1. Centre for Clinical Research in Emergency Medicine; Harry Perkins Institute of Medical Research (formerly the Western Australian Institute of Medical Research); Perth Western Australia Australia
2. School of Primary, Aboriginal and Rural Health Care; University of Western Australia; Perth Western Australia Australia
3. Department of Emergency Medicine; Royal Perth Hospital; Perth Western Australia Australia
4. School of Medicine and Public Health; University of Newcastle; Newcastle New South Wales Australia
5. Department of Clinical Toxicology and Pharmacology; Calvary Mater Newcastle; Newcastle New South Wales Australia