Text and Data Mining valid from 2019-06-11
Received: 13 November 2018
Accepted: 31 May 2019
First Online: 11 June 2019
Ethics approval and consent to participate
: The National Ethics Committee for Health Research (NECHR) of the Ministry of Health, Cambodia (No. 420 NECHR). A written informed consent was obtained from each participant.
: Not applicable.
: The authors declare that they have no competing interests.