Racial differences in survival of patients on dialysis

Kidney Function and Long-Term Risk of End-Stage Kidney Disease and Mortality in a Multiethnic Population

Introduction

Contemporary differences between South Asian and White ethnicities in the incidence of end-stage kidney disease (ESKD) and mortality are poorly described.

Methods

Data for all South Asian patients who had an estimated glomerular filtration rate (eGFR) measure after January 1, 2006, and 1 million randomly selected participants of other ethnicities were extracted from the Clinical Practice Research Datalink (CPRD). All participants were followed-up with from index date until ESKD, all-cause mortality, or end of study. All-cause mortality rate and ESKD incidence rate by age were described among Whites and South Asians, and adjusted hazard ratios (HRs) of these 2 outcomes by baseline eGFR estimated using Cox proportional hazard model.

Results

A total of 40,888 South Asians and 236,634 Whites were followed for a median of 5.3 and 9.4 years for ESKD incidence and mortality outcomes, respectively. All-cause mortality rates were higher among Whites than South Asians; South Asian women aged between 70 and 85 years had a slightly higher ESKD incidence rate compared to their White counterparts. Compared to Whites with a baseline eGFR of 90 ml/min per 1.73 m2, adjusted HRs for all-cause mortality were significantly lower among South Asians than Whites; however, adjusted HRs for ESKD incidence by baseline eGFR were similar in both ethnicities. Calculating South Asian eGFRs using an ethnicity-specific equation had no impact on the results.

Conclusions

South Asians experience lower mortality than Whites but not substantially higher rates of ESKD. Further research is warranted to better understand the reasons for these ethnic differences and possible impacts on chronic kidney disease (CKD) service delivery and patient outcomes.

Chronic kidney disease biomarkers and mortality among older adults: A comparison study of survey samples in China and the United States

OBJECTIVES

Among older adults in China and the US, we aimed to compare the biomarkers of chronic-kidney-diseases (CKD), factors associated with CKD, and the correlation between CKD and mortality.

SETTING

China and the US.

STUDY DESIGN

Cross-sectional and prospective cohorts.

PARTICIPANTS

We included 2019 participants aged 65 and above from the Chinese Longitudinal Healthy Longevity Study (CLHLS) in 2012, and 2177 from US National Health and Nutrition Examination Survey (NHANES) in 2011-2014.

OUTCOMES

Urinary albumin, urinary creatinine, albumin creatinine ratio (ACR), serum creatinine, blood urea nitrogen, plasma albumin, uric acid, and estimated glomerular filtration rate (eGFR). CKD (ACR ≥ 30 mg/g or eGFR< 60 ml/min/1.73m2) and mortality.

ANALYTICAL APPROACH

Logistic regression and Cox proportional hazard models. Covariates included age, sex, race, education, income, marital status, health condition, smoking and drinking status, physical activity and body mass index.

RESULTS

Chinese participants had lower levels of urinary albumin, ACR, and uric acid than the US (mean: 25.0 vs 76.4 mg/L, 41.7 vs 85.0 mg/g, 292.9 vs 341.3 μmol/L). In the fully-adjusted model, CKD was associated with the risk of mortality only in the US group (hazard ratio [HR], 95% CI: 2.179, 1.561-3.041 in NHANES, 1.091, 0.940-1.266 in CLHLS). Compared to eGFR≥90, eGFR ranged 30-44 ml/min/1.73m2 was only associated with mortality in the US population (HR, 95% CI: 2.249, 1.141-4.430), but not in the Chinese population (HR, 95% CI: 1.408, 0.884-2.241).

CONCLUSIONS

The elderly participants in the US sample had worse CKD-related biomarker levels than in China sample, and the association between CKD and mortality was also stronger among the US older adults. This may be due to the biological differences, or co-morbid conditions.

Novel Protein to Phosphorous Ratio Score Predicts Mortality in Hemodialysis Patients

OBJECTIVE

Lowering serum phosphorus in people on hemodialysis may improve their survival. However, prior studies have shown that restricting dietary protein intake, a major source of phosphorus, is associated with higher mortality. We hypothesized that a novel metric that incorporates both these values commensurately can improve survival prediction.

METHODS

We used serum phosphorous and normalized protein catabolic rate (nPCR), a surrogate of dietary protein intake, to form a new metric R that was used to examine the associations with mortality in 63,016 people on hemodialysis (HD) of one year after treatment initiation. Survival models were adjusted for case-mix, malnutrition-inflammation cachexia syndrome (MICS), and residual kidney function (RKF).

RESULTS

Individuals treated with hemodialysis were divided into five groups in accordance with R value. Group 1 included sick individuals with high phosphorous and low nPCR. Group 5 included individuals with low phosphorous and high nPCR. After 1-year follow-up, survival difference between the groups reflected R value, where an increase in R was associated with improved survival. The association of R with mortality was strengthened by adjustment in demographic variables and attenuated after adjustment to MICS. Mortality associations in accordance with R were not influenced by residual kidney function (RKF).

CONCLUSION

The novel protein to phosphorus ratio score R predicts mortality in people on dialysis, probably reflecting both nutrition and inflammation state independent of RKF. The metric enables better phosphorus monitoring, although adequate dietary protein intake is ensured and may improve the prediction of outcomes in the clinical setting.

Transmission of SARS-CoV-2 considering shared chairs in outpatient dialysis: a real-world case-control study

BACKGROUND

SARS-CoV-2 can remain transiently viable on surfaces. We examined if use of shared chairs in outpatient hemodialysis associates with a risk for indirect patient-to-patient transmission of SARS-CoV-2.

METHODS

We used data from adults treated at 2,600 hemodialysis facilities in United States between February 1st and June 8th, 2020. We performed a retrospective case-control study matching each SARS-CoV-2 positive patient (case) to a non-SARS-CoV-2 patient (control) treated in the same dialysis shift. Cases and controls were matched on age, sex, race, facility, shift date, and treatment count. For each case-control pair, we traced backward 14 days to assess possible prior exposure from a 'shedding' SARS-CoV-2 positive patient who sat in the same chair immediately before the case or control. Conditional logistic regression models tested whether chair exposure after a shedding SARS-CoV-2 positive patient conferred a higher risk of SARS-CoV-2 infection to the immediate subsequent patient.

RESULTS

Among 170,234 hemodialysis patients, 4,782 (2.8 %) tested positive for SARS-CoV-2 (mean age 64 years, 44 % female). Most facilities (68.5 %) had 0 to 1 positive SARS-CoV-2 patient. We matched 2,379 SARS-CoV-2 positive cases to 2,379 non-SARS-CoV-2 controls; 1.30 % (95 %CI 0.90 %, 1.87 %) of cases and 1.39 % (95 %CI 0.97 %, 1.97 %) of controls were exposed to a chair previously sat in by a shedding SARS-CoV-2 patient. Transmission risk among cases was not significantly different from controls (OR = 0.94; 95 %CI 0.57 to 1.54; p = 0.80). Results remained consistent in adjusted and sensitivity analyses.

CONCLUSIONS

The risk of indirect patient-to-patient transmission of SARS-CoV-2 infection from dialysis chairs appears to be low.

Transmission of SARS-CoV-2 Considering Shared Chairs in Outpatient Dialysis: A Real-World Case-Control Study

Background:

SARS-CoV-2 is primarily transmitted through aerosolized droplets; however, the virus can remain transiently viable on surfaces.

Objective:

We examined transmission within hemodialysis facilities, with a specific focus on the possibility of indirect patient-to-patient transmission through shared dialysis chairs.

Design:

We used real-world data from hemodialysis patients treated between February 1^st and June 8^th, 2020 to perform a case-control study matching each SARS-CoV-2 positive patient (case) to a non-SARS-CoV-2 patient (control) in the same dialysis shift and traced back 14 days to capture possible exposure from chairs sat in by SARS-CoV-2 patients. Cases and controls were matched on age, sex, race, facility, shift date, and treatment count.

Setting:

2,600 hemodialysis facilities in the United States.

Patients:

Adult (age ≥18 years) hemodialysis patients.

Measurements:

Conditional logistic regression models tested whether chair exposure after a positive patient conferred a higher risk of SARS-CoV-2 infection to the immediate subsequent patient.

Results:

Among 170,234 hemodialysis patients, 4,782 (2.8%) tested positive for SARS-CoV-2 (mean age 64 years, 44% female). Most facilities (68.5%) had 0 to 1 positive SARS-CoV-2 patient. We matched 2,379 SARS-CoV-2 positive cases to 2,379 non-SARS-CoV-2 controls; 1.30% (95%CI 0.90%, 1.87%) of cases and 1.39% (95%CI 0.97%, 1.97%) of controls were exposed to a chair previously sat in by a shedding SARS-CoV-2 patient. Transmission risk among cases was not significantly different from controls (OR=0.94; 95%CI 0.57 to 1.54; p=0.80). Results remained consistent in adjusted and sensitivity analyses.

Limitation:

Analysis used real-world data that could contain errors and only considered vertical transmission associated with shared use of dialysis chairs by symptomatic patients.

Conclusions:

The risk of indirect patient-to-patient transmission of SARS-CoV-2 infection from dialysis chairs appears to be low.

Primary Funding Source:

Fresenius Medical Care North America; National Institute of Diabetes and Digestive and Kidney Diseases (R01DK130067)

Outcomes of patients with end-stage kidney disease hospitalized with COVID-19

Given the high risk of infection-related mortality, patients with end-stage kidney disease (ESKD) may be at increased risk with COVID-19. To assess this, we compared outcomes of patients with and without ESKD, hospitalized with COVID-19. This was a retrospective study of patients admitted with COVID-19 from 13 New York hospitals from March 1, 2020, to April 27, 2020, and followed through May 27, 2020. We measured primary outcome (in-hospital death), and secondary outcomes (mechanical ventilation and length of stay). Of 10,482 patients with COVID-19, 419 had ESKD. Patients with ESKD were older, had a greater percentage self-identified as Black, and more comorbid conditions. Patients with ESKD had a higher rate of in-hospital death than those without (31.7% vs 25.4%, odds ratio 1.38, 95% confidence interval 1.12 - 1.70). This increase rate remained after adjusting for demographic and comorbid conditions (adjusted odds ratio 1.37, 1.09 - 1.73). The odds of length of stay of seven or more days was higher in the group with compared to the group without ESKD in both the crude and adjusted analysis (1.62, 1.27 - 2.06; vs 1.57, 1.22 - 2.02, respectively). There was no difference in the odds of mechanical ventilation between the groups. Independent risk factors for in-hospital death for patients with ESKD were increased age, being on a ventilator, lymphopenia, blood urea nitrogen and serum ferritin. Black race was associated with a lower risk of death. Thus, among patients hospitalized with COVID-19, those with ESKD had a higher rate of in-hospital death compared to those without ESKD.

Peritoneal Dialysis in Asia: An External Perspective

There are almost 30 000 patients maintained on peritoneal dialysis (PD) in Asia, representing about 8% of all Asian dialysis patients. The largest numbers of PD patients are in Japan and China, but the highest PD penetration is in Hong Kong, Korea, and Singapore. Notable features of PD in Asia include the varying rates of use across the different countries. The reasons for this are reviewed here, with particular emphasis on the significance of whether dialysis providers are predominantly private or public. The excellent rates of both patient and technique survival in the richer Asian countries are also examined and interpreted in the context of recent data showing that Asian patients living in North America have generally superior survival on dialysis and better compliance with PD than their Caucasian counterparts. It is concluded that the healthier baseline health status in South East Asian patients, in particular, contributes to their impressive outcomes. The approach to both clearance and ultrafiltration is less aggressive in Asian countries than in the West. Studies looking at the relationship between clearance and clinical outcome in Asia are reviewed and it is concluded that the benefits of higher clearances have been harder to show than in North America because of the relatively better outcomes of the patients. The concern about sclerosing encapsulating peritonitis in Japan particularly is emphasized. The Hong Kong model of dialysis delivery with its high use of PD and the arguments for and against it are also reviewed.

Race and Mortality in CKD and Dialysis: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study

RATIONALE & OBJECTIVES

Few studies have investigated racial disparities in survival among dialysis patients in a manner that considers risk factors and mortality during the phase of kidney disease before maintenance dialysis. Our objective was to explore racial variations in survival among dialysis patients and relate them to racial differences in comorbid conditions and rates of death in the setting of kidney disease not yet requiring dialysis therapy.

STUDY DESIGN

Retrospective cohort study.

SETTINGS & PARTICIPANTS

3,288 black and white participants in the Chronic Renal Insufficiency Cohort (CRIC), none of whom were receiving dialysis at enrollment.

EXPOSURE

Race.

OUTCOME

Mortality.

ANALYTIC APPROACH

Cox proportional hazards regression was used to examine the association between race and mortality starting at: (1) time of dialysis initiation and (2) entry into the CRIC.

RESULTS

During 7.1 years of median follow-up, 678 CRIC participants started dialysis. Starting from the time of dialysis initiation, blacks had lower risk for death (unadjusted HR, 0.67; 95% CI, 0.51-0.87) compared with whites. Starting from baseline CRIC enrollment, the strength of the association between some risk factors and dialysis was notably stronger for whites than blacks. For example, the HR for dialysis onset in the presence (vs absence) of heart failure at CRIC enrollment was 1.30 (95% CI, 1.01-1.68) for blacks versus 2.78 (95% CI, 1.90-4.50) for whites, suggesting differential severity of these risk factors by race. When we included deaths occurring both before and after dialysis, risk for death was higher among blacks (vs whites) starting from CRIC enrollment (HR, 1.41; 95% CI, 1.22-1.64), but this finding was attenuated in adjusted models (HR, 1.08; 95% CI, 0.91-1.28).

LIMITATIONS

Residual confounding.

CONCLUSIONS

The apparent survival advantage among blacks over whites treated with dialysis may be attributed to selected transition of a subset of whites with more severe comorbid conditions onto dialysis.

Angiotensin-related genetic determinants of cardiovascular disease in patients undergoing hemodialysis

BACKGROUND

Cardiovascular mortality in patients receiving dialysis remains unacceptably high, with unexplained ancestry differences suggesting a genetic component.

METHODS

We analyzed DNA samples from 37% of subjects enrolled in the EValuation Of Cinacalcet Hydrochloride (HCl) Therapy to Lower CardioVascular Events (EVOLVE) trial, a randomized trial conducted in patients receiving hemodialysis with secondary hyperparathyroidism, comparing cinacalcet to placebo on a background of usual care. DNA was analyzed for single-nucleotide polymorphisms (SNPs) in the genes encoding the angiotensin-converting enzyme receptor type I (AGTR1) and angiotensin-converting enzyme (ACE). Survival analyses were conducted separately in European Ancestry (EA) and African Ancestry (AfAn) due to known differences in cardiovascular events, minor alleles for the same variant and the frequency of minor alleles. Our primary determination was a meta-analysis across both races.

RESULTS

Meta-analysis showed significant associations between rs5186 in AGTR1 and increased rates by 25-34% for the primary endpoint (composite of death or nonfatal myocardial infarction, hospitalization for unstable angina, heart failure or peripheral vascular event), all-cause mortality, cardiovascular mortality and heart failure; all P < 0.001. Three correlated SNPs in ACE were associated with lower rates of sudden cardiac death (SCD) in EA samples. One ACE SNP, rs4318, only found in the AfAn samples, was associated with a lower rate of SCD in the AfAn samples.

CONCLUSIONS

The C allele in rs5186 in AGTR1 was associated with higher rates of death and major cardiovascular events in a meta-analysis of EA and AfAn patients with end-stage kidney disease. SNPs in ACE were associated with SCD.

Sex Disparities in Risk of Mortality Among Children With ESRD

RATIONALE & OBJECTIVE

In the general population, girls have lower mortality risk compared with boys. However, few studies have focused on sex differences in survival and in access to kidney transplantation among children with end-stage kidney disease.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Children aged 2 to 19 years registered in the US Renal Data System who started renal replacement therapy (RRT) between 1995 and 2011.

PREDICTOR

Study participant sex.

OUTCOME

Time to death and time to kidney transplantation.

ANALYTICAL APPROACH

We used adjusted Cox models to examine the association between sex and all-cause mortality. We used Fine-Gray models to examine the association between sex and kidney transplantation accounting for the competing risk for death.

RESULTS

We included 14,024 children, of whom 1,880 died during a median 7.1 years of follow-up. In adjusted analyses, the HR for death was higher for girls (HR, 1.36; 95% CI, 1.25-1.50) than boys. When we further adjusted our survival models for transplantation as a time-dependent covariate, the hazard rate of death in girls was partially attenuated but remained statistically significantly higher than that for boys (HR, 1.28; 95% CI, 1.17-1.41). Girls were also less likely to receive a kidney transplant than boys (adjusted subdistribution HR, 0.91; 95% CI, 0.88-0.95) in analyses treating death as a competing risk.

LIMITATIONS

Lack of data for disease course before the onset of RRT and observational study data.

CONCLUSIONS

The mortality rate was substantially higher for girls than for boys treated with RRT. Access to transplantation was lower for girls than boys, but differences in transplantation access accounted for only a small proportion of the survival differences by sex.

Characteristics and Clinical Outcomes of End-Stage Renal Disease Patients on Peritoneal Dialysis for over 15 Years: A Single-Center Experience

Background

Maintaining peritoneal dialysis (PD) for a long time is problematic owing to a number of factors. This study aimed to clarify the characteristics and examine the clinical outcomes of patients who received PD as a long-term dialysis modality.

Methods

All end-stage renal disease (ESRD) patients who initiated PD at Yonsei University Health System between 1987 and 2000 were screened. Patients who maintained PD for over 15 years were classified as the long-term PD group and those who were treated with PD for less than 5 years were included in the short-term PD group. Demographic and biochemical data and clinical outcomes were compared between the groups. Independent factors associated with long-term PD maintenance were ascertained using multivariate logistic regression analysis.

Results

Among 1,116 study patients, 87 (7.8%) were included in the long-term group and 293 (26.3%) were included in the short-term group. In the long-term group, the mean patient age at PD initiation was 39.6 ± 11.5 years, 35 patients (40.2%) were male, and the mean PD duration was 205.3 ± 32.7 months. Patients were younger, body weight was lower, the proportion of patients with diabetes or cardiovascular diseases was lower, and the proportion of low to low-average transporters was higher in the long-term group than in the short-term group ( p < 0.001). Multiple logistic regression analysis revealed that age, body mass index (BMI), serum creatinine, type of PD solution, and diabetes were significant independent factors associated with long-term PD maintenance.

Conclusion

Peritoneal dialysis can be considered as a long-term renal replacement therapy option, especially in non-diabetic, not overweight, and young ESRD patients.

Hemodialysis Disparities in African Americans: The Deeply Integrated Concept of Race in the Social Fabric of Our Society

End-stage renal disease (ESRD) is one of the starkest examples of racial/ethnic disparities in health. Racial/ethnic minorities are 1.5 to nearly 4 times more likely than their non-Hispanic White counterparts to require renal replacement therapy (RRT), with African Americans suffering from the highest rates of ESRD. Despite improvements over the last 25 years, substantial racial differences are persistent in dialysis quality measures such as RRT modality options, dialysis adequacy, anemia, mineral and bone disease, vascular access, and pre-ESRD care. This report will outline the current status of racial disparities in key ESRD quality measures and explore the impact of race. While the term race represents a social construct, its association with health is more complex. Multiple individual and community level social determinants of health are defined by the social positioning of race in the U.S., while biologic differences may reflect distinct epigenetic changes and linkages to ancestral geographic origins. Together, these factors conspire to influence dialysis outcomes among African Americans with ESRD.

Racial and Ethnic Disparities in Survival of Children with ESRD

Observational studies have reported that black and Hispanic adults receiving maintenance dialysis survive longer than non-Hispanic white counterparts. Whether there are racial disparities in survival of children with ESRD is not clear. We compared mortality risk among non-Hispanic black, Hispanic, and non-Hispanic white children who started RRT between 1995 and 2011 and were followed through 2012. We examined all-cause mortality using adjusted Cox models. Of 12,123 children included for analysis, 1600 died during the median follow-up of 7.1 years. Approximately 25% of children were non-Hispanic black, and 26% of children were of Hispanic ethnicity. Non-Hispanic black children had a 36% higher risk of death (95% confidence interval [95% CI], 1.21 to 1.52) and Hispanic children had a 34% lower risk of death (95% CI, 0.57 to 0.77) than non-Hispanic white children. Adjustment for transplant as a time-dependent covariate abolished the higher risk of death in non-Hispanic black children (hazard ratio, 0.99; 95% CI, 0.88 to 1.12) but did not attenuate the finding of a lower risk of death in Hispanic children (hazard ratio, 0.59; 95% CI, 0.51 to 0.68). In conclusion, Hispanic children had lower mortality than non-Hispanic white children. Non-Hispanic black children had higher mortality than non-Hispanic white children, which was related to differences in access to transplantation by race. Parity in access to transplantation in children and improvements in strategies to prolong graft survival could substantially reduce disparities in mortality risk of non-Hispanic black children treated with RRT.

Do Automated Peritoneal Dialysis and Continuous Ambulatory Peritoneal Dialysis Have the Same Clinical Outcomes? A Ten-year Cohort Study in Taiwan

This paper reports a comprehensive comparison for mortality and technique failure rates between automated peritoneal dialysis (APD) and continuous ambulatory peritoneal dialysis (CAPD) in Taiwan. A propensity-score matched cohort study was conducted by retrieving APD and CAPD patients identified from the Taiwan National Health Insurance Research Database between 2001 and 2010. The main outcomes were the 5-year mortality and technique failure rates. Further analyses were then carried out based upon the first (2001–2004), second (2005–2007), and third (2008–2010) sub-periods. Similar baseline characteristics were identified for APD (n = 2,287) and CAPD (n = 2,287) patients. The proportion on APD therapy increased rapidly in the second sub-period. As compared to CAPD patients of this sub-period, APD patients had a significantly higher risk of mortality (HR, 1.37; 95% CI 1.09–1.72; p < 0.01) and technique failure (HR, 1.43; 95% CI, 1.10–1.86; p < 0.01), particularly in the first year after peritoneal dialysis commencement. However, APD patients had similar mortality and technique failure rates to those of CAPD patients throughout the full sample period and the first and third sub-periods. These findings do not suggest the presence of a clear advantage of CAPD over APD. Differences observed between these two modalities might be attributed to specials circumstances of sub-periods.

Baseline Predictors of Mortality among Predominantly Rural-Dwelling End-Stage Renal Disease Patients on Chronic Dialysis Therapies in Limpopo, South Africa

BACKGROUND

Dialysis therapy for end-stage renal disease (ESRD) continues to be the readily available renal replacement option in developing countries. While the impact of rural/remote dwelling on mortality among dialysis patients in developed countries is known, it remains to be defined in sub-Saharan Africa.

METHODS

A single-center database of end-stage renal disease patients on chronic dialysis therapies treated between 2007 and 2014 at the Polokwane Kidney and Dialysis Centre (PKDC) of the Pietersburg Provincial Hospital, Limpopo South Africa, was retrospectively reviewed. All-cause, cardiovascular, and infection-related mortalities were assessed and associated baseline predictors determined.

RESULTS

Of the 340 patients reviewed, 52.1% were male, 92.9% were black Africans, 1.8% were positive for the human immunodeficiency virus (HIV), and 87.5% were rural dwellers. The average distance travelled to the dialysis centre was 112.3 ± 73.4 Km while 67.6% of patients lived in formal housing. Estimated glomerular filtration rate (eGFR) at dialysis initiation was 7.1 ± 3.7 mls/min while hemodialysis (HD) was the predominant modality offered (57.1%). Ninety-two (92) deaths were recorded over the duration of follow-up with the majority (34.8%) of deaths arising from infection-related causes. Continuous ambulatory peritoneal dialysis (CAPD) was a significant predictor of all-cause mortality (HR: 1.62, CI: 1.07-2.46) and infection-related mortality (HR: 2.27, CI: 1.13-4.60). On multivariable cox regression, CAPD remained a significant predictor of all-cause mortality (HR: 2.00, CI: 1.29-3.10) while the risk of death among CAPD patients was also significantly modified by diabetes mellitus (DM) status (HR: 4.99, CI: 2.13-11.71).

CONCLUSION

CAPD among predominantly rural dwelling patients in the Limpopo province of South Africa is associated with an increased risk of death from all-causes and infection-related causes.

Long-term outcomes of end-stage kidney disease for patients with lupus nephritis

Patient outcomes in end-stage kidney disease (ESKD) secondary to lupus nephritis have not been well described. To help define this we compared dialysis and transplant outcomes of patients with ESKD due to lupus nephritis to all other causes. All patients diagnosed with ESKD who commenced renal replacement therapy in Australia and New Zealand (1963-2012) were included. Clinical outcomes were evaluated in both a contemporary cohort (1998-2012) and the entire 50-year cohort. Of 64,160 included patients, 744 had lupus nephritis as the primary renal disease. For the contemporary cohort of 425 patients with lupus nephritis, the 5-year dialysis patient survival rate was 69%. Of 176 contemporary patients with lupus nephritis who received their first renal allograft, the 5-year patient, overall renal allograft, and death-censored renal allograft survival rates were 95%, 88%, and 93%, respectively. Patients with lupus nephritis had worse dialysis patient survival (adjusted hazard ratio 1.33, 95% confidence interval 1.12-1.58) and renal transplant patient survival (adjusted hazard ratio 1.87, 95% confidence interval 1.18-2.98), but comparable overall renal allograft survival (adjusted hazard ratio 1.19, 95% confidence interval 0.84-1.68) and death-censored renal allograft survival (adjusted hazard ratio 1.05, 95% confidence interval 0.68-1.62) compared with ESKD controls. Similar results were found in the entire cohort and when using competing-risks analysis. Thus, the ESKD of lupus nephritis was associated with worse dialysis and transplant patient survival but comparable renal allograft survival compared with other causes of ESKD.

Differences in survival on chronic dialysis treatment between ethnic groups in Denmark: a population-wide, national cohort study

BACKGROUND

In Western countries, black and Asian dialysis patients experience better survival compared with white patients. The aim of this study is to compare the survival of native Danish dialysis patients with that of dialysis patients originating from other countries and to explore the association between the duration of residence in Denmark before the start of dialysis and the mortality on dialysis.

METHODS

We performed a population-wide national cohort study of incident chronic dialysis patients in Denmark (≥18 years old) who started dialysis between 1995 and 2010.

RESULTS

In total, 8459 patients were native Danes, 344 originated from other Western countries, 79 from North Africa or West Asia, 173 from South or South-East Asia and 54 from sub-Saharan Africa. Native Danes were more likely to die on dialysis compared with the other groups (crude incidence rates for mortality: 234, 166, 96, 110 and 53 per 1000 person-years, respectively). Native Danes had greater hazard ratios (HRs) for mortality compared with the other groups {HRs for mortality adjusted for sociodemographic and clinical characteristics: 1.32 [95% confidence interval (CI) 1.14-1.54]; 2.22 [95% CI 1.51-3.23]; 1.79 [95% CI 1.41-2.27]; 2.00 [95% CI 1.10-3.57], respectively}. Compared with native Danes, adjusted HRs for mortality for Western immigrants living in Denmark for ≤10 years, >10 to ≤20 years and >20 years were 0.44 (95% CI 0.27-0.71), 0.56 (95% CI 0.39-0.82) and 0.86 (95% CI 0.70-1.04), respectively. For non-Western immigrants, these HRs were 0.42 (95% CI 0.27-0.67), 0.52 (95% CI 0.33-0.80) and 0.48 (95% CI 0.35-0.66), respectively.

CONCLUSIONS

Incident chronic dialysis patients in Denmark originating from countries other than Denmark have a better survival compared with native Danes. For Western immigrants, this survival benefit declines among those who have lived in Denmark longer. For non-Western immigrants, the survival benefit largely remains over time.

Frailty and mortality in dialysis: evaluation of a clinical frailty scale

BACKGROUND AND OBJECTIVES

Frailty is associated with poor outcomes for patients on dialysis; however, previous studies have not taken into account the severity of frailty as a predictor of outcomes. The purpose of this study was to assess if there was an association between the degree of frailty and mortality among patients on incident dialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A cohort study of incident chronic dialysis patients was conducted between January of 2009 and June of 2013 (last follow-up in December of 2013). On the basis of overall clinical impression, the Clinical Frailty Scale (CFS) score was determined for patients at the start of dialysis by their primary nephrologist. This simple scale allocates a single point to different states of frailty (1, very fit; 2, well; 3, managing well; 4, vulnerable; 5, mildly frail; 6, moderately frail; 7, severely frail or terminally ill) with an emphasis on function of the assessed individual. The primary outcome was time to death. Patients were censored at the time of transplantation.

RESULTS

The cohort consisted of 390 patients with completed CFS scores (mean age of 63±15 years old). Most were Caucasian (89%) and men (67%), and 30% of patients had ESRD caused by diabetic nephropathy. The median Charlson Comorbidity Index score was 4 (interquartile range =3-6), and the median CFS score was 4 (interquartile range =2-5). There were 96 deaths over 750 patient-years at risk. In an adjusted Cox survival analysis, the hazard ratio associated with each 1-point increase in the CFS was 1.22 (95% confidence interval, 1.04 to 1.43; P=0.02).

CONCLUSIONS

A higher severity of frailty (as defined by the CFS) at dialysis initiation is associated with higher mortality.

The impact of social disadvantage in moderate-to-severe chronic kidney disease: an equity-focused systematic review*

It is unclear whether a social gradient in health outcomes exists for people with moderate-to-severe chronic kidney disease (CKD). We critically review the literature for evidence of social gradients in health and investigate the ‘suitability’ of statistical analyses in the primary studies. In this equity-focused systematic review among adults with moderate-to-severe CKD, factors of disadvantage included gender, race/ethnicity, religion, education, socio-economic status or social capital, occupation and place of residence. Outcomes included access to healthcare, kidney disease progression, cardiovascular events, all-cause mortality and suitability of analyses. Twenty-four studies in the pre-dialysis population and 34 in the dialysis population representing 8.9 million people from 10 countries were included. In methodologically suitable studies among pre-dialysis patients, a significant social gradient was observed in access to healthcare for those with no health insurance and no home ownership. Low income and no home ownership were associated with higher cardiovascular event rates and higher mortality [HR 1.94, 95% confidence interval (CI) 1.27–2.98; HR 1.28, 95% CI 1.04–1.58], respectively. In methodologically suitable studies among dialysis patients, females, ethnic minorities, those with low education, no health insurance, low occupational level or no home ownership were significantly less likely to access cardiovascular healthcare than their more advantaged dialysis counterparts. Low education level and geographic remoteness were associated with higher cardiovascular event rates and higher mortality (HR 1.54, 95% CI 1.01–2.35; HR 1.21, 95% CI 1.08–1.37), respectively. Socially disadvantaged pre-dialysis and dialysis patients experience poorer access to specialist cardiovascular health services, and higher rates of cardiovascular events and mortality than their more advantaged counterparts.

Black ethnicity predicts better survival on dialysis despite greater deprivation and co-morbidity: a UK study

Background: Observational studies from the United States have identified black race as conferring a survival advantage on dialysis. This study represents the first large single-center study from a UK dialysis unit examining the outcome of ethnic minorities on renal replacement therapy (RRT). Methods: A retrospective analysis of all patients of white or black race initiating RRT at King’s College Hospital Renal Unit, London, between 1996 and 2008 was performed. A total of 1,340 patients were studied, of which 952 (71%) were of white race, and 388 (29%) were of black race. Kaplan-Meier survival curves, the log rank test and Cox’s proportional hazard models were used to compare survival between groups. Results: The results revealed black ethnicity to be associated with a significant survival benefit on dialysis. This was the case even after adjustment for age, gender, diabetes, transplantation, and deprivation. In those patients not transplanted, black race conferred a hazard ratio (HR) of 0.51 (95% CI 0.41 – 0.63) over 5 years. Conclusions: This study provides evidence for a lower mortality rate amongst black patients on dialysis in comparison with their white counterparts in the UK. The reasons behind this remain poorly understood but a lower incidence of cardiovascular disease in black patients and more kidney-limited disease may be important.

Neighborhood socioeconomic status, race, and mortality in young adult dialysis patients

Young blacks receiving dialysis have an increased risk of death compared with whites in the United States. Factors influencing this disparity among the young adult dialysis population have not been well explored. Our study examined the relation of neighborhood socioeconomic status (SES) and racial differences in mortality in United States young adults receiving dialysis. We merged US Renal Data System patient-level data from 11,027 black and white patients ages 18-30 years old initiating dialysis between 2006 and 2009 with US Census data to obtain neighborhood poverty information for each patient. We defined low SES neighborhoods as those neighborhoods in U.S. Census zip codes with ≥20% of residents living below the federal poverty level and quantified race differences in mortality risk by level of neighborhood SES. Among patients residing in low SES neighborhoods, blacks had greater mortality than whites after adjusting for baseline demographics, clinical characteristics, rurality, and access to care factors. This difference in mortality between blacks and whites was significantly attenuated in higher SES neighborhoods. In the United States, survival between young adult blacks and whites receiving dialysis differs by neighborhood SES. Additional studies are needed to identify modifiable factors contributing to the greater mortality among young adult black dialysis patients residing in low SES neighborhoods.

Relationships of clinic size, geographic region, and race/ethnicity to the frequency of missed/shortened dialysis treatments

BACKGROUND

Significant international differences abound in the adherence of hemodialysis (HD) patients to prescribed treatments. Unfortunately, factors influencing adherence within the United States (US) are not well understood. This study explores the hypothesis that race/ethnicity, geographic region and clinic size are associated with differences in the frequency of missed/shortened treatments.

METHODS

A retrospective analysis on all prevalent chronic HD patients treated at Dialysis Clinics Inc. facilities between January 2007 and June 2008. Logistic regression models were computed in which the outcome measures were the odds for missing or shortening treatments.

RESULTS

The cohort consisted of 15,340 HD patients of whom 48% were non-Hispanic whites (NHW), 41% African Americans (AA), 6% Hispanics, 2% Native Americans, 2% Asians, and 1% unknown. Patients were older in the Northeast than in the South (p < 0.001) or West (p = 0.0052). The frequency of missed and shortened treatments was lower in the Northeast than other regions, p < 0.0001. Hospitalization rates were lower in the West than the Northeast (p < 0.01) but mortality rates were similar across all regions. The odds ratio and 95% confidence interval for missed [1.31 (1.14-1.52)] and shortened treatments [1.86 (1.73-2.0)] were greater in clinics with >100 patients than in those with <50 patients. Compared to NHW, the frequencies of missed and shortened treatments were higher in AA, Hispanics and Native Americans (p < 0.001) but lower among Asians (p < 0.001).

CONCLUSION

The frequency of missed and shortened HD varies significantly by race/ethnicity, geographic region and clinic size. The relationship of clinic size to missed/shortened treatments may warrant consideration when planning new HD facilities.

Variation in centre-specific survival in patients starting renal replacement therapy in England is explained by enhanced comorbidity information from hospitalization data

BACKGROUND

Unadjusted survival on renal replacement therapy (RRT) varies widely from centre to centre in England. Until now, missing data on case mix have made it impossible to determine whether this variation reflects genuine differences in the quality of care. Data linkage has the capacity to reduce missing data.

METHODS

Modelling of survival using Cox proportional hazards of data returned to the UK Renal Registry on patients starting RRT for established renal failure in England. Data on ethnicity, socioeconomic status and comorbidity were obtained by linkage to the Hospital Episode Statistics database, using data from hospitalizations prior to starting RRT.

RESULTS

Patients with missing data were reduced from 61 to 4%. The prevalence of comorbid conditions was remarkably similar across centres. When centre-specific survival was compared after adjustment solely for age, survival was below the 95% limit for 6 of 46 centres. The addition of variables into the multivariable model altered the number of centres that appeared to be 'outliers' with worse than expected survival as follows: ethnic origin four outliers, socioeconomic status eight outliers and year of the start of RRT four outliers. The addition of a combination of 16 comorbid conditions present at the start of RRT reduced the number of centres with worse than expected survival to one.

CONCLUSIONS

Linked data between a national registry and hospital admission dramatically reduced missing data, and allowed us to show that nearly all the variation between English renal centres in 3-year survival on RRT was explained by demographic factors and by comorbidity.

Trends in relative mortality between Hispanic and non-Hispanic whites initiating dialysis: a retrospective study of the US Renal Data System

BACKGROUND

Hispanic patients undergoing long-term dialysis experience better survival compared with non-Hispanic whites. It is unknown whether this association differs by age, has changed over time, or is due to differential access to kidney transplantation.

STUDY DESIGN

National retrospective cohort study.

SETTING & PARTICIPANTS

Using the US Renal Data System, we identified 615,618 white patients 18 years or older who initiated dialysis therapy between January 1, 1995, and December 31, 2007.

PREDICTORS

Hispanic ethnicity (vs non-Hispanic whites), year of end-stage renal disease incidence, age (as potential effect modifier).

OUTCOMES

All-cause and cause-specific mortality.

RESULTS

We found that Hispanics initiating dialysis therapy experienced lower mortality, but age modified this association (P < 0.001). Compared with non-Hispanic whites, mortality in Hispanics was 33% lower at ages 18-39 years (adjusted cause-specific HR [HRcs], 0.67; 95% CI, 0.64-0.71) and 40-59 years (HRcs, 0.67; 95% CI, 0.66-0.68), 19% lower at ages 60-79 years (HRcs, 0.81; 95% CI, 0.80-0.82), and 6% lower at 80 years or older (HRcs, 0.94; 95% CI, 0.91-0.97). Accounting for the differential rates of kidney transplantation, the associations were attenuated markedly in the younger age strata; the survival benefit for Hispanics was reduced from 33% to 10% at ages 18-39 years (adjusted subdistribution-specific HR [HRsd], 0.90; 95% CI, 0.85-0.94) and from 33% to 19% among those aged 40-59 years (HRsd, 0.81; 95% CI, 0.80-0.83).

LIMITATIONS

Inability to analyze Hispanic subgroups that may experience heterogeneous mortality outcomes.

CONCLUSIONS

Overall, Hispanics experienced lower mortality, but differential access to kidney transplantation was responsible for much of the apparent survival benefit noted in younger Hispanics.

Renal replacement therapy: can we separate the effects of social deprivation and ethnicity?

Britain's current ethnic mix is largely a consequence of legislation introduced following the Second World War to allow people from the British Empire and Commonwealth unhindered access to enter Britain to help revive the economy. British minority ethnic populations tend to live in more socially deprived areas, making differentiation between the effects of social deprivation and ethnicity difficult to distinguish. Free-at-the-point-of-use health care should minimize finance-related difficulty accessing treatment, and issues of geographical access to treatment will certainly differ from those of larger, more sparsely populated countries. To examine this, the UK Renal Registry has adopted an approach of studying social deprivation separately in the white-only population before studying the effect of ethnicity and social deprivation in the general population. Using this approach, rates of renal replacement therapy have been shown to be higher in individuals from socially deprived areas and, to varying extents, in those from ethnic minority groups. Attainment of standards on RRT, however, tended not to differ. Survival on RRT is lower for individuals from socially deprived areas but higher for South Asian and black patients. Inequalities have been identified in access to transplantation, with reduced access to the transplant waiting list for socially deprived patients and reduced access to transplantation, once on the waiting list, for ethnic minority patients. The reasons for these inequalities, including any contribution from underlying inequities, are the subject of ongoing research.

Risk factors of short-term mortality after acute nonvariceal upper gastrointestinal bleeding in patients on dialysis: a population-based study

Background

Impaired kidney function is an established predictor of mortality after acute nonvariceal upper gastrointestinal bleeding (ANVUGIB); however, which factors are associated with mortality after ANVUGIB among patients undergoing dialysis is unknown. We examined the associations among demographic characteristics, dialysis-specific features, and comorbid conditions with short-term mortality after ANVUGIB among patients on dialysis.

Methods

Design: Retrospective cohort study. Setting: United States Renal Data System (USRDS), a nation-wide registry of patients with end-stage renal disease. Participants: All ANVUGIB episodes identified by validated algorithms in Medicare-covered patients between 2003 and 2007. Measurements: Demographic characteristics and comorbid conditions from 1 year of billing claims prior to each bleeding event. We used logistic regression extended with generalized estimating equations methods to model the associations among risk factors and 30-day mortality following ANVUGIB events.

Results

From 2003 to 2007, we identified 40,016 eligible patients with 50,497 episodes of ANVUGIB. Overall 30-day mortality was 10.7% (95% CI: 10.4-11.0). Older age, white race, longer dialysis vintage, peritoneal dialysis (vs. hemodialysis), and hospitalized (vs. outpatient) episodes were independently associated with a higher risk of 30-day mortality. Most but not all comorbid conditions were associated with death after ANVUGIB. The joint ability of all factors captured to discriminate mortality was modest (c=0.68).

Conclusions

We identified a profile of risk factors for 30-day mortality after ANVUGIB among patients on dialysis that was distinct from what had been reported in non-dialysis populations. Specifically, peritoneal dialysis and more years since initiation of dialysis were independently associated with short-term death after ANVUGIB.

Association of ethnicity and survival in peritoneal dialysis: a cohort study of incident patients in Brazil

BACKGROUND

There are no available epidemiologic studies about the impact of ethnicity on outcomes of patients treated with peritoneal dialysis (PD) in South America. This study aims to assess the effect of ethnicity on the mortality of incident PD patients in Brazil.

STUDY DESIGN

Prospective observational cohort study of incident patients treated with PD.

SETTINGS & PARTICIPANTS

Patients 18 years or older who started PD therapy between December 2004 and October 2007 in 114 Brazilian dialysis centers.

PREDICTORS

Self-reported ethnicity defined by the Brazilian Institute of Geography and Statistics as black and brown versus white patients and baseline demographic, socioeconomic, clinical, and laboratory data were collected at baseline.

OUTCOME

Mortality, using cumulative mortality curves in which kidney transplantation and transfer to hemodialysis therapy were treated as competing end points. Multivariate Cox proportional hazards analysis was used to adjust for gradually more potential explanatory variables, censored for kidney transplantation and transfer to hemodialysis therapy. Analyses were performed for all patients, as well as stratified for elderly (aged ≥65 years) and nonelderly patients.

RESULTS

1,370 patients were white, 516 were brown, and 273 were black. The competing-risk model showed higher mortality in white patients compared with black and brown patients. With white patients as the reference, Cox proportional hazards analysis showed a crude HR for mortality of 0.77 (95% CI, 0.56-1.05) for black and 0.74 (95% CI, 0.59-0.94) for brown patients. After adjusting for potential explanatory factors, HRs were 0.67 (95% CI, 0.48-0.95) and 0.77 (95% CI, 0.43-1.01), respectively. The same results were observed in elderly and nonelderly patients.

LIMITATIONS

Ethnicity was self-determined and some misclassification might have occurred.

CONCLUSIONS

Black and brown Brazilian incident PD patients have a lower mortality risk compared with white patients.

The relationship between obesity and diabetic nephropathy in China

Background

The epidemic of diabetic nephropathy (DN) has been paralleled by rapid increases in both obesity and diabetes in China. The aim of this study was to investigate the natural history of DN and the association of obesity and renal function with diabetes.

Methods

In total, 264 patients with renal biopsy-confirmed DN were examined from 2002 to 2008 and followed up to June 2008 in our institute. Among these, 129 patients were classified into a Kidney Disease Outcomes Quality Initiative (K/DOQI) stage I subgroup. Weight status, clinico-histopathological features, the development of end-stage renal disease (ESRD) and increased proteinuria were evaluated at the baseline of biopsy and during the follow up. Lean, overweight and obese phenotypes were defined as body mass index (BMI) less than 25 kg/m², 25–28 kg/m², and more than 28 kg/m² over, respectively.

Results

In the patients with renal biopsy-confirmed DN, BMI was 25.5 ± 3.39 kg/m², with 122 (46.2%), 83 (31.4%) and 59 (22.3%) having lean, overweight and obese phenotypes, respectively. Mean proteinuria was 3.09 ± 2.32 g/24 h, serum creatinine was 2.02 ± 2.02 mg/dL, and creatinine clearance rate (Ccr) was 96.0 ± 54.0 mL/min/1.73 m². Compared with obese patients, lean patients had a lower Ccr, a higher percentage of anemia, more renal lesions and higher risk for ESRD (HR = 1.812, P = 0.048). The weight in obese patients decreased significantly after 27 months, and lean patients had a longer duration of diabetes than obese patients. Regarding patients at K/DOQI stage I, patients with DN showed similar duration of diabetes regardless of weight status. Minimal weight loss was recorded in obese patients during follow-up, and they exhibited greater glomerular hyperfiltration and higher risk for increased proteinuria (HR = 2.872, P = 0.014) than lean patients.

Conclusions

In China, obesity is common in DN patients undergoing biopsy. Initial high levels of proteinuria and subsequent weight loss are the major characteristics of the natural course of DN. Obesity contributed to increased proteinuria at an early stage, while the lean phenotype was associated with ESRD development, especially at the later stages.

Trends in the incidence of atrial fibrillation in older patients initiating dialysis in the United States

BACKGROUND

One sixth of US dialysis patients 65 years of age have been diagnosed with atrial fibrillation/flutter (AF). Little is known, however, about the incidence of AF in this population.

METHODS AND RESULTS

We identified 258 605 older patients (≥67 years of age) with fee-for-service Medicare initiating dialysis in 1995 to 2007, who had not been diagnosed with AF within the previous 2 years. Patients were followed for newly diagnosed AF. Multivariable proportional hazard regression was used to examine temporal trends and associations of race and ethnicity with incident AF. We also studied temporal trends in the mortality and risk of ischemic stroke after new AF. Over 514 395 person-years of follow-up, 76 252 patients experienced incident AF for a crude AF incidence rate of 148/1000 person-years. Incidence of AF increased by 11% (95% confidence interval, 5-16) from 1995 to 2007. Compared with non-Hispanic whites, blacks (-30%), Asians (-19%), Native Americans (-42%), and Hispanics (-29%) all had lower rates of incident AF. Mortality after incident AF decreased by 22% from 1995 to 2008. Even more pronounced reductions were seen for incident ischemic stroke during these years.

CONCLUSIONS

The incidence of AF is high in older patients initiating dialysis in the United States and has been increasing over the 13 years of study. Mortality declined during that time but remained >50% during the first year after newly diagnosed AF. Because data on warfarin use were not available, we were unable to study whether trends toward better outcomes could be explained by higher rates of oral anticoagulation.

Influence of vascular access type on sex and ethnicity-related mortality in hemodialysis-dependent patients

OBJECTIVES

To determine whether sex- and ethnicity-based mortality differences in patients dependent on hemodialysis (hemodialysis patients) are because of prevalence of vascular access type.

METHODS

Southern California Permanente Medical Group Renal Database, which contained 5821 chronic hemodialysis patients between 2000 and 2008, was studied.

RESULTS

Mean age of the patients was 62 years, and 59% were male. Of the population, 33% were white; 32%, Hispanic; 23%, African American; 9%, Asian/Pacific Islander; and 3%, other race or ethnicity. Predominant access type over the course of the study was arteriovenous fistula (AVF) in 73%, arteriovenous graft (AVG) in 12%, and tunneled catheter in 14%. There was a higher percentage of AVF in whites (71%) than in African Americans (63%). Risk of death was independently increased by age (hazard ratio [HR], 1.04; 95% confidence interval [CI], 1.04-1.05), male sex (HR, 1.33; 95% CI, 1.22-1.45), diabetes (HR, 1.22; 95% CI, 1.12-1.33), use of an AVG (HR, 1.51; 95% CI, 1.34-1.71) or a tunneled catheter (HR, 6.45; 95% CI, 5.78-7.20). Compared with whites, African-American race decreased the risk of death (HR, 0.63; 95% CI, 0.56-0.70), as did Asian/Pacific Islander (HR, 0.58; 95% CI, 0.49-0.69), Hispanic (HR, 0.58; 95% CI, 0.51-0.65), and other race (HR, 0.67; 95% CI, 0.52-0.86).

CONCLUSION

Age, sex, race or ethnicity, access type, and diabetes are independent risk factors for mortality in hemodialysis patients. After controlling for potential confounders, when compared with whites, minorities all demonstrate significantly decreased risk of mortality. African Americans had reduced mortality risk despite a lower prevalence of arteriovenous fistula compared with whites. Male sex increased mortality. Differences in mortality between sexes and ethnicities in this population cannot be accounted for by differences in type of dialysis access.

Determinants of survival in patients receiving dialysis in Libya

Maintenance dialysis is associated with reduced survival when compared with the general population. In Libya, information about outcomes on dialysis is scarce. This study, therefore, aimed to provide the first comprehensive analysis of survival in Libyan dialysis patients. This prospective multicenter study included all patients in Libya who had been receiving dialysis for >90 days in June 2009. Sociodemographic and clinical data were collected upon enrollment and survival status after 1 year was determined. Two thousand two hundred seventy-three patients in 38 dialysis centers were followed up for 1 year. The majority were receiving hemodialysis (98.8%). Sixty-seven patients were censored due to renal transplantation, and 46 patients were lost to follow-up. Thus, 2159 patients were followed up for 1 year. Four hundred fifty-eight deaths occurred, (crude annual mortality rate of 21.2%). Of these, 31% were due to ischemic heart disease, 16% cerebrovascular accidents, and 16% due to infection. Annual mortality rate was 0% to 70% in different dialysis centers. Best survival was in age group 25 to 34 years. Binary logistic regression analysis identified age at onset of dialysis, physical dependency, diabetes, and predialysis urea as independent determinants of increased mortality. Patients receiving dialysis in Libya have a crude 1-year mortality rate similar to most developed countries, but the mean age of the dialysis population is much lower, and this outcome is thus relatively poor. As in most countries, cardiovascular disease and infection were the most common causes of death. Variation in mortality rates between different centers suggests that survival could be improved by promoting standardization of best practice.

Effect of fish oil supplementation on graft patency and cardiovascular events among patients with new synthetic arteriovenous hemodialysis grafts: a randomized controlled trial

CONTEXT

Synthetic arteriovenous grafts, an important option for hemodialysis vascular access, are prone to recurrent stenosis and thrombosis. Supplementation with fish oils has theoretical appeal for preventing these outcomes.

OBJECTIVE

To determine the effect of fish oil on synthetic hemodialysis graft patency and cardiovascular events.

DESIGN, SETTING, AND PARTICIPANTS

The Fish Oil Inhibition of Stenosis in Hemodialysis Grafts (FISH) study, a randomized, double-blind, controlled clinical trial conducted at 15 North American dialysis centers from November 2003 through December 2010 and enrolling 201 adults with stage 5 chronic kidney disease (50% women, 63% white, 53% with diabetes), with follow-up for 12 months after graft creation.

INTERVENTIONS

Participants were randomly allocated to receive fish oil capsules (four 1-g capsules/d) or matching placebo on day 7 after graft creation.

MAIN OUTCOME MEASURE

Proportion of participants experiencing graft thrombosis or radiological or surgical intervention during 12 months' follow-up.

RESULTS

The risk of the primary outcome did not differ between fish oil and placebo recipients (48/99 [48%] vs 60/97 [62%], respectively; relative risk, 0.78 [95% CI, 0.60 to 1.03; P = .06]). However, the rate of graft failure was lower in the fish oil group (3.43 vs 5.95 per 1000 access-days; incidence rate ratio [IRR], 0.58 [95% CI, 0.44 to 0.75; P < .001]). In the fish oil group, there were half as many thromboses (1.71 vs 3.41 per 1000 access-days; IRR, 0.50 [95% CI, 0.35 to 0.72; P < .001]); fewer corrective interventions (2.89 vs 4.92 per 1000 access-days; IRR, 0.59 [95% CI, 0.44 to 0.78; P < .001]); improved cardiovascular event-free survival (hazard ratio, 0.43 [95% CI, 0.19 to 0.96; P = .04]); and lower mean systolic blood pressure (-3.61 vs 4.49 mm Hg; difference, -8.10 [95% CI, -15.4 to -0.85]; P = .01).

CONCLUSIONS

Among patients with new hemodialysis grafts, daily fish oil ingestion did not decrease the proportion of grafts with loss of native patency within 12 months. Although fish oil improved some relevant secondary outcomes such as graft patency, rates of thrombosis, and interventions, other potential benefits on cardiovascular events require confirmation in future studies.

TRIAL REGISTRATION

isrctn.org Identifier: ISRCTN15838383.

Identifying depression in South asian patients with end-stage renal disease: considerations for practice

Depression is a prevalent burden for patients with end-stage renal disease (ESRD) and one that is under-recognized and consequently under-treated. Although several studies have explored the association between depression symptoms, treatment adherence and outcomes in Euro-American patient groups, quantitative and qualitative exploration of these issues in patients from different cultural and ethnic backgrounds has been lacking. This review discusses the methodological issues associated with measuring depression in patients of South Asian origin who have a 3- to 5-fold greater risk of developing ESRD. There is a need to advance research into the development of accurate screening practices for this patient group, with an emphasis on studies utilizing rigorous approaches to evaluating the use of both emic (culture-specific) and etic (universal or culture-general) screening instruments.

The role of psychosocial factors in ethnic differences in survival on dialysis in the Netherlands

INTRODUCTION

Ethnic minority patients on dialysis are reported to have better survival rates relative to Caucasians. The reasons for this finding are not fully understood and European studies are scarce. This study examined whether ethnic differences in survival could be explained by patient characteristics, including psychosocial factors.

METHODS

We analysed data of the Netherlands Cooperative Study on the Adequacy of Dialysis study, an observational prospective cohort study of patients who started dialysis between 1997 and 2007 in the Netherlands. Ethnicity was classified as Caucasian, Black or Asian, assessed by local nurses. Data collected at the start of dialysis treatment included demographic, clinical and psychosocial characteristics. Psychosocial characteristics included data on health-related quality of life (HRQoL), mental health status and general health perception. Cox proportional hazards analysis was used to explore ethnic survival differences.

RESULTS

One thousand seven hundred and ninety-one patients were Caucasian, 45 Black and 108 Asian. The ethnic groups differed significantly in age, residual glomerular filtration rate, diabetes mellitus, erythropoietin use, plasma calcium, parathormone and creatinine, marital status and general health perception. No ethnic differences were found in HRQoL and mental health status. Crude hazard ratios (HRs) for mortality for Caucasians compared to Blacks and Asians were 3.1 [95% confidence interval (CI) 1.6-5.9] and 1.1 (95% CI 0.9-1.5), respectively. After adjustment for a range of potential explanatory variables, including psychosocial factors, the HRs were 2.5 (95% CI 1.2-4.9) compared with Blacks and 1.2 (95% CI 0.9-1.6) compared with Asians.

CONCLUSIONS

Although patient numbers were rather small, this study demonstrates, with 95% confidence, better survival for Black compared to Caucasian dialysis patients and equal survival for Asian compared to Caucasian dialysis patients in the Netherlands. This could not be explained by patient characteristics, including psychosocial factors.

Association of race and age with survival among patients undergoing dialysis

CONTEXT

Many studies have reported that black individuals undergoing dialysis survive longer than those who are white. This observation is paradoxical given racial disparities in access to and quality of care, and is inconsistent with observed lower survival among black patients with chronic kidney disease. We hypothesized that age and the competing risk of transplantation modify survival differences by race.

OBJECTIVE

To estimate death among dialysis patients by race, accounting for age as an effect modifier and kidney transplantation as a competing risk.

DESIGN, SETTING, AND PARTICIPANTS

An observational cohort study of 1,330,007 incident end-stage renal disease patients as captured in the United States Renal Data System between January 1, 1995, and September 28, 2009 (median potential follow-up time, 6.7 years; range, 1 day-14.8 years). Multivariate age-stratified Cox proportional hazards and competing risk models were constructed to examine death in patients who receive dialysis.

MAIN OUTCOME MEASURES

Death in black vs white patients who receive dialysis.

RESULTS

Similar to previous studies, black patients undergoing dialysis had a lower death rate compared with white patients (232,361 deaths [57.1% mortality] vs 585,792 deaths [63.5% mortality], respectively; adjusted hazard ratio [aHR], 0.84; 95% confidence interval [CI], 0.83-0.84; P <.001). However, when stratifying by age and treating kidney transplantation as a competing risk, black patients had significantly higher mortality than their white counterparts at ages 18 to 30 years (27.6% mortality vs 14.2%; aHR, 1.93; 95% CI, 1.84-2.03), 31 to 40 years (37.4% mortality vs 26.8%; aHR, 1.46; 95% CI, 1.41-1.50), and 41 to 50 years (44.8% mortality vs 38.0%; aHR, 1.12; 95% CI, 1.10-1.14; P <.001 for interaction terms between race and each aforementioned age category), as opposed to patients aged 51 to 60 years (51.5% vs 50.9%; aHR, 0.93; 95% CI, 0.92-0.94), 61 to 70 years (64.9% vs 67.2%; aHR, 0.87; 95% CI, 0.86-0.88), 71 to 80 years (76.1% vs 79.7%; aHR, 0.85; 95% CI, 0.84-0.86), and older than 80 years (82.4% vs 83.6%; aHR, 0.87; 95% CI, 0.85-0.88).

CONCLUSIONS

Overall, among dialysis patients in the United States, there was a lower risk of death for black patients compared with their white counterparts. However, the commonly cited survival advantage for black dialysis patients applies only to older adults, and those younger than 50 years have a higher risk of death.

Traditional and nontraditional risk factors as predictors of cerebrovascular events in patients with end stage renal disease

OBJECTIVES AND METHODS

End stage renal disease (ESRD) patients exhibit a higher risk of cerebrovascular events as compared with the general population. In 283 ESRD patients followed up for 10 years, we investigated the long-term predictive value for stroke and transient ischemic attacks of traditional and nontraditional risk factors. Data analysis was performed by a modified Cox regression analysis for repeated events and by a competing risks analysis.

RESULTS

During the follow-up, 61 cerebrovascular events occurred in 47 patients. On univariate Cox analysis, the risk of cerebrovascular outcomes was directly related to age, smoking, diabetes, BMI, systolic and pulse pressures, triglycerides, hemoglobin, history of stroke/transient ischemic attacks, arrhythmia and left ventricular mass index. Nontraditional risk factors in ESRD such as norepinephrine, homocysteine, interleukin-6 and asymmetric dimethylarginine failed to predict these events. In a multivariate Cox model for repeated events only smoking [hazard ratio: 2.45, 95% confidence interval (CI): 1.29-4.65], age (hazard ratio: 1.05, 95% CI: 1.01-1.08), hemoglobin (hazard ratio: 1.28, 95% CI 1.06-1.54), triglycerides (hazard ratio: 1.04, 95% CI 1.01-1.08), pulse pressure (hazard ratio: 1.53, 95% CI 1.01-2.23) and left ventricular mass index (hazard ratio: 1.02, 95% CI 1.01-1.04) maintained an independent relationship with cerebrovascular events. The direct link between hemoglobin and cerebrovascular events was significantly stronger (P < 0.05) than that of the same variable and death.

CONCLUSION

The risk of stroke in ESRD depends mainly on traditional risk factors, high hemoglobin and left ventricular hypertrophy. Multiple interventions aimed to reduce arterial stiffness, left ventricular mass and smoking as well as to maintain hemoglobin within the recommended therapeutic range may have beneficial effects on the risk of cerebrovascular events in ESRD patients.

The increasing prevalence of atrial fibrillation among hemodialysis patients

A half million Americans have ESRD, which puts them at high risk for cardiovascular disease and poor outcomes. Little is known about the epidemiology of atrial fibrillation among patients with ESRD. We analyzed data from annual cohorts (1992 to 2006) of prevalent hemodialysis patients from the United States Renal Data System. In each cohort, we searched 1 year of medical claims for relevant diagnosis codes to determine the prevalence of atrial fibrillation. Among 2.5 million patient observations, 7.7% had atrial fibrillation, with the prevalence increasing 3-fold from 3.5% (1992) to 10.7% (2006). The number of affected patients increased from 3620 to 23,893 (6.6-fold) during this period. Older age, male gender, and several comorbid conditions were associated with increased risk for atrial fibrillation. Compared with otherwise similar Caucasians, the prevalence of atrial fibrillation rates was substantially lower for blacks, Asians, and Native Americans. One-year mortality was twice as high among hemodialysis patients with atrial fibrillation compared with those without (39% versus 19%), and this increased risk was constant during the 15 years of the study. In conclusion, the prevalence of diagnosed atrial fibrillation among patients receiving hemodialysis in the United States is increasing, varies by race, and remains associated with substantially increased mortality. Identifying potentially modifiable risk factors for incident atrial fibrillation requires further investigation.

Reappraisal of the impact of race on survival in patients on dialysis

Racial differences in the cause, natural history, and effects of chronic kidney disease have long been the subject of investigation. Dialysis-dependent kidney failure occurs nearly 4 times more often in African Americans than European Americans. Despite this observation, studies repeatedly show that African Americans have a significant survival advantage after initiating dialysis therapy. Although this phenomenon has been attributed to environmental and socioeconomic factors, recent studies show that inherited factors strongly influence racial differences in the development of diverse kidney diseases and may affect the risk of nephropathy-associated cardiovascular disease. We review relevant studies and propose the hypothesis that inherited factors leading to organ-limited kidney diseases and a lower burden of systemic atherosclerosis contribute in part to the improved survival rates in African American patients on dialysis therapy.

Potential effects of MYH9-associated nephropathy on dialysis and kidney transplant outcomes

Several related disorders comprise the spectrum of nonmuscle myosin heavy chain 9-associated (MYH9) nephropathy. The contribution of variants in this single MYH9 gene to ethnic differences in the incidence rates of end-stage renal disease is now clearly established. The importance of recognizing the role of MYH9 in these inherited kidney disorders goes beyond simple disease association; there may well be effects on clinical outcomes in patients on dialysis and after kidney transplantation. MYH9 polymorphisms may affect treatment outcomes in severe kidney disease and such gene effects are rarely encountered in practice.

Obesity, end-stage renal disease, and survival in an elderly cohort with cardiovascular disease

Obesity is highly prevalent in African Americans and is associated with increased risk of End-Stage Renal Disease (ESRD) and death. It is not known if the effect of obesity is similar among blacks and whites. The aim of this study is to examine racial differences in the association of obesity with ESRD and survival in elderly patients (age >65). Data were obtained for 74,167 Medicare patients with acute myocardial infarction (AMI) between February 1994 and July 1995. BMI was calculated as weight (kg) divided by height (m(2)). We evaluated the association of BMI class with ESRD incidence and death using multivariable Cox proportional hazards models, testing for race-BMI interactions. Compared to whites, African Americans had higher BMI (26.9 vs. 26.0, P < 0.0001) and estimated glomerular filtration rate (72.4 ml/min/1.73 m(2) vs. 66.6 ml/min/1.73 m(2), P < 0.0001). Crude ESRD rates increased with increasing obesity among whites but not among blacks. However, after adjusting for age, sex, and other comorbidities, obesity was not associated with increased ESRD rate among blacks or whites and the interaction between race and BMI was not significant. Furthermore, for both races, patients classified as overweight, class 1 obese, or class 2 obese had similar, significantly better survival abilities compared to normal weight patients and the race BMI interaction was not significant. In conclusion, obesity does not increase risk of ESRD among black or white elderly subjects with cardiovascular disease (CVD). However, both obese blacks and whites, in this population, experience a survival benefit. Further studies need to explore this obesity paradox.

Survival of patients from South Asian and Black populations starting renal replacement therapy in England and Wales

Background. South Asian and Black ethnic minorities in the UK have higher rates of acceptance onto renal replacement therapy (RRT) than Caucasians. Registry studies in the USA and Canada show better survival; there are few data in the UK.

Methods. Renal Association UK Renal Registry data were used to compare the characteristics and survival of patients starting RRT from both groups with those of Caucasians, using incident cases accepted between 1997 and 2006. Survival was analysed by multivariate Cox's proportional hazards regression split by haemodialysis and peritoneal dialysis (PD) due to non-proportionality, and without censoring at transplantation.

Results. A total of 2495 (8.2%) were South Asian and 1218 (4.0%) were Black. They were younger and had more diabetic nephropathy. The age-adjusted prevalence of vascular co-morbidity was higher in South Asians and lower in Blacks; other co-morbidities were generally common in Caucasians. Late referral did not differ. They were less likely to receive a transplant or to start PD. South Asians and Blacks had significantly better survival than Caucasians both from RRT start to Day 90 and after Day 90, and for those on HD or PD at Day 90. Fully adjusted hazard ratios after Day 90 on haemodialysis were 0.70 (0.55–0.89) for South Asians and 0.56 (0.41–0.75) for Blacks.

Conclusion. South Asian and Black minorities have better survival on dialysis. An understanding of the mechanisms may provide general insights for all patients on RRT.

Ethnicity, socioeconomic status, and attainment of clinical practice guideline standards in dialysis patients in the United kingdom

BACKGROUND AND OBJECTIVES

The role of socioeconomic status (SES) and its contribution to ethnic differences in standards attainment among dialysis patients is not known.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We examined associations between area- level SES (Townsend index) and ethnicity (white, black, South Asian) and standards attainment in 14,117 incident dialysis patients (1997-2004) in the UK.

RESULTS

Deprived patients were less likely to achieve hemoglobin (Hb) > or = 10 g/dl (trend P < 0.001) but not after controlling for patient and center characteristics (trend P = 0.1). There was no association with hemodialysis dose and parathyroid hormone (PTH) standard but deprived patients had better attainment of phosphate (PO4) <5.6 mg/dl, calcium (Ca) and Calcium-phosphate (CaPO4) standard (e.g., most deprived versus least deprived adjusted odds ratio [OR] 1.25, 95% confidence intervals [CI] 1.12, 1.38). There was no association with SES using a lower limit for PO4 (3.5 - 5.5 mg/dl). Compared with Whites, Blacks had lower attainment of Hb (adjusted OR 0.57, 95% CI 0.45, 0.71) and PTH standards (adjusted OR 0.27, 95% CI 0.22, 0.33) but better attainment of PO4 and CaPO4, while South Asians experienced better or comparable outcomes for most standards except Ca and PTH.

CONCLUSIONS

There was no evidence of socioeconomic inequity in standards attainment or a consistent pattern of inequity by ethnic group. The lower attainment of some standards in ethnic minorities may reflect biologic differences rather than ethnicity-related inequity of care.

Role of vitamin D in chronic kidney disease

Decline in renal function is related directly to cardiovascular mortality. However, traditional risk factors do not fully account for the high mortality in these patients. Activated vitamin D, a hormone produced by the proximal convoluted tubule of the kidney, appears to have beneficial effects beyond suppressing parathyroid hormone (PTH). However, activated vitamin D also can cause hypercalcemia and hyperphosphatemia in chronic kidney disease. Newer agents such as vitamin D receptor activators (eg, paricalcitol) suppress PTH with reduced risk of hypercalcemia and hyperphosphatemia. Recent evidence from animal and preliminary human studies supports an association between vitamin D receptor activators and reduced risk of cardiovascular disease deaths, irrespective of PTH levels. New pathways of vitamin D regulation also have been discovered, involving fibroblast growth factor-23 and klotho. Although considerable work has been performed to advance our understanding of the effects of vitamin D in health and chronic kidney disease, more investigations and randomized trials need to be performed to elucidate the mechanistic underpinnings of these effects.