UK Renal Registry 15th annual report: Chapter 5 survival and causes of death of UK adult patients on renal replacement therapy in 2011: national and centre-specific analyses.

INTRODUCTION: These analyses examine a) survival from the start of renal replacement therapy (RRT) based on the total incident UK RRT population reported to the UK Renal Registry, b) survival of prevalent patients. Changes in survival between 1997 and 2011 are also reported. METHODS: Survival was calculated for both incident and prevalent patients on RRT and compared between the UK countries after adjustment for age. Survival of incident patients (starting RRT during 2010) was calculated both from the start of RRT and from 90 days after starting RRT, both with and without censoring at transplantation. Prevalent dialysis patients were censored at transplantation; this means that the patient is considered alive up to the point of transplantation, but the patient's status post-transplant is not considered. Both Kaplan-Meier and Cox adjusted models were used to calculate survival. Causes of death were analysed for both groups. The relative risk of death was calculated compared with the general UK population. RESULTS: The unadjusted 1 year after 90 day survival for patients starting RRT in 2010 was 87.3%, representing an increase from the previous year (86.6%). In incident patients aged 18-64 years, the unadjusted 1 year survival had risen from 86.0% in patients starting RRT in 1997 to 92.6% in patients starting RRT in 2010 and for those aged ≥65 it had increased from 63.9% to 77.0% over the same period. The age-adjusted one year survival (adjusted to age 60) of prevalent dialysis patients increased from 88.1% in the 2001 cohort to 89.8% in the 2010 cohort. Prevalent diabetic patient one year survival rose from 82.1% in the 2002 cohort to 84.7% in the 2010 cohort. The age-standardised mortality ratio for prevalent RRT patients compared with the general population was 18 for age group 30-34 and 2.5 at age 85+ years. In the prevalent RRT dialysis population, cardiovascular disease accounted for 22% of deaths, infection and treatment withdrawal 18% each and 25% were recorded as other causes of death. Treatment withdrawal was a more frequent cause of death in those incident patients aged ≥65 than in younger patients. The median life years remaining for a 25-29 year old on RRT was 18 years and approximately three years for a 75+ year old. CONCLUSIONS: Survival of patients starting RRT has improved in the 2010 incident cohort. The relative risk of death on RRT compared with the general population has fallen since 2001.

UK Renal Registry 16th annual report: chapter 8 survival and cause of death of UK adult patients on renal replacement therapy in 2012: national and centre-specific analyses.

INTRODUCTION: These analyses examine: a) survival from the start of renal replacement therapy (RRT); b) survival amongst all prevalent dialysis patients alive on 31st December 2011; c) the cause of death for incident and prevalent patients and d) the projected life years remaining for patients starting RRT. Changes in survival between the 1997 and 2011 cohort are also reported. METHODS: Survival was calculated for both incident and prevalent patients on RRT. Survival of incident patients (starting RRT during 2011) was calculated both from the start of RRT and from 90 days after starting RRT, both with and without censoring at transplantation. Prevalent dialysis patients were censored at transplantation. Both Kaplan-Meier and Cox adjusted models were used to calculate survival. The relative risk of death was calculated and compared with the UK general population. RESULTS: The unadjusted 1 year after 90 day survival for patients starting RRT in 2011 was 87.5%, representing an increase from the previous year (87.3%). The age-adjusted one year survival (adjusted to age 60) of prevalent dialysis patients increased from 88.2% in the 2002 cohort to 89.7% in the 2011 cohort. Prevalent diabetic patient one year survival rose from 81.6% in the 2002 cohort to 84.9% in the 2011 cohort. The age-standardised mortality ratio for prevalent RRT patients compared with the general population was 16.6 for age group 35-39 and 2.7 at age 85+ years. In the prevalent RRT dialysis population, cardiovascular disease accounted for 22% of deaths, infection 17% and treatment withdrawal 19%. The median life years remaining for a 25-29 year old on RRT was 18.5 years and approximately 2.5 for a 75+ year old. CONCLUSIONS: Survival of patients starting RRT has improved in the 2011 incident cohort. The relative risk of death on RRT compared with the general population has fallen since 2001.

Chapter 6 Survival and causes of death of UK adult patients on renal replacement therapy in 2010: national and centre-specific analyses.

INTRODUCTION: These analyses examine a) survival from the start of renal replacement therapy (RRT), based on the total incident UK RRT population reported to the UK Renal Registry, including the 18% who started on PD and the 7% who received a pre-emptive transplant and b) survival of prevalent patients. Changes in survival between 1997 and 2009 are also reported. METHODS: Survival of incident patients (starting RRT during 2009) was calculated both from the start of RRT and from 90 days after starting RRT, both with and without censoring at transplantation. Survival of prevalent dialysis patients was calculated to exclude patients once they were transplanted. Both Kaplan-Meier and Cox adjusted models were used to calculate survival. Causes of death were analysed for both groups. Relative risk of death was calculated compared with the general UK population. RESULTS: The 2009 unadjusted 1 year after 90 day survival for patients starting RRT was 86.6% (87.3% in 2008). In incident patients aged 18-64, the unadjusted 1 year survival had increased from 86.0% in 1997 to 91.3% in 2009. In incident patients aged ≥ 65, unadjusted 1 year survival had improved from 64.1% to 76.2%. There were no survival differences between genders. The relative risk of death compared to the general population decreased from 25 times at age 30-34 to 2.7 times at age 85+. Cause of death data completeness has improved 18% since last year. Cardiac disease is the most common cause of death in prevalent dialysis patients and malignancy most frequent in prevalent transplant patients. CONCLUSIONS: Survival of patients starting RRT has improved for all ages since 1997. The frequency of cardiac disease as the cause of death has decreased since 1997.

UK Renal Registry 13th Annual Report (December 2010): Chapter 6: survival and causes of death of UK adult patients on renal replacement therapy in 2009: national and centre-specific analyses.

INTRODUCTION: These analyses examine (a) survival from the start of renal replacement therapy (RRT), based on the total incident UK RRT population reported to the UK Renal Registry, including the 18% who started on PD and the 6% who received a pre-emptive transplant and (b) survival of prevalent patients. Changes in survival between 1997 and 2008 are also reported. METHODS: Survival was calculated for both incident and prevalent patients on RRT and compared between the UK countries after adjustment for age. Survival of incident patients (starting RRT during 2008) was calculated both from the start of RRT and amongst the cohort who survived at least 90 days after RRT, both with and without censoring at transplantation. Both Kaplan-Meier and Cox adjusted models were used to calculate survival. Causes of death were analysed for both groups. Relative risk of death was calculated compared with the general UK population. RESULTS: The 2008 unadjusted 1 year after 90 day survival for patients starting RRT was 87.3%. In incident patients aged 18-64, the unadjusted 1 year survival had risen from 85.9% in 1997 to 91.9% in 2008 and for those aged ≥ 65 it had risen from 64.2% to 75.8%. The age-adjusted one year survival (adjusted to age 60) of prevalent dialysis patients rose from 85% in 2000 to 89% in 2009. Diabetic prevalent patient one year survival rose from 76.6% in 2000 to 83.6% in 2009. The age-standardised mortality ratio for prevalent RRT patients compared with the general population was 19 at age 30 years and 2.4 at age 85 years. In the prevalent RRT dialysis population, cardiovascular disease accounted for 24% of deaths, infection 19% and treatment withdrawal 14%; 22% were recorded as uncertain. Treatment withdrawal was a more frequent cause of death in patients aged ≥ 65 at start of RRT than in younger patients. The median life years remaining for a 25-29 year old on RRT was 20 years and 4 years for a 75+ year old. CONCLUSIONS: Survival of patients starting RRT, has improved in the 2008 incident cohort. The relative risk of death on RRT compared with the general population has fallen since 2001. Death rates on dialysis in the UK remained lower than when compared with a similar aged population on dialysis in the USA.

UK Renal Registry 13th Annual Report (December 2010): Chapter 1: UK RRT incidence in 2009: national and centre-specific analyses.

INTRODUCTION: This chapter describes the characteristics of adult patients starting renal replacement therapy (RRT) in the UK in 2009 and the acceptance rates for RRT in Primary Care Trusts and Health Boards (PCT/HBs) in the UK. METHODS: The basic demographics and clinical characteristics are reported on patients starting RRT from all UK renal centres. Late presentation, defined as time between first being seen by a nephrologist and start of RRT being <90 days was also studied. Age and gender standardised ratios for acceptance rates in PCT/HBs were calculated. RESULTS: In 2009, the incidence rate in the UK and England was 109 per million population (pmp). Acceptance rates in Scotland (104 pmp), Northern Ireland (88 pmp) and Wales (120 pmp) had all fallen although Wales still remained the country with the highest acceptance rate. There were wide variations between PCT/HBs with respect to the standardised ratios. The median age of all incident patients was 64.8 years (IQR 50.8, 75.1). For transplant centres this was 63.0 years (IQR 49.0, 74.2) and for non-transplanting centres 66.3 years (IQR 52.6, 75.9). The median age for non-Whites was 57.1 years. Diabetic renal disease remained the single most common cause of renal failure (25%). By 90 days, 69.1% of patients were on haemodialysis, 17.7% on peritoneal dialysis, 6.7% had had a transplant and 6.5% had died or stopped treatment. The mean eGFR at the start of RRT was 8.6 ml/min/1.73 m2 which was similar to the previous two years. Late presentation (<90 days) has fallen from 27% in 2004 to 19% in 2009. There was no relationship between social deprivation and presentation pattern. CONCLUSIONS: Acceptance rates have fallen in Northern Ireland, Scotland and Wales whilst they have plateaued in England over the last four years. Wales continued to have the highest acceptance rate of the countries making up the UK.

UK Renal Registry 13th Annual Report (December 2010): Chapter 7: the relationship between the type of vascular access used and survival in UK RRT patients in 2006.

INTRODUCTION: The type of vascular access used by haemodialysis patients is thought to be one of the predictors of patient survival. However, many previous studies have been unable to separate the effect of access type from the effects of other differences between patients groups or have included incident patients. Some centres report excellent outcomes using dialysis catheters in stable prevalent patients and challenge the current guidelines about the use of long term catheters. This is an observational UK centre level study reporting on the relationship between the percentage of established prevalent patients using definitive access and the subsequent 1 year survival. METHOD: Vascular access audit data from 2005 and UKRR survival data at 1 year for patients who had been on HD for over 3 months was obtained from the UKRR database. Regression analysis was used to assess the amount of variation in 1 year survival that could be explained by the percentage of patients using an AVF or AVG in a centre. RESULTS: From the renal centres reporting to the UKRR in 2005, 16,984 patients had vascular access data. The mean centre level 1 year survival was 86.4% (95% CI: 82.2-90.9) and was 86.9% (95% CI: 82.8-91.2) after censoring for transplantation. The mean percentage of haemodialysis patients using definitive access (AVF or AVG) in a centre was 69.8% (SD 10.4). A small positive association was found between the percentage of HD patients using an AVF or AVG in a centre and 1 year uncensored survival (ß = 0.06, p = 0.04). The type of access in use was able to explain 6% of the variation in centre level survival. CONCLUSIONS: To some extent, this study has repeated work done by DOPPS and in the US but for the first time has studied only prevalent dialysis patients and looked at the UK dialysis population. Whilst increased venous catheter use was associated with an increase in one year mortality of prevalent established haemodialysis patients, this effect was very small and only accounted for some 6% of the variation in one year mortality between renal centres. Further work using data from the current large vascular access audit needs to be done to further elucidate best practice within the UK.

UK Renal Registry 13th Annual Report (December 2010): Chapter 8: adequacy of haemodialysis in UK adult patients in 2009: national and centre-specific analyses.

BACKGROUND: Outcome in patients treated with haemodialysis (HD) is influenced by the delivered dose of dialysis. The UK Renal Association (RA) publishes Clinical Practice Guidelines which include recommendations for dialysis dose. The urea reduction ratio (URR) is a widely used measure of dialysis dose. AIM: To determine the extent to which patients received the recommended dose of HD in the UK. METHODS: All seventy-two UK renal centres submitted data to the UK Renal Registry (UKRR). Two groups of patients were included in the analyses: the prevalent patient population on 31st December 2009 and the incident patient population for 2009. Centres returning data on <50% of their patient population were excluded from centre-specific comparisons. RESULTS: Data regarding URR were available from 63 renal centres in the UK. Fifty-one centres provided URR data on more than 90% of prevalent patients. The proportion of patients in the UK who met the UK Clinical Practice Guideline for URR (>65%) increased from 56% in 1998 to 85.5% in 2009. There was considerable variation between centres, with 19 centres attaining the RA clinical practice guideline in >90% of patients and 5 centres attaining the guideline in <70% of patients. The delivered HD dose (URR) was lower in patients who had just commenced dialysis treatment compared to patients who had survived longer on HD. CONCLUSIONS: The delivered dose of HD for patients with established renal failure has increased over the last decade. Whilst the majority of UK patients achieved the target URR there was considerable variation between centres in the percentage of patients achieving the guideline.

UK Renal Registry 13th Annual Report (December 2010): Chapter 9: haemoglobin, ferritin and erythropoietin amongst UK adult dialysis patients in 2009: national and centre-specific analyses.

BACKGROUND: The UK Renal Association (RA) and National Institute for Health and Clinical Excellence (NICE) have published Clinical Practice Guidelines which include recommendations for management of anaemia in established renal failure. AIMS: To determine the extent to which the guidelines for anaemia management are met in the UK. METHODS: Quarterly data were obtained regarding haemoglobin (Hb) and factors that influence Hb from renal centres in England, Wales, Northern Ireland (EWNI) and the Scottish Renal Registry for the incident and prevalent renal replacement therapy (RRT) cohorts for 2009. RESULTS: In the UK, in 2009 55% of patients commenced dialysis therapy with Hb x10.0 g/dl (median Hb 10.2 g/dl). The median Hb of haemodialysis (HD) patients was 11.6 g/dl with an interquartile range (IQR) of 10.6 - 12.4 g/dl. Of HD patients 85% had Hb ≥ 10.0 g/dl. The median Hb of peritoneal dialysis (PD) patients in the UK was 11.7 g/dl (IQR 10.7-12.6 g/dl). Of UK PD patients, 88% had Hb ≥ 10.0 g/dl. The median ferritin in HD patients in EWNI was 441 mg/L (IQR 289-629) and 96% of HD patients had a ferritin ≥ 100 mg/L. The median ferritin in PD patients was 249 mg/L (IQR 142-412) with 86% of PD patients having a ferritin 5100 mg/L. In EWNI the mean Erythropoietin Stimulating Agent (ESA) dose was higher for HD than PD patients (9,507 vs. 6,212 IU/week). CONCLUSIONS: In 2009, 56% of prevalent HD patients had a Hb ≥ 10.5 and ≤ 12.5 g/dl compared with 54% in 2008 and 53% in 2007. Fifty-four percent of prevalent PD patients had a Hb ≥10.5 and ≤12.5 g/dl compared to 55% in 2008.

UK Renal Registry 13th Annual Report (December 2010): Chapter 10: calcium, phosphate, parathyroid hormone, bicarbonate and total cholesterol concentrations amongst patients receiving haemodialysis or peritoneal dialysis in England, Wales and Northern Ireland in 2009: national and centre-specific analyses.

INTRODUCTION: The UK Renal Association Clinical Practice Guidelines include clinical performance measures for biochemical variables in dialysis patients [1]. The UK Renal Registry (UKRR) annually audits dialysis centre performance against these measures as part of its role in promoting continuous quality improvement. METHODS: Cross sectional performance analyses were undertaken to compare dialysis centre achievement of clinical audit measures for prevalent haemodialysis (HD) and peritoneal dialysis (PD) cohorts in 2009. The biochemical variables studied were phosphate, adjusted calcium, parathyroid hormone, bicarbonate and total cholesterol. In addition longitudinal analyses were performed (2000-2009) to show changes in achievement of clinical performance measures over time. RESULTS: Sixty-one percent of HD and 70% of PD patients had phosphate between 1.1-1.8 mmol/L. Seventy-four percent of HD and 75% of PD patients had adjusted calcium between 2.2-2.5 mmol/L. Twenty-eight percent of HD and 32% of PD patients had parathyroid hormone between 16-32 pmol/L. Seventy-two percent of HD and 83% of PD patients achieved the audit measure for bicarbonate. There was significant inter-centre variation for all variables studied. CONCLUSIONS: The UKRR consistently demonstrates significant inter-centre variation in achievement of biochemical clinical audit measures. Understanding the causes of this variation is an important part of improving the care of dialysis patients in the UK.

UK Renal Registry 13th Annual Report (December 2010): Chapter 13: centre variation in access to renal transplantation in the UK (2004-2006).

BACKGROUND: Renal transplantation is recognised as being the optimal treatment modality for many patients with end stage renal disease. This analysis aimed to explore the equity of access to renal transplantation in the UK. METHODS: Transplant activity and waiting list data were obtained from NHS Blood and Transplant, demographic and laboratory data were obtained from the UK Renal Registry. All incident RRT patients starting treatment between 1st January 2004 and 31st December 2006 from 65 renal centres were considered for inclusion. The cohort was followed until 31st December 2008 (or until transplantation or death, whichever was earliest). RESULTS: Age, ethnicity and primary renal diagnosis were associated with both accessing the kidney transplant waiting list and receiving an organ. A patient starting dialysis in a non-transplanting renal centre was less likely to be registered for transplantation (OR 0.90, 95% CI 0.82-0.99) or receive a transplant from a donor after cardiac death or a living kidney donor (OR 0.69, 95% CI 0.60-0.79) compared with patients cared for in transplanting renal centres. Once registered for kidney transplantation, patients in both transplanting and nontransplanting renal centres had an equal chance of receiving a transplant from a donor after brain stem death (OR 0.92, 95% CI 0.78-1.08). CONCLUSION: There is wide variation in access to kidney transplantation between UK renal centres which cannot be explained by differences in case mix.

UK Renal Registry 13th Annual Report (December 2010): Chapter 14: enhancing access to UK Renal Registry data through innovative online data visualisations.

INTRODUCTION: As the volume of data and analyses grows with time, so does the need to present this increasingly complex information in an accessible and clinically informative manner which is responsive to, and reflects the nature of, the enquiries made by those seeking to access the data. THE UK RENAL REGISTRY INTERACTIVE DATA PORTAL: The UK Renal Registry (UKRR) now has a bespoke interactive data portal which provides a focussed point of access to a variety of graphical display formats and analyses of UKRR data including: · Centre-specific reports--a distillation of annual UKRR data including a colour-coded dashboard summary as well as both funnel plots and longitudinal statistical process control charts for a range of clinical parameters. · Interactive flash-based longitudinal Statistical Process Control charts on a per-centre and per-parameter basis allowing for a more detailed review of performance over time. These charts are the interactive correlates of those available in the centre-specific reports. · Rosling/Gapminder-style motion charts on a perparameter basis simultaneously detailing performance and activity data from multiple centres interactively over time (more details below). · An interactive graphical pivot chart solution using OLAP technology allowing users to design and export their own charts/analyses in real-time using UKRR data. CONCLUSION: This work builds strongly on the wealth of information arising from the high-quality validated UKRR datasets. The portal will empower and engage the UK renal community in the comparative analysis of delivered renal care ultimately leading to enhanced quality improvement over time.

UK Renal Registry 13th Annual Report (December 2010): Chapter 2: UK RRT prevalence in 2009: national and centre-specific analyses.

INTRODUCTION: This chapter describes the characteristics of adult patients on renal replacement therapy (RRT) in the UK in 2009. The prevalence rates per million population (pmp) were calculated for Primary Care Trusts in England, Health and Social Care Areas in Northern Ireland, Local Health Boards in Wales and Health Boards in Scotland. These areas will be referred to in this report as 'PCT/HBs'. METHODS: Data were electronically collected from all 72 renal centres within the UK. A series of cross-sectional and longitudinal analyses were performed to describe the demographics of prevalent RRT patients in 2009 at centre and national level. Age and gender standardised ratios for prevalence rates in PCT/HBs were calculated. RESULTS: There were 49,080 adult patients receiving RRT in the UK on 31st December 2009, equating to a UK prevalence of 794 pmp. This represented an annual increase in prevalent numbers of approximately 3.2% although there was significant variation between centres and PCT/HB areas. The growth rate from 2008 to 2009 for prevalent patients by treatment modality in the UK was 4.2% for haemodialysis (HD), a fall of 7.2% for peritoneal dialysis (PD) and a growth of 4.4% with a functioning transplant. There has been a slow but steady decline in the proportion of PD patients from 2000 onwards. Median RRT vintage was 5.4 years. The median age of prevalent patients was 57.7 years (HD 65.9 years, PD 61.2 years and transplant 50.8 years). For all ages, prevalence rates in males exceeded those in females: peaks for males were in the 75-79 years age group at 2,632 pmp and for females in the 70-74 years age group at 1,445 pmp. The most common identifiable renal diagnosis was biopsy-proven glomerulonephritis (16.0%), followed by diabetes (14.7%). Transplantation was the most common treatment modality (48%), HD in 44% and PD 8%. However, HD was increasingly common with increasing age and transplantation less common. CONCLUSIONS: The HD and transplant population continued to expand whilst the PD population contracted. There were national, regional and dialysis centre level variations in prevalence rates. This has implications for service planning and ensuring equity of care for RRT patients.

UK Renal Registry 13th Annual Report (December 2010): Chapter 4: comorbidities and current smoking status amongst patients starting renal replacement therapy in England, Wales and Northern Ireland from 2008 to 2009.

INTRODUCTION: Comorbidity is an important determinant of survival for renal replacement therapy patients and impacts other care processes such as dialysis access creation and transplant wait-listing. The prevalence of comorbidities in incident patients on renal replacement therapy (RRT) changes with age and varies between ethnic groups. This study describes these associations and the independent effect of comorbidities on outcomes. METHODS: Incident patients reported to the UK Renal Registry (UKRR) with comorbidity data in 2008 and 2009 (n = 5,617) were included in analyses exploring the association of comorbidity with patient demographics, treatment modality, haemoglobin and renal function at start of RRT. For analyses examining comorbidity and survival, adult patients starting RRT between 2004 and 2009 in centres reporting to the UKRR with comorbidity data (n = 16,527) were included. The relationship between comorbidities and mortality at 90 days and one year after 90 days from start of RRT was explored using Cox regression. RESULTS: Completeness of comorbidity data was 44.4% in 2009 compared with 52.1% in 2004. Of patients with data, 56.5% had one or more comorbidities. Diabetes mellitus and ischaemic heart disease were the most common conditions seen in 32.9% and 22.5% of patients respectively. Current smoking was recorded for 12.4% of incident RRT patients in the 2-year period. The presence of comorbidities in patients <75 years became more common with increasing age in all ethnic groups. In multivariable survival analysis, malignancy and the presence of ischaemic/neuropathic ulcers were the strongest independent predictors of poor survival at 1 year after 90 days from the start of RRT in patients <65 years. CONCLUSION: Differences in prevalence rates of comorbid illnesses in incident RRT patients may reflect variation in access to health care or competing risk prior to commencing treatment. The interpretation of analyses continues to be limited by poor data completeness.

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.

New adult patients starting renal replacement therapy in the UK in 2005 (chapter 3).

In 2005, the acceptance rate for renal replacement therapy (RRT) in adults in the UK was 108 per million population (pmp). This was derived from complete data for adults in the UK, as data were obtained separately from the five English renal units not currently returning to the Registry. In addition, 87 children started RRT (see Chapter 13) giving a total incidence of 110 pmp. From 2001 to 2005 there has been an 7.3% rise in the acceptance numbers in those 42 renal units with full reporting throughout that period. In the UK, for adults in 2005, the crude acceptance rates in Local Authorities (LA) varied from 0 (in two very small LA areas in Scotland and Northern Ireland) to 271 pmp; the standardized rate ratios for acceptance varied from 0 to 2.76. Excluding the two areas with null returns, 20 areas had significantly low ratios, all of them in England. Thirty had significantly high ratios, seven in Northern Ireland, four in Scotland, three in Wales and seven in London. Over the period 2001-2005, 25 areas had a significantly low standardized acceptance rate; 24 in England and one in Scotland. All except one of these had ethnic minority populations of <10%. Thirty-seven had high standardized acceptance rates, seven in Scotland where ethnicity data were not available, 14 from areas with ethnic minority populations in excess of 10%, and 12 were in Wales or the Southwest of England. The median age of patients starting RRT in England has increased from 63.8 years in 1998 to 65.2 years in 2005. The median age of incident non-White patients is significantly lower at 56.8 years. In England, the acceptance rate is highest in the 75-79 age band at 408 pmp, as in Scotland at 580 pmp; in Wales the peak is in the 80-84 age band at 525 pmp, as in Northern Ireland with a rate of 825 pmp. Diabetic renal disease (20%) remains the most common specific primary renal disease. There was a significant positive correlation between the percentage of incident RRT patients with diabetic renal disease and the percentage of non-Whites in the incident cohort. Haemodialysis (HD) was the first modality of RRT in 76% of patients, peritoneal dialysis (PD) in 21% and pre-emptive transplant in 3%. In 1998, the proportion whose first modality was HD was 58% and this continues to increase. By day 90, 8% had died, a further 1% had stopped treatment or been transferred out leaving 91% of the original cohort on RRT. Of these, 71% were on HD, 26% on PD and 3% had received a transplant. Data on first referral to a nephrologist were available from 22 centres for the period 2000-2005 (for a total of 5611 patients and 59 centre-years). In 2005, the mean percentage of patients referred late (<90 days before dialysis initiation) was 30% (centre range 13-48%). This was similar to the value in 2000. Patients referred late were older, a higher proportion of them were male, a lower proportion non-White, and a lower proportion with no recorded comorbidity. Patients with polycystic kidney disease and diabetic nephropathy tended to be referred early compared with the whole incident cohort and those with uncertain aetiology and no recorded diagnosis referred late. Estimated GFR (eGFR) at the start of RRT appears to be higher in older than younger patients. eGFR is significantly lower in those referred late compared with those referred earlier and this is especially marked in the older patients. The geometric mean eGFR of all patients starting RRT rose from 6 in 1997 to above 7.5 in 2003, since when it has remained stable.

All patients receiving renal replacement therapy in the United Kingdom in 2005 (chapter 4).

Summary data are provided for the whole United Kingdom. There were 41,776 adult patients alive on renal replacement therapy (RRT) in the UK at the end of 2005, a prevalence for adults of 694 pmp. Addition of 748 children under the age of 18 on RRT gives a total prevalence of 706 pmp. The more detailed analysis includes data on 37,534 patients from 65 of the 70 units which returned detailed data to the Registry: all in Northern Ireland, Scotland and Wales, and 45 of the 50 units in England. The annual increase in prevalence in the 38 renal units participating in the Registry since 2000 was 5.0%. There is substantial variation in the crude Local Authority area prevalence from 299 pmp to 1275 pmp. In general, areas with large ethnic minority populations had high standardized prevalence ratios (SPR). Nevertheless several Local Authority areas in South Wales (Methyr Tydfil, Swansea and Rhondda/Cynon/Taff) had a higher SPR than would be predicted from the local ethnic mix. Another group in North West England (Bury, Rochdale, Oldham and Salford), had a lower SPR than expected from the local ethnic mix. The median age of prevalent patients on RRT was 56.6 years, that of patients on HD 64.5 years, PD 59.2 years and transplanted patients 49.7 years. The median vintage of the whole RRT population was 5.1 years: that of transplanted patients was 9.8 years, HD patients 2.8 years and PD patients 2.1 years. The maximal prevalence rate (SPR) occurred in men (2270 pmp) in the 75-79-year age band and women (1144 pmp) in the 65-74-year age band. Of RRT patients in the UK, 45% had a transplant, 41.7% were on centre-based haemodialysis and 12% on peritoneal dialysis. The proportion of patients on home haemodialysis remained very small (1.2%) in spite of the recent NICE guidelines. The haemodialysis population is continuing to expand, mainly through growth in the proportion of patients undergoing dialysis in satellite units. The peritoneal dialysis population is continuing to contract in spite of the small but progressive rise in automated PD. The most common identifiable diagnosis in those under 65 was glomerulonephritis (18.0%) and in those over 65 it was diabetes (13.4%). One-year survival rates of prevalent patients in the different centres contributing to the UK Renal Registry are presented. The centres agreed to remove anonymity. There is no evidence of any significant differences in survival of prevalent patients between UK centres. The one-year survival of prevalent dialysis patients increased significantly from 1998 to 2004 in England (83.3% to 87.1% P = 0.0001 for linear trend), Scotland (84.0% to 87.0% P = 0.023 for linear trend) and Wales (83.4% to 86.1% P = 0.027 for linear trend). The test for non-linearity in this trend (indicating that there has been a large increase which is now tailing off) was significant for England and Wales.

The UK Vascular Access Survey--follow-up data and repeat survey (chapter 5).

In the 2006 Vascular Access Survey, 51% of all patients commenced renal replacement therapy (RRT) using definitive access. Of patients commencing on haemodialysis HD, 37% commenced with definitive access (31% in the 2005 survey). Of those known to the renal units for a year or more, only half started HD with definitive access. Around 4% of patients currently receiving HD were in-patients. Around 30% of staphylococcal line infections were methicillin resistant Staphylococcus aureus (MRSA), which was similar to the 2005 survey. At 6 months after starting RRT, 76% of live patients were using definitive access [defined as the use of peritoneal dialysis (PD), transplant, arteriovenous fistula (AVF) or arteriovenous graft (AVG)] and at 12 months it was 80%. Of the HD patients starting RRT in April 2005, 65% started using venous catheters, at 6 months this had fallen to 35% and at 12 months to 30%. The use of non-tunnelled lines was <1% by 6 months. The proportion on PD had fallen slightly at 12 months (from 20% to 16%) by which time 11% had received a transplant, 1% had recovered and 18% had died. Data returns for the 2006 survey were returned from 37/74 renal units compared with returns from 62 units in the 2005 survey.

Confounding effect of comorbidity in survival studies in patients on renal replacement therapy.

BACKGROUND: After taking other confounding factors into account, the impact of comorbidity on mortality was investigated when comparing mortality between five European countries, dialysis modalities and renal disease groups. METHODS: The study included 15 571 incident patients on renal replacement therapy (RRT) from five national or regional registries participating in the European Renal Association-European Dialysis and Transplant Association Registry that collect comorbidity data. The presence of diabetes mellitus, ischaemic heart disease, peripheral vascular disease, cerebrovascular disease and malignancy was recorded at the start of RRT. RESULTS: The comorbidities were each independently associated with mortality, with hazard ratios (HRs) ranging from 1.40 (95% CI: 1.30-1.51) for peripheral vascular disease to 1.65 (95% CI: 1.48-1.83) for diabetes. Age, gender, primary renal disease, modality and country together explained 14.4% of the variance in mortality; the comorbidities explained an additional 1.9%. In the comparison of renal vascular disease with glomerulonephritis, the crude HR of 2.40 (95% CI: 2.12-2.72) changed to 1.24 (95% CI: 1.09-1.41) after adjustment for age, gender, primary renal disease, treatment modality and country and to 1.06 (95% CI: 0.93-1.22) after further adjustment for the comorbidities. For the comparison between countries and other patient groups, the change in the survival estimate after adjustment for comorbidity was less. CONCLUSION: Comorbidity is an important predictor for mortality. However, after adjustment for age, gender, primary renal disease, treatment modality and country, when comparing outcomes between patient groups the influence of comorbidity may be less important than expected.