1. Acute Intensive Care Unit, Wythenshawe Hospital, Manchester University Foundation Trust, Manchester, UK
2. School of Health and Social Work, University of Hertfordshire, Hatfield, Hertfordshire, UK
3. Anaesthetics and Intensive Care, Norfolk and Norwich University Hospitals NHS Foundation Trust, Norwich, UK
4. Intensive Care and Anaesthesia, Barts Health NHS Trust, London, UK
5. Intensive Care Unit, Royal Infirmary of Edinburgh, Little France, Edinburgh, UK
6. Critical Care Unit, Salford Royal NHS Foundation Trust, Northern Care Alliance NHS Group, Greater Manchester, UK