Assessing the efficacy of coproduction to better understand the barriers to achieving sustainability in NHS chronic kidney services and create alternate pathways.

CONTEXT: Too many people living with chronic kidney disease are opting for and starting on hospital-based dialysis compared to a home-based kidney replacement therapy. Dialysis services are becoming financially unsustainable. OBJECTIVE: This study aimed to assess the efficacy of coproductive research in chronic kidney disease service improvement to achieve greater sustainability. DESIGN: A 2-year coproductive service improvement study was conducted with multiple stakeholders with the specific intention of maximizing engagement with the national health kidney services, patients and public. SETTING AND PARTICIPANTS: A national health kidney service (3 health boards, 18 dialysis units), patients and families (n = 50), multidisciplinary teams including doctors, nurses, psychologists, social workers, and so forth (n = 68), kidney charities, independent dialysis service providers and wider social services were part of this study. FINDINGS: Coproductive research identified underutilized resources (e.g., patients on home dialysis and social services) and their potential, highlighted unmet social care needs for patients and families and informed service redesign. Education packages were reimagined to support the home dialysis agenda including opportunities for wider service input. The impacts of one size fits all approaches to dialysis on specialist workforce skills were made clearer and also professional, patient and public perceptions of key sustainability policies. DISCUSSION AND CONCLUSIONS: Patient and key stakeholders mapped out new ways to link services to create more sustainable models of kidney health and social care. Maintaining principles of knowledge coproduction could help achieve financial sustainability and move towards more prudent adult chronic kidney disease services. PATIENT OR PUBLIC CONTRIBUTION: Involved in developing research questions, study design, management and conduct, interpretation of evidence and dissemination.

Peritoneal inflammation precedes encapsulating peritoneal sclerosis: results from the GLOBAL Fluid Study.

BACKGROUND: Encapsulating peritoneal sclerosis (EPS) is an uncommon condition, strongly associated with a long duration of peritoneal dialysis (PD), which is itself associated with increased fibrosis in the peritoneal membrane. The peritoneal membrane is inflamed during PD and inflammation is often associated with fibrosis. We hypothesized that patients who subsequently develop EPS might have a more inflamed peritoneal membrane during PD. METHODS: We performed a nested, case-control study identifying all EPS cases in the UK arm of the GLOBAL Fluid Study and matching them by centre and duration of PD with two to three controls. Dialysate and plasma samples were taken during repeated peritoneal equilibration tests prior to cessation of PD from cases and controls. Samples were assayed by electrochemiluminescence immunoassay for interleukin-1ß (IL-1ß), tumour necrosis factor α (TNF-α), interferon-γ (IFN-γ) and IL-6. Results were analysed by linear mixed models adjusted for age and time on PD. RESULTS: Eleven EPS cases were matched with 26 controls. Dialysate TNF-α {0.64 [95% confidence interval (CI) 0.23, 1.05]} and IL-6 [0.79 (95% CI 0.03, 1.56)] were significantly higher in EPS cases, while IL-1ß [1.06 (95% CI -0.11, 2.23)] and IFN-γ [0.62 (95% CI -0.06, 1.29)] showed a similar trend. Only IL-6 was significantly higher in the plasma [0.42 (95% CI 0.07, 0.78)]. Solute transport was not significantly different between cases and controls but did increase in both groups with the duration of PD. CONCLUSIONS: The peritoneal cavity has higher levels of inflammatory cytokines during PD in patients who subsequently develop EPS, but neither inflammatory cytokines nor peritoneal solute transport clearly discriminates EPS cases. Increased systemic inflammation is also evident and is probably driven by increased peritoneal inflammation.

Independent effects of systemic and peritoneal inflammation on peritoneal dialysis survival.

Systemic inflammation, as evidenced by elevated inflammatory cytokines, is a feature of advanced renal failure and predicts worse survival. Dialysate IL-6 concentrations associate with variability in peritoneal small solute transport rate (PSTR), which has also been linked to patient survival. Here, we determined the link between systemic and intraperitoneal inflammation with regards to peritoneal membrane function and patient survival as part of the Global Fluid Study, a multinational, multicenter, prospective, combined incident and prevalent cohort study (n=959 patients) with up to 8 years of follow-up. Data collected included patient demographic characteristics, comorbidity, modality, dialysis prescription, and peritoneal membrane function. Dialysate and plasma cytokines were measured by electrochemiluminescence. A total of 426 survival endpoints occurred in 559 incident and 358 prevalent patients from 10 centers in Korea, Canada, and the United Kingdom. On patient entry to the study, systemic and intraperitoneal cytokine networks were dissociated, with evidence of local cytokine production within the peritoneum. After adjustment for multiple covariates, systemic inflammation was associated with age and comorbidity and independently predicted patient survival in both incident and prevalent cohorts. In contrast, intraperitoneal inflammation was the most important determinant of PSTR but did not affect survival. In prevalent patients, the relationship between local inflammation and membrane function persisted but did not account for an increased mortality associated with faster PSTR. These data suggest that systemic and local intraperitoneal inflammation reflect distinct processes and consequences in patients treated with peritoneal dialysis, so their prevention may require different therapeutic approaches; the significance of intraperitoneal inflammation requires further elucidation.

What are the factors that determine treatment choices in patients with kidney failure: a retrospective cohort study using data linkage of routinely collected data in Wales.

OBJECTIVES: To identify the factors that determine treatment choices following pre-dialysis education. DESIGN: Retrospective cohort study using data linkage with univariate and multivariate analyses using linked data. SETTING: Secondary care National Health Service Wales healthcare system. PARTICIPANTS: All people in Wales over 18 years diagnosed with established kidney disease, who received pre-dialysis education between 1 January 2016 and 12 December 2018. MAIN OUTCOME MEASURES: Patient choice of dialysis modality and any kidney replacement therapy started. RESULTS: Mean age was 67 years; n=1207 (60%) were male, n=878 (53%) had ≥3 comorbidities, n=805 (66%) had mobility problems, n=700 (57%) had pain symptoms, n=641 (52%) had anxiety or were depressed, n=1052 (61.6%) lived less than 30 min from their treatment centre, n=619 (50%) were on a spectrum of frail to extremely vulnerable. n=424 (25%) chose home dialysis, n=552 (32%) chose hospital-based dialysis, n=109 (6%) chose transplantation, n=231 (14%) chose maximum conservative management and n=391 (23%) were 'undecided'. Main reasons for not choosing home dialysis were lack of motivation/low confidence in capacity to self-administer treatment, lack of home support and unsuitable housing. Patients who choose home dialysis were younger, had lower comorbidities, lower frailty and higher quality of life scores. Multivariate analysis found that age and frailty were predictors of choice, but we did not find any other demographic associations. Of patients who initially chose home dialysis, only n=150 (54%) started on home dialysis. CONCLUSION: There is room for improvement in current pre-dialysis treatment pathways. Many patients remain undecided about dialysis choice, and others who may have chosen home dialysis are still likely to start on unit haemodialysis.

Human neutrophil clearance of bacterial pathogens triggers anti-microbial γδ T cell responses in early infection.

Human blood Vγ9/Vδ2 T cells, monocytes and neutrophils share a responsiveness toward inflammatory chemokines and are rapidly recruited to sites of infection. Studying their interaction in vitro and relating these findings to in vivo observations in patients may therefore provide crucial insight into inflammatory events. Our present data demonstrate that Vγ9/Vδ2 T cells provide potent survival signals resulting in neutrophil activation and the release of the neutrophil chemoattractant CXCL8 (IL-8). In turn, Vγ9/Vδ2 T cells readily respond to neutrophils harboring phagocytosed bacteria, as evidenced by expression of CD69, interferon (IFN)-γ and tumor necrosis factor (TNF)-α. This response is dependent on the ability of these bacteria to produce the microbial metabolite (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMB-PP), requires cell-cell contact of Vγ9/Vδ2 T cells with accessory monocytes through lymphocyte function-associated antigen-1 (LFA-1), and results in a TNF-α dependent proliferation of Vγ9/Vδ2 T cells. The antibiotic fosmidomycin, which targets the HMB-PP biosynthesis pathway, not only has a direct antibacterial effect on most HMB-PP producing bacteria but also possesses rapid anti-inflammatory properties by inhibiting γδ T cell responses in vitro. Patients with acute peritoneal-dialysis (PD)-associated bacterial peritonitis--characterized by an excessive influx of neutrophils and monocytes into the peritoneal cavity--show a selective activation of local Vγ9/Vδ2 T cells by HMB-PP producing but not by HMB-PP deficient bacterial pathogens. The γδ T cell-driven perpetuation of inflammatory responses during acute peritonitis is associated with elevated peritoneal levels of γδ T cells and TNF-α and detrimental clinical outcomes in infections caused by HMB-PP positive microorganisms. Taken together, our findings indicate a direct link between invading pathogens, neutrophils, monocytes and microbe-responsive γδ T cells in early infection and suggest novel diagnostic and therapeutic approaches.

Prevalence of risk factors for foot ulceration in a general haemodialysis population.

It is well documented that diabetic foot ulceration contributes to increased morbidity and mortality associated with renal replacement therapy. Much less is known about the risk of foot ulceration and lower limb amputation in the non-diabetic dialysis population. The aim of this study was to determine if the prevalence of risks factors for lower limb amputation in a stable haemodialysis population was greater in the diabetic cohort compared with the non-diabetic cohort. The study design is a prospective observational cohort study. Sixty patients attending a satellite haemodialysis unit in Cardiff were invited to have a comprehensive foot assessment as part of a Podiatry service review. The medical notes and hospital information system were used to identify the diabetic cohort. Patients were classified according to diabetic status (diabetic versus non-diabetic). The Renal Foot Screening Tool was developed to prospectively identify risk factors associated with foot ulceration. The assessment included peripheral neuropathy (PN), peripheral arterial disease (PAD) and foot pathology (FP). Fifty-seven patients gave informed verbal consent prior to inclusion. Risk factors for foot ulceration were recorded at baseline in the diabetic (n = 24) and non-diabetic (n = 33) groups and mortality data was revisited after a 3-year period. FP was identified in 79% of patients. Eighteen per cent of the non-diabetic patients had PN. PAD was identified in 45% of diabetic and 30% of non-diabetic patients. Forty-nine per cent of the total cohort had ≥2 of the 3 independent risk factors for foot ulceration (16/24 diabetic versus 12/33 non-diabetic). The presence of PAD and PN was predictive of mortality independent of age. The limitations of this study are its small sample size and patients were from a single satellite dialysis unit. There was a high prevalence of risk factors for foot ulceration in this population, which were not confined to the diabetic cohort. These findings suggest that non-diabetic patients on haemodialysis therapy are also at risk of developing foot ulceration. Further work on strategies to monitor and prevent FP in this high-risk cohort is needed to minimize morbidity and mortality associated with foot ulceration.

Trajectories in chronic disease accrual and mortality across the lifespan in Wales, UK (2005-2019), by area deprivation profile: linked electronic health records cohort study on 965,905 individuals.

Background: Understanding and quantifying the differences in disease development in different socioeconomic groups of people across the lifespan is important for planning healthcare and preventive services. The study aimed to measure chronic disease accrual, and examine the differences in time to individual morbidities, multimorbidity, and mortality between socioeconomic groups in Wales, UK. Methods: Population-wide electronic linked cohort study, following Welsh residents for up to 20 years (2000-2019). Chronic disease diagnoses were obtained from general practice and hospitalisation records using the CALIBER disease phenotype register. Multi-state models were used to examine trajectories of accrual of 132 diseases and mortality, adjusted for sex, age and area-level deprivation. Restricted mean survival time was calculated to measure time spent free of chronic disease(s) or mortality between socioeconomic groups. Findings: In total, 965,905 individuals aged 5-104 were included, from a possible 2.9 m individuals following a 5-year clearance period, with an average follow-up of 13.2 years (12.7 million person-years). Some 673,189 (69.7%) individuals developed at least one chronic disease or died within the study period. From ages 10 years upwards, the individuals living in the most deprived areas consistently experienced reduced time between health states, demonstrating accelerated transitions to first and subsequent morbidities and death compared to their demographic equivalent living in the least deprived areas. The largest difference were observed in 10 and 20 year old males developing multimorbidity (-0.45 years (99% CI: -0.45, -0.44)) and in 70 year old males dying after developing multimorbidity (-1.98 years (99% CI: -2.01, -1.95)). Interpretation: This study adds to the existing literature on health inequalities by demonstrating that individuals living in more deprived areas consistently experience accelerated time to diagnosis of chronic disease and death across all ages, accounting for competing risks. Funding: UK Medical Research Council, Health Data Research UK, and Administrative Data Research Wales.

Current costs of dialysis modalities: A comprehensive analysis within the United Kingdom.

BACKGROUND: Previous evidence suggests home-based dialysis to be more cost-effective than unit-based or hospital-based dialysis. However, previous analyses to quantify the costs of different dialysis modalities have used varied perspectives, different methods, and required assumptions due to lack of available data. The National Institute for Health and Care Excellence reports uncertainty about the differences in costs between home-based and unit-based dialysis. This uncertainty limits the ability of policy makers to make recommendations based on cost effectiveness, which also impacts on the ability of budget holders to model the impact of any service redesign and to understand which therapies deliver better value. The aim of our study was to use a combination of top-down and bottom-up costing methods to determine the direct medical costs of different dialysis modalities in one UK nation (Wales) from the perspective of the National Health Service (NHS). METHODS: Detailed hybrid top-down and bottom-up micro-costing methods were applied to estimate the direct medical costs of dialysis modalities across Wales. Micro-costing data was obtained from commissioners of the service and from interviews with renal consultants, nurses, accountants, managers and allied health professionals. Top-down costing information was obtained from the Welsh Renal Clinical Network (who commission renal services across Wales) and the Welsh Ambulance Service Trust. RESULTS: The annual direct cost per patient for home-based modalities was £16,395 for continuous ambulatory peritoneal dialysis (CAPD), £20,295 for automated peritoneal dialysis (APD) and £23,403 for home-based haemodialysis (HHD). The annual cost per patient for unit-based modalities depended on whether or not patients required ambulance transport. Excluding transport, the cost of dialysis was £19,990 for satellite units run in partnership with independent sector providers and £23,737 for hospital units managed and staffed by the NHS. When ambulance transport was included, the respective costs were £28,931 and £32,678, respectively. CONCLUSION: Our study is the most comprehensive analysis of the costs of dialysis undertaken thus far in the United Kingdom and clearly demonstrate that CAPD is less costly than other dialysis modalities. When ambulance transport costs are included, other home therapies (APD and HHD) are also less costly than unit-based dialysis. This detailed analysis of the components that contribute to dialysis costs will help inform future cost-effectiveness studies, inform healthcare policy and drive service redesign.

Understanding the low take-up of home-based dialysis through a shared decision-making lens: a qualitative study.

OBJECTIVES: To explore how people with chronic kidney disease who are pre-dialysis, family members and healthcare professionals together navigate common shared decision-making processes and to assess how this impacts future treatment choice. DESIGN: Coproductive qualitative study, underpinned by the Making Good Decisions in Collaboration shared decision-model. Semistructured interviews with a purposive sample from February 2019 - January 2020. Interview data were analysed using framework analysis. Coproduction of logic models/roadmaps and recommendations. SETTING: Five Welsh kidney services. PARTICIPANTS: 95 participants (37 patients, 19 family members and 39 professionals); 44 people supported coproduction (18 patients, 8 family members and 18 professionals). FINDINGS: Shared decision-making was too generic and clinically focused and had little impact on people getting onto home dialysis. Preferences of where, when and how to implement shared decision-making varied widely. Apathy experienced by patients, caused by lack of symptoms, denial, social circumstances and health systems issues made future treatment discussions difficult. Families had unmet and unrecognised needs, which significantly influenced patient decisions. Protocols containing treatment hierarchies and standards were understood by professionals but not translated for patients and families. Variation in dialysis treatment was discussed to match individual lifestyles. Patients and professionals were, however, defaulting to the perceived simplest option. It was easy for patients to opt for hospital-based treatments by listing important but easily modifiable factors. CONCLUSIONS: Shared decision-making processes need to be individually tailored with more attention on patients who could choose a home therapy but select a different option. There are critical points in the decision-making process where changes could benefit patients. Patients need to be better educated and their preconceived ideas and misconceptions gently challenged. Healthcare professionals need to update their knowledge in order to provide the best advice and guidance. There needs to be more awareness of the costs and benefits of the various treatment options when making decisions.

Protocol for the development of the Wales Multimorbidity e-Cohort (WMC): data sources and methods to construct a population-based research platform to investigate multimorbidity.

INTRODUCTION: Multimorbidity is widely recognised as the presence of two or more concurrent long-term conditions, yet remains a poorly understood global issue despite increasing in prevalence.We have created the Wales Multimorbidity e-Cohort (WMC) to provide an accessible research ready data asset to further the understanding of multimorbidity. Our objectives are to create a platform to support research which would help to understand prevalence, trajectories and determinants in multimorbidity, characterise clusters that lead to highest burden on individuals and healthcare services, and evaluate and provide new multimorbidity phenotypes and algorithms to the National Health Service and research communities to support prevention, healthcare planning and the management of individuals with multimorbidity. METHODS AND ANALYSIS: The WMC has been created and derived from multisourced demographic, administrative and electronic health record data relating to the Welsh population in the Secure Anonymised Information Linkage (SAIL) Databank. The WMC consists of 2.9 million people alive and living in Wales on the 1 January 2000 with follow-up until 31 December 2019, Welsh residency break or death. Published comorbidity indices and phenotype code lists will be used to measure and conceptualise multimorbidity.Study outcomes will include: (1) a description of multimorbidity using published data phenotype algorithms/ontologies, (2) investigation of the associations between baseline demographic factors and multimorbidity, (3) identification of temporal trajectories of clusters of conditions and multimorbidity and (4) investigation of multimorbidity clusters with poor outcomes such as mortality and high healthcare service utilisation. ETHICS AND DISSEMINATION: The SAIL Databank independent Information Governance Review Panel has approved this study (SAIL Project: 0911). Study findings will be presented to policy groups, public meetings, national and international conferences, and published in peer-reviewed journals.

Peritoneal Protein Clearance Is a Function of Local Inflammation and Membrane Area Whereas Systemic Inflammation and Comorbidity Predict Survival of Incident Peritoneal Dialysis Patients.

It is not clear whether the association of increased peritoneal protein clearance (PPCl) with worse survival on peritoneal dialysis (PD) is a consequence of either local or systemic inflammation or indicative of generalized endothelial dysfunction associated with comorbidity. To investigate this we determined the relationship of PPCl to comorbidity, membrane area (equivalent to low molecular weight peritoneal solute transport rate), local and systemic inflammation and hypoalbuminaemia, and for each of these with patient survival. 257 incident patients from three GLOBAL Fluid Study centers were included in this analysis. Clinical profiles were collected at baseline along with a peritoneal equilibration test, 24-h dialysate protein and paired plasma and dialysate cytokine measurements. Although peritoneal protein clearance was associated with increased age and severe comorbidity on univariate analysis, only dialysate IL-6, peritoneal solute transport rate, plasma albumin and cardiac comorbidities (ischaemic heart disease and left ventricular dysfunction) were independent explanatory variables on multivariate analysis. While peritoneal protein clearance and daily peritoneal protein loss were associated with survival in univariate analysis, on multivariate analysis only plasma IL-6, age, residual kidney function, comorbidity, and plasma albumin were independent predictors. Peritoneal protein clearance is primarily a function of peritoneal membrane area and local membrane inflammation. The association with comorbidity and survival is predominantly explained by its inverse relationship to hypoalbuminaemia, especially in diabetics.

Which factors determine treatment choices in patients with advanced kidney failure? a protocol for a co-productive, mixed methods study.

INTRODUCTION: Kidney disease is common, affecting up to 1 in 10 of the adult population, and the numbers are expected to rise over the next decade. There are three main treatments that are available to patients with kidney disease: transplantation, dialysis and supportive care without dialysis. Dialysis can occur in a dialysis unit or in a person's home, but unit-based dialysis remains the most common initial treatment for patients in Wales. This is a cause for concern as most studies suggest that it is associated with the lowest quality of life and the highest mortality, and is a more expensive treatment option.This study aims to identify the factors that lead to patients choosing unit-based haemodialysis rather than home-based dialysis with a view to informing future changes in patient education and service commissioning in Wales. A secondary aim is to determine if the co-production of research leads to more sustainable services. METHODS AND ANALYSIS: This mixed-method study taking place between October 2018 and September 2020 will use a sequential explanatory design whereby the descriptive quantitative cross-sectional analysis of linked health and administrative data sets inform qualitative data collection from patients, carers and health and care professionals. Qualitative findings will be used to interpret or explain quantitative descriptive results. Additional strands to the study include a review of materials and education provided to patients and an economic review of treatment modalities. ETHICS AND DISSEMINATION: The study will be conducted in accordance with the principles expressed in the Declaration of Helsinki. It has full approval from Health and Care Research Wales Research Ethics Committee #5. As a co-productive study involving patients, clinicians, third sector partners and academics, findings from this study will be shared on a continual basis. Study results will be published in peer-reviewed journals and presented at national and international conferences.

Treatment choices for the glycaemic management of patients with type 2 diabetes and chronic kidney disease: Analysis of the SAIL patient linked dataset.

AIMS: Chronic kidney disease (CKD) is common in type 2 diabetes and limits the treatment choices for glycaemic control. Our aim was to examine real-world prescribing for managing hyperglycaemia in the presence of CKD. METHODS: The SAIL (Secure Anonymised Information Linkage) databank was used to examine prescribing during the period from the 1st of January to 30th December 2014. CKD was defined as:- none or mild CKD, eGFR ≥60mL/min/1.73m2; moderate CKD eGFR <60mL/min/1.73m2; and severe CKD eGFR <30mL/min/1.73m2 or requiring dialysis. RESULTS: We identified 9585 subjects who received any form of glucose lowering therapy (8363 had no/mild CKD; 1137 moderate CKD; 85 severe CKD). There was a linear association between insulin use and CKD severity with approximately 54% of those with severe CKD receiving insulin. Sulphonylureas use did not differ among the CKD groups and was approximately 40%. Metformin showed a linear decrease across the groups, however approximately 21% in the severe CKD group received metformin. The use of dipeptidyl peptidase 4 inhibitors (DPP-4i) was approximately 20% and did not differ among groups. The DPP-4 inhibitor choice was:- 1% vildagliptin, 9% saxagliptin, 58% sitagliptin, and 32% linaglitpin. With respect to sitagliptin and saxagliptin, 72% and 62% received an inappropriately high dose in the setting of CKD. CONCLUSIONS: We observed that a considerable proportion of patients with type 2 diabetes and CKD were receiving metformin and non dose-adjusted DPP-4 inhibitors. Careful consideration of medication use and dosaging is required in the setting of CKD and type 2 diabetes.

Biocompatible Solutions and Long-Term Changes in Peritoneal Solute Transport.

BACKGROUND AND OBJECTIVES: The inflammation-driven increase in peritoneal solute transport rate that occurs during long-term peritoneal dialysis is associated with higher mortality, hospitalization, and encapsulating peritoneal sclerosis. Because biocompatible solutions were developed to mitigate these effects, we examined the association with their use and longitudinal peritoneal solute transport rate. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We analyzed subjects from the multinational prospective Global Fluid Study with three or more peritoneal solute transport rate measurements >2 months from the start of peritoneal dialysis. Follow-up was for 7.5 years (median, 2.3 years; interquartile range, 1.8-3.6) in biocompatible solutions and 12.8 years (median, 3.2 years; interquartile range, 1.9-4.3) for standard solutions. Using a random intercept/slopes multilevel model, we examined the association of patients using biocompatible solutions and peritoneal solute transport rate over time, adjusting for center effects, dialysate dextrose concentration, baseline dialysate IL-6 concentration, icodextrin use, residual kidney function, and peritonitis. RESULTS: Of 366 patients, the 71 receiving biocompatible solutions throughout their time on peritoneal dialysis had a mean adjusted dialysate-to-plasma creatinine ratio of 0.67 compared with 0.72 for standard solutions (P=0.02). With duration of treatment, there was a continuous increase in peritoneal solute transport rate in patients using standard solutions (range, 2 months to 4 years). In contrast, patients using biocompatible solutions had peritoneal solute transport rates that plateaued after 2 years of therapy. These changes in peritoneal solute transport rate were independent of baseline inflammation and time-varying predictors of faster peritoneal solute transport rate. In patients suffering episodes of peritonitis while using standard solutions, there was an associated increase in peritoneal solute transport rate of 0.020 (95% confidence interval, 0.01 to 0.03) per episode, whereas in patients using biocompatible solutions, there was no change in this parameter (-0.014; 95% confidence interval, -0.03 to <0.01). CONCLUSIONS: These data suggest that a different temporal pattern in changes in peritoneal solute transport rate occurs during the course of peritoneal dialysis according to solution type and that patients using biocompatible solutions may avoid the increase in solute transport associated with peritonitis.

Acute kidney injury in the UK: a replication cohort study of the variation across three regional populations.

OBJECTIVES: A rapid growth in the reported rates of acute kidney injury (AKI) has led to calls for greater attention and greater resources for improving care. However, the reported incidence of AKI also varies more than tenfold between previous studies. Some of this variation is likely to stem from methodological heterogeneity. This study explores the extent of cross-population variation in AKI incidence after minimising heterogeneity. DESIGN: Population-based cohort study analysing data from electronic health records from three regions in the UK through shared analysis code and harmonised methodology. SETTING: Three populations from Scotland, Wales and England covering three time periods: Grampian 2003, 2007 and 2012; Swansea 2007; and Salford 2012. PARTICIPANTS: All residents in each region, aged 15 years or older. MAIN OUTCOME MEASURES: Population incidence of AKI and AKI phenotype (severity, recovery, recurrence). Determined using shared biochemistry-based AKI episode code and standardised by age and sex. RESULTS: Respectively, crude AKI rates (per 10 000/year) were 131, 138, 139, 151 and 124 (p=0.095), and after standardisation for age and sex: 147, 151, 146, 146 and 142 (p=0.257) for Grampian 2003, 2007 and 2012; Swansea 2007; and Salford 2012. The pattern of variation in crude rates was robust to any modifications of the AKI definition. Across all populations and time periods, AKI rates increased substantially with age from ~20 to ~550 per 10 000/year among those aged <40 and ≥70 years. CONCLUSION: When harmonised methods are used and age and sex differences are accounted for, a similar high burden of AKI is consistently observed across different populations and time periods (~150 per 10 000/year). There are particularly high rates of AKI among older people. Policy-makers should be careful not draw simplistic assumptions about variation in AKI rates based on comparisons that are not rigorous in methodological terms.

Peritoneal Dialysate Glucose Load and Systemic Glucose Metabolism in Non-Diabetics: Results from the GLOBAL Fluid Cohort Study.

BACKGROUND AND OBJECTIVES: Glucose control is a significant predictor of mortality in diabetic peritoneal dialysis (PD) patients. During PD, the local toxic effects of intra-peritoneal glucose are well recognized, but despite large amounts of glucose being absorbed, the systemic effects of this in non-diabetic patients are not clear. We sought to clarify whether dialysate glucose has an effect upon systemic glucose metabolism. METHODS AND MATERIALS: We analysed the Global Fluid Study cohort, a prospective, observational cohort study initiated in 2002. A subset of 10 centres from 3 countries with high data quality were selected (368 incident and 272 prevalent non-diabetic patients), with multilevel, multivariable analysis of the reciprocal of random glucose levels, and a stratified-by-centre Cox survival analysis. RESULTS: The median follow up was 5.6 and 6.4 years respectively in incident and prevalent patients. On multivariate analysis, serum glucose increased with age (ß = -0.007, 95%CI -0.010, -0.004) and decreased with higher serum sodium (ß = 0.002, 95%CI 0.0005, 0.003) in incident patients and increased with dialysate glucose (ß = -0.0002, 95%CI -0.0004, -0.00006) in prevalent patients. Levels suggested undiagnosed diabetes in 5.4% of prevalent patients. Glucose levels predicted death in unadjusted analyses of both incident and prevalent groups but in an adjusted survival analysis they did not (for random glucose 6-10 compared with <6, Incident group HR 0.92, 95%CI 0.58, 1.46, Prevalent group HR 1.42, 95%CI 0.86, 2.34). CONCLUSIONS: In prevalent non-diabetic patients, random glucose levels at a diabetic level are under-recognised and increase with dialysate glucose load. Random glucose levels predict mortality in unadjusted analyses, but this association has not been proven in adjusted analyses.