[1] Natl Univ Hlth Syst, Natl Univ Hosp, Singapore 119074, Singapore
[2] MOH Holdings Pte Ltd, 1 Maritime Sq, Singapore 099253, Singapore
[3] Univ Nottingham, Queens Med Ctr, Med Sch, Nottingham NG7 2UH, England
[4] Buangkok Green Med Pk, Inst Mental Hlth, 10 Buangkok View, Singapore 539747, Singapore
[5] KK Womens & Childrens Hosp, 100 Bukit Timah Rd, Singapore 229899, Singapore