Search

X-ray computed tomography has established itself as a crucial tool in the analysis of rock materials, providing the ability to visualise intricate 3D microstructures and capture quantitative information about internal phenomena such as structural damage, mineral reactions, and fluid–rock interactions. The efficacy of this tool, however, depends significantly on the precision of image segmentation, a process that has seen varied results across different methodologies, ranging from simple histogram thresholding to more complex machine learning and deep-learning strategies. The irregularity in these segmentation outcomes raises concerns about the reproducibility of the results, a challenge that we aim to address in this work. In our study, we employ the mass balance of a metamorphic reaction as an internal standard to verify segmentation accuracy and shed light on the advantages of deep-learning approaches, particularly their capacity to efficiently process expansive datasets. Our methodology utilises deep learning to achieve accurate segmentation of time-resolved volumetric images of the gypsum dehydration reaction, a process that traditional segmentation techniques have struggled with due to poor contrast between reactants and products. We utilise a 2D U-net architecture for segmentation and introduce machine-learning-obtained labelled data (specifically, from random forest classification) as an innovative solution to the limitations of training data obtained from imaging. The deep-learning algorithm we developed has demonstrated remarkable resilience, consistently segmenting volume phases across all experiments. Furthermore, our trained neural network exhibits impressively short run times on a standard workstation equipped with a graphic processing unit (GPU). To evaluate the precision of our workflow, we compared the theoretical and measured molar evolution of gypsum to bassanite during dehydration. The errors between the predicted and segmented volumes in all time series experiments fell within the 2 % confidence intervals of the theoretical curves, affirming the accuracy of our methodology. We also compared the results obtained by the proposed method with standard segmentation methods and found a significant improvement in precision and accuracy of segmented volumes. This makes the segmented computed tomography images suited for extracting quantitative data, such as variations in mineral growth rate and pore size during the reaction. In this work, we introduce a distinctive approach by using an internal standard to validate the accuracy of a segmentation model, demonstrating its potential as a robust and reliable method for image segmentation in this field. This ability to measure the volumetric evolution during a reaction with precision paves the way for advanced modelling and verification of the physical properties of rock materials, particularly those involved in tectono-metamorphic processes. Our work underscores the promise of deep-learning approaches in elevating the quality and reproducibility of research in the geosciences.

In experiments designed to understand deep shear zones, we show that periodic porous sheets emerge spontaneously during viscous creep and that they facilitate mass transfer. These findings challenge conventional expectations of how viscosity in solid rocks operates and provide quantitative data in favour of an alternative paradigm, that of the dynamic granular fluid pump model. On this basis, we argue that our results warrant a reappraisal of the community's perception of how viscous deformation in rocks proceeds with time and suggest that the general model for deep shear zones should be updated to include creep cavitation. Through our discussion we highlight how the integration of creep cavitation, and its Generalised Thermodynamic paradigm, would be consequential for a range of important solid Earth topics that involve viscosity in Earth materials like, for example, slow earthquakes.

Establishing models for the formation of well-mixed polyphase domains in ultramylonites is difficult because the effects of large strains and thermo-hydro-chemo-mechanical feedbacks can obscure the transient phenomena that may be responsible for domain production. We use scanning electron microscopy and nanotomography to offer critical insights into how the microstructure of a highly deformed quartzo-feldspathic ultramylonite evolved. The dispersal of monomineralic quartz domains in the ultramylonite is interpreted to be the result of the emergence of synkinematic pores, called creep cavities. The cavities can be considered the product of two distinct mechanisms that formed hierarchically: Zener–Stroh cracking and viscous grain-boundary sliding. In initially thick and coherent quartz ribbons deforming by grain-size-insensitive creep, cavities were generated by the Zener–Stroh mechanism on grain boundaries aligned with the YZ plane of finite strain. The opening of creep cavities promoted the ingress of fluids to sites of low stress. The local addition of a fluid lowered the adhesion and cohesion of grain boundaries and promoted viscous grain-boundary sliding. With the increased contribution of viscous grain-boundary sliding, a second population of cavities formed to accommodate strain incompatibilities. Ultimately, the emergence of creep cavities is interpreted to be responsible for the transition of quartz domains from a grain-size-insensitive to a grain-size-sensitive rheology.

Background: Despite the vaccination process in Germany, a large share of the population is still susceptible to SARS-CoV-2. In addition, we face the spread of novel variants. Until we overcome the pandemic, reasonable mitigation and opening strategies are crucial to balance public health and economic interests., Methods: We model the spread of SARS-CoV-2 over the German counties by a graph-SIR-type, metapopulation model with particular focus on commuter testing. We account for political interventions by varying contact reduction values in private and public locations such as homes, schools, workplaces, and other. We consider different levels of lockdown strictness, commuter testing strategies, or the delay of intervention implementation. We conduct numerical simulations to assess the effectiveness of the different intervention strategies after one month. The virus dynamics in the regions (German counties) are initialized randomly with incidences between 75 and 150 weekly new cases per 100,000 inhabitants (red zones) or below (green zones) and consider 25 different initial scenarios of randomly distributed red zones (between 2 and 20% of all counties). To account for uncertainty, we consider an ensemble set of 500 Monte Carlo runs for each scenario., Results: We find that the strength of the lockdown in regions with out of control virus dynamics is most important to avoid the spread into neighboring regions. With very strict lockdowns in red zones, commuter testing rates of twice a week can substantially contribute to the safety of adjacent regions. In contrast, the negative effect of less strict interventions can be overcome by high commuter testing rates. A further key contributor is the potential delay of the intervention implementation. In order to keep the spread of the virus under control, strict regional lockdowns with minimum delay and commuter testing of at least twice a week are advisable. If less strict interventions are in favor, substantially increased testing rates are needed to avoid overall higher infection dynamics., Conclusions: Our results indicate that local containment of outbreaks and maintenance of low overall incidence is possible even in densely populated and highly connected regions such as Germany or Western Europe. While we demonstrate this on data from Germany, similar patterns of mobility likely exist in many countries and our results are, hence, generalizable to a certain extent., (© 2022. The Author(s).)

Non-pharmaceutical interventions (NPIs) are important to mitigate the spread of infectious diseases as long as no vaccination or outstanding medical treatments are available. We assess the effectiveness of the sets of non-pharmaceutical interventions that were in place during the course of the Coronavirus disease 2019 (Covid-19) pandemic in Germany. Our results are based on hybrid models, combining SIR-type models on local scales with spatial resolution. In order to account for the age-dependence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we include realistic prepandemic and recently recorded contact patterns between age groups. The implementation of non-pharmaceutical interventions will occur on changed contact patterns, improved isolation, or reduced infectiousness when, e.g., wearing masks. In order to account for spatial heterogeneity, we use a graph approach and we include high-quality information on commuting activities combined with traveling information from social networks. The remaining uncertainty will be accounted for by a large number of randomized simulation runs. Based on the derived factors for the effectiveness of different non-pharmaceutical interventions over the past months, we provide different forecast scenarios for the upcoming time., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021. Published by Elsevier Inc.)

Background: Erythropoiesis-stimulating agents (ESAs) with intravenous iron supplementation are the main treatment for anaemia in patients with chronic kidney disease. Although observational studies suggest better outcomes for patients who achieve higher haemoglobin (Hb) levels, randomized controlled trials comparing higher and lower Hb targets have led to safety concerns over higher targets and to changes in treatment guidelines., Methods: Quarterly data from 2005 to 2013 were obtained on 28 936 haemodialysis patients from the UK Renal Registry. We examined trends in ESA use and average dose, Hb and ferritin values over time and Hb according to the UK Renal Association guideline range., Results: The average ESA dose declined over time, with sharper decreases of epoetin seen towards the end of 2006 and from 2009. Average Hb for patients on ESAs was 114.1 g/L [95% confidence interval (CI) 113.7, 114.6] in the first quarter of 2005, which decreased to 109.6 g/L (95% CI 109.3, 109.9) by the end of 2013. Average serum ferritin was 353 µg/L (95% CI 345, 360) at the start of 2005, increasing to 386 µg/L (95% CI 380, 392) in the final quarter of 2013. The percentage of patients with Hb in the range of 100-120 g/L increased from 46.1 at the start of 2005 to 57.6 at the end of 2013., Conclusions: Anaemia management patterns for haemodialysis patients changed in the UK between 2005 and 2013. These patterns most likely reflect clinician response to emerging trial evidence and practice guidelines. Registries play an important role in continued observation of anaemia management and will monitor further changes as new evidence on optimal care emerges., (© The Author 2016. Published by Oxford University Press on behalf of ERA-EDTA.)

The incidence rate in the UK increased from 109 per million population (pmp) in 2013 to 115 pmp in 2014 reflecting renal replacement therapy (RRT) initiation for 7,411 new patients. The increase in incidence rate from 2013 to 2014 was seen in England and Scotland (although rates in Scotland have fluctuated around this level since 2008) but not Wales and Northern Ireland. The median age of all incident patients was 64.8 years but this was highly dependant on ethnicity (66.4 for White incident patients; 58.7 for non- White patients). Diabetic renal disease remained the single most common cause of renal failure (26.9%). By 90 days, 66.3% of patients were on haemodialysis, 19.1% on peritoneal dialysis, 9.7% had a functioning transplant and 4.8% had died or stopped treatment. By contrast, in 2007, at 90 days 67% were on HD, 21% PD and only 5% were transplanted. The percentage of patients still on RRT at 90 days who had a functioning transplant at 90 days varied between centres from 0% to 33% (between 7% and 33% for transplanting centres and between 0% and 21% for non-transplanting centres). The mean eGFR at the start of RRT was 8.6 ml/min/1.73 m2 similar to the previous four years. Late presentation (,90 days) fell from 23.9% in 2006 to 17.8% in 2014.

In the UK in 2014: The median haemoglobin (Hb) of patients at the time of starting dialysis was 100 g/L with 50% of patients having a Hb 5100 g/L. The median Hb in patients starting haemodialysis (HD) was 97 g/L (IQR 87-106) and in patients starting peritoneal dialysis (PD) was 108 g/L (IQR 100-117). At start of dialysis, 54% of patients presenting early had Hb 5100 g/L whilst only 33% of patients presenting late had Hb 5100 g/L. The median Hb of prevalent patients on HD was 111 g/L with an IQR of 103-120 g/L. The median Hb of prevalent patients on PD was 112 g/L with an IQR of 103-121 g/L. 81% of HD patients and 83% of PD patients had Hb 5100 g/L. 58% of HD patients and 56% of PD patients had Hb 5100 and 4120 g/L. The median ferritin in HD patients was 432 mg/L (IQR 274–631) and 95% of HD patients had a ferritin 5100 mg/L. The median ferritin in PD patients was 292 mg/L (IQR 168–479) with 88% of PD patients having a ferritin 5100 mg/L. In England, Wales and Northern Ireland in 2014: The median erythropoietin stimulating agent (ESA) dose was higher for HD than PD patients (7,333 vs. 4,148 IU/week).

Introduction: This chapter describes the characteristics of adult patients starting renal replacement therapy (RRT) in the UK in 2013 and the incidence rates for RRT by Clinical Commissioning Groups and Health Boards (CCG/HBs) in the UK., Methods: Basic demographic and clinical characteristics,including presentation time (time between first being seen by a nephrologist and start of RRT), and age/gender standardised incidence ratios in CCG/HBs, are reported on patients starting RRT at all UK renal centres., Results: In 2013, RRT was started in 7,006 patients across the UK,with an incidence rate similar to 2012 at 109 per million population (pmp). There were wide variations between CCG/HBs in standardised incidence ratios. The median age for White patients was 66.0 and for non-White patients 57.0 years. Diabetic renal disease remained the single most common cause of renal failure (25%). By 90 days,66.1% of patients were on haemodialysis (HD), 19.0% on peritoneal dialysis (PD), 9.5% had a functioning transplant and 5.3% had died or stopped treatment. There continued to be variability between centres in the use of PD as an initial treatment. The mean eGFR at the start of RRT was 8.5 ml/min/1.73 m2 similar to previous years. Late presentation(,90 days) fell from 23.9% in 2006 to 18.4% in 2013. Fifty-one percent of patients who started on HD had died within five years of starting. This compared to 33% and 5% for those starting on PD or transplant respectively., Conclusions: The incidence of new patients starting RRT in the UK has remained largely unchanged for almost 10 years in contrast to the rising numbers of prevalent patients (+48% since 2003). The year on year increase in pre-emptive transplantation is encouraging but the variability between centres in the percentages starting on PD should be explored further.

Background: The diagnosis and management of anaemia in chronic kidney disease and the standards to be achieved have been detailed in the UK Renal Association Anaemia of CKD guidelines., Aims: To determine the attainment of standards for anaemia management in the UK., Methods: Quarterly data were obtained for haemoglobin (Hb) and factors that influence Hb from renal centres in England,Wales, Northern Ireland (EW&NI) and the Scottish Renal Registry for the incident and prevalent renal replacement therapy (RRT) cohorts for 2013., Results: In the UK, in 2013,50% of patients commenced dialysis therapy with Hb 5100 g/L (median Hb 100 g/L). Of patients presenting early, 53% started dialysis with Hb 5100 g/L compared to 36% of patients presenting late. The UK median Hb of haemodialysis (HD) & peritoneal dialysis (PD) patients was 112 g/L (inter-quartile range (IQR) 103–120 g/L) and 113 g/L(IQR 103–122 g/L) respectively with 83% of patients having Hb .100 g/L for both treatment modalities. The median ferritin in HD and PD patients was 424 mg/L (IQR 280–616 mg/L) and 285 mg/L (IQR 167–473 mg/L) respectively with the majority of patients achieving ferritin 5100 mg/L.In EW&NI the median ESA dose was higher for HD than PD patients (7,333 vs. 4,000 IU/week). The percentage of patients treated with an ESA and having Hb .120 g/L ranged between centres from 3–29% for HD and from 0–26% for PD., Conclusions: There continues to be significant variation between centres in the use of iron and ESAi n order to achieve the target Hb (100–120 g/L).

Introduction: This chapter describes the characteristics of adult patients starting renal replacement therapy (RRT: kidney dialysis or a kidney transplant) in the UK in 2012 and the incidence rates for RRT in Primary Care Trusts and Health Boards (PCT/HBs) in the UK., Methods: Basic demographic and clinical characteristics are reported on patients starting RRT at all UK renal centres. Presentation time, defined as time between first being seen by a nephrologist and start of RRT, was also studied. Age and gender standardised ratios for incidence rates in PCT/HBs were also calculated., Results: In 2012, RRT was initiated in 6,891 patients across the UK, an incidence rate similar to 2011 at 108 per million population (pmp). There were wide variations between PCT/HBs in standardised incidence ratios. The median age for Whites was 66.1 and for non-Whites 57.8 years. Diabetic renal disease remained the single most common cause of renal failure (26%). By 90 days, 66.9% of patients were on haemodialysis (HD), 19.0% on peritoneal dialysis (PD), 8.3% had had a transplant and 5.9% had died or stopped treatment. There was variability between centres in the use of PD as an initial treatment (3-48%). The mean eGFR at the start of RRT was 8.5 ml/min/1.73 m(2) similar to previous years. Late presentation (<90 days) fell from 23.9% in 2006 to 19.3% in 2012. Fifty-three percent of patients who started on HD had died within five years of starting. This compared to 30% and 4% for those starting on PD or transplant respectively., Conclusions: The incidence of new patients starting renal replacement therapy in the UK has remained unchanged for almost 10 years in contrast to the rising prevalence. The year on year increase in pre-emptive transplantation is encouraging but the variability between centres in the percentages starting on PD should be explored further., (© 2014 S. Karger AG, Basel.)

Introduction: Anaemia treatment in chronic kidney disease (CKD) patients has changed dramatically since the implementation of erythropoietin stimulating agents (ESAs) and has shifted the emphasis from treating severe anaemia in dialysis patients to preventing anaemia. The aim of this chapter is to determine the extent to which the UK Renal Association (RA) and National Institute for Health and Care Excellence (NICE) guidelines for anaemia management are met in the UK., Methods: Quarterly data were obtained for haemoglobin (Hb) and factors that influence Hb from UK renal centres for the incident and prevalent renal replacement therapy (RRT) cohorts for 2012., Results: In the UK, in 2012, 51% of patients commenced dialysis therapy with Hb 100 g/L (median Hb 100 g/L). Of patients in the early presentation group, 54% started dialysis with Hb 100 g/L whilst 34% of patients presenting late started dialysis with Hb 100 g/L. The UK median Hb of haemodialysis (HD) patients was 112 g/L, with 82% of patients having Hb 100 g/L. The median Hb of peritoneal dialysis (PD) patients in the UK was 114 g/L, with 85% of patients having Hb 100 g/L. The median ferritin in HD patients in the UK was 431 µg/L and 95% of HD patients had a ferritin 100 µg/L. In EW&NI the median ferritin in PD patients was 285 µg/L (IQR 164-466) with 88% of PD patients having a ferritin 100 µg/L. In EW&NI the median ESA dose was higher for HD than PD patients (7,248 vs. 4,250 IU/week). The percentage of patients treated with an ESA and having Hb >120 g/L ranged between centres from 7-39% for HD and from 0-33% for PD., Conclusions: There was poor correlation between median Hb achieved and median ferritin and ESA usage across the EW&NI centres. There was also a significant variation between centres in the percentages of patients treated with an ESA and having Hb >120 g/L. © 2014 S. Karger AG, Basel.

Introduction: This chapter describes the characteristics of adult patients starting renal replacement therapy (RRT) in the UK in 2011 and the incidence rates for RRT in Primary Care Trusts and Health Boards (PCT/HBs) in the UK., Methods: Basic demographic and clinical characteristics are reported on patients starting RRT at all UK renal centres. Presentation time, defined as time between first being seen by a nephrologist and start of RRT, was also studied. Age and gender standardised ratios for incidence rates in PCT/HBs were also calculated., Results: In 2011, the incidence rate in the UK was similar to 2010 at 108 per million population (pmp). There were wide variations between PCT/HBs in standardised incidence ratios. For the 2006-2011 incident cohort analysis the range was 0.42 to 2.52 (IQR 0.85, 1.20). The median age of all incident patients was 64.9 years (IQR 50.9, 75.1). For transplant centres this was 63.8 years (IQR 49.5, 74.3) and for non-transplanting centres 66.2 years (IQR 52.4, 76.0). The median age for non-Whites was 58.4 years. Diabetic renal disease remained the single most common cause of renal failure (25%). By 90 days, 67.1% of patients were on haemodialysis, 19.2% on perito- neal dialysis, 7.8% had had a transplant and 5.8% had died or stopped treatment. This is the second year in a row that the percentage on peritoneal dialysis has increased and, in 2011, this was most notable in the 65-74 age group. There was a lot of variability in use of PD with some centres having over twice the average percentage on PD. The mean eGFR at the start of RRT was 8.7 ml/min/1.73 m(2) similar to the previous four years. Late presentation (<90 days) fell from 23.9% in 2006 to 19.6% in 2011. There was no relationship between social deprivation and presentation pattern., Conclusions: Incidence rates have plateaued in England over the last six years. There has been an increase in the percentage of new patients still on RRT at 90 days after starting who were on PD at 90 days (19.2 to 20.4%)., (Copyright © 2013 S. Karger AG, Basel.)

Background: The UK Renal Association (RA) and National Institute for Health and Care 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 for haemoglobin (Hb) and factors that influence Hb from renal centres in England, Wales, Northern Ireland (E, W, NI) and the Scottish Renal Registry for the incident and prevalent renal replacement therapy (RRT) cohorts for 2011., Results: In the UK, in 2011 51% of patients commenced dialysis therapy with Hb ≥10.0 g/dl (median Hb 10 g/dl). Of patients in the early presentation group, 55% started dialysis with Hb ≥10.0 g/dl whilst 37% of patients presenting late started dialysis with Hb ≥10.0 g/dl. The UK median Hb of haemodialysis (HD) patients was 11.2 g/dl with an inter-quartile range (IQR) of 10.3-12.1 g/dl. Of UK HD patients, 82% had Hb ≥10.0 g/dl. The median Hb of peritoneal dialysis (PD) patients in the UK was 11.4 g/dl (IQR 10.5-12.3 g/dl). Of UK PD patients, 85% had Hb ≥10.0 g/dl. The median ferritin in HD patients in the UK was 436 mg/L (IQR 292-625) and 96% of HD patients had a ferritin ≥100 mg/ L. In EW&NI the median ferritin in PD patients was 273 mg/ L (IQR 153-446) with 86% of PD patients having a ferritin ≥100 mg/L. In EW&NI the mean erythropoietin stimulating agent (ESA) dose was higher for HD than PD patients (8,740 vs. 6,624 IU/week)., Conclusions: Prevalent HD and PD patients had 56% and 53% respectively within the Hb ≥10 and ≤12 g/dl target., (Copyright © 2013 S. Karger AG, Basel.)

Background: Control of blood pressure (BP) following renal transplantation may improve allograft and patient survival. Our aims were (i) to describe the distribution of BP and the prevalence of systolic and/or diastolic hypertension in children over the first 5 years following renal transplantation and (ii) to evaluate clinical risk factors and centre-specific factors associated with hypertension in this population., Methods: We conducted a retrospective case note review of all current paediatric kidney transplant patients in the UK, with data collected at 6 months, 1, 2 and 5 years following transplantation in subjects with hypertension (systolic and/or diastolic BP > 95th > ) and non-hypertensive subjects BP ≤ 95th > ., Results: In total, 27.3% (117/428), 27.6% (118/428), 26.0% (95/365) and 25.6% (50/195) of the patients were hypertensive (systolic and/or diastolic BP > 95th > ) at 6 months, 1, 2 and 5 years following transplantation, respectively. A total of 58.4% of the patients at 6 months, 52.8% at 1 year, 48.2% at 2 years and 48.2% at 5 years were receiving anti-hypertensive therapy, of whom 31.6-36.6% remained hypertensive. When subjects were identified as being hypertensive, on anti-hypertensive medication or had untreated hypertension (systolic and/or diastolic BP > 95th > ), 66.4, 61.0, 56.4 and 55.9% of patients were hypertensive at 6 months, 1, 2 and 5 years, respectively. In a multivariate model, odds ratios for systolic hypertension were 4.16 (deceased versus living donor), 2.65 (lowest versus highest quartile of height z-score) and 2.07 (if on anti-hypertensive; yes versus no). There was significant variation in prevalent rates of hypertension between centres (P < 0.0001) that remained significant (P = 0.003) after adjustment for all the factors in the multivariate model., Conclusions: Control of BP after kidney transplantation remains sub-optimal in paediatric centres in the UK. Just over 25% of patients remain hypertensive 5 years following transplantation. Significant differences between centres remain unexplained and may reflect differences in assessment and management of hypertension.

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., Aim: 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 2010., Results: In the UK, in 2010 53.6% of patients commenced dialysis therapy with Hb ≥ 10.0 g/dl (median Hb 10.1 g/dl). The median Hb of haemodialysis (HD) patients was 11.5 g/dl with an interquartile range (IQR) of 10.5-12.3 g/dl. Of HD patients 84.6% had Hb ≥ 10.0 g/dl. The median Hb of peritoneal dialysis (PD) patients in the UK was 11.6 g/dl (IQR 10.6-12.5 g/dl). Of UK PD patients, 87.2% had Hb ≥ 10.0 g/dl. The median ferritin in HD patients in EWNI was 444 µg/L (IQR 299-635) and 96% of HD patients had a ferritin ≥ 100 µg/L. The median ferritin in PD patients was 264 µg/L (IQR 148-426) with 86% of PD patients having a ferritin ≥ 100 µg/L. In EWNI the mean Erythropoietin Stimulating Agent (ESA) dose was higher for HD than PD patients (9,020 vs. 6,202 IU/week)., Conclusions: Of prevalent HD patients, 52.7% had Hb ≥ 10 and ≤ 12 g/dl. Of prevalent PD patients, 54.3% had Hb 10.5-12.5 g/dl., (Copyright © 2012 S. Karger AG, Basel.)

Introduction: This chapter describes the characteristics of adult patients starting renal replacement therapy (RRT) in the UK in 2010 and the incidence 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. Presentation time, defined as time between first being seen by a nephrologist and start of RRT, was also studied. Age and gender standardised ratios for incidence rates in PCT/HBs were also calculated., Results: In 2010, the incidence rates in the UK and England were similar to 2009 at 107 per million population (pmp). The incidence rate fell in Scotland (from 104 pmp to 95 pmp), increased in Northern Ireland (from 88 pmp to 101 pmp) and Wales (from 120 pmp to 128 pmp). There were wide variations between PCT/HBs in standardised incidence ratios. The median age of all incident patients was 64.9 years (IQR 51.0, 75.2). For transplant centres this was 63.1 years (IQR 49.7, 74.2) and for non-transplanting centres 66.5 years (IQR 52.9, 76.0). The median age for non-Whites was 57.1 years. Diabetic renal disease remained the single most common cause of renal failure (24%). By 90 days, 68.3% of patients were on haemodialysis, 18.1% on peritoneal dialysis, 7.7% had had a transplant and 5.9% had died or stopped treatment. The mean eGFR at the start of RRT was 8.7 ml/ min/1.73 m(2) which was similar to the previous three years. Late presentation (<90 days) fell from 28.2% in 2005 to 20.6% in 2010. There was no relationship between social deprivation and presentation pattern., Conclusions: Incidence rates have plateaued in England over the last five years. They have fallen in Scotland and fallen and then risen again in Northern Ireland and Wales. Wales continued to have the highest incidence rate of the countries making up the UK., (Copyright © 2012 S. Karger AG, Basel.)

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., (Copyright © 2011 S. Karger AG, Basel.)

Introduction: RRT incidence rates and the proportion of patients using a home dialysis modality (peritoneal or home haemodialysis) varies widely between centres and persists even after area differences in age, ethnicity and social deprivation structure are taken into account. A nationwide survey was undertaken to identify possible drivers of this variation., Methods: A systematic literature review followed by a two-stage Delphi consensus technique was employed to identify renal centre characteristics and practice patterns that may be important in determining either RRT incidence or home modality usage., Results: All 72 (100%) of UK adult renal centres responded. Questions about staffing numbers, interface with primary care, interface with other secondary care sites, capacity within the HD programme, constituents of pre-dialysis education programmes, conservative management programmes, range of treatments available, dialysis access and training and physician attitudes to home modalities were included., Conclusions: There was wide variation in practice patterns and centre characteristics across the UK. Overall, physician enthusiasm for home dialysis modalities was greater than the actual usage of home dialysis., (Copyright © 2011 S. Karger AG, Basel.)

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., (Copyright © 2011 S. Karger AG, Basel.)

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., (Copyright © 2011 S. Karger AG, Basel.)

Introduction: The prevalence of comorbidities in incident renal replacement therapy (RRT) patients changes with age and varies between ethnic groups. This study describes these associations and the independent effect of comorbidities on outcomes., Methods: Adult patients starting RRT between 2003 and 2008 in centres reporting to the UK Renal Registry (UKRR) with data on comorbidity (n (1/4) 14,909) were included. The UKRR studied the association of comorbidity with patient demographics, treatment modality, haemoglobin, renal function at start of RRT and subsequent listing for kidney transplantation. 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 40.0% compared with 54.3% in 2003. Of patients with data, 53.8% had one or more comorbidities. Diabetes mellitus and ischaemic heart disease were the most common conditions seen in 30.1% and 22.7% of patients respectively. Current smoking was recorded for 14.5% of incident RRT patients in the 6-year period. Comorbidities became more common with increasing age in all ethnic groups although the difference between the 65-74 and 75+ age groups was not significant. Within each age group, South Asians and Blacks had lower rates of comorbidity, despite higher rates of diabetes mellitus. In multivariate survival analysis, malignancy and ischaemic/neuropathic ulcers were the strongest independent predictors of poor survival at 1 year after 90 days from the start of RRT., Conclusion: Differences in prevalence of comorbid illnesses in incident RRT patients may reflect variation in access to health care or competing risk prior to commencing treatment. At the same time, smoking rates remained high in this 'at risk' population. Further work on this and ways to improve comorbidity reporting should be priorities for 2010-11., ((c) 2010 S. Karger AG, Basel.)

Introduction: This chapter describes the characteristics of adult patients starting renal replacement therapy (RRT) in the UK in 2008 and the acceptance rates for RRT in Primary Care Trusts and Local Authorities (PCT/LAs) in the UK., Methods: The basic demographics and clinical characteristics are reported on patients starting RRT from all UK renal centres. Late referral, 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 rate in PCT/LAs were calculated., Results: In 2008, the acceptance rate in the UK was 108 per million population (pmp). Acceptance rates in Scotland (103 pmp), Northern Ireland (97 pmp) and Wales (117 pmp) have all fallen although Wales still remains the country with the highest acceptance rate. There were wide variations between PCT/LAs with respect to the standardised ratios, which were lower in more PCT/LAs in the North West and South East of England and higher in London, the West Midlands, Scotland, Northern Ireland, and Wales. The median age of all incident patients was 64.1 years and for non-Whites 56.1 years. Diabetic renal disease remains the single most common cause of renal failure (24%). By 90 days, 67.7% of patients were on haemodialysis, 19.8% on peritoneal dialysis, 5.9% had had a transplant and 6.6% had died or had stopped treatment. By 90 days, 77.4% of all dialysis patients were on HD. The geometric mean eGFR at the start of RRT was 8.6 ml/min/ 1.73 m(2) which was similar to the eGFR of those starting in 2007. The incidence of late presentation (<90 days) has fallen from 28% in 2003 to 22% in 2008. There was no relationship between social deprivation and referral pattern., Conclusions: Acceptance rates have fallen in Northern Ireland, Scotland and Wales whilst they have plateaued in England over the last three years. Wales continued to have the highest acceptance rate of the countries making up the UK., ((c) 2010 S. Karger AG, Basel.)

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 (haemoglobin (Hb) and factors that influence Hb) extracts from renal centres in England, Wales, Northern Ireland (EWNI), and annual data from the Scottish Renal Registry for incident and prevalent renal replacement therapy (RRT) cohorts for 2008 were analysed by the UK Renal Registry (UKRR)., Results: In the UK, in 2008 57% of patients commenced dialysis therapy with Hb >or= 10.0 g/dl (median Hb 10.2 g/dl). For incident patients the Hb at 3 and 6 months of dialysis treatment was 11.4 and 11.7 g/dl respectively. The median Hb of haemodialysis (HD) patients was 11.6 g/dl with an interquartile range (IQR) of 10.6-12.5 g/dl. Of HD patients 85% had a Hb >or= 10.0 g/dl. The median Hb of peritoneal dialysis (PD) patients in the UK was 11.7 g/dl (IQR 10.8-12.6 g/dl). Of UK PD patients 89% had a Hb >or= 10.0 g/dl. The median ferritin in HD patients in EWNI was 436 mg/L (IQR 289-622) and 95% of HD patients had a ferritin >or= 100 mg/L. The median ferritin in PD patients was 246 mg/L (IQR 141-399) with 84% of PD patients having a ferritin >or= 100 mg/L. In EWNI the mean ESA dose was higher for HD than PD patients (9,166 vs. 6,302 IU/week)., Conclusions: Last year for the first time a small fall (from 85.9% in 2006 to 85.6% in 2007) in the % of HD patients with a Hb of >or= 10 g/dl which was thought to be related to the implementation of the new Hb Standard which has a target range of 10.5-12.5 g/dl was seen. This year attainment of Hb >or= 10 g/dl in HD patients fell again slightly to 85.3%. In HD patients, 54% of patients had a Hb >or= 10.5 and

Introduction: This chapter describes the characteristics of adult patients starting renal replacement therapy (RRT) in the UK in 2007 and the acceptance rate for RRT in Primary Care Trusts (PCT) or equivalent Health Authority (HA) areas in the UK., Methods: The basic demographics are reported for all UK centres and clinical characteristics of patients starting RRT from all except 1 centre in the UK. 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 rate in PCTs or equivalent HAs were calculated., Results: In 2007, the acceptance rate in the UK was 109 per million population (pmp) compared to 111 pmp in 2006. Acceptance rates in England (107 pmp), Scotland (108 pmp) and Northern Ireland (105 pmp) have fallen slightly, whilst that in Wales (140 pmp) has risen. There were wide variations between PCTs/HAs with respect to the standardised ratios which were lower in more PCTs in the North West and South East of England and higher in London, the West Midlands and Wales. The median age of all incident patients was 64.1 years and for non-Whites 57.1 years. There was an excess of males in all age groups starting RRT and nearly 80% of patients were reported to be White. Diabetic renal disease remained the single most common cause of renal failure (21.9%). By 90 days, 67.4% of patients were on haemodialysis, 21.3% on peritoneal dialysis, 5.2% had had a transplant and 6.1% had died or had stopped treatment. The incidence of late presentation in those centres supplying adequate data was 21%., Conclusions: The acceptance rate has fallen in England, Northern Ireland and Scotland but continues to rise in Wales with wide variations in acceptance rate between PCTs/HAs., (Copyright 2009 S. Karger AG, Basel.)

Introduction: The prevalence of 13 comorbid conditions and smoking status at the time of starting renal replacement therapy (RRT) in England, Wales and Northern Ireland are described., Methods: Adult patients starting RRT between 2002 and 2007 in centres reporting to the UK Renal Registry (UKRR) and with data on comorbidity (n = 13,293) were included. The association of comorbidity with patient demographics, treatment modality, haemoglobin, renal function at start of RRT and subsequent listing for kidney transplantation were studied. Association 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 data on comorbidity returned to the UKRR remained poor. Of patients with data, 52% had one or more comorbidities. Diabetes mellitus and ischaemic heart disease were the most common conditions seen in 28.9% and 22.5% of patients respectively. Comorbidities became more common with increasing age (up to the 65-74 age group), were more common amongst Whites and were associated with a lower likelihood of pre-emptive transplantation, a greater likelihood of starting on haemodialysis (rather than peritoneal dialysis) and a lower likelihood of being listed for kidney transplantation. In multivariable survival analysis, malignancy and ischaemic/neuropathic ulcers were the strongest predictors of poor survival at 1 year after 90 days from start of RRT., Conclusions: The majority of patients had at least one comorbid condition and comorbidity is an important predictor of early mortality on RRT., (Copyright 2009 S. Karger AG, Basel.)

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 (haemoglobin (Hb) and factors that influence Hb) extracts from renal centres in England, Wales and Northern Ireland (EWNI), and annual data from the Scottish Renal Registry for incident and prevalent renal replacement therapy (RRT) cohorts for 2007 were analysed by the UK Renal Registry (UKRR)., Results: In the UK, in 2007 58% of patients commenced dialysis therapy with Hb > or = 10.0 g/dl (median Hb 10.3 g/dl). Of incident patients 81% and 87% had a Hb > or = 10.0 g/dl by 3 and 6 months of dialysis treatment respectively. The median Hb of haemodialysis (HD) patients was 11.6 g/dl with an interquartile range (IQR) of 10.6-12.6 g/dl. Of HD patients 86% had a Hb > or = 10.0 g/dl. The median Hb of peritoneal dialysis (PD) patients in the UK was 11.9 g/dl (IQR 11.0-12.8 g/dl). 91% of UK PD patients had a Hb > or = 10.0 g/dl. The median ferritin in HD patients in EWNI was 417 microg/L (IQR 270-598) and 95% of HD patients had a ferritin > or = 100 microg/L. The median ferritin in PD patients was 255 microg/L (IQR 143-411) with 85% of PD patients having a ferritin > or = 100 microg/L. In EWNI the mean ESA dose was higher for HD than PD patients (9,300 vs. 6,100 IU/week)., Conclusions: This year for the first time there has been a small fall (from 85.9% in 2006 to 85.6%) in the percentage of HD patients with an Hb of > or = 10 g/dl. This contrasts with previous annual improvements in this figure and is related to implementation of the new Hb Standard which has a target range of 10.5-12.5 g/dl., (Copyright 2009 S. Karger AG, Basel.)

Many renal units still fail to return blood pressure data to the Renal Registry. In England, Northern Ireland and Wales, the percentage of HD patients achieving the combined blood pressure standard (<140/90 pre-dialysis) averages 43% (inter unit range 16-60%) and post-dialysis (<130/80) average 48% (range 22-66%). On average 27% (range 12-48%) of PD patients achieve the standard of <130/80 and 26% of renal transplant patients (range 16-40%). Over the last 8 years there has been no significant change in systolic or diastolic blood pressure achievement. Better comorbidity data returns are required by the Registry to perform blood pressure survival analyses.

Comorbidity returns have continued to improve, albeit slowly, with centres running Mediqal software having the highest rates of completeness. Diabetes as a primary renal diagnosis accounted for 20% of those starting RRT, but a further 7% had diabetes present as a comorbid condition. The incidence of smoking remained high at 17% of diabetic patients, which was similar to that found in non-diabetics. Twelve percent of the patients starting RRT had a previous myocardial infarction (MI) and 31% of those aged over 65 years starting RRT had ischaemic heart disease (IHD). Patients starting on peritoneal dialysis (PD) were on average 9 years younger than those on haemodialysis (HD) and had fewer comorbidities present. Patients starting RRT without any comorbidity present had a lower median estimated glomerular filtration rate (eGFR) than those with comorbid conditions. Patients with a previous MI or coronary artery bypass grafting (CABG), started RRT with slightly higher mean haemoglobin than those without comorbid conditions or other comorbid conditions. On univariate survival analysis, diabetes was not associated with an increased risk of death amongst patients aged over 65 years, possibly due to its close association with other comorbidities in this age group. In the multivariate survival analysis, the presence of ischaemic/neuropathic ulcers was the predictor of worst survival, followed by malignancy, previous MI and age per 10 year increment. Smoking was less common in both South Asian and black patients than whites (7 vs 17%) starting RRT. Twenty-three percent of both South Asian and white patients started RRT with IHD compared with only 12% of Black patients.

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.

This population-based cross-sectional study in South London looks at the total homocysteine (tHcy) levels in groups of different ethnic background and the possible role of environmental factors and the 677C-->T genetic polymorphism of the methylenetetrahydrofolate reductase (MTHFR). Fasting plasma tHcy was measured in 1392 men and women, age 40-59 years; 475 were white, 465 of African origin (of whom 180 were West Africans and 280 Caribbeans) and 452 South Asian (of whom 222 were Hindus and 167 Muslims). The homozygous MTHFR TT variant had observed frequencies of 0.10 in whites, 0.01 in people of African origin and 0.02 in South Asians (P<0.001). tHcy levels were 16% (95% CI 8-26) higher amongst TT than CC. tHcy levels were 25% (21-29) higher in men than women. Levels were significantly higher in South Asians than whites (8% [3-13]). Vegetarians had higher levels than non-vegetarians (25% [18-33]). These differences were present after adjustments for age, sex, smoking, body mass index (BMI), MTHFR 677C-->T polymorphism and socio-economic status. Compared with whites (10.0 [9.7-10.3] micromol/l), and allowing for confounders, Hindus had significantly higher levels of tHcy (12.1 [11.6-12.6] micromol/l). This difference was attenuated by the inclusion of vegetarianism in the model (11.3 [10.8-11.9] micromol/l). In contrast Muslims had similar tHcy levels to whites while both West Africans and Caribbeans had slightly lower levels, though differences were not significant. The reported higher levels of tHcy in South Asians are due to high levels amongst Hindus only. They are in part accounted for by their vegetarianism. These differences in tHcy are large enough to be important contributors to the risk of vascular disease and may be preventable by simple targeted population strategies.