[1] Duke NUS Med Sch Singapore, Hlth Serv & Syst Res, Singapore, Singapore
[2] Minist Hlth, Singapore, Singapore
[3] Natl Univ Singapore, Saw Swee Hock Sch Publ Hlth, 12 Sci Dr 2, Singapore 117549, Singapore
[4] Natl Univ Singapore, NUS Grad Sch, SG, Integrat Sci & Engn Programme, Singapore, Singapore
[5] Natl Univ Singapore, Dept Sociol, Singapore, Singapore
[6] Natl Univ Singapore, Ctr Family & Populat Res, Singapore, Singapore
[7] Natl Univ Singapore, Yong Loo Lin Sch Med, Hlth Longev Translat Res Programme, 5 Sci Dr 2, Singapore 117545, Singapore
[8] Agcy Sci Technol & Res, Singapore Inst Clin Sci, Singapore, Singapore