1. Department of Medicine, College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
2. Pediatrics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
3. Department of Medicine, King Fahad Medical City, Riyadh, Saudi Arabia
4. Department of Medicine, Respiratory Division, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
5. Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
6. Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
7. Department of Pediatrics, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
8. Department of Respiratory Care, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
9. Department of Paediatrics, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates