Funding for this research was provided by:
Health and Medical Research Fund, Food and Health Bureau, Hong Kong SAR Government (16172831)
Received: 27 June 2019
Accepted: 31 July 2019
First Online: 9 August 2019
Ethics approval and consent to participate
: This study has been approved by the Institutional Review Board of the Hospital Authority Hong Kong New Territories West Cluster (reference NTWC/REC/19001). Written consent will be obtained from the subjects after fully informing them of the study’s purpose and details.
: Not applicable.
: Ho Cheung William Li (Corresponding author) and Man Ping Wang (co-author) are Associate Editors for BMC Public Health. Other authors declare that they have no competing interests.