NHS Digital Data Release Register - reformatted

Royal Liverpool University Hospital

Project 1 — DARS-NIC-161422-Q0K1M

Opt outs honoured: Yes - patient objections upheld (Section 251)

Sensitive: Non Sensitive

When: 2018/06 — 2018/12.

Repeats: Ongoing, One-Off

Legal basis: Section 251 approval is in place for the flow of identifiable data, National Health Service Act 2006 - s251 - 'Control of patient information'.

Categories: Identifiable


  • Hospital Episode Statistics Admitted Patient Care
  • Diagnostic Imaging Dataset


The Royal Liverpool and Broadgreen University Hospitals NHS Trust requires Hospital Episodes Statistics (HES) and Diagnostic Imaging Dataset (DID) data for use in a study titled “A Risk-adjusted and Anatomically Stratified Cohort Comparison Study of Open Surgery, Endovascular Techniques and Medical Management for Juxtarenal Aortic Aneurysms: The UK COMPlex AneurySm Study (UK-COMPASS).” The UK-COMPASS project is being funded by the National Institute for Health Research - Health Technology Assessment (NIHR-HTA). The Chief Investigator of the NIHR-HTA funded UK-COMPASS project is a consultant surgeon employed by Royal Liverpool and Broadgreen University Hospitals NHS Trust. The aim of the study is to answer the research question identified by NIHR-HTA Commissioning Board: What are the clinical and cost-effectiveness of strategies for the management of juxtarenal abdominal aortic aneurysm, including fenestrated endovascular repair?
 Abdominal aortic aneurysm (AAA) is a common condition where the aorta, the largest artery, begins to bulge abnormally. Usually this expands over years and can eventually burst, causing fatal internal bleeding. When an emergency life-saving operation is possible, they have a high failure rate. A planned AAA repair operation prevents a burst aneurysm. AAAs vary in complexity. Juxtarenal AAAs are more complex because they are close to the arteries that supply the kidneys. There are different methods of managing such complex aneurysms and doctors are unsure which is better. The open surgical repair is a durable but large operation involving slow recovery and higher operative death rates compared to alternative methods, of which Fenestrated Endovascular Aneurysm Repair (FEVAR) is the most established. In some patients with juxtarenal aneurysms, doctors are judiciously using standard endovascular repair (Off-label EVAR), a technique originally intended for use in less complex aneurysms. Endovascular methods cause less of a strain leading to faster recovery and fewer operative deaths but are less durable requiring further procedures in the years after. Some patients who are not fit enough to withstand open repair may be able to have endovascular repairs. In some patients no operation may be in their best interest. This study aims to examine how these different treatments compare in terms of clinical benefit and utilisation of NHS resources. The study intends to analyse the outcomes of all patients aged 25 - 100 years, undergoing juxtarenal aneurysm treatment in England without altering their treatment, during a period of 2 years and collect 5 years follow-up data (this would be subject to a further application to NHS Digital). The UK-COMPASS team plan to examine patients’ scans and utilise data that is routinely collected by the NHS. Available data will be analysed to compare the safety and effectiveness of different treatments, and to see if a particular treatment is better suited for particular features so patients can be offered bespoke treatment strategies. 
 This work will be undertaken by the UK-COMPASS team based at the Royal Liverpool University Hospital (part of the Royal University and Broadgreen University Hospitals NHS Trust) with additional support from Liverpool Clinical Trials Unit, University of Liverpool. Only the Royal Liverpool and Broadgreen University Hospital NHS Trust and the University of Liverpool will have access to the data disseminated by NHS Digital and, for the avoidance of doubt, this excludes any other collaborators named within the protocol.

Expected Benefits:

UK-COMPASS will address the clinical and cost-effectiveness of strategies used in the treatment of juxtarenal abdominal aortic aneurysms. Current clinical practice and commissioning would benefit greatly from evidence on how different treatment strategies for juxtarenal aneurysms compare: this is the remit of the NIHR HTA programme commissioned research call 15/153. UK-COMPASS expect 4000 patients to undergo a repair of an abdominal aortic aneurysm each year and of these 1000 will be considered to be juxtarenal aortic aneurysms. Healthcare users can expect to benefit in terms of improved quality of care in the form of improved survival rates and post-operative quality of life. By undertaking this research, a comprehensive overview of current practice in the management of complex AAA will be established. The outcomes following initial management will then be followed up for a further 5 years. At present there is a wide variation in practice amongst hospitals treating this condition; UK-COMPASS will provide answers as to what is the best way of treating complex AAAs. This will ensure that the right patients are having the most appropriate management under the care of the clinicians with the greatest expertise. The findings of UK-COMPASS will allow Commissioners to reallocate funding to ensure the most clinical and cost-effective strategies are utilised thereby improving care. It is envisaged that this will be in the form of a smaller number of more experienced centres that can provide the best outcomes being commissioned to undertake these operations in the future. The UK-COMPASS team expect this study to impact on 1000 patients per year undergoing a complex AAA repair.


This work will lead to peer-reviewed publications in high impact factor journals that will guide clinicians on the treatment of patients with complex AAAs (British Journal of Surgery, Journal of Vascular Surgery, Circulation and the European Journal of Vascular Surgery), treatment guidelines (NICE), commissioning priorities and patient information material. The UK-COMPASS team aims to begin publishing academic papers within the first year of the project based on anatomical observations made on the CT scans reviewed. Commissioning guidelines will be produced over the ensuing 7 years. The UK-COMPASS team will also report back to the NIHR on a 6 monthly basis. MD and PhD students will be enrolled as part of the UK-COMPASS study team to contribute to the retrospective data reviews (outlined above) and the work they undertake will contribute to them achieving MDs and PhDs from the University of Liverpool. For avoidance of doubt, no additional uses of the data will be permitted. A simplified version of the findings will be disseminated to charities, patient groups of interest and be published on the website. All outputs will be aggregated with small numbers suppressed in line with the HES Analysis Guide. Interim findings will be published annually and a final dissemination will take place in 2025.


The study will screen all patients nationally who have undergone a procedure for an abdominal aneurysm of any sort identified from HES data between November 2017 and October 2019. This will be a retrospective data review after the procedure has taken place and will be completed every 2 months during the study period to identify all new cases. Step 1: The initial data set will comprise of HES and linked DID data and will be retrieved from NHS Digital every 2 months. It will include all patients who are at least 1 month post discharge from hospital and will include data on the 6 months prior to and up to 1 month after the procedure date. The initial data set will be transferred directly from NHS Digital to the UK-COMPASS Team at the Royal Liverpool University Hospital. The data collected at this point will be the NHS number and date of birth and will be kept on a secure server in a locked room in the NHS Picture Archiving and Communications System (PACS) office of the Royal Liverpool University Hospital. Step 2: The study is only concerned with patients who are treated for a complex juxtarenal abdominal aortic aneurysm. Therefore, all patients undergoing AAA repair need to be screened and ineligible patients removed. In order to select the eligible patients, the researchers will review all the corresponding CT scans of patients identified in Step 1. This will be done via the PACS system. PACS are digital systems for managing radiological information which are routinely used by clinical staff to review radiological images and reports every day, in every hospital. PACS contains not only radiological images to be simply viewed as they are, but also ‘raw data’ of CT scans (called DICOM data) that are essential for 3-dimensional image analysis using dedicated workstations. DIDs data are needed and will be processed by the UK-COMPASS team in order to identify CT imaging on patients who have undergone complex AAA repairs. Step 3: At the point of retrieving each scan, the UK-COMPASS PACS team will replace all patient identifiable data on the scans with a Study Serial Number and archive them securely within PACS system. The Study Serial Number will be linked to Pseudonymised HES ID. At this point, all patient identifiable data are deleted and neither the scans nor the study data will contain any patient identifiable information. The maximum duration the patient identifiable data will be held before pseudonymisation is 10 weeks. Step 4: The UK-COMPASS clinical study team at the Royal Liverpool University Hospital will then review all the scans and select patients who are eligible for the study. Anatomical measurements done on scans will be entered into the master data set that will accumulate further study data in next steps. All non-eligible patients will then be deleted from the study database and their scans will also be deleted. Over the duration of the project it is estimated that 4000 patients per year will be received in the initial dataset and of these an estimated 1000 per year will be eligible for inclusion. DIDs are needed and will be processed by the UK-COMPASS team in order to identify CT imaging on patients who have undergone complex AAA repairs. Selected HES codes of relevant to the screening review. The master database data for UK-COMPASS will be stored offline on a local secure server kept within in a locked room in LCTU. 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). No data will be shared with third parties. The findings will be shared with clinicians but these will not include any record level data regarding their patients. All outputs will contain only data that is aggregated with small numbers suppressed in line with the HES Analysis Guide. The Data will only be used for the purposes described in this Agreement.