Received: 15 November 2019
Accepted: 19 July 2020
First Online: 4 September 2020
Ethics approval and consent to participate
: The study aim and protocol were reviewed and approved by the Ethical Review Committee for Human Research, Faculty of Public Health, Mahidol University, Bangkok, Thailand. The interviewees were informed in advance that their participation was strictly voluntary and that all information provided would remain confidential. All participants signed a written consent form.
: The manuscript does not contain any data on individual persons.
: The authors declare that they have no competing interests.