Received: 22 December 2019
Accepted: 7 September 2020
First Online: 21 September 2020
Ethics approval and consent to participate
: This study has been approved by Human Subjects Ethics Sub-committee, The Hong Kong Polytechnic University. The reference number is: HSEARS20180528003. All participants have been informed about the content of the study as well as the risks. This study has obtained written consent from all participants.
: Not applicable.
: Author Daniel Lai was an Associate Editor of the journal.