1. Department of Otolaryngology, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam
2. Department of Otolaryngology - Head and Neck Surgery, University Medical Center at Ho Chi Minh City, Ho Chi Minh City, Vietnam
3. International SOS, Center Point Tower at Ho Chi Minh City, Ho Chi Minh City, Vietnam
4. Department of Medical Statistics and Informatics, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam.