1. Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.
2. Division of Emergency Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Bellville, South Africa.
3. Stellenbosch Institute for Advanced Study, Wallenberg Research Centre at Stellenbosch University, Stellenbosch, South Africa.
4. University of South Africa, Pretoria, South Africa.