Title: Emergency Surgery Or noT for common Vascular conditions (the ESORT-V study)
Funder: Department of Health and Social Care

Abstract: Research question How effective and cost-effective is urgent versus elective surgery for patients with common vascular conditions? Background For common vascular conditions including abdominal aortic aneurysms (AAA), carotid artery stenosis and peripheral arterial disease (PAD), it is unclear which patients benefit from urgent versus elective surgery. Aims and Objectives Estimate the effectiveness and cost-effectiveness of urgent versus elective surgery, recognising COVID-19 impact on vascular surgery provision. The objectives are to evaluate the: Clinical and cost-effectiveness of urgent versus elective surgery for common vascular conditions. Clinical and cost-effectiveness in specific patient subgroups (e.g. diagnostic subcategories). Provide recommendations about which subgroups should have urgent versus elective surgery, and define subpopulations/comparison groups for RCT. Methods The study will emulate a target trial . The target population will include patients with AAA, carotid artery stenosis and PAD. The intervention and comparator strategies are: urgent and elective surgery, with precise definitions to be confirmed by a clinical panel. An instrumental variable (IV) design will provide accurate estimates of relative effectiveness, despite unmeasured prognostic differences between groups. The IV will be each vascular centre s &ldquo;tendency to expedite surgery&rdquo;, defined as their propensity to perform surgery before (urgent), or after (elective) defined timepoints. This IV exploits the wide variation across vascular units, in the time to surgery for these conditions. The study will report the effectiveness and cost-effectiveness of urgent versus elective surgery, minimising possible bias from unobserved confounding. This study will use National Vascular Registry (NVR) data, Hospital Episode Statistics (HES) database and linked Office for National Statistics (ONS) mortality data. We will collate information on diagnosis, case-mix, surgical procedures received, resource use and outcomes. The primary outcome of days alive and out of hospital (DAOH) at day 90, has been recommended by the PPI co-applicants and a panel of patients. Other outcomes include mortality, and numbers of re-interventions. We will hold PPI panels at the design stage to help understand the magnitude of difference in DAOH that is important to patients. The cost-effectiveness analyses will use mortality and resource use data from the linked NVR-HES-ONS dataset. Cost-effectiveness analyses will use the best available literature estimates of HRQoL for each condition, combined with survival time to report QALYs, and then with costs to estimate incremental cost-effectiveness. We will report results for subgroups including diagnostic subcategories. We will convene clinical and PPI workshops to guide translation, and inform the design of a future RCT, for the condition and patient subgroups for which a trial would be most useful. Timelines Months 0-3: extract HES index admissions and perform data linkage Months 3-6: design workshops (clinical, PPI), finalise analysis plans Months 6-14: extract HRQoL from literature; data analysis Months 14-18: translation workshops; conference presentations, draft papers, and project report. Anticipated impact Clinical co-applicants and advisory panel will ensure translation to key clinical organisations and guidelines. The study will identify patient subgroups for whom urgent versus elective surgery is worthwhile, to inform clinical practice by Q4-2022. A RCT proposal submitted in 2022, can inform clinical practice in 2026 (pending NIHR funding).

Lay abstract: Many people need major surgery for conditions that affect their blood vessels. Surgery can prevent strokes, limb removal and death. These operations are high risk and costly and require careful planning to improve patient health. For most patients, it is not clear whether it is better to have surgery very soon or have planned surgery at a later date. There is very little proof on which to base advice, and there are differences in the time it takes to have surgery depending on which hospital a patient is in. Sometimes, doctors recommend that patients have surgery at a later date, so that the patient can have other treatments or exercise classes first. This is so they have a better chance of the surgery going well and recovering quicker afterwards. However, delaying surgery can be dangerous, because blood vessel disease sometimes becomes worse very quickly. Patients may also worry about waiting. Our study will find out which patients with blood vessel disease may benefit from having surgery sooner versus those who would benefit from waiting. It will help us understand the benefits, risks and costs in each situation. We will also identify groups of patients who could benefit from new studies in the future, so we can then check to see what the best approach is. We will use information already collected about patients who have had major blood vessel surgery from 2016-20. We will compare patients who had surgery more quickly with those who had more of a delay. We will look at what happens to patients after surgery, e.g. how quickly they leave hospital, and value for money. This will help us to assess which groups of patients (e.g. age groups or types of blood vessel disease) would benefit more from having surgery sooner or later. Two experienced patient representatives co-wrote our application, and patients and members of the public from the National Institute for Health Research (NIHR) Applied Research Collaboration (ARC) North Thames Research Advisory Panel also informed our study design. The study will be supported by the Bristol Vascular Patient Advisory Group, the Vascular Society of Great Britain and Ireland special interest groups and includes ex-patients. We will hold two online discussions with our patient groups to get their advice on how best to explain the study and its results to patients and the public. Our results will be discussed with patient, public and clinical representatives, presented at conferences and published in high-quality research journals. We will use our links with key organisations to include the study findings in guidelines. We will share our results with patients and the public through plain English summaries and updates on our study website, newsletters and social media.

Research activity codes: 8.1 ORGANISATION AND DELIVERY OF SERVICES
Health categories: CARDIOVASCULAR