Funding for this research was provided by:
National Medical Research Council Singapore (NMRC/CG/C026/2017_NUHS)
National University of Singapore (NA)
Received: 22 September 2019
Accepted: 19 February 2020
First Online: 27 February 2020
Ethics approval and consent to participate
: Ethical approval for this study was obtained from the National Healthcare Group Domain Specific Review Board (DSRB). All participants were presented the participant information sheet and signed the consent form to participate in this study.
: Not applicable.
: The authors declare that they have no competing interests.