1. Department of Medicine; Stellenbosch University; Stellenbosch South Africa
2. Department of Anaesthesia and Perioperative Medicine, Faculty of Health Sciences; University of Cape Town; Cape Town South Africa
3. Research and Evaluation Office; Ko Awatea, Middlemore Hospital; Auckland New Zealand
4. Department of Statistics; The University of Auckland; Auckland New Zealand
5. Emergency Medicine; Middlemore Hospital; Auckland New Zealand
6. Emergency Medicine; The University of Auckland; Auckland New Zealand