Received: 15 March 2021
Accepted: 17 May 2021
First Online: 21 June 2021
: The project has been granted ethical approval by the Survey and Behavioral Research Ethics Committee of the Chinese University of Hong Kong (Ref No.: SBRE-19-433). Since all the data used for secondary analysis in this study were retrospective, pre-existing and de-identified, informed consents from the participants were waived by the Survey and Behavioral Research Ethics Committee of the Chinese University of Hong Kong. All methods in this study were performed in accordance with Declaration of Helsinki.
: Not applicable.
: We declare that we have no conflict of interest.