1. West Suffolk NHS Foundation Trust, Bury St Edmunds, UK
2. Division of Anaesthesia, University of Cambridge, Addenbrooke’s Hospital, Cambridge, UK
3. School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Scotland, UK
4. University of Cambridge School of Clinical Medicine, Addenbrooke's Hospital, Cambridge, UK
5. University of Dundee School of Medicine, Ninewells Hospital & Medical School, Dundee, UK
6. Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK
7. Department of Psychiatry, University of Oxford, Oxford, UK