Received: 21 January 2019
Accepted: 16 September 2019
First Online: 16 October 2019
Ethics approval and consent to participate
: The study was performed in accordance with the Declaration of Helsinki. Procedures on clinical research were based on the practical handbook for investigators from Hospital Authority. Approvals from ethics committees from all 5 clusters were obtained in Hospital Authority. References for different clusters were: HKEC-2013-020, KC/KE-13-0055/ER-2, KC/KE-13-0036/ER-1, CREC-2012-492-T, NTWC/CREC/115/13. Certificates for clinical trial were also obtained from Department of Health, Hong Kong, for 5 clusters. Reference numbers were: PR/CT0281/2016, PR/CT 0339/2014, PR/CT0299/2014, PR/CT280/2014, PR/CT/0320/2016. Written consent was obtained from patients before the start of the study.
: Not applicable.
: The authors declare that they have no competing interests.