Received: 3 October 2019
Accepted: 16 December 2019
First Online: 6 January 2020
Ethics approval and consent to participate
: Written informed consent was obtained from a parent or guardian on behalf of any participants under the age of 16. The research protocol was reviewed and approved by the Ethics Committee of the Royal Thai Army Medical Department.
: Not applicable.
: The authors declare that they have no competing interests.