title: Reply.
authors.affiliation: National University Hospital, Singapore, Tower Block Level 10, 1E Kent Ridge Rd, Singapore 119228. Electronic address: mdcmec@nus.edu.sg.
authors.forename: Matthew
authors.initials: M
authors.lastname: Cove
authors.affiliation: National University Hospital, Singapore, Tower Block Level 10, 1E Kent Ridge Rd, Singapore 119228.
authors.forename: Ramanathan
authors.initials: R
authors.lastname: Kollengode
authors.affiliation: National University Hospital, Singapore, Tower Block Level 10, 1E Kent Ridge Rd, Singapore 119228.
authors.forename: Graeme
authors.initials: G
authors.lastname: MacLaren
authors.affiliation: Saw Swee Hock School of Public Health, National University Hospital, Singapore, Tower Block Level 10, 1E Kent Ridge Rd, Singapore 119228.
authors.forename: Chuen Seng
authors.initials: CS
authors.lastname: Tan