1. General Surgery Department, Nhan dan Gia Dinh Hospital, 1 No Trang Long Street, Ward 7, Binh Thanh District, Ho Chi Minh City, Vietnam
2. Department of Medical Statistics and Informatics, University of Medicine and Pharmacy at Ho Chi Minh City, 217 Hong Bang Street, Ward 11, District 5, Ho Chi Minh City, Vietnam
3. Planning Department, Nhan dan Gia Dinh Hospital, 1 No Trang Long Street, Ward 7, Binh Thanh District, Ho Chi Minh City, Vietnam