NHS Digital Data Release Register - reformatted

University Hospitals Bristol NHS Foundation Trust projects

34 data files in total were disseminated unsafely (information about files used safely is missing for TRE/"system access" projects).

MR1240 - Evaluation of centralisation in head and neck cancer — DARS-NIC-147901-2XMLG

Type of data: information not disclosed for TRE projects

Opt outs honoured: No - consent provided by participants of research study, Identifiable, No (Consent (Reasonable Expectation))

Legal basis: Informed Patient consent to permit the receipt, processing and release of data by the HSCIC, Informed Patient consent to permit the receipt, processing and release of data by NHS Digital, Health and Social Care Act 2012 – s261(2)(c), Health and Social Care Act 2012 – s261(2)(c)

Purposes: No (NHS Trust)

Sensitive: Sensitive

When:DSA runs 2019-06-01 — 2020-05-31 2017.09 — 2024.04.

Access method: Ongoing, One-Off

Data-controller type: UNIVERSITY HOSPITALS BRISTOL AND WESTON NHS FOUNDATION TRUST, UNIVERSITY OF BRISTOL

Sublicensing allowed: No

Datasets:

  1. MRIS - Cohort Event Notification Report
  2. MRIS - Cause of Death Report
  3. MRIS - Members and Postings Report
  4. MRIS - Flagging Current Status Report
  5. MRIS - Scottish NHS / Registration
  6. Cancer Registration Data
  7. Civil Registrations of Death
  8. Demographics

Objectives:

The overall aim of the programme is evaluate and disseminate the outcome of centralization in Head and Neck cancer (H&N). In order to accomplish this we will create a clinical cohort of 5,000 people with H&N and follow up this cohort. This study will be large enough to compare groups by age, site and stage. Data are already collected on the care provided to patients with H&N as part of an ongoing National Head and neck cancer audit. The proposed studies will complement these National audit data by investigating the role of patient characteristics not recorded as part of routine care and by examining a broader range of patient centred and clinical outcomes. We will collect data on people with H&N that would include age, sex, diagnosis and treatment. Additional data will be collected on socioeconomic status (including occupation, education and housing): lifestyle (including smoking and alcohol intake); questions on psychological status and general and cancer specific quality of life questions. We will collect a venous blood, saliva and tissue sample for use in future translational studies. The outcome of the study will allow clinicians and managers to design effective patient centred multidisciplinary centralised services for people with H&N.

Yielded Benefits:

To date, 15 peer reviewed papers arising from the study have been published, and these analyses have been presented at a number of scientific meetings. The study is currently supporting around 30 ongoing analysis projects and are part of the World Health Organisation’s International Agency for Research on Cancer (IARC) international consortia, exploring the role of germline and tumour genetics on Head and Neck cancer aetiology and prognosis. As well as published papers findings have been presented at clinical conferences such as BAHNO (British Association of Head & Neck Oncologists) and BAHNON (British Association of Head & Neck Oncology Nurses) and the International Quality of Life Conference for Head & Neck Cancer. To date the findings from Head and Neck 5000 have contributed to knowledge around aetiology and prognosis in people with head and neck cancer. To date these findings have not resulted in any formal changes to policy or guidance but it is anticipated that the work will provide evidence that will inform practice and improve the management of people with head and neck cancer in terms of risk stratification, lifestyle modification and prognostic prediction.

Expected Benefits:

Head and neck cancer (H&N) is one of the commoner cancers with around 7,000 cases per year in England and Wales. The incidence appears to be increasing. The two year all cause mortality is around 35%. A person with H&N requires care from a range of disciplines. These include surgical teams to resect the tumour, dissect the neck and reconstruct the defect; radiotherapists and oncologists to provide radiotherapy and chemotherapy; clinical nurse specialists to offer pre and postoperative support; nutritionists to help with postoperative feeding and nutrition; speech therapists to assist with speech and swallowing; restorative dentists to fit and maintain prostheses and treat dental caries; palliative care physicians to support patients in the terminal stages of H&N and psychologists to provide psychological support. In an attempt to move beyond clinical outcomes, such as the surgical result or survival, quality of life scores have been developed for people with H&N and are being used to guide and monitor response to treatment. Despite their importance there is limited evidence on the modifiable psychological and social determinants of coping for people with H&N. There is thus a need to assess a broad range of patient centred outcomes in studies of H&N.

Outputs:

We will continue the follow up through flagging so participants that survive remain in the study for
10+ years. The MRIS will enable us to trace and identify those that have died to ensure that we do not send out further questionnaires. Furthermore, the flagging will provide ongoing notifications about our participants and will allow the study to compare morbidity and mortality outcomes across different centres. We will also be able to analyze the broad range of patient centred outcomes collected in the study in relation to morbidity and mortality.

Processing:

The overall objective of the study is to recruit a clinical cohort of 5,000 people with H&N and then follow up this cohort for two years. This study will be large enough to compare groups by age, site and stage. Specifically, the objectives are to:
1. Compare morbidity and mortality outcomes across different centres.
2. Compare quality of life outcomes across different centres.
3. Describe the individual economic cost of head and neck cancer care.
4. Identify prognostic indicators for head and neck cancer.
5. Create a resource for translational and applied research in head and neck cancer.
Research nurses at each participating H&N cancer centre together with the research team will recruit and collect data:
• Obtain consent
• Baseline collection
- Collect blood, saliva and tissue sample accordance with the established biological sample protocol
- Administer the base line questionnaire at the clinic
- Provide the additional baseline questionnaire pack to be completed at home which should be sent back to the research team in the provided prepaid envelope.
• The patients will be flagged with the NHS Information Centre (NHSIC) and followed for two years.
• At 4 months, the research team will send out the 4 month questionnaire pack to the participants enrolled for self completion at their home together with a prepaid envelope to return the questionnaire pack.
• At 12 months, the research team will send out the 12 month questionnaire pack to the participants enrolled for self completion at their home together with a prepaid envelope to return the questionnaire pack.

HES/ONS data for the AIRWAYS-2 cluster randomised trial. — DARS-NIC-35562-V6G5W

Type of data: information not disclosed for TRE projects

Opt outs honoured: Yes - patient objections upheld, Identifiable (Section 251, Section 251 NHS Act 2006)

Legal basis: Health and Social Care Act 2012 – s261(7), Health and Social Care Act 2012 – s261(2)(c), Health and Social Care Act 2012 – s261(7), Health and Social Care Act 2012 – s261(7); National Health Service Act 2006 - s251 - 'Control of patient information'.

Purposes: No (NHS Trust)

Sensitive: Non Sensitive, and Sensitive, and Non-Sensitive

When:DSA runs 2019-08-02 — 2022-08-01 2019.05 — 2019.05.

Access method: One-Off

Data-controller type: SOUTH WESTERN AMBULANCE SERVICE NHS FOUNDATION TRUST, UNIVERSITY HOSPITALS BRISTOL AND WESTON NHS FOUNDATION TRUST, UNIVERSITY OF OXFORD

Sublicensing allowed: No

Datasets:

  1. Hospital Episode Statistics Admitted Patient Care
  2. Hospital Episode Statistics Critical Care
  3. Hospital Episode Statistics Outpatients
  4. Hospital Episode Statistics Accident and Emergency
  5. Civil Registration - Deaths
  6. HES:Civil Registration (Deaths) bridge
  7. Civil Registration (Deaths) - Secondary Care Cut
  8. Civil Registrations of Death - Secondary Care Cut
  9. Hospital Episode Statistics Accident and Emergency (HES A and E)
  10. Hospital Episode Statistics Admitted Patient Care (HES APC)
  11. Hospital Episode Statistics Critical Care (HES Critical Care)
  12. Hospital Episode Statistics Outpatients (HES OP)

Objectives:

This study has been funded by the NIHR (12/167/102) under the NIHR Health Technology Assessment Award as part of an Open Call.

Data provided by NHS Digital will be used as part of a research project which will provide the NHS with evidence of how best to treat out of hospital cardiac arrests (OHCA). The study team are undertaking a large randomised controlled trial (RCT) in four English NHS ambulance services and 100 hospitals to determine whether placing a breathing tube in the windpipe (intubation) or the best available supraglottic airway device (called the i-gel) gives the best chance of recovery following OHCA. The four English NHS ambulance services involved are South Western Ambulance Service NHS Foundation Trust (SWAST), Yorkshire Ambulance Service NHS Trust (YAS), East of England Ambulance Service NHS Trust (EAST) and East Midlands Ambulance Service NHS Trust (EMAS). The study team are following up recruited patients for 6 months after OHCA to find out the quality of life of survivors and the NHS resources used. The study team will use HES/ONS data to capture secondary care resource use and deaths that occur after OHCA during study follow up.

Objectives for data processing are to:

- determine which intervention (intubation or i-gel) is more clinically effective and cost effective for treating OHCA;

- optimise the care pathway for patients with OHCA in the NHS;

- improve the outcomes of patients with OHCA in the UK.

HES/ONS data provided by NHS Digital will be linked to trial data collected by the Clinical Trials and Evaluation Unit, University Hospitals Bristol NHS Foundation Trust. University Hospitals Bristol NHS Foundation Trust will share the linked data with the health economists at the Nuffield Department of Population Health, University of Oxford, who will conduct an economic evaluation for the study. The data to be shared will be at record level, and will initially be sent to the ONS named users. The data will be shared with the health economists at the Nuffield Department of Population Health, University of Oxford via the study database, which is stored on NHS servers. Health economists will be required to set up a database account and will be granted access to a specific 'Downloads' section of the study database. At no point will the health economists have access to patient identifiable data on the study database. Files to be downloaded will be password encrypted.

Yielded Benefits:

The main trial results have been published, with a number of additional papers to follow. This has been supported by a wide range of dissemination activity, and the outputs from the trial are now being translated into clinical practice. The trial team are closely monitoring clinical guidance and practice nationally and internationally in order to collect evidence of impact, as outlined in the benefits statement. The study anticipate that clear indications of this will be seen in due course. The trial has also enhanced research capacity and delivery in the ambulance services in England.

Expected Benefits:

Because resuscitation for OHCA is strongly protocol driven, the study team anticipates that the findings from AIRWAYS-2 will be readily adopted into practice (by 2019) through changes to accepted guidelines. Changes to internationally accepted resuscitation guidelines are made by ILCOR, the International Liaison Committee on Resuscitation. ILCOR was formed in 1992 to provide a forum for liaison between principal resuscitation organisations worldwide. At present, ILCOR comprises representatives of:
American Heart Association (AHA)
European Resuscitation Council (ERC) (includes the Resuscitation Council UK)
Heart and Stroke Foundation of Canada (HSFC)
Australian and New Zealand Committee on Resuscitation (ANZCOR)
Resuscitation Councils of Southern Africa (RCSA)
Inter American Heart Foundation (IAHF)
Resuscitation Council of Asia (RCA)

One of the AIRWAYS-2 co-applicant team is a past Chairman of the Resuscitation Council UK. They are Editor-in-Chief of the journal Resuscitation and Vice-Chairman of the European Resuscitation Council, the immediate past co-chairman of ILCOR and co-editor for the 2015 international resuscitation guidelines. Professor Nolan is ideally placed to ensure that the findings from AIRWAYS-2 are immediately incorporated into ILCOR's rapid review process (see https://volunteer.heart.org/apps/pico/Pages/default.aspx ) and then into internationally accepted and adopted resuscitation guidance, thereby ensuring rapid and effective implementation. Supported by the wider research team, Professor Nolan will ensure that ILCOR is fully updated on the findings of AIRWAYS-2 as soon as these become available.

Expected benefits include;
- improved clinical outcomes for patients with OHCA
- evidence-based guidelines
- reduction in inequalities as a result of clear guidelines for treatment in OHCA patients
- rationalisation of training and equipment in ambulance services
- answers to questions about the cost effectiveness of different airway management for the NHS and society as a whole.

The report to the funding body will be sent to the NIHR, and will provide a summary of the work undertaken during the life of the project. The target journals for the main study paper and cost effectiveness publications have not been identified, but these will be Open Access. These will communicate the results of the primary and secondary outcomes. The summary for stakeholders will be aimed both externally (e.g. general public/patients, media, commissioners) and internally (e.g. participating Trust stuff, operational staff).
All outputs will be reviewed by the Chief Investigator and other collaborators, as necessary.

Outputs:

- Report to funding body (HTA): October 2018
- Main study paper: Clinical effectiveness: September 2018
- Cost effectiveness publication: January 2019
- Summary to relevant stakeholders: January 2019

The report to the funding body will be sent to the NIHR, and will provide a summary of the work undertaken during the life of the project. The target journals for the main study paper and cost effectiveness publications have not been identified, but these will be Open Access. These will communicate the results of the primary and secondary outcomes of the study. The summary for stakeholders will be aimed both externally (e.g. general public/patients, media, commissioners) and internally (e.g. participating Trust stuff, operational staff).

All outputs will be reviewed by the Chief Investigator and other collaborators, as necessary. All outputs will be aggregated with small numbers suppressed in line with the HES analysis guide.

Findings will be shared with the National Association of Ambulance Medical Directors (NASMED), the National Ambulance Research Steering Group and the Research and Publications Committee of the Royal College of Emergency Medicine. The Chief Investigator and co-applicants have close links with these groups which are already aware of the trial and awaiting its results, and the study team intend to make presentations at all of them. The Chief Investigator is also the National Clinical Director for Urgent and Emergency Care at NHS England, and so is ideally placed to support national dissemination and implementation. An electronic summary of the results will be circulated widely in a range of formats, and made publicly available. Presentations will be given at national and international conferences relevant to pre-hospital care and emergency medicine. Examples include the 999 EMS Research Forum, the Annual Scientific Meeting of the Royal College of Emergency Medicine, the International Conference on Emergency Medicine and the American Heart Association Resuscitation Science Symposium.

The data will not be linked to any other data not already noted in this agreement.

Processing:

Patient identifiable data (Study ID, NHS Number, Date of Birth, Surname, Forename, Gender, Postcode) will be sent by UHBristol to NHS Digital. HES/ONS data will be returned by NHS Digital to UHBristol. The coordinating centre at UHBristol will undertake 4 main tasks using the HES/ONS data: (1) Check the degree of successful linkage with HES and, if low, explore patterns in the AIRWAYS-2 data set that might explain this, (2) Cross check the length of ICU stay and hospital stay with the information collected on the AIRWAYS-2 data collection forms, including filling in any missing data which can be ascertained from HES. These outcomes will be analysed and reported by the Bristol team, (3) Cross-check and update the survival status of patients who consented to active follow-up where missing. This data is currently missing for 148 patients. This outcome is analysed and reported by the Bristol team, and (4) Code relevant AIRWAYS-2 trial data to the HES records ready for the health economic analysis to proceed.

Following these tasks, the linked trial and HES records will be pseudonymised by the coordinating centre at UHBristol and transferred to the Nuffield Department of Population Health (NDPH) at the University of Oxford. Please note that the Health Economics Research Centre (HERC) is part of the Nuffield Department of Population Health who will undertake analysis.
This pseudonymised data will be shared with the health economists at the Nuffield Department of Population Health at University of Oxford using encrypted email. The coordinating centre at UHBristol will provide the health economists in Oxford with the document ‘Accessing Encrypted Emails Guide for Non-NHSmail users, HSCIC’, and the health economists will register for the encryption service. Guidance in the document ‘Encryption Guide for NHSmail, HSCIC’ will be followed. The coordinating centre at UHBristol will use an NHS.net email account to send the data via encrypted email to the health economists in Oxford. The data attached to the email will also be password protected. The coordinating centre in Bristol will provide the password to the health economists in Oxford via telephone. At no point will the health economists have access to patient identifiable data. SWAST will have oversight of the processes in their role of Sponsor. At no point will SWAST have access to any record level data - they will only see the aggregated outputs with small numbers suppressed in line with the HES analysis guidelines.

Patient identifiable data for AIRWAY-2 patients will be sent to NHS digital along with each patients' unique study ID, in order that HES/ONS data for these patients can be sent back, with a unique study ID together with patient identifiers and relevant data items from HES/ONS.

These data will be linked to the trial data by the team named at CTEU Bristol. The dataset (including HES and ONS data) will be validated before being pseudonymised for transfer to the health economists at the Nuffield Department of Population Health at University of Oxford.

The trial aims to determine whether the i-gel is superior to tracheal intubation in non-traumatic OHCA in adults, in terms of both clinical and cost effectiveness.

One of the secondary outcome measures is mortality; the ONS data will be used to assist in the estimation of the difference in mortality between groups. Those patients who are deceased upon arrival at hospital are included within the study.

One of the main objectives of the study in line with the NIHR objective is to estimate the cost effectiveness of the trial interventions; data (including HES and ONS data) will be used to estimate the costs and Quality Adjusted Life Years (QALYs) gained by each patient over the course of the 6 months of follow-up, and these estimates will be used in the cost-effectiveness analysis. For each patient, data on survival (some of which will be ONS data) and quality of life estimates from survivors will be used to estimate QALYs gained to 6 months. Costs and QALYs will be summarised by trial group.

Explanation of organisations involved in the study can be found below;

South Western Ambulance Service NHS Foundation Trust hold the contract with the DH for the study. Data Controller (joint)
SWAS NHS Trust will have no access to the record level data.

University of Oxford Data Controller (joint) Will have access to the record level data pseudonymised

University Hospital Bristol NHS Foundation Trust Data Controller (joint) will have access to the record level data with identifiers.

University West of England Bristol , Royal United Hospital Bath NHS Trust and Imperial College London were initially involved in the grant proposal and provided initial clinical input into the protocol. These organisations do not have any influence over how the data is being analysed, they will not have access to any data other that what is put in the public domain.


All organisations party to this agreement must comply with the Data Sharing Framework Contract requirements, including those regarding the use (and purposes of that use) by “Personnel” (as defined within the Data Sharing Framework Contract ie: employees, agents and contractors of the Data Recipient who may have access to that data).

South Western Ambulance Service NHS Foundation Trust and the University of Bristol will not have access to any of the data as a processor and will only see aggregated outputs with small numbers suppressed.

There will be no data linkage undertaken with NHS Digital data provided under this agreement that is not already noted in the agreement.

The data controller(s) is/are responsible for the activities of all individuals (“Individuals”) who have access to the patient data disseminated by NHS Digital ("Data") and are engaged by any data controller or data processor listed in this agreement, regardless of whether such Individual is described as an employee, contractor, secondee, PhD or post-doctoral student or honorary employee.

Project 3 — DARS-NIC-319738-F3W3L

Type of data: information not disclosed for TRE projects

Opt outs honoured: N

Legal basis: Informed Patient consent to permit the receipt, processing and release of data by the HSCIC and for the release of ONS mortality data, Informed Patient consent to permit the receipt, processing and release of data by the HSCIC

Purposes: ()

Sensitive: Non Sensitive

When:2016.04 — 2016.08.

Access method: One-Off

Data-controller type:

Sublicensing allowed:

Datasets:

  1. Office for National Statistics Mortality Data (linkable to HES)
  2. Hospital Episode Statistics Admitted Patient Care
  3. Hospital Episode Statistics Outpatients
  4. Hospital Episode Statistics Critical Care
  5. Hospital Episode Statistics Accident and Emergency

Objectives:

The aim of the study is to evaluate the feasibility of setting up a UK multicentre registry to document cardiac magnetic resonance imaging (CMR) use in patients who present to the hospital with a suspected heart attack and activate the primary percutaneous intervention (PPCI) pathway (index admission). Patients were recruited from 4 centres (2 with and 2 without CMR) and data was collected on basic demography, clinical characteristics on presentation, peri-procedural (PPCI) characteristics, biochemistry and imaging reports (echocardiography and CMR imaging) by linking local NHS databases. The Trust wish to link their database with HES /ONS mortality data to:

 Record subsequent inpatient, accident and emergency, critical care, outpatient activity and mortality in the year following the index PPCI admission. The data will be used to describe the patient cohort by centre;
 Identify co-morbidity in the patient cohort using diagnosis codes in the record of the index admission and diagnosis codes in records in the year preceding the index admission;
 Evaluate resource use for the health economic analysis.
One of the objectives of the feasibility study is to define a “proxy” primary outcome (which will be used in the registry) that represents a definitive change in patient management, conditional on having had CMR, that will be credible to cardiologists and other stakeholders as a measure of the “value added” by doing CMR. The treatment/process outcomes that represent a definitive change in management for various patient subgroups have been defined using formal consensus methods. The Trust will use HES data to:
 “Operationalise” the treatment/process outcomes by capturing the HES components that reflect these outcomes (e.g. CMR can differentiate an ischaemic from a non-ischaemic diagnosis in patients with unobstructed coronary arteries on angiography. HES data will reflect new diagnoses, other procedures/tests that patients will have as a result of a new diagnosis, and changes in the frequency of inpatient, outpatient and A&E episodes related to cardiac events. This will allow the Trust to compare patients with/without CMR with respect to changes in clinical management that would be expected to reduce risk of adverse cardiovascular events).
Written informed consent from every patient in this study is in place, giving access to their electronic information held on local NHS databases and information held by the HSCIC.

The data will not be used for commercial purposes or for direct marketing, and will not be provided in record level form to any third party. The data will solely be used for the purpose of the study outlined above.

Expected Benefits:

The benefits to health and social care are twofold:
1) Benefits of the feasibility study to health and social care (basis of the current application for HES data).
The following benefits are anticipated:
a. If feasible, the registry will be rolled out nationally and the Trust will be in a position to answer the question about the effectiveness of cardiac MRI in the study population;
b. The feasibility study (and the composite outcome that will be defined using HES data) will also inform the commissioning of future research to address other research questions likely to improve NHS care and thus to benefit patients. These benefits will be realised when the Trust disseminate their findings and the report to the funder.
2) Benefits of the registry to health and social care (if the feasibility study determines that it is possible and worthwhile to set up the registry). Please note that the use of HES data for the registry will be subject to a separate application. The following benefits of the registry are anticipated:
a. It will provide evidence of the benefit of using CMR in this patient population (patients who have had a heart attack and patients who present with a suspected heart attack but are found not to have had one) or specific subgroups of it;
b. It will highlight inequality of access to CMR across the UK;
c. It will inform the practice of all the cardiologists who participate in the study;
d. The results from the registry can be used to improve the organisation and delivery of cardiac MRI services to this group of patients across the UK.

Outputs:

Report to funder (National Institute for Health Research (NIHR) Health Services & Delivery Programme (HS&DR).
Paper describing feasibility study cohort.
Paper describing the “operationalisation” of the process/treatment outcome defined as representing important changes in patient management using HES data.
Paper on health economics.
All reports and papers due once analysis of data has been completed.

Results of the study will be disseminated at appropriate conferences (e.g. MRC Clinical Trials Methodology Conference; Health Services Research Network Symposium, Society of Social Medicine Annual Scientific Meeting). The results will also be published in peer reviewed scientific journals; it is anticipated that the majority of these will be ‘open access’. A wide audience is anticipated, since the target conferences and journals cover a range of subjects including epidemiology, the medical and health needs of society, the provision and organization of health services and the prevention of disease. The full study report will be published in the NIHR Health Services and Research Journal, which is open access.
All outputs will contain aggregate data only (there will be no record level data) with small numbers supressed in line with HES analysis guide). The research will determine whether setting up a registry using routine data collection is feasible and inform the design of a prospective multicentre registry.

A registry set up on the basis of this feasibility study will provide information on prognostic value of CMR, highlight specific groups of STEMI patients likely to benefit from CMR, and highlight inequality of access to CMR across the UK, all of which have the potential to improve the health of patients who activate the PPCI pathway. The Trust is unclear at this stage whether this registry will be set up because it depends on the outcome of the feasibility study. The Trust will not proceed with the next phase (setting up the registry) if they find that this is not feasible to set up such a registry using routine data linkage.

Processing:

The University Hospitals Bristol NHS Foundation Trust will supply identifiable data to the HSCIC (NHS Number, Date of Birth and Postcode). Each patient’s record will have a unique study ID. The HSCIC will link the data and extract the relevant HES data for all records from 13/05/2012 and the HES/ONS data from 13/05/2013 onwards. The HSCIC would supply pseudonymised data back to the University Hospitals Bristol NHS Foundation Trust containing the unique study ID that the University Hospitals Bristol NHS Foundation Trust can use to reidentify the cohort in order to link with the data already collected on each participant using local NHS databases (basic demography; clinical characteristics on presentation (index admission); peri- and post-procedural (primary percutaneous coronary intervention) characteristics; biochemistry (index admission); imaging tests (echocardiography and cardiac magnetic resonance imaging (CMR) reports); medications on discharge). Data have been collected on an NHS server (HES data will be added to this database). The “look up” table for the unique participant identifier will remain on the NHS server. Standard operating procedures for database use, data validation and data cleaning will be available and regularly maintained. Data will not be accessible by a third party organisation or across multiple locations within the University of Bristol Hospitals NHS Foundation Trust.
The data will be used to establish proof of principle of two key objectives: to characterise patients’ co-morbidity; and to apply the “proxy” primary outcome developed through formal consensus to the patient cohort by querying hospital activities in the year following the index procedure. Since this study is a feasibility study the Trust will not estimate a particular exposure effect.