1. Perioperative Care of Older People undergoing Surgery (POPS), Department of Ageing and Health, Guy’s and St Thomas’ NHS Foundation Trust, London, UK
2. National Emergency Laparotomy Audit, Royal College of Anaesthetists, London, UK
3. Division of Primary Care and Public Health Sciences, Faculty of Life Sciences and Medicine, King’s College London, London, UK
4. Health Systems Research, UCL Division of Targeted Intervention, London, UK
5. Department of Anaesthesia, James Cook University Hospital, Middlesbrough, UK
6. Department of Anaesthesia, Medway Maritime Hospital, Kent, UK
7. General Surgery Unit, Bradford Royal Infirmary, Bradford Teaching Hospitals, Bradford, UK
8. School of Population Health & Environmental Sciences, King’s College London, London, UK
9. Division of Surgery and Interventional Science, University College London, London, UK