1. Intensive Care Unit Glasgow Royal Infirmary and School of Medicine Dentistry and Nursing University of Glasgow UK
2. University of the West of Scotland Glasgow UK
3. NHS Greater Glasgow and Clyde Glasgow UK
4. Belfast Health and Social Care Trust Belfast UK
5. University of Glasgow Library Glasgow UK
6. Center for Clinical Epidemiology and Biostatistics Division of Pulmonary, Allergy, and Critical Care Medicine Perelman School of Medicine University of Pennsylvania Philadelphia PA USA
7. Centre for Clinical Management Research VA Ann Arbor Health System Ann Arbor MI USA
8. Department of Internal Medicine Division of Pulmonary and Critical Care University of Michigan Ann Arbor MI USA
9. MRC/CSO Social and Public Health Sciences Unit University of Glasgow Glasgow UK
10. Clinical Physics NHS Greater Glasgow and Clyde Glasgow UK
11. School of Medicine Dentistry and Nursing University of Glasgow Glasgow UK
12. Intensive Care Unit Glasgow Royal Infirmary Glasgow UK