Received: 22 September 2019
Accepted: 25 August 2020
First Online: 11 September 2020
Ethics approval and consent to participate
: Proposal of this research was approved by IRB of Hanoi Medical University (Number 0618/HDDDDHYHN). Participants were asked to give written informed consent and were informed that they could withdraw at any time.
: The authors declare that they have no competing interests.