1. Emergency Medical Service of Castilla y León–Sacyl, 47007 Valladolid, Spain
2. Red de Investigación de Emergencias Prehospitalarias (RINVEMER), Sociedad Española de Urgencias y Emergencias (SEMES), 28020 Madrid, Spain
3. Department of Nursing, Faculty of Nursing, University of Valladolid, 47005 Valladolid, Spain
4. Emergency Medical Service of Madrid–SUMMA 112, 28045 Madrid, Spain
5. Department of Health Sciences, University of Burgos, 09001 Burgos, Spain
6. Department of Medicine, Faculty of Biomedical and Health Sciences, European University of Madrid, 28670 Madrid, Spain
7. Emergency Service, HLA Moncloa University Hospital, 28080 Madrid, Spain
8. Department of Nursing, Faculty of Medicine, Autonomous University of Madrid, 2029 Madrid, Spain