1. Research Center, King Fahad Medical City, Riyadh, Saudi Arabia
2. Epidemiology Department of Health Sciences, University of Leicester, Centre for Medicine, University Road, Leicester LE1 7RH, UK
3. King Saud University Medical City, Riyadh, Saudi Arabia
4. Neonatal Intensive Care Unit, King Fahad Medical City, Children Specialized Hospital, Riyadh, Saudi Arabia
5. Emergency Medicine Department, College of Medicine and University Medical City, King Saud University, Riyadh, Saudi Arabia