Title: Defining the high-risk surgical population in the National Health Service
Funder: Department of Health and Social Care

Abstract: Background The findings of my preliminary work revealed that more than 5 million surgical procedures are performed in the NHS each year at a cost of 9.5 billion (8% of NHS budget). Overall, the 30-day post-operative mortality rate is low (1%) but this figure does not reflect outcomes for a smaller high-risk sub-population which accounts for four out of five deaths. Despite the huge scale of NHS surgical services, we lack the most basic information describing numbers of patients who undergo different types of surgery, their age, and how many die. Experience from national audits of a few selected surgical procedures (e.g. cardiac, bowel cancer) shows that robust epidemiological data are essential for planning and delivering safe, effective surgical services.Aims 1. To provide an accurate, epidemiological description of the overall NHS surgical population. 2. To describe how the risk of short-term (90-day) post-operative mortality relates to the ongoing risk of death over the subsequent five years amongst patients who survive the acute surgical episode. 3. To describe equivalent surgical populations within other international healthcare systems, providing comparative benchmarks for NHS surgical care. 4. To explore how patients' burden of healthcare need changes after surgery, using data describing both the primary and secondary care they receive. 5. To compare quality of life outcomes during the year after surgery for different surgical risk categories.Methods Analysing 50 million NHS surgical patient episodes from 2005-2015, I will outline the baseline characteristics of the UK surgical population. I will use multivariable Cox proportional-hazards regression analysis to identify sub-groups according to differing levels of risk of short-term mortality, and describe the long-term survival for patients in these sub-groups. To develop regression models, plausible variables will be entered into a backward step selection process. I will then conduct equivalent, comparative analyses of international datasets from Sweden and Canada. I will use linked primary and secondary care data describing patients in East London to explore changes in healthcare burden before and after surgery. Finally, I will combine individual patient data from various sources including large randomised trials to explore how surgery affects quality of life as measured by the EuroQol five dimension (EQ-5D) tool. Timeline Complete project 1 (aims 1 & 2) by the end of year 1, project 2 (aim 3) by the end of year 2, and projects 3 and 4 (aims 4 & 5) by the middle of year 3. This timeline provides contingency for project over-runs and time to disseminate my findings. Information governance approvals are already in place or in preparation for access to all the necessary datasets.Impact and dissemination This work will provide a definitive and long-awaited epidemiological description of the NHS surgical population, with particular focus on the short-term harm and long-term success of surgery for high-risk patients. This information will transform current treatment for this patient group, enabling shared decision-making for patients, allowing doctors to tailor NHS services to patients with complex needs, and informing healthcare policy makers as they plan safe and effective surgical services.

Lay abstract: BackgroundMore than 5 million surgical procedures are performed in the NHS each year, with 49,000 deaths within 30 days. We spend 9.5 billion a year on surgical treatments (8% of NHS budget), yet we know surprisingly little about the patients who undergo surgery. Some specialities, such as cardiac surgery, collect and analyse detailed data on their patients, but this does not occur for most procedures. We therefore lack the most basic statistical information describing numbers of patients who undergo different types of surgery, their age, and how many die.Importantly, a sub-group of around 250,000 high-risk surgical patients is concealed within the larger surgical population. These patients are typically older with complex long-term illnesses such as diabetes, heart failure or lung disease. They often experience poor outcomes after surgery and account for four out of five deaths. Patients who survive to leave hospital may still experience a poor quality of life, and are likely to have high primary and social care needs. We know that high throughput NHS services struggle to provide the individualised care these patients require.To plan safe and effective surgical care for this important patient group, we need up to date information describing the number of patients at risk, the short-term harms of surgery, and the long-term success in terms of quality of life and survival. We also need to understand how high-risk surgical patients in the UK compare to other countries. This information will help patients to make better choices about surgical treatments, support doctors to care for individuals with complex needs, and inform policy makers in planning cost effective surgical services which deliver better patient outcomes.Aims1. To describe the overall NHS surgical population, the number of procedures performed and the age and health of those having surgery. 2. To describe how the short-term risk of death after surgery relates to the long-term risk of poor patient outcomes. 3. To compare the NHS surgical population with similar patients in other international healthcare systems. 4. To explore how patients' need for healthcare changes after surgery, using data describing the GP and hospital care they receive. 5. To compare quality of life during the year after surgery amongst different patient risk categories.MethodsUsing data for all NHS patients undergoing surgery over a 10-year period (~50 million patients), I will apply advanced statistical techniques to outline the characteristics of the NHS surgical population and identify sub-groups of patients with differing risks of death. We will compare our results in the NHS surgical population to those of patients undergoing surgery in Sweden and Canada. I will then analyse a linked database of GP and hospital records in East London to describe all healthcare needs of patients in the years after surgery. Finally, I will combine data from previous large studies to understand how quality of life is affected after surgery.Expected outcomes This project will provide a definitive and up to date description of NHS surgical patients, and the outcomes they experience after surgery to identify patient groups at greatest risk, their long-term outcomes and healthcare needs.Patient & Public InvolvementThis project meets research priorities identified by patients and doctors in the James Lind Alliance Priority Setting Partnership in Anaesthesia and Perioperative Care. We are grateful for detailed advice from the Royal College of Anaesthetists PPI group, which has helped us develop this proposal. Our named patient representative has lived experience of major surgery, and will advise on the patient perspective throughout this research, and dissemination of our findings.

Research activity codes: 6.4 SURGERY
Health categories: GENERIC HEALTH RELEVANCE