Incident Renal Replacement Therapy Patients Research Articles

Neurocognitive Function with Conventional Hemodialysis versus Post-Dilution Hemofiltration as Initial Treatment in ESKD Patients: A Randomized Controlled Trial – The DA-VINCI Study

Introduction: The ideal modality choice and dialysis prescription during the first renal replacement therapy (RRT) session remain unclear. We conducted a pilot study to determine the safety risk for hemodialysis (HD) versus hemofiltration (HF) and its relationship with neurocognitive assessment on incident RRT patients. Methods: Twenty-four incident RRT patients were included. Patients were randomized to the conventional HD group or post-dilution HF group. Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MOCA) tests were applied in all patients before and after session, and brain magnetic resonance image (MRI) was performed in 7 patients from the conventional HD group and 8 patients from the post-dilution HF group before and after the intervention. Results: Baseline characteristics were similar between groups. Compared to conventional HD, post-dilution HF had longer treatment time. There were no significant changes in blood pressure after RRT in both groups. The MMSE test showed no significant differences between groups or within groups. The MOCA test showed an increase in the total score for the post-dilution HF group with no significant changes between groups. The MRI evaluation showed no differences between or within groups. Conclusion: Post-dilution HF is a safe alternative for the first HD session in incident RRT; it allows longer treatment time if ultrafiltration is required and has a similar neurological risk than conventional HD. This is a pilot study and that larger studies are needed to confirm the findings.

Cost-effectiveness analysis of renal replacement therapy strategies in Guangzhou city, southern China

ObjectivesThis study aims to assess the cost-effectiveness of three renal replacement therapy (RRT) modalities as well as proposed changes of scheduled policies in RRT composition in Guangzhou city.MethodsFrom a payer...

P0772CLINICAL CHARACTERISTICS OF THE UK CHINESE POPULATION WITH KIDNEY FAILURE: A UK RENAL REGISTRY ANALYSIS

Abstract Background and Aims Data from the UK Renal Registry (UKRR) has shown that 0.5% of those in the UK with kidney failure are of Chinese ethnicity. The UK Chinese population is growing. Ethnic differences in cause of renal disease and dialysis rates have been described in UK individuals of White, South Asian, and Black ethnicity. However, the clinical demographics of the UK Chinese population with renal disease have not previously been investigated. The China Kidney Disease Network and the Hong Kong Renal Registry have reported the main cause of chronic kidney disease in their populations is diabetes, but the causes of renal disease in other Chinese diaspora have not been well described. We investigated the clinical characteristics of the UK Chinese population on renal replacement therapy (RRT) as compared with the UK White RRT population in this UKRR analysis. Method Data on all adult patients >=18 years who started RRT between 1/1/97 and 31/12/16 were extracted from the UKRR. Patients with ethnicity recorded as anything other than “Chinese” or “White” were excluded from analysis. Patients with ethnicity data missing were also excluded. Socioeconomic status was measured using country-specific Index of Multiple Deprivation (IMD) quintiles derived from patients’ postcodes (1= most deprived, 5= least deprived). The Chi-square (*) and Mann-Whitney U (**) tests were used to compare baseline characteristics between Chinese and White ethnic groups. Results The dataset comprised of 92,857 incident RRT patients, of which 0.5% (n=501) were of Chinese ethnicity and 76% (n=70,575) were White. Clinical characteristics of the UK Chinese population as compared to the UK White population are presented in Table 1. UK Chinese patients were younger at start of RRT than white patients (61.4 years vs 65.6 years, p<0.001**). Any difference in the proportion of male patients (60.7% vs 63.0%, p=0.29*) or socioeconomic status (p=0.75*) between the two groups was consistent with chance. There were marked differences in the causes of renal disease: UK Chinese patients had more diabetic renal disease (29% versus 20%, p<0.001*) and glomerulonephritis that white patients (21% vs 13%, p<0.001*) There was modest evidence that more UK Chinese patients started RRT on peritoneal dialysis (PD) compared to the White population (26% vs 23%, p=0.01*) Conclusion We found evidence that the UK Chinese RRT population differs from the UK White RRT population. To our knowledge, this is the first study describing renal disease in the UK Chinese population, and one of the first to describe disease in the Chinese diaspora. Our finding of a greater burden of diabetes in the UK Chinese RRT population compared to the White RRT population may reflect the high prevalence of diabetes in the UK Chinese, as in mainland China and Hong Kong. Further investigation is needed to understand the causes behind the higher burden of glomerulonephritis in the UK Chinese population. The increased rates of PD in UK Chinese patients may be associated with lower average Body Mass Index (BMI) in the Chinese population. The quantity of missing BMI data in the UKRR dataset prevented investigation of this association. Hong Kong has had a successful “PD first” policy for >30 years. Familiarity with this as a mode of dialysis may have led to higher rates of PD in the UK Chinese population. Studies from Hong Kong have also suggested that lower dialysis volumes are required for Chinese PD patients, and that high transporter status is less common in their population. It would be beneficial to elucidate whether this is also the case in UK Chinese patients.

P1660ACCESS TO KIDNEY TRANSPLANTATION IN THE UK CHINESE POPULATION: A UK RENAL REGISTRY ANALYSIS

Abstract Background and Aims Previous UK Renal Registry (UKRR) analyses and the Access to Transplantation and Transplant Outcome Measures (ATTOM) study have shown ethnic disparity in access to kidney transplants in the UK, but access to transplantation for the UK Chinese population has not been investigated In this UKRR analysis, we compared the likelihood of kidney transplantation between the UK White and UK Chinese renal populations, aiming to investigate whether there was evidence of ethnic disparity in access to kidney transplantation for this specific ethnic group. Method Data on all adult patients >=18 years who started renal replacement therapy (RRT) between 1/1/97 and 31/12/16 were extracted from the UKRR. Patients with ethnicity recorded as anything other than “Chinese” or “White” were excluded from analysis. Patients with ethnicity data missing were also excluded. Patients aged >= 75 years at the start of RRT were excluded because of the high prevalence of comorbidity which decreases the likelihood of transplantation and the very small proportion of patients receiving a kidney transplant in the UK in this age group. Socioeconomic status (SES) was measured using country-specific Index of Multiple Deprivation (IMD) quintiles derived from patient postcodes (1= most deprived, 5= least deprived). The independent variable of interest was Chinese ethnicity (Chinese vs White). Multivariable logistic regression models were used to investigate the relationship between Chinese ethnicity and being listed on the deceased donor transplant waiting list i) at start of RRT ii) 2 years after start of RRT iii) pre-emptive kidney transplantation, iv) kidney transplantation at 3 years after start of RRT, and v) living-donor kidney transplantation. The models were run unadjusted and then adjusted for the confounders, specified a priori, age, sex, primary renal disease and SES. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using robust standard errors to account for clustering by renal centre. Results The dataset comprised of 92,857 incident RRT patients. 0.5% (n=501) were of Chinese ethnicity, 76% (n=70,575) were White. The findings of the multivariable logistic regression analyses are presented in Table 1. Even after adjustment for potential confounders UK Chinese patients had lower odds of being waitlisted at the start of RRT (OR 0.71, [95% CI 0.54-0.94]) but were more likely to be waitlisted at 2 years (OR 1.28, [95% CI 1.02-1.61]) compared to White patients. UK Chinese individuals were also less likely to receive a pre-emptive kidney transplant (OR 0.47, [95% CI 0.29-0.78]), less likely to be transplanted within 3 years of starting RRT (OR 0.69, [95% CI 0.52-0.92]) or have a living-donor kidney transplant(LDKT) (OR 0.39, [95% CI 0.26-0.59]) compared to White patients. Conclusion This is the first study that has shown that UK Chinese renal patients are less likely to have the opportunity to receive a living or deceased kidney transplant. Future research needs to test whether later presentation or more rapid progression of renal disease could explain these observations. The higher odds of transplant listing at 2 years suggests fitness for transplantation is not a significant barrier. The reasons why this ethnic group are less likely to receive a LDKT is also not well understood. Understanding whether these disparities reflect modifiable policy, health system or donor/recipient level barriers will help ensure equitable access to transplantation.

Access to waitlisting for deceased donor kidney transplantation in Australia.

A detailed analysis of waitlisting for deceased donor kidney transplantation in Australia has not previously been reported. We aimed to determine if patient characteristics associated with waitlisting identify areas of potential inequality in access to transplantation in Australia. A competing risk time-to-event model was used to determine predictors of waitlisting for all adult incident renal replacement therapy patients in Australia between 2006 and 2015. Secondary analysis was performed to determine predictors of overall access to transplantation (using a combined outcome of waitlisting and living donor transplantation). The cohort consisted of 21 231 patients with a median age of 63 years. Overall, 4361 (20.5%) were waitlisted and 1239 (5.8%) received a living donor transplant without being previously waitlisted. Primary analysis revealed that medical comorbidities, older age, smoking status and body mass index were all significant predictors of waitlisting and that and there was variation in waitlisting practice across states Despite adjustment for the above factors, demographic characteristics, including Indigenous ethnicity (subdistribution hazard ratios (SHR) 0.46 (95% confidence interval (CI) 0.38-0.55)), female gender (SHR 0.85 (95% CI 0.80, 0.91)) and residence in a regional area (SHR 0.88 (95% CI 0.81-0.95)) were also associated with a lower likelihood of waitlisting. Secondary analysis showed younger age and higher socio-economic advantage were additional predictors of overall access to transplantation, driven by higher rates of living donor transplantation. Demographic as well as clinical characteristics are associated with reduced likelihood of waitlisting for kidney transplantation in Australia. Further analysis and auditing should be considered to determine if this reflects other unmeasured factors or highlights a need to address inequality.

Women and renal replacement therapy in Europe: lower incidence, equal access to transplantation, longer survival than men.

In 2018, World Kidney Day (WKD) and International Women’s Day coincide. The WKD editorial focuses on women’s kidney health. The European Renal Association–European Dialysis and Transplant Association (ERA-EDTA) Registry Annual Report 2015 summary provides an excellent snapshot of renal replacement therapy (RRT) epidemiology and women in Europe. The WKD editorial reports a lower incidence of RRT in women in major registries and potential limitations to women’s access to transplantation. What is the situation in Europe? In Europe, the incidence of RRT is also lower in women: 38% of incident RRT patients are women. Does it represent milder chronic kidney disease (CKD) in women or barriers to RRT access? The question arises from the higher prevalence of CKD Stages G3–G5 in women than in men. However, in some European countries, such as Spain, non-dialysis CKD Stages G4–G5 is less frequent in women than in men, recapitulating the difference in RRT incidence. In the ERA-EDTA Registry, the incidence of transplantation as a first modality on Day 1 was slightly higher for women and survival on RRT was similar for women and men in the first 3 months, but an intergender gap favouring women increased as RRT vintage increased. However, women on RRT are worse off regarding survival when compared with women in the general population than men on RRT compared with men in the general population. In conclusion, the ERA-EDTA Registry Annual Report 2015 and European epidemiology data suggest a lower incidence of end-stage kidney disease in women, no gender differences in access to transplantation and better RRT survival in women.

Can we routinely measure patient involvement in treatment decision-making in chronic kidney care? A service evaluation in 27 renal units in the UK.

BackgroundShared decision making is considered an important aspect of chronic disease management. We explored the feasibility of routinely measuring kidney patients' involvement in making decisions about renal replacement therapy (RRT) in National Health Service settings.MethodsWe disseminated a 17-item paper questionnaire on involvement in decision-making among adult patients with established kidney failure who made a decision about RRT in the previous 90 days (Phase 1) and patients who had been receiving RRT for 90–180 days (Phase 2). Recruitment rates were calculated as the ratio between the number of included and expected eligible patients (I : E ratio). We assessed our sample's representativeness by comparing demographics between participants and incident patients in the UK Renal Registry.ResultsThree hundred and five (Phase 1) and 187 (Phase 2) patients were included. For Phase 1, the I : E ratio was 0.44 (range, 0.08–2.80) compared with 0.27 (range, 0.04–1.05) in Phase 2. Study participants were more likely to be white compared with incident RRT patients (88 versus 77%; P < 0.0001). We found no difference in age, gender or social deprivation. In Phases 1 and 2, the majority reported a collaborative decision-making style (73 and 69%), and had no decisional conflict (85 and 76%); the median score for shared decision-making experience was 12.5 (Phase 1) and 10 (Phase 2) out of 20.ConclusionOur study shows the importance of assessing the feasibility of data collection in a chronic disease context prior to implementation in routine practice. Routine measurement of patient involvement in established kidney disease treatment decisions is feasible, but there are challenges in selecting the measure needed to capture experience of involvement, reducing variation in response rate by service and identifying when to capture experience in a service managing people's chronic disease over time.

Renal replacement therapy in Europe: a summary of the 2013 ERA-EDTA Registry Annual Report with a focus on diabetes mellitus.

BackgroundThis article provides a summary of the 2013 European Renal Association–European Dialysis and Transplant Association (ERA-EDTA) Registry Annual Report (available at http://www.era-edta-reg.org), with a focus on patients with diabetes mellitus (DM) as the cause of end-stage renal disease (ESRD).MethodsIn 2015, the ERA-EDTA Registry received data on renal replacement therapy (RRT) for ESRD from 49 national or regional renal registries in 34 countries in Europe and bordering the Mediterranean Sea. Individual patient data were provided by 31 registries, while 18 registries provided aggregated data. The total population covered by the participating registries comprised 650 million people.ResultsIn total, 72 933 patients started RRT for ESRD within the countries and regions reporting to the ERA-EDTA Registry, resulting in an overall incidence of 112 per million population (pmp). The overall prevalence on 31 December 2013 was 738 pmp (n = 478 990). Patients with DM as the cause of ESRD comprised 24% of the incident RRT patients (26 pmp) and 17% of the prevalent RRT patients (122 pmp). When compared with the USA, the incidence of patients starting RRT pmp secondary to DM in Europe was five times lower and the incidence of RRT due to other causes of ESRD was two times lower. Overall, 19 426 kidney transplants were performed (30 pmp). The 5-year adjusted survival for all RRT patients was 60.9% [95% confidence interval (CI) 60.5–61.3] and 50.6% (95% CI 49.9–51.2) for patients with DM as the cause of ESRD.

Understanding cost of care for patients on renal replacement therapy: looking beyond fixed tariffs.

In a number of countries, reimbursement to hospitals providing renal dialysis services is set according to a fixed tariff. While the cost of maintenance dialysis and transplant surgery are amenable to a system of fixed tariffs, patients with established renal failure commonly present with comorbid conditions that can lead to variations in the need for hospitalization beyond the provision of renal replacement therapy. Patient-level cost data for incident renal replacement therapy patients in England were obtained as a result of linkage of the Hospital Episodes Statistics dataset to UK Renal Registry data. Regression models were developed to explore variations in hospital costs in relation to treatment modality, number of years on treatment and factors such as age and comorbidities. The final models were then used to predict annual costs for patients with different sets of characteristics. Excluding the cost of renal replacement therapy itself, inpatient costs generally decreased with number of years on treatment for haemodialysis and transplant patients, whereas costs for patients receiving peritoneal dialysis remained constant. Diabetes was associated with higher mean annual costs for all patients irrespective of treatment modality and hospital setting. Age did not have a consistent effect on costs. Combining predicted hospital costs with the fixed costs of renal replacement therapy showed that the total cost differential for a patient continuing on dialysis rather than receiving a transplant is considerable following the first year of renal replacement therapy, thus reinforcing the longer-term economic advantage of transplantation over dialysis for the health service.

RENAL FUNCTION REPLACEMENT SERVICES IN ROMANIA

Chronic renal failure consists of the progressive, slow loss of the kidney function over several years, as a long-term chronic condition affecting effective kidney functioning. In Romania, nephrology medical care is given in outpatient facilities, nephrology facilities with beds, dialysis facilities (haemo- and peritoneal dialysis) and renal transplant facilities. In 2007 – 2012, the period under study, the number of incident renal replacement therapy patients doubled in Romania, whereas their median age range increased by 4.5 years while area coverage with this type of medical service unfortunately remained poor. Keywords: Chronic renal failure, dialysis, transplant, market share, dialysis centres Normal 0 21 false false false RO X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:Table Normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri,sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Times New Roman; mso-bidi-theme-font:minor-bidi; mso-fareast-language:EN-US;}

Renal replacement therapy associated with lithium nephrotoxicity in Australia

To analyse the annual incidence of end-stage renal disease (ESRD) associated with lithium-induced nephropathy (LiN) in Australia. Retrospective cohort study of patients commencing renal replacement therapy (RRT) in Australia. We compared patients with LiN with all other RRT patients between 1January 1991and 31December 2011, using Australia and New Zealand Dialysis and Transplant Registry data. Numbers and characteristics of incident RRT patients, primary kidney disease (LiN or other, based on clinical diagnosis). LiN contributed to 187people in Australia commencing RRT between 1January 1991and 31December 2011. The incidence rate increased from 0.14cases/million population/year (95% CI, 0.06-0.22) in 1992-1996to 0.78(95% CI, 0.67-0.90) in 2007-2011. This increase is unlikely to be attributed solely to demographic changes in Australia. LiN patients were more likely than non-LiN patients to be women, to be white, to smoke, and to have a higher body mass index, but were less likely to have undergone renal biopsy. Rates of ESRD attributed to LiN are increasing rapidly. Currently accepted lithium dosages and duration of treatment might induce ESRD in a large cohort of patients. We encourage clinicians to exercise discretion when prescribing lithium, check renal function regularly, stop lithium if there is a deterioration in two consecutive readings, and consider substitution with other drugs.

Timing and Outcome of Renal Replacement Therapy in Patients with Congenital Malformations of the Kidney and Urinary Tract

Congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of ESRD in children, but the proportion of patients with individual CAKUT entities progressing to ESRD during adulthood and their long-term clinical outcomes are unknown. This study assessed the age at onset of renal replacement therapy (RRT) and patient and renal graft survival in patients with CAKUT across the entire age range. Patients with CAKUT were compared with age-matched patients who were undergoing RRT for other renal disorders on the basis of data from the European Renal Association-European Dialysis and Transplant Association Registry. Competing risk and Cox regression analyses were conducted. Of 212,930 patients commencing RRT from 1990 to 2009, 4765 (2.2%) had renal diagnoses consistent with CAKUT. The proportion of incident RRT patients with CAKUT decreased from infancy to childhood and then increased until age 15-19 years, followed by a gradual decline throughout adulthood. Median age at RRT start was 31 years in the CAKUT cohort and 61 years in the non-CAKUT cohort (P<0.001). RRT was started earlier (median, 16 years) in patients with isolated renal dysplasia than in those with renal hypoplasia and associated urinary tract disorders (median, 29.5-39.5 years). Patients with CAKUT survived longer than age- and sex-matched non-CAKUT controls because of lower cardiovascular mortality (10-year survival rate, 76.4% versus 70.7%; P<0.001). CAKUT leads to ESRD more often at adult than pediatric age. Treatment outcomes differ from those of acquired kidney diseases and vary within CAKUT subcategories.

The importance of early referral for the treatment of chronic kidney disease: a Danish nationwide cohort study

BackgroundMany patients with advanced chronic kidney disease are referred late to renal units. This is associated with negative aspects. The purpose of the present study was to characterize late versus early referrals for renal replacement therapy including their renal disease, health care contacts and medical treatment before renal replacement therapy (RRT) and the consequences for RRT modality and mortality.MethodsNationwide cohort study including 4495 RRT patients identified in the Danish Nephrology Registry 1999–2006. The cohort was followed to end 2007 by linkage to other national registries. Late referral: follow-up ≤16 weeks in renal unit before RRT start. Cox proportional hazards models were used to estimate the relative risk of mortality or waiting list status within 365 days in late referrals versus early referrals.ResultsA total of 1727 (38%) incident RRT patients were referred late. Among these, 72% were treated in non-nephrology hospital departments and 91% in general practice 2 years to 16 weeks before RRT start. Fewer late referrals received recommended pre-RRT treatment as judged by renin-angiotensin-system blockade: 32% versus 57% or the D-vitamin analogue alfacalcidol: 5% versus 30% (P < .001). Primary RRT modality was peritoneal dialysis: 18% in late versus 32% in early referrals (P < .001), 7% versus 30%, respectively, had an arteriovenous dialysis-fistula (P < .001) and 0.2% versus 6% were on the waiting-list for renal transplantation (P < .001) before RRT start. One-year-mortality was higher in late referrals: hazard ratio 1.55 (CI 95% 1.35–1.78). In a subgroup, 30% (CI 95% 25–35%) late and 9% (CI 95% 6–12%) early referrals had plasma creatinine ≤150% of upper reference limit within 1 to 2 years before RRT start (P < .001).ConclusionsLate nephrology referrals were well-known to the healthcare system before referral for RRT start and more often had near normal plasma creatinine levels within 2 years before RRT start. They infrequently received available treatment or optimal first RRT modality. An increased effort to identify these patients in the healthcare system in time for proper pre-dialysis care including preparation for RRT is needed.

Time-dependent impact of diabetes on the mortality of patients on renal replacement therapy: A population-based study in Germany (2002–2009)

Aims To estimate the impact of diabetes on the mortality of patients with incident renal replacement therapy (RRT). Methods We assessed the mortality of 544 incident RRT patients aged ≥30 years between 2002 and 2009 (57.9% men, mean age 70.3 years, 49.6% patients with diabetes) by analyzing the data of all dialysis centers covering a German region. We compared the estimated time-dependent hazard ratios of patients with and without diabetes by using the Cox proportional-hazards regression model. Results Overall, 319 patients had died (158 diabetic), approximately 50% after 3 years. Up to about 3 years, the mortality rate was lower in diabetic than in nondiabetic patients. Thereafter, the survival curves crossed (interaction diabetes × time, p = 0.002; adjusted hazard ratios for diabetes: baseline, 0.66; year 1, 0.84; year 2, 1.05; year 3, 1.33; year 4, 1.68). The results were similar in men and women; however, the interaction of diabetes and time was significant only in men ( p = 0.004). Further significant risk factors of mortality were age, sex, initial central venous catheter, cardiovascular disease, and malignancy. Conclusions In this population-based study, the influence of diabetes was time-dependent, with a lower mortality in diabetic versus non-diabetic patients in the first three years but a higher mortality in these patients after 3 years. Results were similar in men and women.

Suboptimal initiation of dialysis with and without early referral to a nephrologist

Our objective was to examine patients who initiate renal replacement therapy (RRT) at 10 representative Canadian centers, characterize their initiation as inpatient or outpatient and describe their initial type of dialysis access, duration of pre-dialysis care and clinical status at the time of dialysis initiation. We also examined the impact of an optimal dialysis start (i.e. initiated as an outpatient with an arteriovenous fistula, arteriovenous graft or peritoneal dialysis catheter) on subsequent health outcomes. Charts of consecutive incident RRT patients were identified from 1 July to 31 December 2006. Information was collected until 6 months after the initiation or until death, transplant or transfer. Three hundred and thirty-nine incident RRT patients were studied: 39.6% initiated as an inpatient; 54% started hemodialysis (HD) with a central venous catheter; 15.3% had <1 month predialysis care, while 64.6% had >1 year. Optimal starts occurred in 39.5% of patients. For HD patients, optimal starts occurred in 19.8%. Suboptimal starts were noted in patients referred <12 months prior to end-stage renal disease (44%) and in patients referred earlier (56%). The composite end point of death, transfusion or subsequent hospitalization was significantly reduced with an optimal start [hazard ratio 0.47 (95% confidence interval 0.32-0.68), P = 0.0001]. Suboptimal initiation of dialysis is common in patients referred early or late. The benefits of early referral are lost if dialysis is initiated suboptimally. There is a need to identify factors that lead to suboptimal initiation despite early referral.

The issue of studying the effect of interventions in renal replacement therapy -- to what extent may we be deceived by selection and competing risk?

Patients with chronic kidney disease (CKD) who live up to renal replacement therapy (RRT) are a selected group of patients with a high mortality risk. The aim of this paper is to contribute a potential epidemiological explanation as to why therapeutic interventions - targeting specific causes of death - of which the effectiveness has been shown in the general population may not have a similar impact in a highly selected population like RRT patients. In this perspective, selection processes over the course of renal disease progression as well as the potential 'dilution' of an effect in the presence of highly increased mortality from other causes need attention. We suggest that the results from well-conducted high-quality studies in incident RRT patients without or with only very limited in- and exclusion criteria are likely the ones best qualified to be extrapolated to other RRT populations.

Incidence of renal replacement therapy (RRT) in the diabetic compared with the non-diabetic population in a German region, 2002-08

This study was conducted to estimate incidences of renal replacement therapy (RRT) in the diabetic and non-diabetic populations in Germany, as well as relative and attributable risks of RRT due to diabetes. Using the data of a regional dialysis centre (region population of 310 000), we assessed all incident RRT patients aged 30 years or older in 2002-08. We estimated sex- and age-specific and -standardized incidences of RRT in the diabetic and non-diabetic populations, which were estimated by applying diabetes prevalences from a population-based study, and relative and attributable risks due to diabetes. Of all subjects with incident RRT (n = 544), 49.6% had diabetes. Fifty-eight percent were male, mean age (SD) was 70.3 years (11.4 years). Incidences per 100 000 person-years (standardized to the 2004 German population) in the diabetic and the non-diabetic populations were 213.7 [95% confidence interval (95% CI), 159.5-267.8] and 26.9 (95% CI, 22.5-31.3) in men and 130.2 (95% CI, 65.6-194.9) and 16.4 (95% CI, 13.5-19.3) in women, respectively. Standardized relative risks were 7.9 (5.9-10.8) in men and 8.0 (4.7-13.5) in women. There was a significant interaction between age and diabetes, with lower relative risks in higher ages. Attributable risks among diabetic individuals were 0.87 in men and women, and population-attributable risks were 0.41 and 0.35 in men and women, respectively. In this population-based study in a German region, we found the relative risk of RRT in the estimated adult diabetic population to be 8-fold increased compared with the non-diabetic population. A high proportion of the RRT risk can be attributed to diabetes in the diabetic as well as in the whole population.

Regional and social inequalities in chronic renal replacement therapy in Denmark

The incidence of chronic renal replacement therapy (RRT) varies markedly between Danish nephrology centres. The aim of the present study was to establish if there is regional and social variation in the incidence of chronic RRT in Denmark when analysed according to patient residence. The importance of diabetic nephropathy and patients aged 70 years or older was also studied. Incident patients on chronic RRT in the period 1995-2006 were identified in the Danish National Registry on Regular Dialysis and Transplantation. Information on residence, income, educational status and ethnic origin was obtained from Statistics Denmark. Rates of incident RRT patients were standardized for regional differences of sex and age as well as income, educational status and ethnic origin. Poisson regression was used when comparing rates. Age- and sex-standardized incident chronic RRT rates among individuals with low income or short educational level were higher (P < 0.0001) compared to other groups. Also, standardized rates of patients in total and patients aged 70 years or older were higher in the catchment areas of the nephrology centres located in the two largest cities than for patients with residence in other areas of the country (P < 0.0001). Standardizing for regional differences of ethnic origin did not change the rates. The incident chronic RRT rate caused by diabetic nephropathy was higher for patients with residence in the catchment area of the nephrology centre in the largest city [49 per million people (p.m.p.) (95% CI = 40-57 p.m.p.)] compared to the catchment area of the nephrology centre located in the second largest city [31 (95% CI = 26-37 p.m.p.)] and other areas [29 p.m.p. (95% CI = 26-31 p.m.p.)] in 2001-06. When standardizing for differences in income among the 30-69-year-old persons, the rate of patients with residence in the catchment area of the nephrology centre located in the largest city decreased but was still higher than in other regions (P = 0.0003). There are marked socio-economic and regional differences in rates of incident RRT patients. The rates of incident RRT patients are highest in the catchment areas of the two largest nephrology centres and this may be partly explained by a higher frequency of end-stage diabetic nephropathy and a new treatment programme targeting frail, mainly elderly, patients.

The Danish Registry on Regular Dialysis and Transplantation:completeness and validity of incident patient registration

The Danish National Registry on Regular Dialysis and Transplantation (NRDT) provides systematic information on the epidemiology and treatment of end-stage chronic kidney disease in Denmark. It is therefore of major importance that the registry is valid and complete. The aim of the present study was to evaluate the registration of incident patients on chronic renal replacement therapy (RRT). Incident patients on chronic RRT in the period 2001-2004 were identified in NRDT and in the National Patient Registry, which contains information on hospital admissions and treatments. In the National Patient Registry, identification of patients was as follows: patients receiving the procedure of dialysis during a minimum of 90 days and for a minimum of 12 times or the procedure of renal transplantation. Only patients with at least 2 years of dialysis-free interval before and never being transplanted were included. The completeness of NRDT was calculated as the percentage of new patients on chronic RRT registered in the National Patient Registry also found in NRDT. Validity of data in NRDT was assessed by information from medical records and analysed using kappa statistics. Completeness of NRDT: Of 3020 patients registered in the National Patient Registry as incident chronic RRT patients, 97.2% were found in NRDT but 22.5% with another year of entry. There were no differences in completeness between hospitals or regions. Validity of NRDT: Validity of common renal diagnoses and RRT modality was high: diabetic nephropathy (kappa = 0.98), adult polycystic kidney disease (kappa = 0.95), chronic glomerulonephritis (kappa = 0.78) and RRT modality (kappa = 0.94). The diagnosis CKD of unknown aetiology and type of diabetes were less valid (kappa = 0.62, 0.60 and 0.73, respectively). The date of RRT start had also high validity. Completeness of incident patient registration in NRDT was highly acceptable. Validity of incident patient data was also good, except for type of diabetes.

Analgesic Nephropathy and Renal Replacement Therapy in Australia

This study examined age-specific incidence and prevalence of renal replacement therapy attributed to analgesic nephropathy from 1971 through 2005 and adjusted comorbidity prevalence and survival of patients who had analgesic nephropathy and were on renal replacement therapy (compared with control subjects without diabetes). This retrospective cohort study, using data from the Australia and New Zealand Dialysis and Transplant registry, included all patients who were aged 35 to 84 yr and started long-term renal replacement therapy in Australia from 1971 through 2006. Of 31,654 incident renal replacement therapy patients, 10.2% had analgesic nephropathy. Incidence and prevalence of renal replacement therapy attributed to analgesic nephropathy decreased earlier and faster among younger (age <55 yr) patients. Prevalence of analgesic nephropathy among 75- to 84-yr-old renal replacement therapy patients is still increasing. Compared with control subjects without diabetes, comorbidities (coronary artery, cerebrovascular, peripheral vascular, and chronic lung diseases) were more prevalent among patients with analgesic nephropathy at renal replacement therapy start. All-cause, cardiovascular, infection, and cancer mortality were higher among patients who had analgesic nephropathy and were on renal replacement therapy. For both comorbidities and mortality, the associations were stronger in younger patients. Trends in renal replacement therapy attributed to analgesic nephropathy differed by age. Patients with analgesic nephropathy have more comorbidities and poorer survival on renal replacement therapy, especially among younger patients.