Funding for this research was provided by:
General Research Fund, Research Grant Council (9042296)
Text and Data Mining valid from 2020-02-12
Received: 7 June 2019
Accepted: 3 February 2020
First Online: 12 February 2020
Ethics approval and consent to participate
: This study was approved by the research ethical committee of the City University of Hong Kong. Its procedure was in compliance with the Declaration of Helsinki guidelines. All of the participants gave written consent prior to the study.
: Not applicable.
: The authors declare that they have no competing interests.