Hospitalization risks related to vascular access type among incident US hemodialysis patients.

BACKGROUND: The excess morbidity and mortality related to catheter utilization at and immediately following dialysis initiation may simply be a proxy for poor prognosis. We examined hospitalization burden related to vascular access (VA) type among incident patients who received some predialysis care. METHODS: We identified a random sample of incident US Dialysis Outcomes and Practice Patterns Study hemodialysis patients (1996-2004) who reported predialysis nephrologist care. VA utilization was assessed at baseline and throughout the first 6 months on dialysis. Poisson regression was used to estimate the risk of all-cause and cause-specific hospitalizations during the first 6 months. RESULTS: Among 2635 incident patients, 60% were dialyzing with a catheter, 22% with a graft and 18% with a fistula at baseline. Compared to fistulae, baseline catheter use was associated with an increased risk of all-cause hospitalization [adjusted relative risk (RR) = 1.30, 95% confidence interval (CI): 1.09-1.54] and graft use was not (RR = 1.07, 95% CI: 0.89-1.28). Allowing for VA changes over time, the risk of catheter versus fistula use was more pronounced (RR = 1.72, 95% CI: 1.42-2.08) and increased slightly for graft use (RR = 1.15, 95% CI: 0.94-1.41). Baseline catheter use was most strongly related to infection-related (RR = 1.47, 95% CI: 0.92-2.36) and VA-related hospitalizations (RR = 1.49, 95% CI: 1.06-2.11). These effects were further strengthened when VA use was allowed to vary over time (RR = 2.31, 95% CI: 1.48-3.61 and RR = 3.10, 95% CI: 1.95-4.91, respectively). A similar pattern was noted for VA-related hospitalizations with graft use. Discussion. Among potentially healthier incident patients, hospitalization risk, particularly infection and VA-related, was highest for patients dialyzing with a catheter at initiation and throughout follow-up, providing further support to clinical practice recommendations to minimize catheter placement.

Physical exercise among participants in the Dialysis Outcomes and Practice Patterns Study (DOPPS): correlates and associated outcomes.

BACKGROUND: Levels of physical exercise among haemodialysis patients are low. Increased physical activity in this population has been associated with improved health-related quality of life (HRQoL) and survival. However, results of previous studies may not be applicable to the haemodialysis population as a whole. The present study provides the first description of international patterns of exercise frequency and its association with exercise programmes and clinical outcomes among participants in the Dialysis Outcomes and Practice Patterns Study (DOPPS). METHODS: Data from a cross section of 20,920 DOPPS participants in 12 countries between 1996 and 2004 were analysed. Regular exercise was defined as exercise frequency equal to or more than once/week based on patient self-report. Linear mixed models and logistic regression assessed associations of exercise frequency with HRQoL and other psychosocial variables. Mortality risk was calculated in Cox proportional hazard models using patient-level (patient self-reported exercise frequency) and facility-level (the dialysis facility percentage of regular exercisers) predictors. RESULTS: Regular exercise frequency varied widely across countries and across dialysis facilities within a country. Overall, 47.4% of participants were categorized as regular exercisers. The odds of regular exercise was 38% higher for patients from facilities offering exercise programmes (adjusted odds ratio = 1.38 [95% confidence interval: 1.03-1.84]; P = 0.03). Regular exercisers had higher HRQoL, physical functioning and sleep quality scores; reported fewer limitations in physical activities; and were less bothered by bodily pain or lack of appetite (P

Modifiable practice patterns and patient outcomes: implications for nephrology nursing care.

Data indicate that patient outcomes are significantly affected by factors that can be modified through clinical practices, such as vascular access choice, dialysis dose, interdialytic weight gain, albumin and hemoglobin levels, and mineral and bone disorders. This article reviews recommended treatment guidelines for these factors and the ways patient outcomes are affected when targets are not achieved. Insights on how nursing practices can positively affect these components of care are also provided.

Conversion of vascular access type among incident hemodialysis patients: description and association with mortality.

BACKGROUND: Limited data exist describing vascular access conversions during the first year on dialysis therapy or the effect of converting to and from a catheter on subsequent mortality risk. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: We studied a random sample of incident US hemodialysis patients (initiated long-term dialysis < 30 days before study entry) in the Dialysis Outcomes and Practice Patterns Study (DOPPS; 1996-2004). PREDICTORS: At dialysis therapy initiation, we assessed vascular access type in use (arteriovenous fistula [AVF], arteriovenous graft [AVG], or catheter) and other patient characteristics. We characterized changes in vascular access type (conversions) by using regularly collected functional status information. OUTCOME & MEASUREMENTS: We assessed time to all-cause mortality. We first described conversions, then used time-dependent Cox regression to estimate mortality hazard ratios (HRs) for conversions from a catheter to a permanent vascular access (versus no conversion) and conversions from a permanent vascular access to a catheter (versus no conversion). RESULTS: The study included 4,532 patients; 69.2% were dialyzing with a catheter; 17.6%, with an AVG; and 13.1%, with an AVF. In patients initiating therapy with an AVF or AVG, 22% experienced a conversion (failure), and median times to first failure were 62 and 84 days, respectively. In catheter patients, 59% converted to an AVF/AVG (predominantly AVG [57%]); median times to first conversion were 92 and 66 days, respectively. Conversion to a permanent access was associated with an adjusted mortality HR of 0.69 (95% confidence interval, 0.55 to 0.85). The effect was similar for conversion to an AVF or AVG, and these persisted across demographic groups and facilities with different conversion practices. Conversion from a permanent vascular access to a catheter was associated with an adjusted mortality HR of 1.81 (95% confidence interval, 1.22 to 2.68). LIMITATIONS: Potential for residual confounding because of unmeasured factors influencing decision to convert. CONCLUSION: Vascular access conversions are common in incident patients. Continued efforts to increase early nephrologist referral and permanent vascular access placement may help decrease mortality risk in incident dialysis patients.

High alkaline phosphatase levels in hemodialysis patients are associated with higher risk of hospitalization and death.

We evaluated risks associated with elevated alkaline phosphatase in hemodialysis patients using longitudinal data from the Dialysis Outcomes and Practice Patterns Study, a prospective observational study of hemodialysis patients in 12 countries. Alkaline phosphatase levels were normalized by the upper limit of the laboratory-reported reference range. Cause-specific hospitalization and mortality risks were evaluated using Cox proportional hazards models, stratified by region and adjusted for phosphorus, calcium, albumin, parathyroid hormone, case mix, and numerous comorbidities. The odds of high normalized alkaline phosphatase were increased twofold in the United States in comparison to Japan. Elevations of normalized alkaline phosphatase were significantly associated with several comorbid conditions, increased fractures, parathyroidectomy, risk of hospitalization due to major adverse cardiac events, higher all-cause cardiovascular, and infection-related mortality risk. Our results also show that elevated serum normalized alkaline phosphatase was associated with higher risks of hospitalization and death in hemodialysis patients, independent of calcium, phosphorus, and parathyroid hormone levels.

Exploring relative mortality and epoetin alfa dose among hemodialysis patients.

BACKGROUND: Confounding-by-indication is a bias in nonexperimental studies that occurs when outcomes are compared for treated and untreated patients and the treatment or medication dose is related to predictors of the outcome. Two recent publications reported that greater epoetin alfa (EPO) doses were associated with increased mortality rates. We assessed whether confounding-by-indication might account for these results. STUDY DESIGN: We used a retrospective cohort study design. SETTING & PARTICIPANTS: Hemodialysis patients were randomly selected from a large dialysis organization from July 2000 to June 2002 and were required to have completed a 9-month baseline period. PREDICTOR: EPO dose assessed during months 7 to 9 of the baseline period and monthly throughout the follow-up period. Hemoglobin (Hb) was assessed as average value during months 4 to 6 of the baseline period and monthly throughout the follow-up period. All other covariates were assessed during months 1 to 6 of the baseline period. OUTCOME: All-cause mortality during the 1 year of follow-up. Baseline Cox models were fitted with log EPO and Hb with and without adjustment for baseline patient characteristics. Time-dependent models were fitted with time-varying log EPO and Hb and, separately, lagged log EPO and Hb, with adjustment for baseline patient characteristics. RESULTS: 22,955 patients met our inclusion criteria. In the unadjusted model, we observed increased mortality risk with increasing EPO dose (hazard ratio [HR], 1.31 per log unit increase; 95% confidence interval [CI], 1.26 to 1.36). Adjustment for baseline patient characteristics resulted in an appreciably decreased HR (HR, 1.21; 95% CI, 1.15 to 1.28). In the lagged time-dependent analyses, estimates ranged from HR of 0.93 (95% CI, 0.92 to 0.95) to HR of 1.01 (95% CI, 0.99 to 1.03) for the 1- and 2-month lagged models, respectively. LIMITATIONS: This analysis was limited to prevalent hemodialysis patients, and inhospital EPO dosing information was unavailable. CONCLUSIONS: The observed mortality risk estimates associated with EPO dose in nonexperimental studies in dialysis patients may be highly sensitive to the analytic method used. This highlights the complexity of evaluating the association between EPO dose, Hb level, and mortality in these studies.

Safety of erythropoiesis stimulating agents in patients on dialysis: current issues for nephrology nurses.

Clinical data have repeatedly shown that the erythropoiesis stimulating agents (ESAs) Epoetin alfa and darbepoetin alfa are safe and efficacious to treat anemia in patients on dialysis when used in accordance with the product label The safety profile of ESAs has recently been updated based on reports from clinical investigations that studied off-label uses of ESAs at doses designed to raise the Hb to above 13.0 g/dL. This article reviews the recent safety data and the current prescribing recommendations, with an emphasis on the need to follow the guidelines found in the products' package inserts to ensure the safe and efficacious use of these agents.

Peripheral arterial disease in patients with end-stage renal disease: observations from the Dialysis Outcomes and Practice Patterns Study (DOPPS).

BACKGROUND: Patients with end-stage renal disease are at high risk for cardiovascular morbidity and mortality. The aims of the present study were to describe the prevalence of peripheral arterial disease (PAD) and its effects on prognosis and health-related quality of life (HRQOL) in an international cohort of patients on hemodialysis. METHODS AND RESULTS: Data from the Dialysis Outcomes and Practice Patterns Study (DOPPS), a prospective, international, observational study of hemodialysis patients (n=29,873), were analyzed. Associations between baseline clinical variables and PAD were evaluated by logistic regression analysis. Cox regression models were used to test the association between PAD and risk for all-cause mortality, cardiac mortality, and hospitalization. PAD was diagnosed in 7411 patients (25.3%) with significant geographic variation. Traditional cardiovascular risk factors including age, male sex, diabetes, hypertension, and smoking were identified, together with the duration of hemodialysis, as significant correlates of PAD. Diagnosis of PAD was associated with increased all-cause mortality (hazard ratio [HR]=1.36; P<0.0001), cardiac mortality (HR=1.43; P<0.0001), all-cause hospitalization (HR=1.19; P<0.0001), and hospitalization for a major adverse cardiovascular event (HR=2.05; P<0.0001). HRQOL questionnaires revealed physical health scores that were significantly lower in PAD compared with non-PAD patients (P<0.0001). CONCLUSIONS: PAD is common in hemodialysis patients and is associated with increased risk of cardiovascular mortality, morbidity, and hospitalization and reduced HRQOL.

Pruritus in haemodialysis patients: International results from the Dialysis Outcomes and Practice Patterns Study (DOPPS).

BACKGROUND: Pruritus affects many haemodialysis (HD) patients. In this study, pruritus and its relationship to morbidity, mortality, quality of life (QoL), sleep quality and patient laboratory measures were analysed in >300 dialysis units in 12 countries. METHODS: Pruritus data were collected from 18 801 HD patients in the Dialysis Outcomes and Practice Patterns Study (DOPPS) (1996-2004). Analyses were adjusted for age, gender, black race, Kt/V, haemoglobin, serum albumin, albumin-corrected serum calcium, serum phosphorus, 13 comorbidities, depression, years on dialysis, country and facility clustering effects. RESULTS: Moderate to extreme pruritus was experienced by 42% of prevalent HD patients in DOPPS during 2002/2003. Many patient characteristics were significantly associated with pruritus, but this did not explain the large differences in pruritus between countries (ranging from 36% in France to 50% in the UK) and between facilities (5-75%). Pruritus was slightly less common in patients starting HD than in patients on dialysis >3 months. Pruritus in new end-stage renal disease (ESRD) patients likely results from pre-existing conditions and not haemodialysis per se, indicating the need to understand development of pruritus before ESRD. Patients with moderate to extreme pruritus were more likely to feel drained [adjusted odds ratio (AOR) = 2.3-5.2, P < 0.0001] and to have poor sleep quality (AOR = 1.9-4.1, P < or = 0.0002), physician-diagnosed depression (AOR = 1.3-1.7, P < or = 0.004), and QoL mental and physical composite scores 3.1-8.6 points lower (P < 0.0001) than patients with no/mild pruritus. Pruritus in HD patients was associated with a 17% higher mortality risk (P < 0.0001), which was no longer significant after adjusting for sleep quality measures. CONCLUSIONS: The pruritus/mortality relationship may be substantially attributed to poor sleep quality. The many poor outcomes associated with pruritus underscore the need for better therapeutic agents to provide relief for the 40-50% of HD patients affected by pruritus.

Factors associated with "do not resuscitate" orders and rates of withdrawal from hemodialysis in the international DOPPS.

BACKGROUND: Worldwide statistics on practice patterns regarding "do not resuscitate" (DNR) orders and patient withdrawal from hemodialysis have not been uniformly collected or analyzed. METHODS: Using data concerning adult hemodialysis patients randomly selected from 308 representative dialysis facilities in France, Germany, Italy, Japan, Spain, the United Kingdom, and the United States participating in the Dialysis Outcomes and Practice Patterns Study, DNR orders were tabulated at study entry from a prevalent cross-section of patients (N = 8615), using multivariate logistic regression to investigate characteristics associated with DNR status, Cox models to identify risk factors for withdrawal from hemodialysis, and scores from the mental component summary (MCS) and physical component summary (PCS) of the SF-36 to assess health-related quality of life. RESULTS: The United States had the highest prevalence of DNR orders (7.5%) and rate of withdrawal from hemodialysis (3.5 per 100 patient-years). Significant and independent associations with higher odds ratio (OR) of DNR were observed for older age (OR 1.16 per 10 years higher, P = 0.03) and nursing home residence (OR 2.34, P = 0.003), and with higher relative risk (RR) of withdrawal from dialysis (RR 2.38, P < 0.001). Patients who withdrew from hemodialysis died within a mean of 7.8 days and a median of 6.0 days. CONCLUSION: The higher prevalence of DNR and rate of withdrawal from hemodialysis in the United States are consistent with its greater legal and cultural emphasis on patient autonomy. By showing characteristics associated with these outcomes, this study contributes to our understanding of why hemodialysis patients request DNR or withdraw from treatment.

Dose of dialysis: key lessons from major observational studies and clinical trials.

Analyses based on the National Cooperative Dialysis Study (NCDS) provided the impetus for routine quantification of delivered dialysis dose in hemodialysis practice throughout the world, by suggesting minimum targets for small solute (urea) clearance. Morbidity and mortality in dialysis populations remain high despite many technological advances in dialysis delivery. A number of observational studies reported association between higher dose of dialysis as measured by Kt/V urea or urea reduction ratio with lower mortality risk. During the 1990s, a steady increase in dialysis dose and a modest reduction in mortality on dialysis were observed. However, observational studies only reveal associations and are limited by selection bias and confounding. The Kidney Disease Outcomes Quality Initiative guidelines on dialysis adequacy are based on results of observational studies and expert opinion. Since the NCDS, the HEMO Study was the first major randomized clinical trial designed to study the effect of dose of dialysis and dialyzer flux on patient outcomes. Despite adequate separation of dose and flux, however, results of the trial did not prove a beneficial effect of higher dose. The Dialysis Outcomes and Practice Patterns Study (DOPPS), in a major international effort designed to examine the effect of practice patterns on outcomes, has made significant contributions to the topic of dialysis dose. The following review critically examines data from observational studies, including the DOPPS, and from the HEMO Study, emphasizing important lessons from both, and discusses future paradigms for achieving dialysis adequacy to improve patient outcomes.

Association of predialysis serum bicarbonate levels with risk of mortality and hospitalization in the Dialysis Outcomes and Practice Patterns Study (DOPPS).

BACKGROUND: Experimental and some clinical data suggest that metabolic acidosis contributes to poor nutritional status, a strong predictor for mortality in hemodialysis patients. However, recent cross-sectional studies indicate that severe predialysis metabolic acidosis is associated with a greater normalized protein catabolic rate (nPCR) and greater serum albumin levels. Given this controversy, we analyzed data from the Dialysis Outcomes and Practice Pattern Study (DOPPS) for associations between predialysis serum bicarbonate and albumin concentrations, nPCR, and patient risk for mortality and hospitalization. METHODS: Data from more than 7,000 representative and randomly selected hemodialysis DOPPS patients from France, Germany, Italy, Japan, Spain, the United Kingdom, and the United States were analyzed. Serum bicarbonate (total CO2 ) levels predialysis were corrected to the midweek interdialytic interval. RESULTS: The midweek predialysis serum bicarbonate level averaged 21.9 mEq/L (mmol/L) and correlated inversely with nPCR, serum albumin, and serum phosphorus values. Before and after adjusting for 15 comorbidities, nutrition, and equilibrated Kt/V, a U-curve best represented the association between predialysis serum bicarbonate level and risk for mortality or hospitalization. Patients with midweek predialysis serum bicarbonate levels of 20.1 to 21.0 mEq/L (mmol/L) faced the lowest risk for mortality, whereas those with bicarbonate levels of 21.1 to 22.0 mEq/L faced the lowest risk for hospitalization. Both high (>27 mEq/L) and low (< or =17 mEq/L) serum bicarbonate levels were associated with increased risk for mortality and hospitalization. CONCLUSION: Moderate predialysis acidosis seems to be associated with better nutritional status and lower relative risk for mortality or hospitalization than is observed in patients with normal ranges of midweek predialysis serum bicarbonate concentration (approximately 24 mEq/L) or severe acidosis (<16 mEq/L).

Nonadherence in hemodialysis: associations with mortality, hospitalization, and practice patterns in the DOPPS.

BACKGROUND: Nonadherence among hemodialysis patients compromises dialysis delivery, which could influence patient morbidity and mortality. The Dialysis Outcomes and Practice Patterns Study (DOPPS) provides a unique opportunity to review this problem and its determinants on a global level. METHODS: Nonadherence was studied using data from the DOPPS, an international, observational, prospective hemodialysis study. Patients were considered nonadherent if they skipped one or more sessions per month, shortened one or more sessions by more than 10 minutes per month, had a serum potassium level openface>6.0 mEq/L, a serum phosphate level openface>7.5 mg/dL (>2.4 mmol/L), or interdialytic weight gain (IDWG)>5.7% of body weight. Predictors of nonadherence were identified using logistic regression. Survival analysis used the Cox proportional hazards model adjusting for case-mix. RESULTS: Skipping treatment was associated with increased mortality [relative risk (RR) = 1.30, P = 0.01], as were excessive IDWG (RR = 1.12, P = 0.047) and high phosphate levels (RR = 1.17, P = 0.001). Skipping also was associated with increased hospitalization (RR = 1.13, P = 0.04), as were high phosphate levels (RR = 1.07, P = 0.05). Larger facility size (per 10 patients) was associated with higher odds ratios (OR) of skipping (OR = 1.03, P = 0.06), shortening (OR = 1.03, P = 0.05), and IDWG (OR = 1.02, P = 0.07). An increased percentage of highly trained staff hours was associated with lower OR of skipping (OR = 0.84 per 10%, P = 0.02); presence of a dietitian was associated with lower OR of excessive IDWG (OR = 0.75, P = 0.08). CONCLUSION: Nonadherence was associated with increased mortality risk (skipping treatment, excessive IDWG, and high phosphate) and with hospitalization risk (skipping, high phosphate). Certain patient/facility characteristics also were associated with nonadherence.

The effects of higher hemoglobin levels on mortality and hospitalization in hemodialysis patients.

BACKGROUND: The introduction of recombinant human erythropoietin for the treatment of anemia of chronic renal failure provided the opportunity to correct anemia in this patient population. The optimal target hemoglobin for patients with end-stage renal disease (ESRD) remains controversial. A large database of hemodialysis patients was analyzed to determine whether increasing hemoglobin level above the current Kidney Dialysis Outcomes Quality Initiative (K/DOQI) recommendations was associated with increased risk of mortality and hospitalization. METHODS: A longitudinal study of hemodialysis patients in Fresenius Medical Care-North America facilities was performed. Selection was restricted to patients in the census for 6 consecutive months from July 1, 1998 through June 30, 2000. Patient mean hemoglobin and other covariates measured during the initial 6 months were related to survival, number of hospitalizations, and length of stay over the subsequent 6 months of follow-up. RESULTS: Patients with hemoglobin <9 g/dL had an adjusted relative risk of death of 2.11 compared to those patients with 11 /=13 g/dL had an adjusted length of stay of 9.6 days compared to 10.9 days for those with 11 12 g/dL.