Funding for this research was provided by:
Research Grants Council of the Hong Kong Special Administrative Region, China (17126115)
Text and Data Mining valid from 2019-11-11
Received: 19 December 2018
Accepted: 30 October 2019
First Online: 11 November 2019
Ethics approval and consent to participate
: Ethical clearance for this study was obtained prior to the start of this study from the University of Hong Kong West Cluster (UW-12-280). A written consent from 18 years or older subjects, and parents/primary caregivers of subjects younger than 18 years old, were obtained from all participants. A local ethics committee ruled that no formal ethics approval was required in this particular case.
: Not applicable.
: The authors declare that they have no competing interests.