Anna Casula

UK Renal Registry 17th Annual Report: Chapter 2 UK Renal Replacement Therapy Prevalence in 2013: National and Centre-specific Analyses

INTRODUCTION This chapter describes the characteristics of adult patients on renal replacement therapy (RRT) in the UK in 2013. METHODS Data were electronically collected from all 71 renal centres within the UK. A series of cross sectional and longitudinal analyses were performed to describe the demographics of prevalent RRT patients in 2013 at centre and national level. RESULTS There were 56,940 adult patients receiving RRT in the UK on 31st December 2013. The UK adult prevalence of RRT was 888 pmp which represented an annual increase of 4%,with transplantation the most common treatment modality(52%). There was variation between centres, Clinical Commissioning Groups and Health Boards. The number of patients increased by 1.2% for haemodialysis (HD) and 7.1% for functioning transplant but decreased 3.3% for peritoneal dialysis (PD). The number of patients receiving home HD has increased by 3% since 2012. Median RRT vintage for patients on HD was 3.4 years, PD 1.7 years and for transplant, 10.1 years. The median age of prevalent patients was 58 years (HD 67 years, PD 64 years, transplant 53 years)compared to 55 years in 2000. For all ages the prevalence rate in men exceeded that in women. The most common recorded renal diagnosis was glomerulonephritis (biopsy proven/not biopsy proven) (19%). CONCLUSIONS The HD and transplant population continued to expand; but the prevalent PD population continues to decline. There were national, regional and centre level variations in prevalence rates. This has continued implications for service planning and ensuring equity of care for RRT patients.

Social deprivation, ethnicity, and access to the deceased donor kidney transplant waiting list in England and Wales.

Background. Socioeconomic and ethnic inequity in access to kidney transplant waiting list has been described in the United States but not examined in a universal healthcare system. Methods. Eleven thousand two hundred ninety-nine patients aged 18 to 69 years starting renal replacement therapy (January 1, 1997 to December 31, 2004) in England and Wales were included. Multivariable Cox proportional hazards models were used to assess time to activation on the transplant waiting list for socially deprived patients among white patients. The effect of ethnic origin (South Asians and blacks compared with whites) was examined among all patients. Results. Among white patients, in the fully adjusted model, the hazard ratio (HR) for the most deprived quintile was 0.60 (95% confidence interval [CI] 0.54–0.68, P trend <0.0001) compared with the least deprived. Deprivation effects were more pronounced among those 50 years and older (P value for interaction <0.0001). Non-whites had a lower risk of being waitlisted than whites (for blacks: HR 0.89, 95% CI 0.79–1.01; for South Asians: HR 0.91, 95% CI 0.83–0.99, P value for heterogeneity=0.03). These differences were attenuated in a fully adjusted model. However non-whites who were 50 years and older were more likely to be transplant waitlisted than whites (interaction P=0.002). Conclusions. Individuals living in socially deprived areas have reduced access to the transplant waiting list. Understanding the reasons for this apparent inequity is important if we wish to ensure equitable access to renal transplants. There were no major differences by ethnicity, and if anything, older white patients were less likely to be waitlisted.

Glycated Hemoglobin and Risk of Death in Diabetic Patients Treated With Hemodialysis: A Meta-analysis

BACKGROUND Studies investigating the association between glycated hemoglobin (HbA1c) level and mortality risk in diabetic patients receiving hemodialysis have shown conflicting results. STUDY DESIGN We conducted a systematic review and meta-analysis using MEDLINE, EMBASE, Web of Science, and the Cochrane Library. SETTING & POPULATION Diabetic patients on maintenance hemodialysis therapy. SELECTION CRITERIA FOR STUDIES Observational studies or randomized controlled trials investigating the association between HbA1c values and mortality risk. Study authors were asked to provide anonymized individual patient data or reanalyze results according to a standard template. PREDICTOR Single measurement or mean HbA1c values. Mean HbA1c values were calculated using all individual-patient HbA1c values during the follow-up period of contributing studies. OUTCOME HR for mortality risk. RESULTS 10 studies (83,684 participants) were included: 9 observational studies and one secondary analysis of a randomized trial. After adjustment for confounders, patients with baseline HbA1c levels ≥ 8.5% (≥ 69 mmol/mol) had increased mortality (7 studies; HR, 1.14; 95% CI, 1.09-1.19) compared with patients with HbA1c levels of 6.5%-7.4% (48-57mmol/mol). Likewise, patients with a mean HbA1c value ≥ 8.5% also had a higher adjusted risk of mortality (6 studies; HR,1.29; 95% CI, 1.23-1.35). There was a small but nonsignificant increase in mortality associated with mean HbA1c levels ≤ 5.4% (≤ 36 mmol/mol; 6 studies; HR, 1.09; 95% CI, 0.89-1.34). Sensitivity analyses in incident (≤ 90 days of hemodialysis) and prevalent patients (>90 days of hemodialysis) showed a similar pattern. In incident patients, mean HbA1c levels ≤ 5.4% also were associated with increased mortality risk (4 studies; HR, 1.29; 95% CI, 1.23-1.35). LIMITATIONS Observational study data and inability to adjust for diabetes type in all studies. CONCLUSIONS Despite concerns about the utility of HbA1c measurement in hemodialysis patients, high levels (≥ 8.5%) are associated with increased mortality risk. Very low HbA1c levels (≤ 5.4%) also may be associated with increased mortality risk.

UK Renal Registry 17th Annual Report: Chapter 3 Demographic and Biochemistry Profile of Kidney Transplant Recipients in the UK in 2013: National and Centre-specific Analyses

Introduction: Outcomes following renal transplantation are usually reported as graft or patient survival. However, graft function, haemoglobin and blood pressure are also importantIntroduction: Outcomes following renal transplantation are usually reported as graft or patient survival. However, graft function, haemoglobin and blood pressure are also important measures of quality of care. Methods: Transplant activity and incident graft survival data were obtained from NHS Blood and Transplant (NHSBT), laboratory and clinical variables and prevalent survival data were obtained from the UK Renal Registry (UKRR). Data were analysed separately for prevalent and one year post-transplant patients. Results: Increasing live and non-heartbeating donors were responsible for the increasing transplant activity. Transplant waiting list numbers continued to rise by 8%. Graft failure occurred in 3.2% of prevalent transplant patients. Death rates remained stable at 2.3/100 patient years. Malignancy accounted for 21% of these deaths. There was centre variation in outcomes such as eGFR and haemoglobin in prevalent and 1 year post-transplant recipients. Analysis of prevalent transplants by chronic kidney disease stage showed 16% with eGFR <30 and 2.2% <15. Of those in stage 5T, 26% had Hb <10 g/dl, 27% phosphate ≥ 1.8 mmol/L and 50% an iPTH ≥ 32 pmol/L. These patients were less likely to achieve the UK standards in comparison to CKD5 dialysis patients. Conclusion: Wide variations in clinical and biochemical outcomes may be secondary to variations in the care administered to transplant recipients across the UK.

UK Renal Registry 11th Annual Report (December 2008): Chapter 4 ESRD prevalent rates in 2007 in the UK: national and centre-specific analyses.

Introduction: This chapter describes the demographics of UK RRT patients in 2007. Methods: Complete data were electronically collected from 71 UK centres with the remaining 1 centre submitting summary data. A series of crosssectional and longitudinal analyses were performed to describe the demographics of prevalent UK RRT patients in 2007 at a centre and a national level. Results: There were 45,484 adult patients receiving RRT on 31/12/2007. The population prevalence for adults was 746 per million population per year (pmp) with an annual increase in prevalence of approximately 5% per annum. There was substantial variation in standardised prevalence ratios between Primary Care Trust (PCT)/Health Authority (HA) areas which were associated with geographical factors and differences in ethnicity with mean standardised prevalence ratios (SPR) significantly higher in PCTs/HAs with a high proportion of ethnic minorities. The median age of prevalent RRT patients was 57 years (HD 65 years, PD 60 years, transplant 50 years). Median RRT vintage was 5.3 years (HD 2.8 years, PD 2.1 years, transplant 10.4 years). For all ages, crude prevalence rates in males exceeded those in females, peaking in the 75–79 year age band for males at 2,506 pmp and in females in the 70–74 year age band at 1,314 pmp. The most common identifiable diagnosis was glomerulonephritis (15.3%) but in those over 65 it was diabetes (15.1%). The most common treatment modality was transplantation (46.6%), closely followed by centrebased HD (42.1%) in either the primary centre (25.2%) or the satellite unit (16.9%). The HD population has continued to expand, and the PD population to contract. HD was increasingly prominent with increasing age at the expense of transplantation. Conclusions: There were national, area and dialysis centre level variation in the prevalent UK RRT population. This has implications for service planning and ensuring equity of care for RRT patients.

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 Coxs 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.

Social deprivation, ethnicity, and uptake of living kidney donor transplantation in the United Kingdom

Background. Socioeconomic disparities and their contribution to the ethnic differences in living kidney donor transplantation have not been adequately studied. Methods. A total of 12,282 patients aged 18 to 69 years starting renal replacement therapy (January 1, 1997, to December 31, 2004) in the United Kingdom were included. Logistic regression models were used to examine probability of living donor transplantation within 3 years of renal replacement therapy. The effect of area deprivation (Townsend index) was studied among whites only adjusted for patient characteristics and the effect of ethnic origin (South Asians and blacks compared with whites) was then examined among all patients adjusting for area deprivation. Results. Among whites, increasing social deprivation was associated with lower odds of living donor transplantation. In the fully adjusted model, odds ratio (OR) for the most deprived quintile was 0.40 (95% confidence interval [CI] 0.33, 0.49; P trend<0.0001) compared with the least deprived. These gradients were more pronounced among centers performing more live donor transplants (P value for interaction <0.0001). South Asians and blacks had lower odds of living donor transplantation compared with whites, but there was an interaction with age (P<0.0001), so that this disparity was observed only in those younger than 50 years (blacks: OR, 0.31; 95% CI, 0.18, 0.54; South Asians: OR, 0.55; 95% CI, 0.34, 0.90; P value <0.0001). Conclusions. Socially deprived and younger ethnic minority patients have lower probability of living kidney donor transplantation. The extent to which these inequalities reflect modifiable societal healthcare system barriers and donor/recipient factors requires further study.

UK Renal Registry 11th Annual Report (December 2008): Chapter 14 UK Renal Registry and international comparisons

Background: The aim of this study is to report Renal Replacement Therapy (RRT) incidence and prevalence rates, the percentage of incident patients with diabetes mellitus as cause of renal disease, the RRT modality mix and the transplant rate in different countries. The number of national or regional registries collecting and reporting data pertaining to traditional cardiovascular (CV) risk factors in prevalent dialysis patients is also examined. Methods: Data on numbers of incident and prevalent RRT patients in England, Wales, Scotland and Northern Ireland for the year 2007 were collected from the UK Renal Registry (UKRR) database and collated to meet the specifications on the US Renal Data System (USRDS) international data collection form. Results: In 2007, the incidence and prevalence of RRT in the UK were 110 and 759 per million of the population (pmp) respectively. Incidence of RRT placed the UK 34th out of the 43 countries reporting to the USRDS in 2006. In the majority of reporting countries, 20–44% have diabetes as the primary cause of end stage renal disease. Only the Finnish, Malaysian and US Renal Registries were found to routinely report attainment of cardiovascular risk standards. Conclusions: A comparison among international renal registries about RRT epidemiology and reporting cardiovascular risk factors in prevalent RRT patients forms an important part of the quality improvement process and often allows for improving standards and performances between reporting countries. Despite the high CV morbidity associated with RRT, few renal registries routinely report data on CV risk management; where data are reported there is little agreement in what represents quality of care, making direct comparison difficult.

Association Between Glycemia and Mortality in Diabetic Individuals on Renal Replacement Therapy in the U.K.

OBJECTIVE In the U.K., one-third of patients receiving treatment with dialysis have diabetes. Guidelines from organizations representing patients with renal disease or diabetes advocate tight glycemic control in patients with end-stage renal disease, despite glucose-lowering trials having excluded these patients. RESEARCH DESIGN AND METHODS Using national UK Renal Registry data, we tested whether glycemia as measured by hemoglobin (Hb) A1c (HbA1c) level is associated with death in adults with diabetes starting hemodialysis or peritoneal dialysis between 1997 and 2006, and observed for at least 6 months. Of 7,814 patients, we excluded those who had died within 6 months; had received transplants; were lost/recovered; or lacked measures of HbA1c, ethnicity, or Hb. Categorizing HbA1c measured in the first 6 months of starting dialysis as <6.5% (<48 mmol/mol), 6.5–7.4% (48–57 mmol/mol) (reference value), 7.5–8.4% (58–68 mmol/mol), and ≥8.5% (≥69 mmol/mol), we adjusted in proportional hazards models for age, sex, ethnicity, deprivation, year, dialysis type, and Hb, and tested for interactions. RESULTS Of 3,157 patients observed for a median time of 2.7 years, 1,688 died. For patients ≥60 years of age, we found no association between HbA1c and death; among younger patients, relative to those with HbA1c values 6.5–7.4%, the hazard ratio for HbA1c level 7.5–8.4% was 1.2 (95% CI 0.9–1.5), and for HbA1c level >8.5% was 1.5 (1.2–1.9). The projected difference in median survival time between younger patients with a reference HbA1c value versus >8.5% was 1 year. CONCLUSIONS In the absence of trials, and confounding notwithstanding, these observational data support improved glycemic control in younger patients prior to and during dialysis.

UK Renal Registry 15th annual report: Chapter 4 demography of the UK paediatric renal replacement therapy population in 2011.

Aims: To describe the demographics of the paediatric RRT population under the age of 16 years in the UK and to analyse changes in demography with time. Methods: Data were collected from all 13 paediatric renal centres within the UK. A series of cross-sectional and longitudinal analyses were performed to describe the demographics of paediatric RRT patients. Results: A total of 856 children and young people under 18 with ERF were receiving treatment at paediatric nephrology centres in 2011. At the census date, 80.1% had a functioning transplant, 10.5% were receiving peritoneal dialysis (PD) and 9.4% were receiving haemodialysis (HD). In patients aged <16 years the prevalence of ERF was 56.8 pmarp and the incidence 8.3 pmarp. Analysis of trends over the last 15 years shows that both incidence and prevalence are increasing. A third of the prevalent patients had one or more reported comorbidities. At transfer to adult services, 86% of patients had a functioning renal transplant. Pre-emptive transplantation was seen to occur in 31% of children starting RRT under 16 years, with lower rates seen in girls and ethnic minorities. Survival in childhood amongst children starting RRT was the lowest in those aged less than 2 years. Conclusions: The data provided in this report show increasing trends over 15 years in the incidence and prevalence of established renal failure. This is important for the planning of the provision of care for children needing renal replacement therapy. Further research is required to understand the gender and ethnic differences in pre-emptive transplantation rates and the reduced survival amongst children aged less than 2 years.