Received: 26 November 2020
Accepted: 23 March 2021
First Online: 7 April 2021
: The SPA received ethical approval from the Institute for Population and Social Research of Mahidol University with annual update: COA. N0. 2016–07-166 (SPA2016), COA. N0. 2017–06-152 (SPA2017), COA. No. 2018.06–192(SPA2018), COA. No. 2019/04–152 (SPA2019). All participants provided voluntary informed consent prior to their inclusion in the study.
: Not applicable.
: None of the authors have any competing interests.