Funding for this research was provided by:
Singapore National Medical Research Council (NMRC/CSA-SI/0010/2017)
Received: 13 June 2020
Accepted: 22 March 2021
First Online: 1 April 2021
: The study was approved by the Domain Specific Review Board (Reference number: 2011/01716) of the National Healthcare Group, and was performed according to the declaration of Helsinki. Informed written consent was obtained from all participants.
: Not applicable.
: The authors declare that they have no competing interests.