Catriona Shaw

UK Renal Registry 16th Annual Report: Chapter 2 UK RRT Prevalence in 2012: National and Centre-specific Analyses

Introduction: This chapter describes the characteristics of adult patients on renal replacement therapy (RRT) in the UK in 2012. Methods: Data were electronically collected from all 71 renal centres within the UK. A series of crosssectional and longitudinal analyses were performed to describe the demographics of prevalent RRT patients in 2012 at centre and national level. Results: There were 54,824 adult patients receiving RRT in the UK on 31st December 2012. The UK adult prevalence of RRT was 861 pmp. This represented an annual increase in absolute prevalent numbers of approximately 3.7%, although there was variation between centres and Primary Care and Health Board areas. The actual number of patients increased across all modalities: 2.3% haemodialysis (HD), 0.3% peritoneal dialysis (PD) and 5.6% for those with a functioning transplant. The number of patients receiving home HD has increased by 19.3% since 2011. Median RRT vintage for patients on HD was 3.4 years, PD 1.7 years and for those patients with a transplant, 10.2 years. The median age of prevalent patients was 58 years (HD 66 years, PD 63 years, transplant 52 years) compared to 55 years in 2005. For all ages the prevalence rate in men exceeded that in women. The most common recorded renal diagnosis was glomerulonephritis (biopsy proven/not biopsy proven) (18.8%). Transplantation was the most common treatment modality (50.4%) Conclusions: The HD and transplant population continued to expand; the decline in the size of the prevalent PD population has plateaued. There were national, regional and dialysis centre level variations in prevalence rates. Prevalent patients were on average three years older than the prevalent RRT cohort 7 years ago. This has continued implications for service planning and ensuring equity of care for RRT patients.

UK Renal Registry 15th annual report: Chapter 2 UK RRT prevalence in 2011: national and centre-specific analyses.

Introduction: This chapter describes the characteristics of adult patients on renal replacement therapy (RRT) in the UK in 2011. 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 (HB) in Scotland (PCT/HB areas). Methods: Data were electronically collected from all 71 renal centres within the UK. A series of cross-sectional and longitudinal analyses were performed to describe the demographics of prevalent RRT patients in 2011 at centre and national level. Age and gender standardised ratios for prevalence rates in PCT/ HBs were calculated. Results: There were 53,207 adult patients receiving RRT in the UK on 31st December 2011. The UK adult prevalence of RRT was 842 pmp. This represented an annual increase in prevalent numbers of approximately 4%, although there was variation between centres and PCT/HB areas. The growth rate from 2010 to 2011 for prevalent patients by treatment modality in the UK was an increase of 1.7% for haemodialysis (HD), a fall of 2.2% for peritoneal dialysis (PD) and an increase of 4.7% with a functioning transplant. There has been a slow but steady decline in the proportion of dialysis patients receiving PD since 2000. In contrast, the number of patients receiving home HD has increased 16% since 2010. Median RRT vintage for patients on HD was 3.3 years, PD 1.8 years and for those patients with a transplant, 10.3 years. The median age of prevalent patients was 58.2 years (HD 66.5 years, PD 62.7 years, transplant 51.7 years) compared to 55 years in 2000. For all ages the prevalence rate in men exceeded that in women, peaking in age group 75-79 years at 2,918 pmp in males. For females the peak was in age group 65-69 years at 1,460 pmp. The most common recorded renal diagnosis was glomerulonephritis (biopsy proven/not biopsy proven) (19%), followed by uncertain (18%). Transplantation was the most common treatment modality (48.6%), HD in 43.9% and PD 7.6%. 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. Prevalent patients were on average three years older than 10 years ago. This has implications for service planning and ensuring equity of care for RRT patients.

UK Renal Registry 18th Annual Report 2015

The UK Renal Registry (UKRR) continues to provide a national source of NHS healthcare data on patients dependent on renal replacement therapy (RRT) across the four nations. Using electronic reporting and substantial integration across the 71 adult and 13 paediatric renal centres independent audit and analysis of dialysis and transplant activity and care across the UK is provided. The UKRR is part of the UK Renal Association and is funded directly by participating renal centres through an annual capitation fee per patient per annum, currently £19 or 0.01% of annual RRT running costs. The UKRR remains relatively unique amongst renal registries in publishing both centre-specific analyses of indicators of quality of care, such as haemoglobin and also ageadjusted survival statistics for each renal centre [1].

Inpatient Coronary Angiography and Revascularisation following Non-ST-Elevation Acute Coronary Syndrome in Patients with Renal Impairment: A Cohort Study Using the Myocardial Ischaemia National Audit Project

Background International guidelines support an early invasive management strategy (including early coronary angiography and revascularisation) for non-ST-elevation acute coronary syndrome (NSTE-ACS) in patients with renal impairment. However, evidence from outside the UK suggests that this approach is underutilised. We aimed to describe practice within the NHS, and to determine whether the severity of renal dysfunction influenced the provision of angiography and modified the association between early revascularisation and survival. Methods We performed a cohort study, using multivariable logistic regression and propensity score analyses, of data from the Myocardial Ischaemia National Audit Project for patients presenting with NSTE-ACS to English or Welsh hospitals between 2008 and 2010. Findings Of 35 881 patients diagnosed with NSTE-ACS, eGFR of <60 ml/minute/1.73 m2 was present in 15 680 (43.7%). There was a stepwise decline in the odds of undergoing inpatient angiography with worsening renal dysfunction. Compared with an eGFR>90 ml/minute/1.73 m2, patients with an eGFR between 45–59 ml/minute/1.73 m2 were 33% less likely to undergo angiography (adjusted OR 0.67, 95% CI 0.55–0.81); those with an eGFR<30/minute/1.73 m2 had a 64% reduction in odds of undergoing angiography (adjusted OR 0.36, 95%CI 0.29–0.43). Of 16 646 patients who had inpatient coronary angiography, 58.5% underwent inpatient revascularisation. After adjusting for co-variables, inpatient revascularisation was associated with approximately a 30% reduction in death within 1 year compared with those managed medically after coronary angiography (adjusted OR 0.66, 95%CI 0.57–0.77), with no evidence of modification by renal function (p interaction = 0.744). Interpretation Early revascularisation may offer a similar survival benefit in patients with and without renal dysfunction, yet renal impairment is an important determinant of the provision of coronary angiography following NSTE-ACS. A randomised controlled trial is needed to evaluate the efficacy of an early invasive approach in patients with severe renal dysfunction to ensure that all patients who may benefit are offered this treatment option.

Chapter 4 Comorbidities and Current Smoking Status amongst Patients starting Renal Replacement Therapy in England, Wales and Northern Ireland from 2009 to 2010

Introduction: Comorbidities are an important determinant of survival for patients requiring renal replacement therapy (RRT) and influence other care processes such as dialysis access formation and transplant wait-listing. The prevalence of comorbidities in incident RRT patients 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 2009 and 2010 (n ¼ 6,130) were included in analyses exploring the association of comorbidities with patient demographics, treatment modality, haemoglobin and renal function at start of RRT. For analyses examining association between comorbidities and survival, adult patients starting RRT between 2005 and 2010 in centres reporting to the UKRR with comorbidity data (n ¼ 17,184) were included. The relationship between comorbidities and mortality at 90 days and one year after 90 days from start of RRT were explored using Cox regression. Results: Completeness of comorbidity data was 49.1% in 2010 compared with 48.9% in 2005. Of patients with data, 55.4% had one or more comorbidities. Diabetes mellitus and ischaemic heart disease were the most common conditions, observed in 33.3% and 21.1% of patients respectively. 13.2% of incident RRT patients in the 2-year period were recorded as current smokers. The prevalence of comorbidity increased with increasing age across all ethnic groups. In multivariable survival analysis, malignancy and the presence of ischaemic/neuropathic ulcers were strong 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 generalisability of these analyses continues to be limited by poor data completeness.

Methodological challenges when carrying out research on CKD and AKI using routine electronic health records

Research regarding chronic kidney disease (CKD) and acute kidney injury (AKI) using routinely collected data presents particular challenges. The availability, consistency, and quality of renal data in electronic health records has changed over time with developments in policy, practice incentives, clinical knowledge, and associated guideline changes. Epidemiologic research may be affected by patchy data resulting in an unrepresentative sample, selection bias, misclassification, and confounding by factors associated with testing for and recognition of reduced kidney function. We systematically explore the issues that may arise in study design and interpretation when using routine data sources for CKD and AKI research. First, we discuss how access to health care and management of patients with CKD may have an impact on defining the target population for epidemiologic study. We then consider how testing and recognition of CKD and AKI may lead to biases and how to potentially mitigate against these. Illustrative examples from our own research within the UK are used to clarify key points. Any research using routine renal data has to consider the local clinical context to achieve meaningful interpretation of the study findings.

UK Renal Registry 17th Annual Report: Chapter 8 Biochemical Variables amongst UK Adult Dialysis Patients in 2013: National and Centre-specific Analyses

INTRODUCTION The UK Renal Association clinical practice guidelines include clinical performance measures for biochemical variables in dialysis patients. 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 2013. The biochemical variables studied were phosphate, adjusted calcium, parathyroid hormone and bicarbonate.In addition, longitudinal analyses were performed (2002–2013) to show changes in achievement of clinical performance measures over time. RESULTS Fifty-seven percent of HD and 62% of PD patients achieved a phosphate within the range recommended by the RA clinical practice guidelines. Seventy-eight percent of HD and of PD patients had adjusted calcium between 2.2–2.5 mmol/L. Fifty-seven percent of HD and 63% of PD patients had parathyroid hormone between 16–72 pmol/L. Fifty-nine percent of HD and 79% 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.

Impact of an Early Invasive Strategy versus Conservative Strategy for Unstable Angina and Non-ST Elevation Acute Coronary Syndrome in Patients with Chronic Kidney Disease: A Systematic Review.

Background Clinical practice guidelines support an early invasive approach after NSTE-ACS in patients with chronic kidney disease (CKD). There is no direct randomised controlled trial evidence in the CKD population, and whether the benefit of an early invasive approach is maintained across the spectrum of severity of CKD remains controversial. Methods We conducted a systematic review to evaluate the association between an early invasive approach and all-cause mortality in patients with CKD. We searched MEDLINE and EMBASE (1990-May 2015) and article reference lists. Data describing study design, participants, invasive management strategies, renal function, all-cause mortality and risk of bias were extracted. Results 3,861 potentially relevant studies were identified. Ten studies, representing data on 147,908 individuals with NSTE-ACS met the inclusion criteria. Qualitative heterogeneity in the definitions of early invasive approach, comparison groups and renal dysfunction existed. Meta-analysis of the RCT derived and observational data were generally supportive of an early invasive approach in CKD (RR0.76 (95% CI 0.49–1.17) and RR0.50 (95%CI 0.42–0.59) respectively). Meta-analysis of the observational studies demonstrated a large degree of heterogeneity (I2 79%) driven in part by study size and heterogeneity across various kidney function levels. Conclusions The observational data support that an early invasive approach after NSTE-ACS confers a survival benefit in those with early-moderate CKD. Local opportunities for quality improvement should be sought. Those with severe CKD and the dialysis population are high risk and under-studied. Novel and inclusive approaches for CKD and dialysis patients in cardiovascular clinical trials are needed.

Could sickle cell trait be a predisposing risk factor for CKD

Whilst the needs of individuals with sickle cell disorder (SCD) may be apparent, individuals with sickle cell trait (SCT) are generally reassured that their health will not be affected by their carrier status. Renal failure is a recognized complication of SCD; however, little is known concerning the relationship between SCTand the development of chronic kidney disease (CKD). In this short article, we discuss the rationale for further studies into this area, which we believe could impact on global public health recommendations.

UK Renal Registry 17th Annual Report: Appendix B Definitions and Analysis Criteria

The take-on population is defined as all patients over 18 who started renal replacement therapy (RRT) at UK renal centres and did not have a recovery lasting more than 90 days within 90 days of starting RRT. The treatment timeline is used to define take-on patients as follows. If a patient has timeline entries from more than one centre then these are all combined and sorted by date. Then, the first treatment entry gives the first date of when they received RRT. This is defined as a ‘start date’. However, in the following situations there is evidence that the patient was already receiving RRT before this ‘start date’ and these people are not classed as takeon patients: