Funding for this research was provided by:
National Medical Research Council (NMRC/TCR/016-NNI/2016)
Received: 11 June 2019
Accepted: 13 January 2020
First Online: 31 January 2020
Ethics approval and consent to participate
: This retrospective review was carried out with waiver of consent by the SingHealth Centralized Institutional Review Board.
: Not applicable.
: The authors declare that they have no conflict of interest.