Tang, Hong K. http://orcid.org/0000-0003-2410-9177
Nguyen, Chi T.C. http://orcid.org/0000-0002-4669-6010
Vo, Ngoc H.T. http://orcid.org/0000-0002-0300-4387
Article History
Received: 24 February 2021
Accepted: 9 June 2021
First Online: 13 September 2021
Declarations
:
: The ethics committee for Medical research of Pham Ngoc Thach University of Medicine (PNTUM) approved the study (Decision No. 2300/2019/HD-TDHYKPNT). Also the study was approved by the Education Department and the school principals at each of the selected schools. Written consent was obtained from both students and their parents before the data collection.
: None.
: Informed consent was sent and signed by participant parents or legal guardians. All subjects were also asked to give verbal assent immediately before examination.