Funding for this research was provided by:
Singapore Ministry of Health’s National Medical Research Council under the Centre Grant Programme (Grant No.: NMRC/CG/004/2014)
Received: 29 March 2019
Accepted: 27 July 2019
First Online: 14 August 2019
Ethics approval and consent to participate
: Ethics approval (DSRB 2014/01099) was obtained from the Domain Specific Review Board of the National Healthcare Group, Singapore. Written informed consent was obtained from all participants.
: Not applicable.
: The authors declare they have no competing interests.