Funding for this research was provided by:
National Research Council of Thailand
Thailand Research Fund
Higher Education Research Promotion
Received: 7 January 2018
Accepted: 25 August 2019
First Online: 18 September 2019
Ethics approval and consent to participate
: This study was conducted in accordance with the Helsinki Declaration and approved by the Ethics Committee, Ramathibodi Hospital, Mahidol University, Thailand. Written informed consent was obtained.
: Not applicable
: The authors declare that they have no competing interests.