1. Royal Lancaster Infirmary; Patient Safety Research Department; Pointer Court 1, Ashton Road Lancaster UK LA1 4RP
2. Royal Bolton Hospital; Department of Gastroenterology; Minerva Road Brighton UK BL4 0JR
3. Royal United Hospitals Bath NHS Trust; Department of Anaesthesia; Combe Park Bath UK BA1 3NG
4. Royal Lancaster Infirmary; Department of Anaesthesia; Ashton Road Lancaster Lancashire UK LA1 4RP