Received: 5 November 2020
Accepted: 18 February 2021
First Online: 11 March 2021
: This study was approved by the Survey and Behavioral Research Ethics Committee of The Chinese University of Hong Kong. The study protocol was in accordance with the Declaration of Helsinki. Informed consent was obtained from all participants.
: Not applicable.
: The authors declare that they have no competing interests as defined by BMC, or other interests that might be perceived to influence the results and/or discussion reported in this paper.