Survival differences between peritoneal dialysis and hemodialysis among "large" ESRD patients in the United States

BACKGROUND: It has been hypothesized that peritoneal dialysis compared to hemodialysis may be less effective in large patients with end-stage renal disease (ESRD). METHODS: We tested this hypothesis in a cohort of 134,728 new ESRD patients who were initiated on dialysis from May 1, 1995 to July 31, 1997 using data from United States Renal Data System (USRDS). Cox regression models evaluated the association of body mass index (BMI) in quintiles (8.8-20.9, 20.9-23.5, 23.5-26.1, 26.1-30.0, 30.0-75.2 kg/m(2)) with mortality over 2 years in peritoneal dialysis and hemodialysis patients separately, while time-dependent models evaluated the relative risk (RR) of death by modality for each BMI quintile. RESULTS: For hemodialysis, the adjusted RR of death was greatest for patients with BMI 30.0 (RR = 0.97, 95% CI 0.96-0.99 for diabetic and RR = 0.97, 95% CI 0.95-0.98 for nondiabetic patients) compared with the referent (23.5-26.1; RR = 1.00). For peritoneal dialysis, the RR of death was also higher for patients with a BMI <20.9 (RR = 1.20, 95% CI 1.00-1.43 for diabetic and RR = 1.39, 95% CI 1.19-1.64 for nondiabetic patients) but no survival advantage was associated with higher BMI values. The RR of death (peritoneal dialysis/hemodialysis) for each BMI quintile was 0.99, 1.12, 1.26 (P < 0.01), 1.15 (P < 0.01), and 1.44 (P < 0.0001) for diabetic and were 1.07, 1.01, 0.96, 1.04, and 1.22 (P < 0.01) for nondiabetic patients, respectively. CONCLUSION: We conclude that body size modifies the impact of dialysis modality on mortality risk among new ESRD patients in the United States. The selection of hemodialysis over peritoneal dialysis was associated with a survival advantage in patients with large body habitus.     

Mortality differences by dialysis modality among incident ESRD patients with and without coronary artery disease

It is unclear whether peritoneal dialysis (PD) compared with hemodialysis (HD) confers a survival advantage in end-stage renal disease (ESRD) patients with coronary artery disease (CAD). This hypothesis was tested in a national cohort of 107,922 patients starting dialysis therapy between May 1, 1995, and July 31, 1997. Data on patient characteristics were obtained from the Center for Medicare and Medicaid Services Medical Evidence Form (CMS) and linked to mortality data from the United States Renal Data System (USRDS). Patients were classified on the basis of CAD presence and followed until death or the end of 2 yr. Nonproportional Cox regression models estimated the relative risk (RR) of death for patients with and without CAD by dialysis modality using primarily the intent-to-treat but also the as-treated approach. Diabetic patients (DM) and nondiabetic patients (non-DM) were analyzed separately. Among DM, patients with CAD treated with PD had a 23% higher RR (95% CI, 1.12 to 1.34) compared with similar HD patients, whereas patients without CAD receiving PD had a 17% higher RR (CI, 1.08 to 1.26) compared with HD. Among non-DM, patients with CAD treated with PD had a 20% higher RR (CI. 1.10 to 1.32) compared with HD patients, whereas patients without CAD had similar survival on PD or HD (RR = 0.99; CI, 0.93 to 1.05). The mortality risk for new ESRD patients with CAD differed by treatment modality. In both DM and non-DM, patients with CAD treated with PD had significantly poorer survival compared with HD. Whether differences in solute clearance and/or cardiac risk profiles between PD and HD may explain these findings deserves further investigation.     

Body mass index, dialysis modality, and survival: analysis of the United States Renal Data System Dialysis Morbidity and Mortality Wave II Study

BACKGROUND: The impact of obesity on survival in end-stage renal disease (ESRD) patients as related to dialysis modality (i.e., a direct comparison of hemodialysis with peritoneal dialysis) has not been assessed adjusting for differences in medication use, follow-up > or =2 years, or accounting for changes in dialysis modality. METHODS: We performed a retrospective cohort study of the United States Renal Data System (USRDS) Dialysis Morbidity and Mortality Wave II Study (DMMS) patients who started dialysis in 1996, and were followed until October 31 2001. Cox regression analysis was used to model adjusted hazard ratios (AHR) for mortality for categories of body mass index (BMI), both as quartiles and as > or =30 kg/m2 vs. lower. Because such a large proportion of peritoneal dialysis patients changed to hemodialysis during the study period (45.5%), a sensitivity analysis was performed calculating survival time both censoring and not censoring on the date of change from peritoneal dialysis to hemodialysis. RESULTS: There were 1675 hemodialysis and 1662 peritoneal dialysis patients. Among hemodialysis patients, 5-year survival for patients with BMI > or =30 kg/m2 was 39.8% vs. 32.3% for lower BMI (P < 0.01 by log-rank test). Among peritoneal dialysis patients, 5-year survival for patients with BMI >/=30 kg/m2 was 38.7% vs. 40.4% for lower BMI (P > 0.05 by log-rank test). In adjusted analysis, BMI > or = 30 kg/m2 was associated with improved survival in hemodialysis patients (AHR 0.89; 95% CI 0.81, 0.99; P= 0.042) but not peritoneal dialysis patients (AHR = 0.99; 95% CI, 0.86, 1.15; P= 0.89). Results were not different on censoring of change from peritoneal dialysis to hemodialysis. CONCLUSION: We conclude that any survival advantage associated with obesity among chronic dialysis patients is significantly less likely for peritoneal dialysis patients, compared to hemodialysis patients.     

Polycystic kidney disease at end-stage renal disease in the United States: patient characteristics and survival

BACKGROUND: The patient characteristics and mortality associated with autosomal dominant polycystic kidney disease have not been characterized for a national sample of end-stage renal disease (ESRD) patients. METHODS: 375,152 patients in the United States Renal Data System were initiated on ESRD therapy (including patients who eventually received renal transplants) between January 1, 1992 and June 30, 1997 and analyzed in an historical cohort study of polycystic kidney disease. RESULTS: Of the study population, 5,799 (1.5%) had polycystic kidney disease. In logistic regression, polycystic kidney disease was associated with Caucasian race (odds ratio 3.31, 95% CI, 3.09-3.54), women (1.10, 1.04-1.16), receipt of renal transplant (4.15, 3.87-4.45), peritoneal dialysis (vs. hemodialysis, 1.37, 1.27-1.49), younger age, and more recent year of first treatment for ESRD. Use of pre-dialysis EPO but not the level of serum hemoglobin at initiation of ESRD was significantly higher in patients with polycystic kidney disease. Patients with polycystic kidney disease had lower mortality compared to patients with other causes of ESRD, but patients with polycystic kidney disease had a higher adjusted risk of mortality associated with hemodialysis (vs. peritoneal dialysis) compared to patients with other causes of ESRD (hazard ratio 1.40, 1.13-1.75). CONCLUSIONS: Hematocrit at presentation to ESRD was not significantly different in patients with polycystic kidney disease compared with patients with other causes of ESRD. Peritoneal dialysis is a more frequent modality than hemodialysis in patients with polycystic kidney disease, and patients with polycystic kidney disease had an adjusted survival benefit associated with peritoneal dialysis, compared to patients with other causes of renal disease.     

Comparison and survival of hemodialysis and peritoneal dialysis in the elderly

Comparisons of clinical outcomes in hemodialysis (HD) and peritoneal dialysis (PD) patients have been marked by inconsistent results depending on the population studied and the methods used. In order to address this limitation of previous U.S. studies and to more specifically evaluate the higher-risk elderly population, we undertook a study of Medicare patients > or =67 years of age and assessed the comorbidity before they entered end-stage renal disease (ESRD) treatment. We then evaluated their survival outcomes at 6 month intervals in the follow-up period. In order to adequately assess the comorbidity we employed the Charlson comorbidity index and applied it to the comorbidity of the ESRD population up to 2 years before ESRD to characterize conditions from the start of ESRD treatment. We also counted inpatient hospital days in the 2 years prior to initiation of ESRD therapy as a marker of severity of disease. These two determinants of comorbidity were used to adjust the analysis along with other demographic and laboratory data. In the diabetic population, HD patients are shown to have a decreased risk of death, with the decrease ranging from 8% [relative risk (RR) (HD:PD) 0.82, 95% confidence interval (CI) 0.75-0.90] at month 6 to 54% [RR (HD:PD) 0.46, 95% CI 0.30-0.70] at month 48. In the nondiabetic population, HD patients are shown to have a 17% [RR (HD:PD) 1.17, 95% CI 1.07-1.28] increased risk of death in the first 6 months, and a decreased risk of death from months 6 to 48, a decrease ranging from 17% to 34%. Relative risks were significantly different from 1.0 at all intervals. These overall findings suggest that in the elderly population in the United States treated with PD had outcomes that were significantly worse than their HD patient counterparts, even after adjusting basic patient demographics, the comorbidity index, severity of disease with hospital days, demographics, and glomerular filtration rate (GFR) at the time of start of dialysis.     

Comparison of mortality risk for dialysis patients and cadaveric first renal transplant recipients in Ontario, Canada

In population-based studies, renal transplantation has been shown to improve survival compared to dialysis patients awaiting transplantation in the United States. However, dialysis mortality in the United States is higher than in Canada. Whether transplantation offers a survival advantage in regions where dialysis survival is superior to that in the United States is uncertain. This study examines a cohort of 1156 patients who started end-stage renal disease (ESRD) therapy and were wait-listed for cadaveric renal transplantation in the province of Ontario, Canada between January 1, 1990 and December 31, 1994. Patients were followed from wait-listing for renal transplant (n = 1156), to cadaveric first renal transplant (n = 722), to death, or to study end (December 31, 1995). The annual crude mortality rates for wait-listed dialysis patients and transplanted patients were 5.0 and 3.4%, respectively. In Cox proportional hazards models, mortality in wait-listed patients was associated with increased age and diabetes, but not time from onset of ESRD to wait-listing. Factors associated with death following transplantation include older age, diabetes, and longer time spent on the waiting list before transplantation. In a time-dependent Cox regression model, the relative risk of death after transplantation compared to dialysis varied in a time-dependent manner. Covariates associated with increased risk included older age, diabetes, and time from onset of ESRD to wait-listing. The average relative risk (RR) of dying was 2.91 (95% confidence interval [CI], 1.34 to 6.32) in the first 30 d after transplantation, but was significantly lower 1 yr after transplantation (RR 0.25; 95% CI, 0.14 to 0.42), indicating a beneficial long-term effect when compared to wait-listed dialysis patients. This long-term benefit was most evident in subgroups of patients with diabetes (RR 0.38; 95% CI, 0.17 to 0.87) and glomerulonephritis (RR 0.13; 95% CI, 0.04 to 0.39) as the cause of ESRD. The survival advantage associated with renal transplantation is evident in this cohort of patients with a lower wait-listed dialysis mortality than that reported previously in the United States. The magnitude of the treatment effect is consistent across studies.     

Impact of initial dialysis modality and modality switches on Medicare expenditures of end-stage renal disease patients

BACKGROUND: The number of end-stage renal disease (ESRD) enrollees and Medicare expenditures have increased dramatically. Pathways and associated Medicare expenditures in ESRD treatment need to be examined to potentially improve the efficiency of care. METHODS: This study examines the impact of initial dialysis modality choice and subsequent modality switches on Medicare expenditure in a 3-year period. The Dialysis Morbidity and Mortality Study Wave 2 data by the United States Renal Data System (USRDS) is used along with the USRDS Core CD and USRDS claims data. RESULTS: A total of 3423 incident dialysis patients (approximately equal number of peritoneal dialysis and hemodialysis) were included in the analysis. Unadjusted average annual Medicare expenditure (in 2004 dollars) for peritoneal dialysis as first modality was 53,277 dollars(95% CI 50,626 dollars-55,927 dollars), and 72,189 dollars (95% CI 67,513 dollars-76,865 dollars) for hemodialysis. Compared to "hemodialysis, no switch" subgroup, "peritoneal dialysis, no switch" had a significantly lower annual expenditure (44,111 dollars vs. 72,185 dollars) (P < 0.001). "Peritoneal dialysis, with at least one switch" and "hemodialysis, with at least one switch" had a lower or similar annual expenditure of 66,639 dollars and 72,335 dollars, respectively. After adjusting for patient characteristics, annual Medicare expenditure was still significantly lower for patients with peritoneal dialysis as the initial modality (56,807 dollars vs. 68,253 dollars) (P < 0.001). Similarly, compared to "hemdialysis, no switch" subgroup, "peritoneal dialysis, no switch" and "peritoneal dialysis, with at least one switch" had a significantly lower total expenditure. Further analysis showed that time-to-first switch also independently impacted total expenditure. CONCLUSION: Initial modality choice (peritoneal dialysis or hemodialysis) and subsequent modality switches had significant implications for Medicare expenditure on ESRD treatments.     

Changes in the prognosis for survival of patients with end-stage renal disease (ESRD) treated by hemodialysis

We started dialysis treatment in our institution in 1966, and have improved hemodialysis (HD) treatment through the induction of a biocompatible dialysis membrane, recombinant human erythropoietin, activated vitamin D and purification of the dialysate. We verified improvement of the prognosis for survival of patients with ESRD during this forty-year period, retrospectively. A total of 1,690 patients who began dialysis therapy in our hospital between January 1966 and December 2005 was studied (men: 1,047, women: 643, age: 58.6 +/- 17.4 years. They were divided into four groups (A: patients who started dialysis in the period from 1966 to 1975; n = 280, B: 1976-1985; n = 455, C: 1986-1995; n = 499, D: 1996-2005; n = 456). The mean follow-up period was 8.48 +/- 8.53 years. Of the patients 1,588 were treated with HD, 78 with peritoneal dialysis (PD), and 24 with PD or HD. Age at the initiation of dialysis increased gradually (A: 40.1 +/- 14.2 y-o, B: 53.2 +/- 15.8 y-o, C: 60.0 +/- 16.0 y-o, D: 66.4 +/- 13.8 y-o), and diabetics increased (A: 6.4%, B: 19.5%, C: 25.6%, D: 33.4%). A total of 1,180 patients died; 48.5% of these patients died of cardiovascular disease, 21.3% of infectious disease, and 6.4% of malignancy. Only 13 patients had kidney-transplants. With the Cox proportional hazard model for HD cases, age at the initiation of dialysis, gender, cause of renal disease, and the periods were significant predictors of mortality. The relative risk of mortality compared with that in A was reduced progressively: 0.796 in period B (95% confidence interval [CI]: 0.659-0.961, p = 0.0178), 0.505 in period C (95% CI: 0.409-0.623, p < 0.0001), and 0.286 in period D (95% CI: 0.223-0.366, p < 0.0001). CONCLUSIONS: Although the number of high-aged patients or diabetics with ESRD increased in these 40 years, the survival of the patients with ESRD improved.     

Survival and development of cardiovascular disease by modality of treatment in patients with end-stage renal disease.

Patients undergoing dialysis are at high risk for cardiovascular disease (CVD). The aim of this study was to evaluate the influence of hemodialysis (HD) versus peritoneal dialysis (PD) on survival and the risk of developing de novo CVD. Of the 4191 patients with end-stage renal disease (ESRD) who started renal replacement treatment (RRT) in Lombardy between 1994 and 1997, 4064 (who were on dialysis 30 d after the start of RRT) were considered for survival analysis: 2772 were on HD (mean age 60.9 yr; 21.2% diabetic) and 1292 on PD (mean age 63.6 yr; 16% diabetic). The 3120 patients who were free of CVD at the start of RRT were included in the analysis of the risk of developing de novo CVD. HD and PD were compared by use of a Cox-regression proportional hazard model, stratified by diabetic status; the explanatory covariates were age and gender. The death rate was 13.3 per 100 patient-years (13.0 on HD and 13.9 on PD); 197 (6.3%) of the 3120 patients included in the CVD analysis developed de novo CVD (128 on HD and 69 on PD). After adjustment for age, gender, and established CVD and stratification by diabetic status, there was no significant between-treatment difference in 4-yr survival (relative risk [RR], 0.91; 95% confidence interval [CI], 0.79 to 1.06). The risk of de novo CVD did not differ significantly by treatment modality (RR, 1.06; 95% CI, 0.79 to 1.43). The risk of mortality and de novo CVD for new patients with ESRD assigned to HD or PD was similar in Lombardy in the period 1994 through 1997.     

Survival analysis of pediatric dialysis patients in Taiwan

Aim: The long‐term survival of Taiwanese children with end‐stage renal disease (ESRD) has not been reported before. This study aimed to determine the long‐term survival, mortality hazards and causes of death in paediatric patients receiving dialysis. Methods: Paediatric patients (aged 19 years and younger) with incident ESRD who were reported to the Taiwan Renal Registry from 1995 to 2004 were included. A total of 319 haemodialysis (HD) and 156 peritoneal dialysis (PD) patients formed the database. After stratification by dialysis modality, multivariate Cox proportional‐hazards model was constructed with age, sex and co‐morbidity as predictive variables. Results: The annual paediatric ESRD incidence rate was 8.12 per million of age‐related populations. The overall 1‐, 5‐, and 10‐year survival rates for PD patients were 98.1%, 88.0% and 68.4%, respectively, and were 96.9%, 87.3% and 78.5% for HD patients. The survival analysis showed no significant difference between HD and PD (P = 0.4878). Using ‘15–19 years’ as a reference group, the relative risk (RR) of the youngest group (0–4 years) was 6.60 (95% CI: 2.50–17.38) for HD, and 5.03 (95% CI: 1.23–20.67) for PD. The death rate was 24.66 per 1000 dialysis patient‐years. The three major causes of death were infection (23.4%), cardiovascular disease (13.0%) and cerebrovascular disease (10.4%). Hemorrhagic stroke (87.5%) was the main type of foetal cerebrovascular accident. Conclusion: We conclude that there was no significant difference of paediatric ESRD patient survival between HD and PD treatment in Taiwan. The older paediatric ESRD patients had better survival than younger patients.     

Comparative mortality of hemodialysis and peritoneal dialysis in Canada

BACKGROUND: Comparisons of mortality rates in patients on hemodialysis versus those on peritoneal dialysis have been inconsistent. We hypothesized that comorbidity has an important effect on differential survival in these two groups of patients. METHODS: Eight hundred twenty-two consecutive patients at 11 Canadian institutions with irreversible renal failure had an extensive assessment of comorbid illness collected prospectively, immediately prior to starting dialysis therapy. The cohort was assembled between March 1993 and November 1994; vital status was ascertained as of January 1, 1998. RESULTS: The mean follow-up was 24 months. Thirty-four percent of patients at baseline, 50% at three months, and 51% at six months used peritoneal dialysis. Values for a previously validated comorbidity score were higher for patients on hemodialysis at baseline (4.0 vs. 3.1, P < 0.001), three months (3.7 vs. 3.2, P = 0.001), and six months (3.6 vs. 3.2, P = 0.005). The overall mortality was 41%. The unadjusted peritoneal dialysis/hemodialysis mortality hazard ratios were 0.65 (95% CI, 0. 51 to 0.83, P = 0.0005), 0.84 (95% CI, 0.66 to 1.06, P = NS), and 0. 83 (95% CI, 0.64 to 1.08, P = NS) based on the modality of dialysis in use at baseline, three months, and six months, respectively. When adjusted for age, sex, diabetes, cardiac failure, myocardial infarction, peripheral vascular disease, malignancy, and acuity of renal failure, the corresponding hazard ratios were 0.79 (95% CI, 0. 62 to 1.01, P = NS), 1.00 (95% CI, 0.78 to 1.28, P = NS), and 0.95 (95% CI, 0.73 to 1.24, P = NS). Adjustment for a previously validated comorbidity score resulted in hazard ratios of 0.74 (95% CI, 0.58 to 0.94, P = 0.01), 0.94 (95% CI, 0.74 to 1.19, P = NS), and 0.88 (95% CI, 0.68 to 1.13, P = NS) at baseline, three months, and six months. There was no survival advantage for either modality in any of the major subgroups defined by age, sex, or diabetic status. CONCLUSIONS: The apparent survival advantage of peritoneal dialysis in Canada is due to lower comorbidity and a lower burden of acute onset end-stage renal disease at the inception of dialysis therapy. Hemodialysis and peritoneal dialysis, as practiced in Canada in the 1990s, are associated with similar overall survival rates.     

Renal replacement in end-stage renal disease patients over 75 years old

BACKGROUND: Over the last decade, the age of dialysis patients has been increasing steadily in several units in Canada. Our main objective was to assess prevalence, co-morbidity and outcome of ESRD patients over 75 years old at the beginning of dialysis treatment in our center. As a group, they were compared to younger dialysis patients treated simultaneously. METHODS: In the last 5 years, all cases beginning dialysis in our institution who were above 75 years of age were reviewed, as well as cases aged between 50 and 60 years who started dialysis during the same period. Between January 1996 and December 2000, among a total of 429 new chronic dialysis patients, 67 ESRD patients over 75 years (15.6%) and 66 patients between 50 and 60 years (15.4%) began dialysis treatment. RESULTS--PRIMARY AND SECONDARY: Diabetes was present in 37% of elderly and in 56% of the younger patients. Younger patients had been referred earlier to our nephrologists than the older ones (42 vs. 27%). Elderly were more frequently treated by hemodialysis than peritoneal dialysis (81 vs. 19%) when compared to their younger counterparts (65 vs. 35%). Long-term catheters for hemodialysis were used more often in elderly patients. No renal transplantation were performed in older patients while 7 younger patients received a renal graft. Survival rates after 1 and 3 years were, respectively, 93 and 74% for patients between 50 and 60 years, whereas it decreased to 80 and 45% for those over 75 years (p = 0.002). More than 50% of patients older than 75 years died within 2 years after starting dialysis; their mean survival was 31 months; patients starting dialysis between 50 and 60 years survived on the average 44 months during the study period. According to the multivariate logistic regression model, risk factors for increased mortality in the older group were: number of hospitalization days during the past 3 months (OR 34.8, 95% CI 8.3-145.7, p < 0.001) and lower weight (OR 16.6, 95% CI 2.0-139.0, p = 0.001). CONCLUSION: We may conclude that, in our hands, life expectancy of patients who began dialysis above 75 years is significantly shorter than for patients for whom dialysis is initiated between age 50 and 60 years, especially if they have a low weight, lose weight and/or require hospitalization.     

Elevated risk of stroke among patients with end-stage renal disease

BACKGROUND: Although end-stage renal disease (ESRD) has been associated with accelerated vascular disease of the cerebral circulation, there are no prior studies that have estimated the risk of hemorrhagic and ischemic stroke among the United States dialysis population relative to the general population. METHODS: We performed a population-based cohort study to compare rates of hospitalized ischemic and hemorrhagic stroke among incident dialysis patients in the United States Renal System database and non-ESRD subjects from the general population identified in the National Hospital Discharge Survey. RESULTS: After adjustment for age, gender, and race, estimated rates of hospitalized stroke were markedly higher for dialysis patients compared to the general population. The age-adjusted relative risk (RR) of stroke among dialysis patients compared to the general population was 6.1 [95% Confidence Interval (95% CI) 5.1, 7.1] for Caucasian males, 4.4 (95% CI 3.3, 5.5) for African American males, 9.7 (95%CI 8.2, 11.2) for Caucasians females and 6.2 (95%CI 4.8, 7.6) for African American females. When considered as separate outcomes, hospitalization rates for hemorrhagic and ischemic stroke were both markedly elevated for subjects treated with dialysis (ischemic, RR = 4.3 to 10.1; hemorrhagic, RR = 4.1 to 6.7). CONCLUSION: Incident dialysis patients are at markedly higher risk for hospitalized stroke when compared to the general population. Although prior public health initiatives have focused primarily on cardiac disease among patients treated with dialysis, our data suggest that new initiatives are needed to control the high risk of stroke in this population.     

HMG-CoA reductase inhibitors are associated with reduced mortality in ESRD patients.

BACKGROUND.: Patients with end-stage renal disease (ESRD) suffer from markedly higher rates of cardiovascular disease than the general population. Although therapy with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors ("statins") has been demonstrated to reduce the mortality from cardiovascular disease in patients without ESRD, only 10% of patients on dialysis are treated with these medications by day 60 of ESRD. We determined whether the use of statins is associated with a reduction in cardiovascular-specific death and total mortality in ESRD patients. METHODS: Data were analyzed from the U.S. Renal Data System Dialysis Morbidity and Mortality Wave-2 study, a cohort of randomly selected patients who were initiating dialysis in 1996. Information about the use of statins as well as other baseline characteristics was abstracted from the patients' dialysis records by dialysis personnel. Cox proportional hazards models were developed to determine the association between use of statins at baseline and subsequent risk of mortality, with adjustment for known mortality risk factors. RESULTS: Follow-up data were available for 3716 patients through July 1998. At baseline, 362 (9.7%) of patients were using statins. These patients had a mortality rate of 143/1000 person-years, compared with a rate of 202/1000 person-years for patients not using statins. Statin use was independently associated with a reduced risk of total mortality [relative risk (RR)=0.68, 95% confidence interval (CI)=0.54, 0.87] as well as cardiovascular-specific mortality (RR=0.64, 95% CI=0.45, 0.91). In contrast, the use of fibrates was not associated with reduced mortality (RR=1.29). CONCLUSIONS: Statin use was associated with a reduction in cardiovascular-specific death and total mortality in patients on dialysis.     

Screening for depression in hemodialysis patients: associations with diagnosis, treatment, and outcomes in the DOPPS

BACKGROUND: Depressive symptoms and depression are the most frequent psychologic problems reported by hemodialysis patients. We assessed the prevalence of depressive symptoms and physician-diagnosed depression, their variations by country, and associations with treatment by antidepressants among hemodialysis patients. We also assessed whether depressive symptoms were independently associated with mortality, hospitalization, and dialysis withdrawal. METHODS: The sample was represented by 9382 hemodialysis patients randomly selected from dialysis centers of 12 countries enrolled in the Dialysis Outcomes and Practice Patterns Study (DOPPS II). Depressive symptoms were assessed by the short version of the Center for Epidemiological Studies Depression Screening Index (CES-D), using > or =10 CES-D score as the cut-off value. RESULTS: Overall prevalence of physician-diagnosed depression was 13.9%, and percentage of CES-D score > or =10 43.0%. While the smallest prevalence of physician-diagnosed depression was observed in Japan (2.0%) and France (10.6%), the percentage of CES-D score > or =10 in these counties was similar to the whole sample. Patients on antidepressants also varied by country, 34.9% and 17.3% among those with physician-diagnosed depression and CES-D scores > or =10, respectively. In Cox models adjusted for several comorbidities, CES-D scores > or =10 were associated with significantly higher relative risks (RR) of death (RR = 1.42; 95% CI = 1.29 to 1.57), hospitalization (RR = 1.12; 95% CI = 1.03 to 1.22), and dialysis withdrawal (RR = 1.55; 95% CI = 1.29 to 1.85). CONCLUSION: The data suggest that depression is underdiagnosed and undertreated among hemodialysis patients. CES-D can help identify hemodialysis patients who are at higher risk of death and hospitalization. Interventions should target these patients with the goal to improve survival and reduce hospitalizations.     

Vintage, nutritional status, and survival in hemodialysis patients

BACKGROUND: The link between dialysis "vintage" (length of time on dialysis in months to years) and survival has been difficult to define, largely because of selection effects. End-stage renal disease (ESRD) is thought to be a wasting illness, but there are no published reports describing the associations between vintage and body composition in hemodialysis patients. METHODS: We explored the relationships among vintage, nutritional status, and survival in a 3009 patient cohort of prevalent hemodialysis patients. Body weight, total body water, body cell mass, and phase angle by bioelectrical impedance analysis were the body composition parameters of interest. We examined vintage as an explanatory variable in multiple linear regression analyses (adjusted for age, gender, race, and diabetes) using body composition parameters and biochemical indicators of nutritional status as dependent variables. Proportional hazards regression was used to evaluate the association of vintage and survival with and without adjustment for case mix and laboratory variables. RESULTS: Dialysis vintage was 3.8 +/- 3.7 (median 2.6) years. Body composition parameters tended to be lower after dialysis year 2. Linear estimates per year of vintage beyond year 2 include -0.66 kg body wt (P < 0.0001), -0.17 kg total body water (P = 0.0003), -0.14 kg body cell mass (P < 0.0001), and -0.07 degrees phase angle (P < 0.0001). In unadjusted analyses, vintage was not associated with survival, either as a linear or higher order term. The adjustment for case mix yielded a vintage term associated with an increased relative risk (RR) of death (RR 1.04 (95% CI, 1.01 to 1.07 per year). A further adjustment for laboratory data yielded a RR of 1.06 (95% CI, 1.03 to 1.09 per year). CONCLUSION: Dialysis vintage is related to nutritional status in hemodialysis patients, with vintage of more than years associated with a significant decline in all measured nutritional parameters. Cross-sectional analyses probably underestimate these effects. A year accrued on dialysis is associated with a 6% increase in the risk of death, all else equal. Longitudinal assessments of nutritional status, including body composition, are required to better understand the natural history of wasting with ESRD and its implications for long-term survival.     

Pulmonary hypertension in dialysis patients

Cardiovascular complications are encountered frequently in end-stage renal disease (ESRD) patients. The study was designed as a prospective cohort study and a total of 105 dialysis patients, 77 hemodialysis and 28 peritoneal dialysis patients, were investigated. All patients had undergone M-Mode Doppler echocardiography every 6 months by which their systolic pulmonary arterial pressures (sPAPs) and left ventricular mass indices (LVMIs) were recorded. Thirty-nine (37.1%) patients had pulmonary hypertension (PHT), that is, a mean sPAP of more than 35 mmHg. The frequency of PHT was higher in peritoneal dialysis patients but the difference was insignificant (p = 0.08). However, the frequency of left ventricular hypertrophy (LVH) was found to be significantly higher in peritoneal dialysis patients than in hemodialysis patients (p = 0.001). When patients with and without PHT were compared, the duration of dialysis (p = 0.02), hemoglobin (p = 0.01), HbA1c (p = 0.03), and serum albumin levels (p = 0.003) were found to be significantly higher in patients with PHT than those without PHT. In conclusion, although nonsignificant, we found a higher prevalence of PHT in peritoneal dialysis patients when compared with hemodialysis patients. This might be due to the significantly higher prevalence of LVH, hence hypervolemia, in peritoneal dialysis patients. The prevention and treatment of PHT in dialysis patients is very important for the improvement of survival in these patients. Hence, the increased prevalence of PHT in ESRD patients necessitates understanding the multiple and interacting factors, such as LVH, serum albumin and hemoglobin levels, and control of diabetes, that might contribute to this pathology in these patients.     

The differential impact of risk factors on mortality in hemodialysis and peritoneal dialysis

BACKGROUND: While the survival ramifications of dialysis modality selection are still debated, it seems reasonable to postulate that outcome comparisons are not the same for all patients at all times. Trends in available data indicate the relative risk of death with hemodialysis (HD) compared to peritoneal dialysis (PD) varies by time on dialysis and the presence of various risk factors. This study was undertaken to identify key patient characteristics for which the risk of death differs by dialysis modality. METHODS: Analyses utilized incidence data from 398,940 United States Medicare patients initiating dialysis between 1995 and 2000. Proportional hazards regression identified the presence of diabetes, age, and the presence of comorbidity as factors that significantly interact with treatment modality. Stratifying by these factors, proportional and nonproportional hazards models were used to estimate relative risks of death [RR (HD:PD)]. RESULTS: Of the 398,940 patients studied, 11.6% used PD as initial therapy, 45% had diabetes mellitus (DM), 51% were 65 years or older, and 55% had at least one comorbidity. Among the 178,693 (45%) patients with no baseline comorbidity, adjusted mortality rates in nondiabetic (non-DM) patients were significantly higher on HD than on PD [age 18-44: RR (95% CI) = 1.24 (1.07, 1.44); age 45-64: RR = 1.13 (1.02, 1.25); age 65+: RR = 1.13 (1.05, 1.21)]. Among diabetic (DM) patients with no comorbidity, HD was associated with a higher risk of death among younger patients [age 18-44: RR = 1.22(1.05, 1.42)] and a lower risk of death among older patients [age 45-64: RR = 0.92 (0.85, 1.00); age 65+: RR = 0.86 (0.79, 0.93)]. Within the group of 220,247 (55%) patients with baseline comorbidity, adjusted mortality rates were not different between HD and PD among non-DM patients [age 18-44: RR = 1.19 (0.94, 1.50); age 45-64: RR = 1.01 (0.92, 1.11); age 65+: RR = 0.96 (0.91, 1.01)] and younger DM patients [age 18-44: RR = 1.10 (0.92, 1.32)], but were lower with HD among older DM patients with baseline comorbidity [age 45-64: RR = 0.82 (0.77, 0.87); age 65+: RR = 0.80 (0.76, 0.85)]. CONCLUSION: Valid mortality comparisons between HD and PD require patient stratification according to major risk factors known to interact with treatment modality. Survival differences between HD and PD are not constant, but vary substantially according to the underlying cause of ESRD, age, and level of baseline comorbidity. These results may help identify technical advances that will improve outcomes of patients on dialysis.     

Automated external defibrillators and survival from cardiac arrest in the outpatient hemodialysis clinic

Automated external defibrillators (AED) have been recommended for use in outpatient dialysis clinics to improve outcomes from cardiac arrest, the most common cause of death in patients with ESRD. The effectiveness of this policy is unknown. The study cohort consisted of 43,200 hemodialysis patients in the US Gambro Healthcare System from 2002 to 2005. Of these, 729 patients who sustained an in-center cardiac arrest were identified. Baseline characteristics at the time of the event were compared between patients who underwent hemodialysis in clinics with and without an AED on site. Unadjusted survival and survival adjusted for potential confounders was measured using Cox proportional hazards regression models. Unadjusted survival at 30 d was 19 versus 15% (P = 0.12) and 9.5 versus 7.8% at 1 yr (P = 0.39) in the AED-present and AED-absent groups, respectively. AED presence was not associated with outcome in unadjusted analysis (hazard ratio [HR] 0.91; 95% confidence interval [CI] 0.78 to 1.07; P = 0.26). Univariable analysis identified age (HR 1.07 per decade; 95% CI 1.01 to 1.13), serum albumin (HR 0.91 per 0.7-mg/dl increase; 95% CI 0.82 to 1.01), and indwelling dialysis catheters (HR 1.21; 95% CI 1.02 to 1.42) as potential confounders. Medications including angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, beta blockers, calcium channel blockers, other BP medications, aspirin, antibiotics, and antiarrhythmics were associated with survival and considered confounders. After controlling for case mix and confounders, AED presence was not associated with outcome (HR 0.98; 95% CI 0.82 to 1.18; P = 0.83). Presence of AED in the dialysis clinic is not sufficient by itself to improve the abysmal outcome from in-clinic cardiac arrest in hemodialysis patients in the United States.