1. Singapore Society of Intensive Care Medicine's National Investigators for Clinical Epidemiology and Research, Singapore
2. Division of Respiratory and Critical Care Medicine, Department of Medicine, National University Hospital.
3. Department of Respiratory and Critical Care Medicine, Tan Tock Seng Hospital.
4. Department of Respiratory Medicine, Changi General Hospital.
5. Department of Respiratory and Critical Care Medicine, Singapore General Hospital and Respiratory Medical Associates, Gleneagles Medical Centre.
6. Medical Intensive Care Unit, Khoo Teck Puat Hospital.
7. Department of Anaesthesiology, Intensive Care and Pain Medicine, Tan Tock Seng Hospital.
8. Department of Anaesthesiology, Singapore General Hospital.
9. Department of Anaesthesia, Khoo Teck Puat Hospital.
10. Department of Anaesthesia, National University Hospital.
11. Department of Anaesthesia and Surgical Intensive Care, Changi General Hospital.
12. Biostatistician, Biostatistics Unit, Yong Loo Lin School of Medicine, National University of Singapore.
13. Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.