Dialysate and serum potassium in hemodialysis.

Most patients with end-stage renal disease depend on intermittent hemodialysis to maintain levels of serum potassium and other electrolytes within a normal range. However, one of the challenges has been the safety of using a low-potassium dialysate to achieve that goal, given the concern about the effects that rapid and/or large changes in serum potassium concentrations may have on cardiac electrophysiology and arrhythmia. Additionally, in this patient population, there is a high prevalence of structural cardiac changes and ischemic heart disease, making them even more susceptible to acute arrhythmogenic triggers. This concern is highlighted by the knowledge that about two-thirds of all cardiac deaths in dialysis are due to sudden cardiac death and that sudden cardiac death accounts for 25% of the overall death for end-stage renal disease. Developing new approaches and practice standards for potassium removal during dialysis, as well as understanding other modifiable triggers of sudden cardiac death, such as other electrolyte components of the dialysate (magnesium and calcium), rapid ultrafiltration rates, and safety of a number of medications (ie, drugs that prolong the QT interval or use of digoxin), are critical in order to decrease the unacceptably high cardiac mortality experienced by hemodialysis-dependent patients.

Provision of antioxidant therapy in hemodialysis (PATH): a randomized clinical trial.

Increased markers of oxidative stress and acute-phase inflammation are prevalent in patients undergoing maintenance hemodialysis therapy (MHD), and are associated with increased mortality and hospitalization rates and decreased erythropoietin responsiveness. No adequately powered studies have examined the efficacy of antioxidant therapies on markers of inflammation and oxidative stress. We tested the hypothesis that oral antioxidant therapy over 6 months would decrease selected biomarkers of acute-phase inflammation and oxidative stress and improve erythropoietic response in prevalent MHD patients. In total, 353 patients were enrolled in a prospective, placebo-controlled, double-blind clinical trial and randomly assigned to receive a combination of mixed tocopherols (666 IU/d) plus α-lipoic acid (ALA; 600 mg/d) or matching placebos for 6 months (NCT00237718); 238 patients completed the study. High-sensitivity C-reactive protein (hsCRP) and IL-6 concentration were measured as biomarkers of systemic inflammation, and F2 isoprostanes and isofurans were measured as biomarkers of oxidative stress. The groups did not significantly differ at baseline. At 3 and 6 months, the treatment had no significant effect on plasma hsCRP, IL-6, F2 isoprostane, or isofuran concentrations and did not improve the erythropoietic response. No major adverse events were related to the study drug, and both groups had similar mortality and hospitalization rates during the study. In conclusion, the administration of mixed tocopherols and ALA was generally safe and well tolerated, but did not influence biomarkers of inflammation and oxidative stress or the erythropoietic response.

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.

Dialysis frequency versus dialysis time, that is the question.

We reviewed a number of prospective randomized and multiple retrospective cohort studies of different dialysis prescriptions: longer dialysis time, at a frequency of at least three times a week, or a frequency of daily hemodialysis with a shorter dialysis time. Interestingly, the retrospective analyses have generally found significant survival benefits in the intensive dialysis groups, whereas more modest effects were observed in the prospective randomized controlled trials. The reason for this discrepancy may be related to the retrospective nature of the studies and possible selection bias; for example, the patients who were prescribed more frequent dialysis may have had more difficulties with volume control or high blood pressure. In contrast, the randomized controlled trials of increased dialysis frequency, which have shown indirect and modest benefits in complex coprimary end points, have small sample sizes and are plagued with difficulties in recruitment and compliance with the randomly allocated more frequent dialysis. This review, which attempts to balance the potential benefits of more frequent dialysis with the burden on the patient's lifestyle, an increased risk of access malfunction, as well as societal costs of such intensive dialysis prescriptions, concludes in favor of the conventional three times per week dialysis (at a minimum) but at longer dialysis times than is currently prescribed based on the Kt/Vurea metric alone.

Improving outcomes by changing hemodialysis practice patterns.

PURPOSE OF REVIEW: This review examines recent advances in understanding of how clinical outcomes for hemodialysis patients may be improved by achieving longer or more frequent treatment times, lower ultrafiltration rates (UFRs), improving nutritional status, and individualizing dialysate composition. This review also discusses the controversy related to timing of dialysis initiation. RECENT FINDINGS: Many observational studies and several randomized controlled trials indicate longer dialysis treatment times, particularly nocturnal dialysis, and/or more frequent dialysis improve morbidity and mortality. Recent evidence also suggests that lower UFR and more consistent achievement of 'dry weight' may help minimize the damage from myocardial stunning and chronic volume overload that occurs in the majority of patients who receive conventional hemodialysis during the day with a standard schedule of 3-5 h, 3 times a week. Other aspects of the dialysis procedure such as appropriate estimated glomerular filtration rate for dialysis initiation and individualizing dialysate composition may also minimize cardiovascular risk. Finally, several studies have highlighted the benefits of oral nutritional supplementation (ONS) during dialysis. SUMMARY: Greater treatment times per week with slower UFR, consistent attainment of 'dry weight', individualized dialysate prescriptions, and administration of ONS to malnourished patients are likely to reduce hospitalizations and improve survival in this high-risk population of end-stage renal disease patients.

Prevalence and outcomes of antimicrobial treatment for Staphylococcus aureus bacteremia in outpatients with ESRD.

Staphylococcus bacteremia is a common and life-threatening medical emergency, but it is treatable with appropriate antibiotic therapy. To identify opportunities that may reduce morbidity and mortality associated with S. aureus, we analyzed data from 293,094 chronic hemodialysis outpatients to characterize practices of antibiotic selection. In the study population, the overall rate of bacteremia was 15.4 per 100 outpatient-years; the incidence rate for methicillin-sensitive (MSSA) was 2.1 per 100 outpatient-years, and the incidence rate for methicillin-resistant (MRSA) S. aureus was 1.9 per 100 outpatient-years. One week after the collection of the index blood culture, 56.1% of outpatients with MSSA bacteremia were receiving vancomycin, and 16.7% of outpatients with MSSA were receiving cefazolin. Among MSSA-bacteremic patients who did not die or get hospitalized 1 week after blood culture collection, use of cefazolin was associated with a 38% lower risk for hospitalization or death compared with vancomycin (adjusted HR=0.62, 95% CI=0.46-0.84). In conclusion, vancomycin is commonly used to treat MSSA bacteremia in outpatients receiving chronic dialysis, but there may be more risk of treatment failure than observed among those individuals who receive a ß-lactam antibiotic such as cefazolin.

Survival with three-times weekly in-center nocturnal versus conventional hemodialysis.

Whether the duration of hemodialysis treatments improves outcomes remains controversial. Here, we evaluated survival and clinical changes associated with converting from conventional hemodialysis (mean=3.75 h/treatment) to in-center nocturnal hemodialysis (mean=7.85 h/treatment). All 959 consecutive patients who initiated nocturnal hemodialysis for the first time in 77 Fresenius Medical Care facilities during 2006 and 2007 were eligible. We used Cox models to compare risk for mortality during 2 years of follow-up in a 1:3 propensity score-matched cohort of 746 nocturnal and 2062 control patients on conventional hemodialysis. Two-year mortality was 19% among nocturnal hemodialysis patients compared with 27% among conventional patients. Nocturnal hemodialysis associated with a 25% reduction in the risk for death after adjustment for age, body mass index, and dialysis vintage (hazard ratio=0.75, 95% confidence interval=0.61-0.91, P=0.004). With respect to clinical features, interdialytic weight gain, albumin, hemoglobin, dialysis dose, and calcium increased on nocturnal therapy, whereas postdialysis weight, predialysis systolic blood pressure, ultrafiltration rate, phosphorus, and white blood cell count declined (all P<0.001). In summary, notwithstanding the possibility of residual selection bias, conversion to treatment with nocturnal hemodialysis associates with favorable clinical features, laboratory biomarkers, and improved survival compared with propensity score-matched controls. The potential impact of extended treatment time on clinical outcomes while maintaining a three times per week hemodialysis schedule requires evaluation in future clinical trials.

Outcomes associated with intradialytic oral nutritional supplements in patients undergoing maintenance hemodialysis: a quality improvement report.

BACKGROUND: Insufficient clinical data exist to determine whether provision of oral nutritional supplements during dialysis can improve survival in hypoalbuminemic maintenance hemodialysis patients. STUDY DESIGN: Retrospective matched-cohort study. SETTING & PARTICIPANTS: All oral nutritional supplement program-eligible in-center maintenance hemodialysis patients with albumin level ≤3.5 g/dL in quarter 4 of 2009 without oral nutritional supplements in the prior 90 days at Fresenius Medical Care, North America facilities. QUALITY IMPROVEMENT PLAN: Monitored intradialytic oral nutritional supplements were provided to eligible maintenance hemodialysis patients upon physician order, to continue for a year or until serum albumin level was ≥4.0 g/dL. OUTCOME: Mortality (including deaths and withdrawals), followed up until December 31, 2010. MEASUREMENTS: Both an intention-to-treat (ITT) and an as-treated analysis was performed using a 1:1 geographic region and propensity score-matched study population (using case-mix, laboratory test, access type, 30-day prior hospitalization, and incident patient status) comparing patients treated with intradialytic oral nutritional supplements with usual-care patients. Cox models were constructed, unadjusted and adjusted for facility standardized mortality ratio and case-mix and laboratory variables. RESULTS: The ITT and as-treated analyses both showed lower mortality in the oral nutritional supplement group. The conservative ITT models with 5,227 matched pairs had 40% of controls subsequently receiving oral nutritional supplements after January 1, 2010 (because many physicians delayed participation), with comparative death rates of 30.1% versus 30.4%. The corresponding as-treated (excluding crossovers) death rates for 4,289 matched pairs were 30.9% versus 37.3%. The unadjusted ITT mortality HR for oral nutritional supplement use was 0.95 (95% CI, 0.88-1.01), and the adjusted HR was 0.91 (95% CI, 0.85-0.98); the corresponding as-treated HRs were 0.71 (95% CI, 0.66-0.76) and 0.66 (95% CI, 0.61-0.71) before and after adjustment, respectively. LIMITATIONS: Limited capture of oral nutritional supplement intake outside the facility and potential residual confounding from unmeasured variables, such as dietary intake. CONCLUSIONS: Maintenance hemodialysis patients with albumin levels ≤3.5 g/dL who received monitored intradialytic oral nutritional supplements showed survival significantly better than similar matched patient controls, with the as-treated analysis highlighting the potentially large effect of this strategy in clinical practice.

Combined angiotensin-converting enzyme inhibition and receptor blockade associate with increased risk of cardiovascular death in hemodialysis patients.

To compare the relative effectiveness of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) in reducing cardiovascular mortality in chronic hemodialysis patients, we conducted an observational analysis of all patients initiated on ACEI or ARB therapy undergoing chronic hemodialysis at a large dialysis provider. Survival curves with mortality hazard ratios (HRs) were generated using the Kaplan-Meier method and Cox regression. Outcomes were compared using inverse probability of treatment weighting and propensity score matching. Over 6 years, 22,800 patients were newly initiated on an ACEI and 5828 on an ARB after at least 60 days of chronic hemodialysis. After adjustment for baseline cardiovascular risk factors, there was no significant difference in the risk of cardiovascular, all-cause, or cerebrovascular mortality in patients initiated on an ARB compared with an ACEI (HR of 0.96). A third of 28,628 patients, newly started on an ACEI or ARB, went on to another antihypertensive medication in succession. After adjustment for risk factors, 701 patients initiated on combined ACEI and ARB therapy (HR of 1.45) or 6866 patients on ACEI and non-ARB antihypertensive agent (HR of 1.27) were at increased risk of cardiovascular death compared with 1758 patients initiated on an ARB and non-ACEI antihypertensive therapy. Thus, an ARB, in combination with another antihypertensive medication (but not an ACEI), may have a beneficial effect on cardiovascular mortality. As observational studies may be confounded by indication, even when adjusted, randomized clinical trials are needed to confirm these findings.

Effects of a nationwide predialysis educational program on modality choice, vascular access, and patient outcomes.

BACKGROUND: Patients' education about transplant, hemodialysis (HD), peritoneal dialysis (PD), and conservative care often is provided by nephrologists as needed and occurs as time allows. STUDY DESIGN: Quality improvement report. SETTING & PARTICIPANTS: Attendees of a national treatment options program (TOPs) who initiated long-term dialysis therapy (median, 3.4 months) at Fresenius Medical Care, North America facilities throughout 2008 were compared with period-prevalent incident patients receiving usual care. QUALITY IMPROVEMENT PLAN: Standardized predialysis treatment options education. OUTCOMES: Rates of opting for PD modality, arteriovenous HD access at initiation, and early (90-day) mortality risk. MEASUREMENTS: Logistic regression (for choice of PD and HD access type) and Cox models (for early mortality) were constructed, including a 1:1 matched cohort. A post hoc sensitivity analysis also compared a propensity score-matched cohort. RESULTS: 3,165 TOPs attendees (10.5% of 30,217 incident patients admitted between January 1 and December 31, 2008), were younger, more likely to be white, and had slightly larger body surface area. The unadjusted OR for TOPs attendees for selecting PD therapy was 8.45 (95% CI, 7.63-9.37) with a case-mix plus laboratory-adjusted OR of 5.13 (95% CI, 3.58-7.35). For patients who opted for in-center HD therapy, the OR was 2.14 (95% CI, 1.96-2.33) and adjusted OR was 2.06 (95% CI, 1.88-2.26) for starting with a fistula or graft. The unadjusted early mortality HR was 0.51 (95% CI, 0.43-0.60) and case-mix plus laboratory-adjusted adjusted HR was 0.61 (95% CI, 0.50-0.74) for TOPs attendees (all outcomes, P < 0.001). These results were consistent in the 1:1 matched analysis and propensity score-matched analysis. LIMITATIONS: It is possible that physicians who referred to these programs were more likely to prescribe PD therapy or place arteriovenous accesses. Motivated, treatment-adherent patients (who would have better outcomes) may have self-selected to attend education sessions. CONCLUSION: Attending an options class predialysis was associated with more frequent selection of home dialysis, fewer tunneled HD catheters, and lower mortality risk during the first 90 days of dialysis therapy.

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.

Low health literacy associates with increased mortality in ESRD.

Limited health literacy is common in the United States and associates with poor clinical outcomes. Little is known about the effect of health literacy in patients with advanced kidney disease. In this prospective cohort study we describe the prevalence of limited health literacy and examine its association with the risk for mortality in hemodialysis patients. We enrolled 480 incident chronic hemodialysis patients from 77 dialysis clinics between 2005 and 2007 and followed them until April 2008. Measured using the Rapid Estimate of Adult Literacy in Medicine, 32% of patients had limited (<9th grade reading level) and 68% had adequate health literacy (≥9th grade reading level). Limited health literacy was more likely in patients who were male and non-white and who had fewer years of education. Compared with adequate literacy, limited health literacy associated with a higher risk for death (HR 1.54; 95% CI 1.01 to 2.36) even after adjustment for age, sex, race, and diabetes. In summary, limited health literacy is common and associates with higher mortality in chronic hemodialysis patients. Addressing health literacy may improve survival for these patients.

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.

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.

Hemodialysis access failure: a call to action--revisited.

Eighty-two percent (82%) of patients initiating hemodialysis in the United States in 2006 did so with a catheter as the functioning access. Even in patients who have been followed by nephrologists for 6 months or more, 74% of patients initiated dialysis with a catheter. This is a multifactoral problem that requires attention and solutions from all stakeholders, including the nephrologist, the vascular surgeon, the hospital, and the insurance industry, as well as the patient and family. We propose a series of specific proposals that include a process for the timely referral and timely placement of a permanent access based on the patient's estimated or measured glomerular filtration rate (GFR), and a 'pay-for-performance' measure for vascular surgeons and nephrologists who admit patients with functional permanent accesses; such pay for performance would place a higher value for patients who are admitted with a functional arteriovenous (AV) fistula than for patients who are admitted with an AV graft. We also propose that hospitals develop a less permissive process for placement of PICC (peripherally inserted central catheters) lines in patients with GFR <60 ml/min and to consider surgery for access placement as 'urgent'. Finally, a more proactive educational process for patients and their families, including an 'informed non-consent' for patients who defer placement of a permanent access needs to be considered. The morbidity, mortality, and health-care costs associated with prolonged catheter use mandate urgent attention to this problem.

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.

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.