The Renal Association, UK Renal Registry - audit application

The UK Renal Registry (UKRR) is part of the Renal Association, a not-for-profit organisation registered with the Charity Commission (https://register-of-charities.charitycommission.gov.uk/charity-search/-/charity-details/800733). The UK Renal Registry is among a number of organisations that form part of the UK Renal Data Collaboration; whose main aim is to improve and standardise the scope and detail of data that is recorded in renal units. The UK Renal Registry is recognised as having one of the very few high quality clinical databases open to requests from researchers. (Researchers can access UKRR audit data only and not data disseminated by NHS England.) The UK Renal Registry collects, analyses and reports on data from 70 adult and 13 paediatric renal centres, as well as hospital laboratories in England. Participation is mandated in England through the NHS National Service Specification and the Chief Executive of each Trust is responsible for adherence to this contract.

The UK Renal Registry was set up as a National Audit in 1995, reaching full coverage of the UK in 2007. Its primary purpose remains national audit. Initially the UK Renal Registry collected data on people receiving dialysis treatment or a kidney transplant, but extended its audit remit in recent years to include:

- All cases of acute kidney injury (AKI) in primary and secondary care from 2015 (following a level 3 Patient Safety Alert issued by NHS England).

- All cases of advanced, pre-dialysis chronic kidney disease (stages 2 to 5) in secondary care from 2016 (at the request of the National Clinical Reference Group).

Reporting of data to the UK Renal Registry is mandated in NHS Commissioning’s Internal medicine - A06 Dialysis Specification (https://www.england.nhs.uk/commissioning/spec-services/npc-crg/group-a/a06/). Internal Medicine is one of six National Programmes of Care (NPoCs) overseeing the commissioning of specialised and highly specialised services. Specialised services support people with a range of rare and complex conditions.

The UK Renal Registry relies on the following legal bases under the General Data Protection Regulation (EU/2016) as incorporated into UK law under the Data Protection Act when processing data for audit purposes:

For processing of general categories of personal data, the UKRR relies on article 6(1)(f) legitimate interests. The UK Renal Registry relies on the legitimate interests of the renal health and social care services in the UK to provide high standards of care to patients with kidney disease or other kidney related illnesses (as defined by service specification A06. Renal Services). Processing personal data is therefore necessary for UKRR's legitimate interests. The data to which access is requested are proportionate and necessary to achieve those interests. UKRR has completed a legitimate interests assessment (LIA) and is satisfied that the interests of the data subjects do not override UKRR’s legitimate interests; that they would reasonably expect the processing and it would not cause unjustified harm. The UKRR closely monitors potential threats to the data it processes and implements appropriate measures and safeguards to minimise the risks, including compliance with the National Data Guardian standards for the secure and appropriate use of patient health and social care information, and pseudonymisation or anonymisation of all patient data.

For processing of special category personal data, the UKRR relies on article 9(2)(h) which allows for special category data to be used for the provision and

management of health management systems. Without this special category data, the UKRR would be unable to conduct the level of in depth analysis that makes the audit an effective tool. The UKRR's audit functions meet Schedule 1 Part 1 Paragraph 2 as the processing is necessary for health and social care purposes. In processing confidential clinical data the UKRR is subject to the standards set by the National Data Guardian for the secure and appropriate use of patient health and social care information.

The Renal Association (the legal entity under which the UK Renal Registry sits) is the sole data controller for the audit functions of the UK Renal Registry, defining both the purposes (albeit based on service specification A06 produced by NHS England) and means of the processing. The Renal Association also processes the data for the audit with its staff processing the data from collection, through validation, to analysis and publication. The Renal Association also engages Arrow Business Communications Limited (ARO) as a data processor for the purposes described in 'Processing Activities'.

It is also recognised that the renal centres across the UK are the respective data controllers of the data submitted to the UK Renal Registry and that the renal IT system providers who assist renal units, are data processors on their behalf. The role of data controller for the respective data sets is transferred from the renal centres to the Renal Association at the point of data submission. There are no other organisations, funders or commissioners involved in the audit function of the Renal Association.

The linkage with data provided by NHS England is to strengthen national audit of renal services by:

- enabling adjustment for case-mix in outcome comparisons (at the moment this is not possible as the UK Renal Registry co-morbidity data are about 50% incomplete).

- establishing lateness of presentation with end-stage kidney disease requiring dialysis/ kidney transplantation (this data is collected already by UK Renal Registry but completeness is less than 80% in 27 of 52 adult renal units in England for the period 1997-2017).

- enabling hospital admissions and length of stay to be compared. Time spent in hospital is a major concern for dialysis patients and varies considerably between renal units.

- enabling the reporting of cause of death, which is currently not completely returned by all centres.

- determining whether rates of AKI (and harm associated with AKI) vary from hospital to hospital and, if so, whether this is explained by different rates of AKI and severity of AKI in the community vs in hospital.

These results will be published in the UK Renal Registry Annual Report, which is circulated to all renal units, their Trust Chief Executives, national kidney patient charities and the specialist commissioners. The AKI outcomes (which are relevant in primary and secondary care) will be reported quarterly to clinical commissioning groups. All outputs (aggregated with small numbers suppressed) will be made available on the Registry’s open-access website.

The Renal Association has a Patient Council that meets every 2-3 months. The Patient Council annually reviews all patient information, such as the privacy notice, information on who the UK Renal Registry is, how patient data are used and information on patient opt-out. The UK Renal Registry is working on an equalities report for and with the Patient Council. The Patient Council also reviews all submitted and approved data applications. Any substantial changes in data access procedures and data flows will be discussed by the Patient Council before a Confidentiality Advisory Group amendment is submitted. The Patient Council initiated the development of an infographic, which is a summary of the annual report in plain English with visual aids making the annual audit report more accessible to patients. All Information Governance incidents, near misses and actions implemented are reported and discussed at patient council meetings.

The use of data provided by NHS England under this agreement renewal is only permitted to be used as part of the UK Renal Registry's audit function. Other agreements between the Renal Association and NHS England may permit re-use of this data for further purposes. The patients from the UK Renal Registry dataset to be linked with HES and mortality data are patients starting renal replacement therapy (dialysis and transplantation), patients with chronic kidney disease (stage 2 to 5) and patients with an acute kidney injury in secondary and primary care. The cohort size for all patients (new and existing) are currently about 2.5 million.

The minimum number of datasets required is requested to perform the audit and quality improvement function of the UK Renal Registry:

- Hospital Episodes Statistics: Civil Registration (Deaths), period up to 2020/21 or most recent to be provided. The Renal Association’s survival and causes of death audit require death information on all patients with chronic kidney disease and acute kidney injury. The UKRR collects information on first start of kidney replacement therapy from 2017 onwards and hold information on patients that have been on kidney replacement treatments for more than 40 years who started on dialysis or transplantation as children and are followed-up over time.

- Hospital Episodes Statistics Admitted Patient Care, period 1997/98 to 2020/21 or most recent. The UK Renal Registry collection of new patients starting kidney replacement therapy started from 1997 onwards and as part of the audit reporting, identifying variation and improvement over time, data is requested from 1997 onwards. Many patients have been on kidney replacement treatments for more than 40 years that started on dialysis or transplantation as children and are followed-up over time. To identify variation and improvement over time for all patients the UK Renal Registry require some HES datasets from 1997 onwards. Historical data are needed to determine comorbidities and new (accrued) comorbidities over time as these have long term effects on outcomes for patients with chronic kidney disease and those with an acute kidney injury.

- Hospital Episodes Statistics Critical Care, period 2014/15 to 2020/21 or most recent. The UK Renal Registry began collecting acute kidney injury data in 2015, so no critical care data requested prior to 2015. Only data items that are relevant to people with kidney disease have been requested.

- Hospital Episodes Statistics Outpatients, period 2003/04 to 2020/21 or most recent. Since outpatient episodes are only available from this date, audit, variation and quality improvement will be limited to this time period. The UK Renal Registry collects data on new kidney replacement starters from 1997 onwards and would ideally have wanted access to Outpatient information from 1997 onwards but will limit analysis on referral patterns and first attendance of pre-dialysis clinics to 2003/04.

Civil Registration of Death - Secondary Care Cut data will be disseminated quarterly. The UK Renal Registry is a registry for acute and chronic kidney disease. We provide audit reports and highlight unwanted variation between kidney centres, including mortality variation in new and existing patients. The UK Renal Registry audit reports are used by NHS England and NHS specialised commissioning for kidney services. It is essential to calculate mortality rates and variation accurately by having access to timely dates of death. It’s also important to know which patients are alive at different points in time to work out accurate patient numbers for audit and so that the UK Renal Registry can ensure all relevant information for the patient is submitted by the kidney centre for audit and commissioning purposes.

Data items requested from HES are mapped to specific audit and quality improvement measures.

Data are only requested for the cohort of patients with chronic kidney disease and acute kidney injury. The UK Renal Registry has in effect already applied a specific diagnosis (chronic kidney disease and acute kidney injury) to the patient cohort supplied to NHS England. The patient cohort will be submitted to NHS England and updated as new patients with chronic kidney disease are seen in kidney centres or people experience a new acute kidney injury. NHS England will apply filtering by linking the UK Renal Registry patient cohort to the required datasets and only data for matching patients will be returned to the UK Renal Registry.

For audit and quality improvement, the information gained from Hospital Episodes Statistics and Civil Registrations data can’t be achieved in a less intrusive way or by using anonymised or pseudonymised HES data:

• The UK Renal Registry has shown that the AKI patients in HES is underreported compared to the AKI biochemical data submitted to the UK Renal Registry via laboratories. So only using anonymised data from HES without a linkage with UK Renal Registry data would underestimate the prevalence of AKI patients.

• The full patient pathway for patients on kidney replacement therapy is also not fully represented in HES as dialysis sessions are not well reported and coded in HES and a linkage with UK Renal Registry data is required.

• The UK Renal Registry has rich data that is required in conjunction with the HES data to effectively perform audit reporting, identifying variation and improvement over time for all patients with kidney disease.

Filtering for geography or demographics such as age can’t be applied as the UK Renal Registry is a national registry having full coverage of the UK and covering all patients with chronic and acute kidney disease. The data is already filtered by the UK Renal Registry for diagnosis, as the UK Renal Registry collects data on patients with a specific diagnosis, namely chronic and acute kidney disease.

Some audit measures do have a timeframe, such as access preparation for starting dialysis, but most audit measures do not and require all patient episodes. For instance, all patient episodes are required to determine new and accrued comorbidities over time as comorbidities have very important long-term effects on outcomes for patients with chronic kidney disease and those with an acute kidney injury. Many patients have been on kidney replacement treatments for a very long time (>40 years) and started on dialysis or transplantation as children and are followed-up over time. To identify variation and improvement over time for these patients all episodes are required.

All analyses involving HES, and Civil Registration Mortality data will be undertaken by substantive employees of the Renal Association who are employed in the UK Renal Registry function. Record level HES and Civil Registration Mortality data will therefore not be released to any external organisation.

All outputs will be at the aggregate level with small numbers suppressed in line with HES analysis guide.

1. National Audit and Quality Improvement: end-stage kidney disease – dialysis, transplantation, and pre-dialysis patients:

Every year, the UK Renal Registry publishes an open access report detailing quality of care at renal unit level. If this renewal is approved, the UKRR-HES and Civil Registration Mortality linked data will be included in some of these chapters, particularly:

- To enable adjustment for case-mix between centres in analyses of survival and attainment of national standards (requires HES). This will be presented in the relevant chapter of the UK Renal Registry Annual Report (i.e., co-morbidity, incidence, prevalence, transplant outcome).

- Co-morbidities present in new and existing dialysis/transplant patients will be presented in a descriptive way in relevant chapters.

- In the other chapters, case-mix will be added as a variable that can be adjusted for in the multi-variable models, so the output does not change much in appearance or format.

- Late presentation to kidney services for patients with chronic kidney disease will be added to relevant chapters and referral pattern variation highlighted between centres. Dialysis Access associated with early or late presentation will also be added to relevant chapters

These open access annual report chapters include survival and attainment of quality indicators by renal unit, which allows renal unit performance to be compared by clinical teams, commissioners, regional teams, and patients. When a renal unit is an outlier for survival, they are written to by UK Renal Registry and must provide evidence that their Chief Executive and Commissioner have been informed and that an investigation has taken place. Being able to adjust for case-mix will make the UK Renal Registry more confident that the outliers are due to practice differences rather than case-mix differences. Target date: annual report/dashboard* published on an annual basis from 2022 onwards, peer reviewed journal 2023.

*Dashboards will display summary results in a tabular and visual format. When summary data from the UKRR-HES linked dataset are displayed, small numbers will be suppressed in line with the HES Analysis guide.

2. To report variation in hospital admission rates between centres (requires HES):

- Patients on dialysis state that time spent in hospital has a major impact on their quality of life. UK Renal Registry would like to include in a regular report/dashboard the differences between centres in rates of admission/re-admissions to hospital, length of stay in hospital and critical care admissions for end-stage kidney disease and acute kidney injury patients. Hospitalisation data would be presented un-adjusted initially and then adjusted for case-mix, including co-morbidity derived from HES data. Target date: annual report/dashboard published on an annual basis from 2022 onwards.

3. To explore differences in cause of death between centres (requires Civil Registration Mortality data):

- Mortality is high for patients on dialysis and following kidney transplantation, with cardiovascular and infection events being the major contributors. At the moment, UK Renal Registry can only compare all-cause mortality between renal units and there are significant differences. As well as being able to adjust for case-mix (see above), being able to explore differences in cardiovascular and infection-related deaths would help focus quality improvement efforts aimed at primary or secondary prevention. Target date: Annual report from 2023 onwards.

These annual report chapters are also written as 'plain English' summaries (with infographics to be included in latest reports) making them more accessible to patients and the public. In 2018, these were published at the same time as the main UK Renal Registry Annual Report on the UK Renal Registry website. Additional information using linked data will be published in the next UK Renal Registry Annual Report.

4. National Audit and Quality Improvement: Acute Kidney Injury (AKI):

In addition, AKI data will be reported to NHS England, commissioners, and NHS Trusts. NHS England invested £2m in the National Programme to improve patient safety and is waiting for the linkage to HES and Civil Registration Mortality data to enable the data to be used to reduce harm from AKI. The UKRR-HES- Civil Registration Mortality data will also be used to drive national quality improvement through the Kidney Quality Improvement Partnership (www.thinkkidneys.nhs.uk/kquip/).

Reporting of the AKI data currently takes the form of:

- An open access website that summarises AKI reporting to UK Renal Registry and is updated monthly.

- An annual AKI report was published on the UK Renal Registry website in 2020 and the information are now published in an AKI dashboard, with some measures updated quarterly and others annually. Target date: annual AKI dashboard from 2022 onwards.

- An AKI laboratory-level report was previously sent to all biochemistry laboratories in England but is now incorporated in the AKI dashboard on the open access website and updated quarterly.

- The AKI rates report at CCG-level previously sent to CCGs is now also available on the UK Renal Registry open access website in the AKI dashboard but by Integrated Care System level and updated quarterly.

The UK Renal Registry have done work on the HES and Civil Registration Mortality linked data to distinguish between AKI that happens in the community and in hospital and results of this analyses was published in the 1st AKI annual report on the UK Renal Registry open access website in 2020. The HES linked data that will be reported in the AKI annual report/dashboard are for instance:

- community and hospital AKI rates and re-admission rates

- mortality associated with AKI in the community and in hospital

- length of stay associated with AKI.

Target date: 2022

5. Meetings and conferences:

UK Renal Registry presents audit data at a number of national meetings including:

1. The Renal Association's and The British Renal Society's Annual Conference 'UK Kidney Week' - attended by nephrologists, scientists, other members of the multi-professional team, and some patients.

2. The National Kidney Federation's annual conference - attended by patients from all over the UK.

As a part of the Kidney Quality Improvement Partnership, the UK Renal Registry holds regional meetings with clinical teams, patients, and commissioners where the regional data is presented and used to focus quality improvement initiatives. Quality improvement regional meetings were severely affected by the Covid-19 pandemic as face-to-face meetings were not possible and virtual meetings affected by clinical staff working in the care of patients. During the Covid-19 pandemic the Renal Association’s Kidney Quality Improvement Partnership (KQuIP) worked within the regions to understand the change in practice patterns, vaccinations and infections and created a weekly heat map for use by commissioners, kidney units and patients. KQuIP supported the submission of Covid-19 infections data that the UK Renal Registry used to publish a weekly report used extensively by commissioners, patients and kidney centres. Before and after the pandemic the KQuIP programme facilitated regional improvement across nine English regions, Wales and the paediatric kidney programme, supporting patients and the multidisciplinary team (MDT) to address variation in services for people with kidney disease.

Regional meetings include representatives from the region and include clinical staff, patients and commissioners. Key variations in services were identified using UK Renal Registry data and focussed on nationally through quality improvement projects aimed at improving access to home dialysis therapies, increase in definitive vascular access rates and an increase in pre-emptive transplantation. Each region chose which area of improvement to focus on. The UK Renal Registry presented relevant regional data at baseline and updated information when it became available. The Renal Association provided leadership and quality improvement training to assist kidney units in the mapping of improvement in a targeted way that is owned locally by clinical teams and patients. On-going data collection that is automated and timely is paramount in evidencing the ongoing improvement at regional level to reflect recommendations in the national GIRFT and Renal Services Transformation Plan. Timely data is used to drive cycles of change with teams being upskilled in the importance of using data for improvements such as creating run charts. Ideas for improvement are tested locally, and learning and outcomes shared regionally to spread successes and overcome challenges.

The data provided by NHS England is permitted for use as part of the UK Renal Registry's audit function under the terms of this agreement. Other agreements between the Renal Association and NHS England may permit re-use of this data for further purposes.

1. Use of the HES and Civil Registration Mortality data to report centre-level differences in case-mix adjustment for end-stage kidney disease patients:

- Case mix adjustment for survival outcomes was published in the 24th, 25th and 26th UK Renal Registry annual report in 2020, 2021, and 2022 respectively. The number of outlying centres reduced following case-mix adjustment and highlighted possible practice differences in survival outcomes. Benefit to patients: the reduction in the number of kidney centres that are survival outliers means that there are fewer centres that have lower than expected survival, given the size and characteristics of the patients they treat. There is a Renal Association process for centres to follow when they are a survival outlier with lower-than-expected survival: they need to inform the Trust’s Chief Executive, Clinical Governance Lead and the Commissioner of their survival outlier status. Internally the centre reviews their clinical practice and implement strategies to improve patient care. The HES survival case-mix adjustment and notification process improved standards of patient care and survival over time for patients with chronic kidney disease.

2. Use of the HES and Civil Registration Mortality data to report centre-level differences hospital admission rates between centres:

- Inpatient and outpatient days by treatment modality. GIRFT renal report 2020 and 2021, UK Renal Registry ESKD Data Portal 2022. Benefit to patients: The GIRFT national report used the results and published recommendations on outpatient services relating to equity of access and timeliness. For example, Trusts should ensure equity of patient access to sub-specialty renal clinics within each regional network. Recommendations were published for inpatient services relating to reporting patterns of hospitalisation identifying unwarranted variation between trusts, access to healthcare professional support and services to reduce hospitalisations and renal services to implement initiatives to better understand factors that drive hospitalisation in kidney care. These recommendations are being implemented in kidney centres and improve standards of care for patients and access to health services including as part of the quality improvement programmes run by the Renal Association.

- Access and re-intervention procedures prior and after start of HD and PD by late/early presentation to renal services, GIRFT renal report 2020 and 2021. Benefit to patients: The GIRFT national report used the results and published recommendations on vascular access for haemodialysis patients relating to the day case surgery rate for arteriovenous fistula/graft and reducing variation in definitive haemodialysis vascular access rates. These recommendations are being implemented in kidney centres, improving patient care and outcomes.

The following abstracts were presented, and papers published:

3.Use of the HES and Civil Registration Mortality data to publish measures of care and highlight variation in acute kidney injury patients:

- Length of stay in hospital for people with AKI electronic alerts. AKI annual report 2022. Benefit to patients: Findings showed that 68% of patients with an AKI episode had a hospital stay. These results have important implications for the detection and earlier treatment of AKI patients in primary care.

- Mortality following post-hospitalisation AKI. AKI annual report 2022. Benefit to patients: 19% of patients with an AKI episode died within 30 days of the first alert and mortality increased with age and AKI stage. A seasonal pattern is seen in AKI deaths. These findings contribute to the identification of high-risk patients in both primary and secondary care.

The following abstracts were presented, and papers published:

- Acute kidney injury identification: use of electronic AKI alerts versus electronic health records in Hospital Episode Statistics. UK Kidney week abstract 2020. Benefit to patients: The aim of the project was to determine whether episodes of AKI identified in the UKRR Master Patient Index correspond to coded diagnoses on the discharge record held in HES. Results showed that the use of HES to identify cases of AKI is likely to underestimate the incidence of AKI, especially for AKI stage 1, though a high proportion of the most severe cases will be captured. Improvements in data capture and reporting of AKI alerts has already better-informed NHS commissioning.

- Epidemiology of childhood acute kidney injury in England using e-alerts. Published paper 2023. Benefit to patients: The aim of this project was to describe a national cohort of children who received an AKI warning and their clinical course. Over half of AKI episodes in children were associated with hospitalisation. AKI is frequently seen in children with co-existing disease and higher length of stay, admission to critical care and death within 30 days more frequently seen among youngest children. These are novel findings in children which leads to better understanding of AKI and clinical outcomes for children.

- Do outcomes for hospitalized patients with an Acute Kidney Injury (AKI) vary across specialties in England? Published 2023. Benefit to patients: the aim was to determine if 30-day mortality differ by speciality. Results show that treatment specially was associated with mortality of patients who develop an AKI post admission. This finding contributes to better management of patients in hospital and improvements in AKI patient care.

- Centre variation in length of stay following post-hospitalisation acute kidney injury: analysis of a large national cohort. Poster at UKKA AKI meeting 2023. Benefit to patients: Routine monitoring of outcomes for patients with acute kidney injury is important to drive ongoing quality improvement in patient care. This work identified unwarranted variation in length of stay that was not explained by patient characteristics, readmission rates or delayed transfer of care. Centres identified as outliers need to interrogate local care pathways to understand and address reasons for the high mortality. ]

- A National audit of the care of patients with acute kidney injury in England and Wales in 2019 and the association with patient outcomes. Published paper 2024. Benefit to patients: This paper summarises the finding from a national audit that assessed the care received by patients with AKI in 24 hospital Trusts. The audit highlighted variation in attainment of important AKI-care standards, and their association with mortality, indicating more work is needed to assess whether improving and standardising care improves patient outcomes.

- Long-term kidney failure following acute kidney injury in a national cohort of children. UK Kidney Week poster 2024. Benefit to patients: This was the first national study to examine the association between AKI and long-term kidney failure in children, and will support clinicians in assessing long-term prognosis following AKI. Interventions to reduce AKI disease progression may help lower the incidence of long-term

kidney failure.

- Seasonal mortality trends for hospitalised patients with acute kidney injury across England. Paper published 2023. Benefit to patients: Measurement of AKI incidence and outcomes has frequently been described as a valuable patient safety barometer for NHS hospitals. The excess mortality risk in winter may reflect higher pressure on NHS services. Trusts that were identified as high outliers in the analysis may benefit from further review to better understand and address factors that may be contributing to excess winter mortality risk for their AKI patients. Conversely, trusts without excess winter AKI mortality could share their experience and best practice in order to improve performance of less well performing trusts.

-Acute kidney injury in a national cohort of children who have undergone a kidney transplant. epidemiology and outcomes. UK Kidney Week poster 2023. This work showed that AKI was a common event in a 5-year period with most AKI episodes being initially detected outside of hospital settings and most requiring subsequent hospitalisation and almost 10% with an AKI episode required dialysis within 30 days. This finding improves our understanding of the risk of AKI and associated outcomes in transplanted children.

- People coded with delirium are overrepresented in people in hospital with acute kidney injury – A UKRR cross-sectional study. UK Kidney Week oral presentation 2023. Benefit to patients: This study showed that delirium is a common co-morbidity in hospitalised patients with AKI which impacts considerably on the subsequent length of stay, readmission rates and mortality. The findings demonstrate that addressing delirium should be a key target for quality improvement initiatives amongst people with AKI.

4.Use of the HES and Civil Registration Mortality data to assess data capture

- The spectrum of co-existing disease in children with established kidney failure using registry and linked electronic health record data. Paper published 2024. Benefit to patients: This study examined the prevalence of comorbidities in children on kidney replacement therapy, comparing what is captured in the electronic hospital record versus the UK Renal Registry (UKRR), to ascertain validity and quality of data which are fundamental when auditing patient care.

- Uncovering the uncaptured: Exploring characteristics and outcomes of Acute Kidney Injury (AKI) cases overlooked by the NHS England AKI algorithm due to missing baseline creatinine. UK Kidney Week poster 2024. Benefit to patients: The study found that while one-third of patients were rechecked as recommended within 14 days, another third did not undergo rechecking within a year, highlighting a gap in care.

- Causes of death in a national cohort of children receiving kidney replacement therapy. UK Kidney Week poster 2024. Benefit to patients: This study identified that infection and cardiac di

The UK Renal Registry (UKRR) is part of the Renal Association, a not-for-profit organisation registered with the Charity Commission (https://register-of-charities.charitycommission.gov.uk/charity-search/-/charity-details/800733). The UK Renal Registry is among a number of organisations that form part of the UK Renal Data Collaboration; whose main aim is to improve and standardise the scope and detail of data that is recorded in renal units. The UK Renal Registry is recognised as having one of the very few high quality clinical databases open to requests from researchers. (Researchers can access UKRR audit data only and not data disseminated by NHS Digital.) The UK Renal Registry collects, analyses and reports on data from 70 adult and 13 paediatric renal centres, as well as hospital laboratories in England. Participation is mandated in England through the NHS National Service Specification and the Chief Executive of each Trust is responsible for adherence to this contract.

The UK Renal Registry was set up as a National Audit in 1995, reaching full coverage of the UK in 2007. Its primary purpose remains national audit. Initially the UK Renal Registry collected data on people receiving dialysis treatment or a kidney transplant, but extended its audit remit in recent years to include:

- All cases of acute kidney injury (AKI) in primary and secondary care from 2015 (following a level 3 Patient Safety Alert issued by NHS England).

- All cases of advanced, pre-dialysis chronic kidney disease (stages 2 to 5) in secondary care from 2016 (at the request of the National Clinical Reference Group).

Reporting of data to the UK Renal Registry is mandated in NHS Commissioning’s Internal medicine - A06 Dialysis Specification (https://www.england.nhs.uk/commissioning/spec-services/npc-crg/group-a/a06/). Internal Medicine is one of six National Programmes of Care (NPoCs) overseeing the commissioning of specialised and highly specialised services. Specialised services support people with a range of rare and complex conditions.

The UK Renal Registry relies on the following legal bases under the General Data Protection Regulation (EU/2016) as incorporated into UK law under the Data Protection Act when processing data for audit purposes:

For processing of general categories of personal data, the UKRR relies on article 6(1)(f) legitimate interests. The UK Renal Registry relies on the legitimate interests of the renal health and social care services in the UK to provide high standards of care to patients with kidney disease or other kidney related illnesses (as defined by service specification A06. Renal Services). Processing personal data is therefore necessary for UKRR's legitimate interests. The data to which access is requested are proportionate and necessary to achieve those interests. UKRR has completed a legitimate interests assessment (LIA) and is satisfied that the interests of the data subjects do not override UKRR’s legitimate interests; that they would reasonably expect the processing and it would not cause unjustified harm. The UKRR closely monitors potential threats to the data it processes and implements appropriate measures and safeguards to minimise the risks, including compliance with the National Data Guardian standards for the secure and appropriate use of patient health and social care information, and pseudonymisation or anonymisation of all patient data.

For processing of special category personal data, the UKRR relies on article 9(2)(h) which allows for special category data to be used for the provision and

management of health management systems. Without this special category data, the UKRR would be unable to conduct the level of in depth analysis that makes the audit an effective tool. The UKRR's audit functions meet Schedule 1 Part 1 Paragraph 2 as the processing is necessary for health and social care purposes. In processing confidential clinical data the UKRR is subject to the standards set by the National Data Guardian for the secure and appropriate use of patient health and social care information.

The Renal Association (the legal entity under which the UK Renal Registry sits) is the sole data controller for the audit functions of the UK Renal Registry, defining both the purposes (albeit based on service specification A06 produced by NHS England) and means of the processing. The Renal Association also processes the data for the audit with its staff processing the data from collection, through validation, to analysis and publication. The Renal Association also engages North Bristol NHS Trust and AIMES as data processors for the purposes described in 'Processing Activities'.

It is also recognised that the renal centres across the UK are the respective data controllers of the data submitted to the UK Renal Registry and that the renal IT system providers who assist renal units, are data processors on their behalf. The role of data controller for the respective data sets is transferred from the renal centres to the Renal Association at the point of data submission. There are no other organisations, funders or commissioners involved in the audit function of the Renal Association.

The linkage with data provided by NHS Digital is to strengthen national audit of renal services by:

- enabling adjustment for case-mix in outcome comparisons (at the moment this is not possible as the UK Renal Registry co-morbidity data are about 50% incomplete).

- establishing lateness of presentation with end-stage kidney disease requiring dialysis/ kidney transplantation (this data is collected already by UK Renal Registry but completeness is less than 80% in 27 of 52 adult renal units in England for the period 1997-2017).

- enabling hospital admissions and length of stay to be compared. Time spent in hospital is a major concern for dialysis patients and varies considerably between renal units.

- enabling the reporting of cause of death, which is currently not completely returned by all centres.

- determining whether rates of AKI (and harm associated with AKI) vary from hospital to hospital and, if so, whether this is explained by different rates of AKI and severity of AKI in the community vs in hospital.

These results will be published in the UK Renal Registry Annual Report, which is circulated to all renal units, their Trust Chief Executives, national kidney patient charities and the specialist commissioners. The AKI outcomes (which are relevant in primary and secondary care) will be reported quarterly to clinical commissioning groups. All outputs (aggregated with small numbers suppressed) will be made available on the Registry’s open-access website.

The Renal Association has a Patient Council that meets every 2-3 months. The Patient Council annually reviews all patient information, such as the privacy notice, information on who the UK Renal Registry is, how patient data are used and information on patient opt-out. The UK Renal Registry is working on an equalities report for and with the Patient Council. The Patient Council also reviews all submitted and approved data applications. Any substantial changes in data access procedures and data flows will be discussed by the Patient Council before a Confidentiality Advisory Group amendment is submitted. The Patient Council initiated the development of an infographic, which is a summary of the annual report in plain English with visual aids making the annual audit report more accessible to patients. All Information Governance incidents, near misses and actions implemented are reported and discussed at patient council meetings.

The use of data provided by NHS Digital under this agreement renewal is only permitted to be used as part of the UK Renal Registry's audit function. Other agreements between the Renal Association and NHS Digital may permit re-use of this data for further purposes. The patients from the UK Renal Registry dataset to be linked with HES and mortality data are patients starting renal replacement therapy (dialysis and transplantation), patients with chronic kidney disease (stage 2 to 5) and patients with an acute kidney injury in secondary and primary care. The cohort size for all patients (new and existing) are currently about 2.5 million.

The minimum number of datasets required is requested to perform the audit and quality improvement function of the UK Renal Registry:

- Hospital Episodes Statistics: Civil Registration (Deaths), period up to 2020/21 or most recent to be provided. The Renal Association’s survival and causes of death audit require death information on all patients with chronic kidney disease and acute kidney injury. The UKRR collects information on first start of kidney replacement therapy from 2017 onwards and hold information on patients that have been on kidney replacement treatments for more than 40 years who started on dialysis or transplantation as children and are followed-up over time.

- Hospital Episodes Statistics Admitted Patient Care, period 1997/98 to 2020/21 or most recent. The UK Renal Registry collection of new patients starting kidney replacement therapy started from 1997 onwards and as part of the audit reporting, identifying variation and improvement over time, data is requested from 1997 onwards. Many patients have been on kidney replacement treatments for more than 40 years that started on dialysis or transplantation as children and are followed-up over time. To identify variation and improvement over time for all patients the UK Renal Registry require some HES datasets from 1997 onwards. Historical data are needed to determine comorbidities and new (accrued) comorbidities over time as these have long term effects on outcomes for patients with chronic kidney disease and those with an acute kidney injury.

- Hospital Episodes Statistics Critical Care, period 2014/15 to 2020/21 or most recent. The UK Renal Registry began collecting acute kidney injury data in 2015, so no critical care data requested prior to 2015. Only data items that are relevant to people with kidney disease have been requested.

- Hospital Episodes Statistics Outpatients, period 2003/04 to 2020/21 or most recent. Since outpatient episodes are only available from this date, audit, variation and quality improvement will be limited to this time period. The UK Renal Registry collects data on new kidney replacement starters from 1997 onwards and would ideally have wanted access to Outpatient information from 1997 onwards but will limit analysis on referral patterns and first attendance of pre-dialysis clinics to 2003/04.

Data items requested from HES are mapped to specific audit and quality improvement measures.

Data are only requested for the cohort of patients with chronic kidney disease and acute kidney injury. The UK Renal Registry has in effect already applied a specific diagnosis (chronic kidney disease and acute kidney injury) to the patient cohort supplied to NHS Digital. The patient cohort will be submitted to NHS Digital and updated as new patients with chronic kidney disease are seen in kidney centres or people experience a new acute kidney injury. NHS Digital will apply filtering by linking the UK Renal Registry patient cohort to the required datasets and only data for matching patients will be returned to the UK Renal Registry.

For audit and quality improvement, the information gained from Hospital Episodes Statistics and Civil Registrations data can’t be achieved in a less intrusive way or by using anonymised or pseudonymised HES data:

• The UK Renal Registry has shown that the AKI patients in HES is underreported compared to the AKI biochemical data submitted to the UK Renal Registry via laboratories. So only using anonymised data from HES without a linkage with UK Renal Registry data would underestimate the prevalence of AKI patients.

• The full patient pathway for patients on kidney replacement therapy is also not fully represented in HES as dialysis sessions are not well reported and coded in HES and a linkage with UK Renal Registry data is required.

• The UK Renal Registry has rich data that is required in conjunction with the HES data to effectively perform audit reporting, identifying variation and improvement over time for all patients with kidney disease.

Filtering for geography or demographics such as age can’t be applied as the UK Renal Registry is a national registry having full coverage of the UK and covering all patients with chronic and acute kidney disease. The data is already filtered by the UK Renal Registry for diagnosis, as the UK Renal Registry collects data on patients with a specific diagnosis, namely chronic and acute kidney disease.

Some audit measures do have a timeframe, such as access preparation for starting dialysis, but most audit measures do not and require all patient episodes. For instance, all patient episodes are required to determine new and accrued comorbidities over time as comorbidities have very important long-term effects on outcomes for patients with chronic kidney disease and those with an acute kidney injury. Many patients have been on kidney replacement treatments for a very long time (>40 years) and started on dialysis or transplantation as children and are followed-up over time. To identify variation and improvement over time for these patients all episodes are required.

All analyses involving HES, and Civil Registration Mortality data will be undertaken by substantive employees of the Renal Association who are employed in the UK Renal Registry function. Record level HES and Civil Registration Mortality data will therefore not be released to any external organisation.

All outputs will be at the aggregate level with small numbers suppressed in line with HES analysis guide.

1. National Audit and Quality Improvement: end-stage kidney disease – dialysis, transplantation, and pre-dialysis patients:

Every year, the UK Renal Registry publishes an open access report detailing quality of care at renal unit level. If this renewal is approved, the UKRR-HES and Civil Registration Mortality linked data will be included in some of these chapters, particularly:

- To enable adjustment for case-mix between centres in analyses of survival and attainment of national standards (requires HES). This will be presented in the relevant chapter of the UK Renal Registry Annual Report (i.e., co-morbidity, incidence, prevalence, transplant outcome).

- Co-morbidities present in new and existing dialysis/transplant patients will be presented in a descriptive way in relevant chapters.

- In the other chapters, case-mix will be added as a variable that can be adjusted for in the multi-variable models, so the output does not change much in appearance or format.

- Late presentation to kidney services for patients with chronic kidney disease will be added to relevant chapters and referral pattern variation highlighted between centres. Dialysis Access associated with early or late presentation will also be added to relevant chapters

These open access annual report chapters include survival and attainment of quality indicators by renal unit, which allows renal unit performance to be compared by clinical teams, commissioners, regional teams, and patients. When a renal unit is an outlier for survival, they are written to by UK Renal Registry and must provide evidence that their Chief Executive and Commissioner have been informed and that an investigation has taken place. Being able to adjust for case-mix will make the UK Renal Registry more confident that the outliers are due to practice differences rather than case-mix differences. Target date: annual report/dashboard* published on an annual basis from 2022 onwards, peer reviewed journal 2023.

*Dashboards will display summary results in a tabular and visual format. When summary data from the UKRR-HES linked dataset are displayed, small numbers will be suppressed in line with the HES Analysis guide.

2. To report variation in hospital admission rates between centres (requires HES):

- Patients on dialysis state that time spent in hospital has a major impact on their quality of life. UK Renal Registry would like to include in a regular report/dashboard the differences between centres in rates of admission/re-admissions to hospital, length of stay in hospital and critical care admissions for end-stage kidney disease and acute kidney injury patients. Hospitalisation data would be presented un-adjusted initially and then adjusted for case-mix, including co-morbidity derived from HES data. Target date: annual report/dashboard published on an annual basis from 2022 onwards.

3. To explore differences in cause of death between centres (requires Civil Registration Mortality data):

- Mortality is high for patients on dialysis and following kidney transplantation, with cardiovascular and infection events being the major contributors. At the moment, UK Renal Registry can only compare all-cause mortality between renal units and there are significant differences. As well as being able to adjust for case-mix (see above), being able to explore differences in cardiovascular and infection-related deaths would help focus quality improvement efforts aimed at primary or secondary prevention. Target date: Annual report from 2023 onwards.

These annual report chapters are also written as 'plain English' summaries (with infographics to be included in latest reports) making them more accessible to patients and the public. In 2018, these were published at the same time as the main UK Renal Registry Annual Report on the UK Renal Registry website. Additional information using linked data will be published in the next UK Renal Registry Annual Report.

4. National Audit and Quality Improvement: Acute Kidney Injury (AKI):

In addition, AKI data will be reported to NHS England, commissioners, and NHS Trusts. NHS England invested £2m in the National Programme to improve patient safety and is waiting for the linkage to HES and Civil Registration Mortality data to enable the data to be used to reduce harm from AKI. The UKRR-HES- Civil Registration Mortality data will also be used to drive national quality improvement through the Kidney Quality Improvement Partnership (www.thinkkidneys.nhs.uk/kquip/).

Reporting of the AKI data currently takes the form of:

- An open access website that summarises AKI reporting to UK Renal Registry and is updated monthly.

- An annual AKI report was published on the UK Renal Registry website in 2020 and the information are now published in an AKI dashboard, with some measures updated quarterly and others annually. Target date: annual AKI dashboard from 2022 onwards.

- An AKI laboratory-level report was previously sent to all biochemistry laboratories in England but is now incorporated in the AKI dashboard on the open access website and updated quarterly.

- The AKI rates report at CCG-level previously sent to CCGs is now also available on the UK Renal Registry open access website in the AKI dashboard but by Integrated Care System level and updated quarterly.

The UK Renal Registry have done work on the HES and Civil Registration Mortality linked data to distinguish between AKI that happens in the community and in hospital and results of this analyses was published in the 1st AKI annual report on the UK Renal Registry open access website in 2020. The HES linked data that will be reported in the AKI annual report/dashboard are for instance:

- community and hospital AKI rates and re-admission rates

- mortality associated with AKI in the community and in hospital

- length of stay associated with AKI.

Target date: 2022

5. Meetings and conferences:

UK Renal Registry presents audit data at a number of national meetings including:

1. The Renal Association's and The British Renal Society's Annual Conference 'UK Kidney Week' - attended by nephrologists, scientists, other members of the multi-professional team, and some patients.

2. The National Kidney Federation's annual conference - attended by patients from all over the UK.

As a part of the Kidney Quality Improvement Partnership, the UK Renal Registry holds regional meetings with clinical teams, patients, and commissioners where the regional data is presented and used to focus quality improvement initiatives. Quality improvement regional meetings were severely affected by the Covid-19 pandemic as face-to-face meetings were not possible and virtual meetings affected by clinical staff working in the care of patients. During the Covid-19 pandemic the Renal Association’s Kidney Quality Improvement Partnership (KQuIP) worked within the regions to understand the change in practice patterns, vaccinations and infections and created a weekly heat map for use by commissioners, kidney units and patients. KQuIP supported the submission of Covid-19 infections data that the UK Renal Registry used to publish a weekly report used extensively by commissioners, patients and kidney centres. Before and after the pandemic the KQuIP programme facilitated regional improvement across nine English regions, Wales and the paediatric kidney programme, supporting patients and the multidisciplinary team (MDT) to address variation in services for people with kidney disease.

Regional meetings include representatives from the region and include clinical staff, patients and commissioners. Key variations in services were identified using UK Renal Registry data and focussed on nationally through quality improvement projects aimed at improving access to home dialysis therapies, increase in definitive vascular access rates and an increase in pre-emptive transplantation. Each region chose which area of improvement to focus on. The UK Renal Registry presented relevant regional data at baseline and updated information when it became available. The Renal Association provided leadership and quality improvement training to assist kidney units in the mapping of improvement in a targeted way that is owned locally by clinical teams and patients. On-going data collection that is automated and timely is paramount in evidencing the ongoing improvement at regional level to reflect recommendations in the national GIRFT and Renal Services Transformation Plan. Timely data is used to drive cycles of change with teams being upskilled in the importance of using data for improvements such as creating run charts. Ideas for improvement are tested locally, and learning and outcomes shared regionally to spread successes and overcome challenges.

The data provided by NHS Digital is permitted for use as part of the UK Renal Registry's audit function under the terms of this agreement. Other agreements between the Renal Association and NHS Digital may permit re-use of this data for further purposes.

1. Use of the HES and Civil Registration Mortality data to report centre-level differences in case-mix adjustment for end-stage kidney disease patients:

- Case mix adjustment for survival outcomes was published in the 22nd and 23rd UK Renal Registry annual report in 2020 and 2021. The number of outlying centres reduced following case-mix adjustment and highlighted possible practice differences in survival outcomes. Benefit to patients: the reduction in the number of kidney centres that are survival outliers means that there are fewer centres that have lower than expected survival, given the size and characteristics of the patients they treat. There is a Renal Association process for centres to follow when they are a survival outlier with lower-than-expected survival: they need to inform the Trust’s Chief Executive, Clinical Governance Lead and the Commissioner of their survival outlier status. Internally the centre reviews their clinical practice and implement strategies to improve patient care. The HES survival case-mix adjustment and notification process improved standards of patient care and survival over time for patients with chronic kidney disease.

2. Use of the HES and Civil Registration Mortality data to report centre-level differences hospital admission rates between centres:

- Inpatient and outpatient days by treatment modality. GIRFT renal report 2020 and 2021, UK Renal Registry CKD Annual Report 2021. Benefit to patients: The GIRFT national report used the results and published recommendations on outpatient services relating to equity of access and timeliness. For example, Trusts should ensure equity of patient access to sub-specialty renal clinics within each regional network. Recommendations were published for inpatient services relating to reporting patterns of hospitalisation identifying unwarranted variation between trusts, access to healthcare professional support and services to reduce hospitalisations and renal services to implement initiatives to better understand factors that drive hospitalisation in kidney care. These recommendations are being implemented in kidney centres and improve standards of care for patients and access to health services including as part of the quality improvement programmes run by the Renal Association.

- Access and re-intervention procedures prior and after start of HD and PD by late/early presentation to renal services, GIRFT renal report 2020 and 2021. Benefit to patients: The GIRFT national report used the results and published recommendations on vascular access for haemodialysis patients relating to the day case surgery rate for arteriovenous fistula/graft and reducing variation in definitive haemodialysis vascular access rates. These recommendations are being implemented in kidney centres, improving patient care and outcomes.

The following abstracts were presented, and papers published:

- Annual burden of emergency hospital admissions for patients on Renal Replacement Therapy. UK Kidney week abstract 2020. Benefit to patients: There is a high burden of hospitalisation for patients on all three kidney replacement therapy modalities, but particularly in patients on dialysis. PD patients, those in more deprived socio-economic groups, aged over 60, Caucasian ethnicity and female gender are at higher risk of admission. Complications associated with dialysis access and infections appear to form the bulk of admissions. These findings contribute to improvements in patient care, especially for dialysis access complications and infection prevention and control.

- Incidence and risk factors for amputation within 5 years of commencing dialysis in England. UK Kidney week abstract 2020. Benefit to patients: this study set out to report, for the first time, incidence, risk factors and unwarranted renal centre variation in rates of lower limb amputation (LLA) for patients on dialysis in England – selected by GIRFT as an important care quality metric for kidney units. Findings highlighted rates of LLA in dialysis patients with diabetes are high, with considerable National variation. Provision of high-quality foot care for diabetic patients on dialysis must be prioritised to minimise the significant burden of LLA for our patients. Recommendations from the GIRFT report are being implemented to reduce variation in amputation rates and optimise care for dialysis patients with diabetes.

- English transplant centre variation in early (30 day) and late (365 day) readmission rates following renal transplantation. Kidney week abstract 2020. Benefit to patients: Study findings show that 1/5 adult renal transplant recipients in England require emergency hospital readmission (EHR) within 30 days of their surgery. Over ½ will have at least one EHR within the first-year post-transplant. Recipients of deceased donor (DD) and living donor kidneys had similar EHR rates at 30 days but by 365 days recipients of a DD kidney had a higher EHR rate. Female sex, age over 60 and social deprivation are all risk factors for admission. These findings contribute to a better understanding of factors underlying variation and helps kidney services to reduce emergency post renal transplant readmissions. These findings formed part of the GIRFT renal report, which recommended that analysis of hospitalisation data form part of routine quality assurance.

3.Use of the HES and Civil Registration Mortality data to publish measures of care and highlight variation in acute kidney injury patients:

- Emergency and elective AKI admissions rates by hospital. AKI annual report 2020. Benefit to patients: Results showed that the AKI rate was particularly high in people admitted to hospital as an emergency compared to elective admissions. Greater understanding of the risk of AKI and identification of hospitals with particularly high rates helps to improve AKI patient care and treatment for emergency admissions.

- Length of stay in hospital for people with AKI electronic alerts. AKI annual report 2020. Benefit to patients: Findings showed that 71% of patients with an AKI episode had a hospital stay. These results have important implications for the detection and earlier treatment of AKI patients in primary care.

- Mortality following post-hospitalisation AKI. AKI annual report 2020. Benefit to patients: 18% of patients with an AKI episode died within 30 days of the first alert and mortality increased with age and AKI stage. A seasonal pattern is seen in AKI deaths. These findings contribute to the identification of high-risk patients in both primary and secondary care.

The following abstracts were presented, and papers published:

- Acute kidney injury identification: use of electronic AKI alerts versus electronic health records in Hospital Episode Statistics. UK Kidney week abstract 2020. Benefit to patients: The aim of the project was to determine whether episodes of AKI identified in the UKRR Master Patient Index correspond to coded diagnoses on the discharge record held in HES. Results showed that the use of HES to identify cases of AKI is likely to underestimate the incidence of AKI, especially for AKI stage 1, though a high proportion of the most severe cases will be captured. Improvements in data capture and reporting of AKI alerts has already better informed NHS commissioning.

- Acute kidney injury in a national cohort of children: epidemiology and outcomes using linked electronic health data. UK Kidney week abstract 2020. Benefit to patients: The aim of this project was to describe a national cohort of children who received an AKI warning and their clinical course. Over half of AKI episodes in children were associated with hospitalisation. AKI is frequently seen in children with co-existing disease and higher length of stay, admission to critical care and death within 30 days more frequently seen among youngest children. These are novel findings in children which leads to better understanding of AKI and clinical outcomes for children.

- Do outcomes for hospitalized patients with an Acute Kidney Injury (AKI) vary across specialties in England? UK Kidney week abstract 2020. Benefit to patients: the aim was to determine if 30-day mortality differ by speciality. Results show that treatment specially was associated with mortality of patients who develop an AKI post admission. This finding contributes to better management of patients in hospital and improvements in AKI patient care.

- Acute kidney injury (AKI) identification for pharmacoepidemiologic studies: use of laboratory electronic AKI alerts versus electronic health records in Hospital Episode Statistics (HES). Published paper 2021. Benefit to patients: The aim of this study was to determine the degree of correspondence between the UKRR-MPI and AKI International Classification Disease-10 (ICD-10) N17 coding in Hospital Episode Statistics (HES) and whether hospital N17 coding correlated with 30-day mortality and emergency re-admission after AKI. Coding of AKI in HES is influenced by many factors that result in an underestimation of AKI. Using e-alerts to triangulate the true incidence of AKI could provide a better understanding of the factors that affect hospital coding, potentially leading to improved coding, patient care and pharmacoepidemiologic research.

- Centre variation in mortality following post-hospitalisation acute kidney injury: analysis of a large national cohort. Published paper 2022. Benefit to patients: Routine monitoring of outcomes for patients with acute kidney injury is important to drive ongoing quality improvement in patient care. The paper demonstrated the considerable risk associated with developing even mild elevations in serum creatinine and identified unwarranted variation in mortality rates. Centres identified as outliers need to interrogate local care pathways to understand and address reasons for the high mortality. This metric and methodology has been approved for the ‘Model Hospital’.

The UK Renal Registry (UKRR) is part of the Renal Association, a not-for-profit organisation registered with the Charity Commission (https://register-of-charities.charitycommission.gov.uk/charity-search/-/charity-details/800733). The UK Renal Registry is among a number of organisations that form part of the UK Renal Data Collaboration; whose main aim is to improve and standardise the scope and detail of data that is recorded in renal units. The UK Renal Registry is recognised as having one of the very few high quality clinical databases open to requests from researchers. (Researchers can access UKRR audit data only and not data disseminated by NHS Digital.) The UK Renal Registry collects, analyses and reports on data from 70 adult and 13 paediatric renal centres, as well as hospital laboratories in England. Participation is mandated in England through the NHS National Service Specification and the Chief Executive of each Trust is responsible for adherence to this contract.

The UK Renal Registry was set up as a National Audit in 1995, reaching full coverage of the UK in 2007. Its primary purpose remains national audit. Initially the UK Renal Registry collected data on people receiving dialysis treatment or a kidney transplant, but extended its audit remit in recent years to include:

- All cases of acute kidney injury (AKI) in primary and secondary care from 2015 (following a level 3 Patient Safety Alert issued by NHS England).

- All cases of advanced, pre-dialysis chronic kidney disease (stages 2 to 5) in secondary care from 2016 (at the request of the National Clinical Reference Group).

Reporting of data to the UK Renal Registry is mandated in NHS Commissioning’s Internal medicine - A06 Dialysis Specification (https://www.england.nhs.uk/commissioning/spec-services/npc-crg/group-a/a06/). Internal Medicine is one of six National Programmes of Care (NPoCs) overseeing the commissioning of specialised and highly specialised services. Specialised services support people with a range of rare and complex conditions.

The UK Renal Registry relies on the following legal bases under the General Data Protection Regulation (EU/2016) as incorporated into UK law under the Data Protection Act when processing data for audit purposes:

For processing of general categories of personal data, the UKRR relies on article 6(1)(f) legitimate interests. The UK Renal Registry relies on the legitimate interests of the renal health and social care services in the UK to provide high standards of care to patients with kidney disease or other kidney related illnesses (as defined by service specification A06. Renal Services). Processing personal data is therefore necessary for UKRR's legitimate interests. The data to which access is requested are proportionate and necessary to achieve those interests. UKRR has completed a legitimate interests assessment (LIA) and is satisfied that the interests of the data subjects do not override UKRR’s legitimate interests; that they would reasonably expect the processing and it would not cause unjustified harm. The UKRR closely monitors potential threats to the data it processes and implements appropriate measures and safeguards to minimise the risks, including compliance with the National Data Guardian standards for the secure and appropriate use of patient health and social care information, and pseudonymisation or anonymisation of all patient data.

For processing of special category personal data, the UKRR relies on article 9(2)(h) which allows for special category data to be used for the provision and

management of health management systems. Without this special category data, the UKRR would be unable to conduct the level of in depth analysis that makes the audit an effective tool. The UKRR's audit functions meet Schedule 1 Part 1 Paragraph 2 as the processing is necessary for health and social care purposes. In processing confidential clinical data the UKRR is subject to the standards set by the National Data Guardian for the secure and appropriate use of patient health and social care information.

The Renal Association (the legal entity under which the UK Renal Registry sits) is the sole data controller for the audit functions of the UK Renal Registry, defining both the purposes (albeit based on service specification A06 produced by NHS England) and means of the processing. The Renal Association also processes the data for the audit with its staff processing the data from collection, through validation, to analysis and publication. The Renal Association also engages North Bristol NHS Trust and AIMES as data processors for the purposes described in 'Processing Activities'.

It is also recognised that the renal centres across the UK are the respective data controllers of the data submitted to the UK Renal Registry and that the renal IT system providers who assist renal units, are data processors on their behalf. The role of data controller for the respective data sets is transferred from the renal centres to the Renal Association at the point of data submission. There are no other organisations, funders or commissioners involved in the audit function of the Renal Association.

The linkage with data provided by NHS Digital is to strengthen national audit of renal services by:

- enabling adjustment for case-mix in outcome comparisons (at the moment this is not possible as the UK Renal Registry co-morbidity data are about 50% incomplete).

- establishing lateness of presentation with end-stage kidney disease requiring dialysis/ kidney transplantation (this data is collected already by UK Renal Registry but completeness is less than 80% in 27 of 52 adult renal units in England for the period 1997-2017).

- enabling hospital admissions and length of stay to be compared. Time spent in hospital is a major concern for dialysis patients and varies considerably between renal units.

- enabling the reporting of cause of death, which is currently not completely returned by all centres.

- determining whether rates of AKI (and harm associated with AKI) vary from hospital to hospital and, if so, whether this is explained by different rates of AKI and severity of AKI in the community vs in hospital.

These results will be published in the UK Renal Registry Annual Report, which is circulated to all renal units, their Trust Chief Executives, national kidney patient charities and the specialist commissioners. The AKI outcomes (which are relevant in primary and secondary care) will be reported quarterly to clinical commissioning groups. All outputs (aggregated with small numbers suppressed) will be made available on the Registry’s open-access website.

The Renal Association has a Patient Council that meets every 2-3 months. The Patient Council annually reviews all patient information, such as the privacy notice, information on who the UK Renal Registry is, how patient data are used and information on patient opt-out. The UK Renal Registry is working on an equalities report for and with the Patient Council. The Patient Council also reviews all submitted and approved data applications. Any substantial changes in data access procedures and data flows will be discussed by the Patient Council before a Confidentiality Advisory Group amendment is submitted. The Patient Council initiated the development of an infographic, which is a summary of the annual report in plain English with visual aids making the annual audit report more accessible to patients. All Information Governance incidents, near misses and actions implemented are reported and discussed at patient council meetings.

The use of data provided by NHS Digital under this agreement renewal is only permitted to be used as part of the UK Renal Registry's audit function. Other agreements between the Renal Association and NHS Digital may permit re-use of this data for further purposes. The patients from the UK Renal Registry dataset to be linked with HES and mortality data are patients starting renal replacement therapy (dialysis and transplantation), patients with chronic kidney disease (stage 2 to 5) and patients with an acute kidney injury in secondary and primary care. The cohort size for all patients (new and existing) are currently about 2.5 million.

The minimum number of datasets required is requested to perform the audit and quality improvement function of the UK Renal Registry:

- Hospital Episodes Statistics: Civil Registration (Deaths), period up to 2020/21 or most recent to be provided. The Renal Association’s survival and causes of death audit require death information on all patients with chronic kidney disease and acute kidney injury. The UKRR collects information on first start of kidney replacement therapy from 2017 onwards and hold information on patients that have been on kidney replacement treatments for more than 40 years who started on dialysis or transplantation as children and are followed-up over time.

- Hospital Episodes Statistics Admitted Patient Care, period 1997/98 to 2020/21 or most recent. The UK Renal Registry collection of new patients starting kidney replacement therapy started from 1997 onwards and as part of the audit reporting, identifying variation and improvement over time, data is requested from 1997 onwards. Many patients have been on kidney replacement treatments for more than 40 years that started on dialysis or transplantation as children and are followed-up over time. To identify variation and improvement over time for all patients the UK Renal Registry require some HES datasets from 1997 onwards. Historical data are needed to determine comorbidities and new (accrued) comorbidities over time as these have long term effects on outcomes for patients with chronic kidney disease and those with an acute kidney injury.

- Hospital Episodes Statistics Critical Care, period 2014/15 to 2020/21 or most recent. The UK Renal Registry began collecting acute kidney injury data in 2015, so no critical care data requested prior to 2015. Only data items that are relevant to people with kidney disease have been requested.

- Hospital Episodes Statistics Outpatients, period 2003/04 to 2020/21 or most recent. Since outpatient episodes are only available from this date, audit, variation and quality improvement will be limited to this time period. The UK Renal Registry collects data on new kidney replacement starters from 1997 onwards and would ideally have wanted access to Outpatient information from 1997 onwards but will limit analysis on referral patterns and first attendance of pre-dialysis clinics to 2003/04.

Data items requested from HES are mapped to specific audit and quality improvement measures.

Data are only requested for the cohort of patients with chronic kidney disease and acute kidney injury. The UK Renal Registry has in effect already applied a specific diagnosis (chronic kidney disease and acute kidney injury) to the patient cohort supplied to NHS Digital. The patient cohort will be submitted to NHS Digital and updated as new patients with chronic kidney disease are seen in kidney centres or people experience a new acute kidney injury. NHS Digital will apply filtering by linking the UK Renal Registry patient cohort to the required datasets and only data for matching patients will be returned to the UK Renal Registry.

For audit and quality improvement, the information gained from Hospital Episodes Statistics and Civil Registrations data can’t be achieved in a less intrusive way or by using anonymised or pseudonymised HES data:

• The UK Renal Registry has shown that the AKI patients in HES is underreported compared to the AKI biochemical data submitted to the UK Renal Registry via laboratories. So only using anonymised data from HES without a linkage with UK Renal Registry data would underestimate the prevalence of AKI patients.

• The full patient pathway for patients on kidney replacement therapy is also not fully represented in HES as dialysis sessions are not well reported and coded in HES and a linkage with UK Renal Registry data is required.

• The UK Renal Registry has rich data that is required in conjunction with the HES data to effectively perform audit reporting, identifying variation and improvement over time for all patients with kidney disease.

Filtering for geography or demographics such as age can’t be applied as the UK Renal Registry is a national registry having full coverage of the UK and covering all patients with chronic and acute kidney disease. The data is already filtered by the UK Renal Registry for diagnosis, as the UK Renal Registry collects data on patients with a specific diagnosis, namely chronic and acute kidney disease.

Some audit measures do have a timeframe, such as access preparation for starting dialysis, but most audit measures do not and require all patient episodes. For instance, all patient episodes are required to determine new and accrued comorbidities over time as comorbidities have very important long-term effects on outcomes for patients with chronic kidney disease and those with an acute kidney injury. Many patients have been on kidney replacement treatments for a very long time (>40 years) and started on dialysis or transplantation as children and are followed-up over time. To identify variation and improvement over time for these patients all episodes are required.

All analyses involving HES, and Civil Registration Mortality data will be undertaken by substantive employees of the Renal Association who are employed in the UK Renal Registry function. Record level HES and Civil Registration Mortality data will therefore not be released to any external organisation.

All outputs will be at the aggregate level with small numbers suppressed in line with HES analysis guide.

1. National Audit and Quality Improvement: end-stage kidney disease – dialysis, transplantation, and pre-dialysis patients:

Every year, the UK Renal Registry publishes an open access report detailing quality of care at renal unit level. If this renewal is approved, the UKRR-HES and Civil Registration Mortality linked data will be included in some of these chapters, particularly:

- To enable adjustment for case-mix between centres in analyses of survival and attainment of national standards (requires HES). This will be presented in the relevant chapter of the UK Renal Registry Annual Report (i.e., co-morbidity, incidence, prevalence, transplant outcome).

- Co-morbidities present in new and existing dialysis/transplant patients will be presented in a descriptive way in relevant chapters.

- In the other chapters, case-mix will be added as a variable that can be adjusted for in the multi-variable models, so the output does not change much in appearance or format.

- Late presentation to kidney services for patients with chronic kidney disease will be added to relevant chapters and referral pattern variation highlighted between centres. Dialysis Access associated with early or late presentation will also be added to relevant chapters

These open access annual report chapters include survival and attainment of quality indicators by renal unit, which allows renal unit performance to be compared by clinical teams, commissioners, regional teams, and patients. When a renal unit is an outlier for survival, they are written to by UK Renal Registry and must provide evidence that their Chief Executive and Commissioner have been informed and that an investigation has taken place. Being able to adjust for case-mix will make the UK Renal Registry more confident that the outliers are due to practice differences rather than case-mix differences. Target date: annual report/dashboard* published on an annual basis from 2022 onwards, peer reviewed journal 2023.

*Dashboards will display summary results in a tabular and visual format. When summary data from the UKRR-HES linked dataset are displayed, small numbers will be suppressed in line with the HES Analysis guide.

2. To report variation in hospital admission rates between centres (requires HES):

- Patients on dialysis state that time spent in hospital has a major impact on their quality of life. UK Renal Registry would like to include in a regular report/dashboard the differences between centres in rates of admission/re-admissions to hospital, length of stay in hospital and critical care admissions for end-stage kidney disease and acute kidney injury patients. Hospitalisation data would be presented un-adjusted initially and then adjusted for case-mix, including co-morbidity derived from HES data. Target date: annual report/dashboard published on an annual basis from 2022 onwards.

3. To explore differences in cause of death between centres (requires Civil Registration Mortality data):

- Mortality is high for patients on dialysis and following kidney transplantation, with cardiovascular and infection events being the major contributors. At the moment, UK Renal Registry can only compare all-cause mortality between renal units and there are significant differences. As well as being able to adjust for case-mix (see above), being able to explore differences in cardiovascular and infection-related deaths would help focus quality improvement efforts aimed at primary or secondary prevention. Target date: Annual report from 2023 onwards.

These annual report chapters are also written as 'plain English' summaries (with infographics to be included in latest reports) making them more accessible to patients and the public. In 2018, these were published at the same time as the main UK Renal Registry Annual Report on the UK Renal Registry website. Additional information using linked data will be published in the next UK Renal Registry Annual Report.

4. National Audit and Quality Improvement: Acute Kidney Injury (AKI):

In addition, AKI data will be reported to NHS England, commissioners, and NHS Trusts. NHS England invested £2m in the National Programme to improve patient safety and is waiting for the linkage to HES and Civil Registration Mortality data to enable the data to be used to reduce harm from AKI. The UKRR-HES- Civil Registration Mortality data will also be used to drive national quality improvement through the Kidney Quality Improvement Partnership (www.thinkkidneys.nhs.uk/kquip/).

Reporting of the AKI data currently takes the form of:

- An open access website that summarises AKI reporting to UK Renal Registry and is updated monthly.

- An annual AKI report was published on the UK Renal Registry website in 2020 and the information are now published in an AKI dashboard, with some measures updated quarterly and others annually. Target date: annual AKI dashboard from 2022 onwards.

- An AKI laboratory-level report was previously sent to all biochemistry laboratories in England but is now incorporated in the AKI dashboard on the open access website and updated quarterly.

- The AKI rates report at CCG-level previously sent to CCGs is now also available on the UK Renal Registry open access website in the AKI dashboard but by Integrated Care System level and updated quarterly.

The UK Renal Registry have done work on the HES and Civil Registration Mortality linked data to distinguish between AKI that happens in the community and in hospital and results of this analyses was published in the 1st AKI annual report on the UK Renal Registry open access website in 2020. The HES linked data that will be reported in the AKI annual report/dashboard are for instance:

- community and hospital AKI rates and re-admission rates

- mortality associated with AKI in the community and in hospital

- length of stay associated with AKI.

Target date: 2022

5. Meetings and conferences:

UK Renal Registry presents audit data at a number of national meetings including:

1. The Renal Association's and The British Renal Society's Annual Conference 'UK Kidney Week' - attended by nephrologists, scientists, other members of the multi-professional team, and some patients.

2. The National Kidney Federation's annual conference - attended by patients from all over the UK.

As a part of the Kidney Quality Improvement Partnership, the UK Renal Registry holds regional meetings with clinical teams, patients, and commissioners where the regional data is presented and used to focus quality improvement initiatives. Quality improvement regional meetings were severely affected by the Covid-19 pandemic as face-to-face meetings were not possible and virtual meetings affected by clinical staff working in the care of patients. During the Covid-19 pandemic the Renal Association’s Kidney Quality Improvement Partnership (KQuIP) worked within the regions to understand the change in practice patterns, vaccinations and infections and created a weekly heat map for use by commissioners, kidney units and patients. KQuIP supported the submission of Covid-19 infections data that the UK Renal Registry used to publish a weekly report used extensively by commissioners, patients and kidney centres. Before and after the pandemic the KQuIP programme facilitated regional improvement across nine English regions, Wales and the paediatric kidney programme, supporting patients and the multidisciplinary team (MDT) to address variation in services for people with kidney disease.

Regional meetings include representatives from the region and include clinical staff, patients and commissioners. Key variations in services were identified using UK Renal Registry data and focussed on nationally through quality improvement projects aimed at improving access to home dialysis therapies, increase in definitive vascular access rates and an increase in pre-emptive transplantation. Each region chose which area of improvement to focus on. The UK Renal Registry presented relevant regional data at baseline and updated information when it became available. The Renal Association provided leadership and quality improvement training to assist kidney units in the mapping of improvement in a targeted way that is owned locally by clinical teams and patients. On-going data collection that is automated and timely is paramount in evidencing the ongoing improvement at regional level to reflect recommendations in the national GIRFT and Renal Services Transformation Plan. Timely data is used to drive cycles of change with teams being upskilled in the importance of using data for improvements such as creating run charts. Ideas for improvement are tested locally, and learning and outcomes shared regionally to spread successes and overcome challenges.

The data provided by NHS Digital is permitted for use as part of the UK Renal Registry's audit function under the terms of this agreement. Other agreements between the Renal Association and NHS Digital may permit re-use of this data for further purposes.

1. Use of the HES and Civil Registration Mortality data to report centre-level differences in case-mix adjustment for end-stage kidney disease patients:

- Case mix adjustment for survival outcomes was published in the 22nd and 23rd UK Renal Registry annual report in 2020 and 2021. The number of outlying centres reduced following case-mix adjustment and highlighted possible practice differences in survival outcomes. Benefit to patients: the reduction in the number of kidney centres that are survival outliers means that there are fewer centres that have lower than expected survival, given the size and characteristics of the patients they treat. There is a Renal Association process for centres to follow when they are a survival outlier with lower-than-expected survival: they need to inform the Trust’s Chief Executive, Clinical Governance Lead and the Commissioner of their survival outlier status. Internally the centre reviews their clinical practice and implement strategies to improve patient care. The HES survival case-mix adjustment and notification process improved standards of patient care and survival over time for patients with chronic kidney disease.

2. Use of the HES and Civil Registration Mortality data to report centre-level differences hospital admission rates between centres:

- Inpatient and outpatient days by treatment modality. GIRFT renal report 2020 and 2021, UK Renal Registry CKD Annual Report 2021. Benefit to patients: The GIRFT national report used the results and published recommendations on outpatient services relating to equity of access and timeliness. For example, Trusts should ensure equity of patient access to sub-specialty renal clinics within each regional network. Recommendations were published for inpatient services relating to reporting patterns of hospitalisation identifying unwarranted variation between trusts, access to healthcare professional support and services to reduce hospitalisations and renal services to implement initiatives to better understand factors that drive hospitalisation in kidney care. These recommendations are being implemented in kidney centres and improve standards of care for patients and access to health services including as part of the quality improvement programmes run by the Renal Association.

- Access and re-intervention procedures prior and after start of HD and PD by late/early presentation to renal services, GIRFT renal report 2020 and 2021. Benefit to patients: The GIRFT national report used the results and published recommendations on vascular access for haemodialysis patients relating to the day case surgery rate for arteriovenous fistula/graft and reducing variation in definitive haemodialysis vascular access rates. These recommendations are being implemented in kidney centres, improving patient care and outcomes.

The following abstracts were presented, and papers published:

- Annual burden of emergency hospital admissions for patients on Renal Replacement Therapy. UK Kidney week abstract 2020. Benefit to patients: There is a high burden of hospitalisation for patients on all three kidney replacement therapy modalities, but particularly in patients on dialysis. PD patients, those in more deprived socio-economic groups, aged over 60, Caucasian ethnicity and female gender are at higher risk of admission. Complications associated with dialysis access and infections appear to form the bulk of admissions. These findings contribute to improvements in patient care, especially for dialysis access complications and infection prevention and control.

- Incidence and risk factors for amputation within 5 years of commencing dialysis in England. UK Kidney week abstract 2020. Benefit to patients: this study set out to report, for the first time, incidence, risk factors and unwarranted renal centre variation in rates of lower limb amputation (LLA) for patients on dialysis in England – selected by GIRFT as an important care quality metric for kidney units. Findings highlighted rates of LLA in dialysis patients with diabetes are high, with considerable National variation. Provision of high-quality foot care for diabetic patients on dialysis must be prioritised to minimise the significant burden of LLA for our patients. Recommendations from the GIRFT report are being implemented to reduce variation in amputation rates and optimise care for dialysis patients with diabetes.

- English transplant centre variation in early (30 day) and late (365 day) readmission rates following renal transplantation. Kidney week abstract 2020. Benefit to patients: Study findings show that 1/5 adult renal transplant recipients in England require emergency hospital readmission (EHR) within 30 days of their surgery. Over ½ will have at least one EHR within the first-year post-transplant. Recipients of deceased donor (DD) and living donor kidneys had similar EHR rates at 30 days but by 365 days recipients of a DD kidney had a higher EHR rate. Female sex, age over 60 and social deprivation are all risk factors for admission. These findings contribute to a better understanding of factors underlying variation and helps kidney services to reduce emergency post renal transplant readmissions. These findings formed part of the GIRFT renal report, which recommended that analysis of hospitalisation data form part of routine quality assurance.

3.Use of the HES and Civil Registration Mortality data to publish measures of care and highlight variation in acute kidney injury patients:

- Emergency and elective AKI admissions rates by hospital. AKI annual report 2020. Benefit to patients: Results showed that the AKI rate was particularly high in people admitted to hospital as an emergency compared to elective admissions. Greater understanding of the risk of AKI and identification of hospitals with particularly high rates helps to improve AKI patient care and treatment for emergency admissions.

- Length of stay in hospital for people with AKI electronic alerts. AKI annual report 2020. Benefit to patients: Findings showed that 71% of patients with an AKI episode had a hospital stay. These results have important implications for the detection and earlier treatment of AKI patients in primary care.

- Mortality following post-hospitalisation AKI. AKI annual report 2020. Benefit to patients: 18% of patients with an AKI episode died within 30 days of the first alert and mortality increased with age and AKI stage. A seasonal pattern is seen in AKI deaths. These findings contribute to the identification of high-risk patients in both primary and secondary care.

The following abstracts were presented, and papers published:

- Acute kidney injury identification: use of electronic AKI alerts versus electronic health records in Hospital Episode Statistics. UK Kidney week abstract 2020. Benefit to patients: The aim of the project was to determine whether episodes of AKI identified in the UKRR Master Patient Index correspond to coded diagnoses on the discharge record held in HES. Results showed that the use of HES to identify cases of AKI is likely to underestimate the incidence of AKI, especially for AKI stage 1, though a high proportion of the most severe cases will be captured. Improvements in data capture and reporting of AKI alerts has already better informed NHS commissioning.

- Acute kidney injury in a national cohort of children: epidemiology and outcomes using linked electronic health data. UK Kidney week abstract 2020. Benefit to patients: The aim of this project was to describe a national cohort of children who received an AKI warning and their clinical course. Over half of AKI episodes in children were associated with hospitalisation. AKI is frequently seen in children with co-existing disease and higher length of stay, admission to critical care and death within 30 days more frequently seen among youngest children. These are novel findings in children which leads to better understanding of AKI and clinical outcomes for children.

- Do outcomes for hospitalized patients with an Acute Kidney Injury (AKI) vary across specialties in England? UK Kidney week abstract 2020. Benefit to patients: the aim was to determine if 30-day mortality differ by speciality. Results show that treatment specially was associated with mortality of patients who develop an AKI post admission. This finding contributes to better management of patients in hospital and improvements in AKI patient care.

- Acute kidney injury (AKI) identification for pharmacoepidemiologic studies: use of laboratory electronic AKI alerts versus electronic health records in Hospital Episode Statistics (HES). Published paper 2021. Benefit to patients: The aim of this study was to determine the degree of correspondence between the UKRR-MPI and AKI International Classification Disease-10 (ICD-10) N17 coding in Hospital Episode Statistics (HES) and whether hospital N17 coding correlated with 30-day mortality and emergency re-admission after AKI. Coding of AKI in HES is influenced by many factors that result in an underestimation of AKI. Using e-alerts to triangulate the true incidence of AKI could provide a better understanding of the factors that affect hospital coding, potentially leading to improved coding, patient care and pharmacoepidemiologic research.

- Centre variation in mortality following post-hospitalisation acute kidney injury: analysis of a large national cohort. Published paper 2022. Benefit to patients: Routine monitoring of outcomes for patients with acute kidney injury is important to drive ongoing quality improvement in patient care. The paper demonstrated the considerable risk associated with developing even mild elevations in serum creatinine and identified unwarranted variation in mortality rates. Centres identified as outliers need to interrogate local care pathways to understand and address reasons for the high mortality. This metric and methodology has been approved for the ‘Model Hospital’.

The UK Renal Registry is part of the Renal Association, a not for profit organisation registered with the Charity Commission. The UK Renal Registry is among a number of organisations that form part of the UK Renal Data Collaboration; whose main aim is to improve and standardise the scope and detail of data that is recorded in renal units. The UK Renal Registry is recognised as having one of the very few high quality clinical databases open to requests from researchers. The UK Renal Registry collects, analyses and reports on data from 71 adult and 13 paediatric renal centres. Participation is mandated in England through the NHS National Service Specification and the Chief Executive of each Trust is responsible for adherence to this contract.

The UK Renal Registry was set up as a National Audit in 1995, reaching full coverage of the UK in 2007. Its primary purpose remains national audit. Initially the UK Renal Registry collected data on people receiving dialysis treatment or a kidney transplant, but extended its audit remit in recent years to include:

- All cases of acute kidney injury (AKI) in primary and secondary care from 2015 (following a level 3 Patient Safety Alert issued by NHS England).

- All cases of advanced, pre-dialysis chronic kidney disease (stages 2 to 5) in secondary care from 2016 (at the request of the National Clinical Reference Group).

Reporting of data to the UK Renal Registry is mandated in NHS Commissioning’s Internal medicine - A06 Dialysis Specification. Internal Medicine is one of six National Programmes of Care (NPoCs) overseeing the commissioning of specialised and highly specialised services. Specialised services support people with a range of rare and complex conditions.

The UK Renal Registry relies on the following legal bases under the General Data Protection Regulation (EU/2016) as incorporated into UK law under the Data Protection Act when processing data for audit purposes:

For processing of general categories of personal data the UK Renal Registry relies on:

- Article 6 (1)(f) “Legitimate interest” – The UK Renal Registry relies on the legitimate interests of the renal health and social care services in the UK to provide high standards of care to patients with kidney disease or other kidney related illnesses (as defined by service specification A06. Renal Services).

For processing of special category personal data the UK Renal Registry relies on:

- Article 9 (2)(j) “For the purposes of archiving in the public interest, and using data for scientific research purposes, and statistical analysis” – For the purposes of the UK Renal Registry’s audit function, the registry relies primarily on the “statistical analysis” portion of the article as the analysis of the data received from renal centres is a vital part of the audit.

Aggregate data by renal centre and for England are published in the UK Renal Registry’s annual report and there are no moral or ethical issues raised by publishing data on incidence, prevalence, outcomes and care of patients by renal centre. There is no risk to the public by publishing above listed audit data in the UK Renal Registry’s annual report.

The Renal Association (the legal entity under which the UK Renal Registry sits) is the sole data controller for the audit functions of the UK Renal Registry, defining both the purposes (albeit based on service specification A06 produced by NHS England) and means of the processing. The Renal Association is also the data processor for the audit with its staff processing the data from collection, through validation, to analysis and publication. The Renal Association also engages North Bristol NHS Trust and AIMES for the purposes described in 5b.

It is also recognised that the renal centres across the UK are the respective data controllers of the data submitted to the UK Renal Registry and that the renal IT system providers who assist renal units, are data processors on their behalf. The role of data controller for the respective data sets is transferred from the renal centres to the Renal Association at the point of data submission. There are no other organisations, finders of commissioners involved in the audit function of the Renal Association.

The linkage with data provided by NHS Digital is to strengthen national audit of renal services by:

- enabling adjustment for case-mix in outcome comparisons (at the moment this is not possible as the UK Renal Registry co-morbidity data are about 50% incomplete).

- establishing lateness of presentation with end-stage kidney disease requiring dialysis/ kidney transplantation (this data is collected already by UK Renal Registry but completeness is less than 80% in 27 of 52 adult renal units in England for the period 1997-2017).

- enabling hospital admissions and length of stay to be compared. Time spent in hospital is a major concern for dialysis patients and varies considerably between renal units.

- enabling the reporting of cause of death, which is currently not completely returned by all centres.

- determining whether rates of AKI (and harm associated with AKI) vary from hospital to hospital and, if so, whether this is explained by different rates of AKI and severity of AKI in the community vs in hospital.

These results will be published in the UK Renal Registry Annual Report, which is circulated to all renal units, their Trust Chief Executives, national kidney patient charities and the specialist commissioners. The AKI outcomes (which are relevant in primary and secondary care) will be reported quarterly to clinical commissioning groups. All outputs (aggregated with small numbers suppressed) will be made available on the Registry’s open-access website.

The use of data provided by NHS Digital for this agreement renewal is only permitted to be used as part of the UK Renal Registry's audit function. The patients from the UK Renal Registry dataset to be linked with HES and mortality data are patients starting renal replacement therapy (dialysis and transplantation), patients with chronic kidney disease (stage 2 to 5) and patients with an acute kidney injury in secondary and primary care.

The datasets that are required from HES are:

• Hospital Episodes Statistics: Civil Registration (Deaths) bridge. Data up to 2020/21 to be provided.

• Hospital Episodes Statistics Admitted Patient Care, period 1997/98 – 2020/21. The UK Renal Registry collection of new patients starting renal replacement therapy started from 1997 onwards and as part of the audit reporting, identifying variation and improvement over time, data is requested from 1997 onwards. About 32% of the available HES data items are requested.

• Hospital Episodes Statistics Critical Care, period 2014/15-2020/21. The UK Renal Registry began collecting AKI data in 2015, so no critical care data requested prior to 2015. Only data items that are relevant to people with kidney disease have been requested. About 52% of available HES data items are requested.

• Hospital Episodes Statistics Outpatients, period 2003/04 to 2020/21. About 29% of available HES data fields are requested. Since outpatient episodes are only available from this date, audit, variation and quality improvement will be limited to this time period.

• Civil Registration (Deaths) – Secondary Care cut. About 18% of available fields are requested. Period: data up to 2020/21. The Renal Association’s survival and causes of death audit require death information on all patients with kidney disease and acute kidney injury.

Data items requested from HES are mapped to specific audit and quality improvement measures.

The UK Renal Registry is a UK wide registry and data are required for all renal patients in England. The audit objectives require a patient level linkage of the UK Renal Registry data with HES and Civil Registration Mortality Data. Data returned to the UK Renal Registry will be pseudonymised and will include a HES ID and UK Renal Registry study ID.

The UK Renal Registry can confirm that there are no alternative, less intrusive way of achieving the audit reporting obligations, for instance for case-mix adjusted outcomes, cause of death, length of stay, hospitalisations, referral patterns, outpatient appointments and hospital acquired acute kidney injury. Despite many efforts at national meetings and correspondence with clinical directors and renal units, the completeness of many data items is not improving and in some instances is declining.

All analyses involving HES and Civil Registration Mortality data will be undertaken by substantive employees of the Renal Association who are employed in the UK Renal Registry function. Record level HES and Civil Registration Mortality data will therefore not be released to any external organisation.

All outputs will be at the aggregate level with small numbers suppressed in line with HES analysis guide.

1. National Audit and Quality Improvement: end-stage kidney disease - dialysis and transplantation

Every year, the UK Renal Registry publishes an open access report detailing quality of care at renal unit level. If this linkage is approved, the UKRR-HES and Civil Registration Mortality linked data will be included in some of these chapters, particularly:

- To enable adjustment for case-mix between centres in analyses of survival and attainment of national standards (requires HES). This will be presented in the relevant chapter of the UK Renal Registry Annual Report (i.e. co-morbidity, incidence, prevalence, transplant outcome).

- In the co-morbidity chapter, the co-morbidities present in new and existing dialysis/ transplant patients will be presented in a descriptive way.

- In the other chapters, case-mix will be added as a variable that can be adjusted for in the multi-variable models, so the output does not change much in appearance or format.

These open access annual report chapters include survival and attainment of quality indicators by renal unit, which allows renal unit performance to be compared by clinical teams, commissioners and patients. When a renal unit is an outlier for survival, they are written to by UK Renal Registry and have to provide evidence that their Chief Executive and Commissioner have been informed and that an investigation has taken place. Being able to adjust for case-mix will make the UK Renal Registry more confident that the outliers are due to practice differences rather than case-mix differences.

2. To report variation in hospital admission rates between centres (requires HES):

- Patients on dialysis state that time spent in hospital has a major impact on their quality of life. UK Renal Registry would like to include a new annual report chapter that presented the differences between centres in rates of admission to hospital and length of stay in hospital. Hospitalisation data would be presented un-adjusted initially and then adjusted for case-mix, including co-morbidity derived from HES data.

3. To explore differences in cause of death between centres (requires Civil Registration Mortality data):

- Mortality is high for patients on dialysis and following kidney transplantation, with cardiovascular and infection events being the major contributors. At the moment, UK Renal Registry can only compare all-cause mortality between renal units and there are significant differences. As well as being able to adjust for case-mix (see above), being able to explore differences in cardiovascular and infection-related deaths would help focus quality improvement efforts aimed at primary or secondary prevention.

These annual report chapters are also written as 'plain English' summaries (with infographics to be included in latest reports) making them more accessible to patients and the public. In 2018, these were published within 2 weeks of the main UK Renal Registry Annual Report on the UK Renal Registry website. Additional information using linked data will be published in the next UK Renal Registry Annual Report (22nd Annual Report).

4. National Audit and Quality Improvement: Acute Kidney Injury (AKI):

In addition, AKI data will be reported to NHS England, commissioners and NHS Trusts. The UK Renal Registry’s work on AKI is currently being managed through the Think Kidneys AKI National Programme with NHS England. NHS England invested £2m in the National Programme to improve patient safety and is waiting for the linkage to HES and Civil Registration Mortality data to enable the data to be used to reduce harm from AKI. The UKRR-HES- Civil Registration Mortality data will also be used to drive national quality improvement through the Kidney Quality Improvement Partnership (www.thinkkidneys.nhs.uk/kquip/). AKI is a key component of the KQuIP regional quality improvement days with clinical teams, commissioners and patients.

Reporting of the AKI data currently takes the form of:

- An open access website that summarises AKI reporting to UK Renal Registry

- An AKI laboratory-level report send to all biochemistry laboratories in England

- An AKI rates report at CCG-level sent to CCGs and also available on the UK Renal Registry open access website (https://www.thinkkidneys.nhs.uk/aki/aki-data/aki-data-ccg/) by clicking on the CCG code

- An annual AKI report to be published on the UK Renal Registry website in the Autumn of 2019

The UK Renal Registry have done work on the HES and Civil Registration Mortality linked data to distinguish between AKI that happens in the community and in hospital and results of this analyses will be published in the 1st AKI annual report on the UK Renal Registry open access website later this year. The linked data that will be reported in the new AKI annual report are rates of:

- community and hospital AKI

- mortality associated with AKI in the community and in hospital

- length of stay associated with AKI.

5. Meetings and conferences:

UK Renal Registry presents audit data at a number of national meetings including:

1. The Renal Association's UK Kidney Week - attended by nephrologists, scientists, other members of the multi-professional team and some patients.

2. The British Renal Society's Annual Conference - attended by nephrologists, scientists, other members of the multi-professional team and some patients.

3. The National Kidney Federation's annual conference - attended by patients from all over the UK.

As a part of the Kidney Quality Improvement Partnership, the UK Renal Registry holds regional meetings with clinical teams, patients and commissioners where the regional data is presented and used to focus quality improvement initiatives. In 2017, regional meetings were held in Yorkshire and Humber, East Midlands and the North West; in 2018 in Oxford and Thames valley, South-West and a national paediatric quality improvement meeting. Four regional meetings are planned for 2019: the North-East meeting has taken place in April; the South-East meeting is scheduled to take place in June and the other two meetings are yet to be arranged.

The data provided by NHS Digital is permitted for use as part of the UK Renal Registry's audit function under the terms of this agreement

Use of the HES and Civil Registration Mortality data to report centre-level differences in duration of admission to hospital for RRT patients:

1. Number of inpatient days (emergency) per prevalent transplant patient (median, days)

2. Number of outpatient visits for prevalent transplant patients (median, days)

3. Number of inpatient days (emergency) per HD patient (median, days)

4. Number of renal outpatient attendances for HD patients (median, days)

5. Number of non-renal outpatient attendances for in-centre HD patients (median, days)

Use of the HES and Civil Registration Mortality data to report centre-level differences in rates and reasons for admission to hospital for RRT patients:

1. Definitive access procedure prior to HD start – timely presentation (%)

2. Definitive access procedures prior to HD start (%)

3. Definitive access procedures in the 12 months after RRT start (untimely presentation, HD & PD, %)

4. Multiple access procedures in the 12 months before RRT start (HD & PD, %)

5. Incident PD patients with a PD re-intervention procedure in the 12 months after PD start (%)

6. Access procedures in 2016 for prevalent dialysis patients (%)

7. Amputations in dialysis patients up to 5 years post dialysis start (%)

Use of the HES and Civil Registration Mortality data to determine whether acute kidney injury occurred before or during admission to hospital:

1. Elective hospital admissions where AKI was hospital acquired (median, days)

2. Emergency hospital admissions where AKI was hospital acquired (median, days)

3. Hospital admissions (elective and emergency) with AKI reaching stage 3 (hospital and community acquired, per 100 admissions)

4. Hospital admissions with AKI reaching stage 3 that were coded with N17 diagnostic codes (%)

Use of the HES and Civil Registration Mortality data to report the impact of acute kidney injury on hospital resources such as intensive care and length of stay:

1. Length of stay for emergency admissions with hospital-acquired AKI (median, days)

2. Length of stay for emergency admissions with community-acquired AKI (median, days)