of dialysis had the highest risk for stroke compared with nonusers (hazard ratio 2.79; 95% confidence interval 1.65 to 4.70). Warfarin use did not associate with statistically significant increases in all-cause mortality or hospitalization. In conclusion, warfarin use among patients with both ESRD and atrial fibrillation associates with an increased risk for stroke. The risk is greatest in warfarin users who do not receive in-facility INR monitoring.

Association between repeat hospitalization and early intervention in dialysis patients following hospital discharge.

Dialysis patients have a greater number of hospitalization events compared to patients without renal failure. Here we studied the relationship between different post-discharge interventions and repeat hospitalization in over 126,000 prevalent hemodialysis patients to explore outpatient strategies that minimize the risk of repeat hospitalization. The primary outcome was repeat hospitalization within 30 days of discharge. Compared to pre-hospitalization values, the levels of hemoglobin, albumin, phosphorus, calcium, and parathyroid hormone and weight were significantly decreased after hospitalization. Using covariate-adjusted models, those patients whose hemoglobin was monitored within the first 7 days after discharge, followed by modification of their erythropoietin dose had a significantly reduced risk for repeat-hospitalization when compared to the patients whose hemoglobin was not checked, nor was the dose of erythropoietin changed. Similarly, administration of vitamin D within the 7 days following discharge was significantly associated with reduced repeat hospitalization when compared to patients on no vitamin D. Therefore, it appears that immediate re-evaluation of anemia management orders and resumption of vitamin D soon after discharge may be an effective way to reduce repeat hospitalization.

Hemodialysis facility-based quality-of-care indicators and facility-specific patient outcomes.

BACKGROUND: We evaluated whether incremental achievement of up to 8 facility quality goals was associated with improvement in facility-specific mortality and hospitalization rates. STUDY DESIGN: Prospective observational study. SETTING & PARTICIPANTS: 1,085 Fresenius Medical Care, North America facilities providing hemodialysis (HD) for 25 or more patients during January 2006. MEASUREMENTS: The facility average for the period up to December 31, 2006, was used to determine achievement of each goal for equilibrated Kt/V, missed HD treatments, hemoglobin level, bicarbonate level, albumin level, phosphorus level, fistulae, and HD catheters. Linear regression models were used to relate facility-wide achievement of goals with facility-specific hospital days and standardized mortality ratios. RESULTS: Most facilities (64%) achieved 2 to 4 of 8 goals, with only 8% meeting more than 5 quality goals. Achieving more than 5 goals averaged 3.5 fewer hospital days/patient-year and 20% lower standardized mortality ratios (all P < 0.001). The incremental number of goals met also was associated with improvement in facility mortality (P < 0.001) and hospital days (P < 0.001). Catheter and albumin level goals were achieved least (6% and 9% of facilities, respectively), but they had the best outcomes. Facilities achieving more than 5 goals had older patients (64.0 versus 61.5 years; P < 0.001), fewer African American patients (16% versus 38%; P < 0.001), and fewer women (44% versus 46%; P = 0.003) compared with the average. LIMITATIONS: Observational design with residual confounding from unmeasured patient-, facility-, and treatment-related factors. CONCLUSIONS: Achieving more facility quality goals was significantly associated with better facility-based measurements of patient outcomes. Although these results do not establish a causal relationship, findings agree with the present practice of monitoring facility performance for continuous quality improvement.

Anticoagulant and antiplatelet usage associates with mortality among hemodialysis patients.

Many prescribe anticoagulants and antiplatelet medications to prevent thromboembolic events and access thrombosis in dialysis patients despite limited evidence of their efficacy in this population. This retrospective cohort study examined whether use of warfarin, clopidogrel, and/or aspirin affected survival in 41,425 incident hemodialysis patients during 5 yr of follow-up. The prescription frequencies for warfarin, clopidogrel, and aspirin were 8.3, 10.0, and 30.4%, respectively, during the first 90 d of initiating chronic hemodialysis. Compared with the 24,740 patients receiving none of these medications, Cox proportional hazards analysis suggested that exposure to these medications was associated with increased risk for mortality (warfarin hazard ratio [HR] 1.27 [95% confidence interval (CI) 1.18 to 1.37]; clopidogrel HR 1.24 [95% CI 1.13 to 1.35]; and aspirin HR 1.06 [95% CI 1.01 to 1.11]). The increased mortality associated with warfarin or clopidogrel use remained in stratified analyses. A covariate- and propensity-adjusted time-varying analysis, which accounted for longitudinal changes in prescription, produced similar results. In addition, matching for treatment facility and attending physician revealed similar associations between prescription and mortality. We conclude that warfarin, aspirin, or clopidogrel prescription is associated with higher mortality among hemodialysis patients. Given the possibility of confounding by indication, randomized trials are needed to determine definitively the risk and benefit of these medications.

Associates of mortality and hospitalization in hemodialysis: potentially actionable laboratory variables and vascular access.

BACKGROUND: To determine the most significant potentially actionable clinical variables associated with mortality and hospitalization risk in hemodialysis (HD) patients. STUDY DESIGN: Cohort study. SETTING & PARTICIPANTS: Adult maintenance HD patients in the Fresenius Medical Care, North America database as of January 1, 2004, with baseline information from October 1, 2003, to December 31, 2003, comprising approximately 26% of the US HD population. PREDICTORS: Case-mix (age, sex, race, diabetes, vintage, and body surface area), vascular access, and laboratory (albumin, equilibrated Kt/V, hemoglobin, calcium, phosphorus, creatinine, bicarbonate, biointact parathyroid hormone, transferrin saturation, and white blood cell count) variables. OUTCOMES: 1-year mortality and hospitalization risk from January 1 to December 31, 2004. MEASUREMENTS: Cox proportional hazards models for death and hospitalization. RESULTS: The cohort (N = 78,420) had a mean age of 61.4 +/- 15.0 years, 47% were women, 49% were white, 41% were black race (10% defined as "other"), and 52% had diabetes. The top 5 actionable variables were the same for mortality and hospitalization. Final case-mix plus laboratory-adjusted hazard ratios for these top 5 actionable variables indicate 177% increased risk of death and 67% increased risk of hospitalization per 1-g/dL decrease in albumin level, 39% and 45% greater risk with catheters compared with fistulas, 18% and 9% greater risk per 1-mg/dL greater phosphorus level, 11% and 9% lower risk per 1-g/dL greater hemoglobin level, and 5% and 2% greater risk per 0.1-unit decrease in equilibrated Kt/V, respectively (all P < 0.0001). LIMITATIONS: Observational cross-sectional study with limited comorbidity adjustment (for diabetes). CONCLUSION: The same variables are associated with both mortality and hospitalization in HD patients. The top 5 potentially actionable variables are readily identifiable, with albumin level and catheter use the most prominent, and all 5 are appropriate targets for improvement.

The association of race with erythropoietin dose in patients on long-term hemodialysis.

BACKGROUND: Medicare data indicate that black hemodialysis patients receive greater doses of erythropoietin (EPO) than white patients when achieving similar hemoglobin levels. We confirmed and evaluated this observed association between race and EPO dose. STUDY DESIGN: Cross-sectional cohort study. SETTING & PARTICIPANTS: Primary Medicare-insured white (57%) and black (43%) adult long-term hemodialysis patients treated by Fresenius Medical Care who received EPO from January 1 to 31, 2004 (N = 44,721). PREDICTOR: White/black race. OUTCOMES: Average weekly EPO dose. MEASUREMENTS: Associations between race and baseline demographic and laboratory variables were evaluated by using logistic and linear regression models. Correlates of log-transformed weekly EPO dose were determined using linear regression models. RESULTS: Black patients received 12.6% more EPO than white patients (95% limits, 10.9% to 14.3%; P < 0.001). This racial difference in EPO dose was observed across similar hemoglobin levels despite fewer catheters (P < 0.001) and fewer prior hospitalization events in black patients (P = 0.002). Black patients were younger and had larger body size and greater albumin and biointact parathyroid hormone levels, but lower equilibrated Kt/V and white blood cell counts (all P < 0.001). In the 95th percentile of EPO dose (those receiving > 60,000 U/wk), there was a greater proportion of black patients (6% of total black population compared with only 4% in all white patients; P < 0.001). The difference in EPO dose between black and white patients was modified by age and was significant at ages younger than 45 and 65 years or older. LIMITATIONS: Observational study limited to white and black adult Medicare patients only, correlating with EPO doses from a single month, without adjustment for comorbid conditions. CONCLUSIONS: Black patients were administered approximately 12% greater EPO doses than white patients while achieving similar hemoglobin levels. We identified variables that differed across race that may explain this difference, but they were either not actionable or presented limited opportunity for intervention. Additional studies are needed to define a physiological (or pathological) basis for these observations.

Comparison of hemodialysis blood access flow rates using online measurement of conductivity dialysance and ultrasound dilution.

BACKGROUND: Routine access flow (AF) surveillance is recommended by the Kidney Disease Outcomes Quality Initiative as one of several components for an arteriovenous vascular access maintenance program. A reliable, but affordable, measurement tool is needed for outpatient hemodialysis facilities. STUDY DESIGN: Diagnostic test study. SETTING & PARTICIPANTS: 50 adult patients with 27 grafts and 23 fistulas from a single center who consented to sequential AF measurements, all performed within the first 90 minutes of the hemodialysis treatment. INDEX TEST: AF measured by using online conductivity dialysance (OLC-AF). REFERENCE TEST: AF measured by using ultrasound dilution (UD-AF). RESULTS: Mean UD-AF was 1,086 +/- 629 mL/min, and mean OLC-AF was 951 +/- 575 mL/min, with a mean difference of 135 +/- 229 mL/min. OLC-AF correlated significantly with UD-AF (0.93; P < 0.0001), becoming tighter for flows less than 1,000 mL/min (0.95; P < 0.0001). The coefficient of variation for sequential measurement by using UD was 6.4%, and for OLC, 11.5%, with the difference becoming insignificant (7.6% versus 8.8%; P = 0.5) for flows less than 1,000 mL/min. The average of 2 sequential UD-AF measurements correlated tightly with that of OLC-AF (0.99; P < 0.0001). LIMITATIONS: Tests were performed by 2 highly trained coordinators in a single clinic with a small sample size, and clinical outcomes were not evaluated. CONCLUSION: The OLC method is a reasonable alternative to UD for flow surveillance of arteriovenous hemodialysis accesses and provides an option for widespread implementation of a vascular access surveillance program. Additional studies are needed to determine whether routine use impacts on clinical outcomes.

Potential impact of nutritional intervention on end-stage renal disease hospitalization, death, and treatment costs.

OBJECTIVE: Our objective was to estimate the effect of an improvement in nutrition, represented by albumin concentrations, on hospitalization, mortality, and Medicare end-stage renal disease (ESRD) program cost. DESIGN: Based on published trials, the impact of an improvement in serum albumin of +0.2 g/dL from a hypothetical nutritional program for severely malnourished patients with albumin < or = 3.5 g/dL (base case) was estimated by reassigning patients to higher albumin categories, along with outcome risks associated with the new albumin category. SETTING: Data from Fresenius Medical Care North America (Waltham, MA) were utilized in regression models to determine the association between albumin and change in albumin concentration with outcomes. RESULTS: Albumin < or = 3.5 g/dL was associated with a > 2-fold increase in death and hospitalization risk, compared to > or = 4 g/dL (P < .001) in this population. An increase in albumin concentration was associated with a lower risk of death and hospitalization, whereas a declining albumin concentration led to worse outcomes. Projections for the United States dialysis population from the base case showed approximately 1400 lives saved, approximately 6000 hospitalizations averted, and approximately $36 million in Medicare cost savings resulting from a reduction of approximately 20,000 hospital days. A sensitivity analysis, varying the albumin response to +0.1 and +0.3 g/dL combined with varying albumin responder rates to 25% and 75% of patients, revealed robust results. CONCLUSION: Nutritional interventions that increase serum albumin by > or = 0.2 g/dL (e.g., via oral nutritional supplements) may lead to considerable improvements in mortality, hospitalization, and treatment costs.