[1] Natl Univ Healthcare Syst, Natl Univ Hosp, Univ Med Cluster, Div Adv Internal Med, 1E Kent Ridge Rd,NUHS Tower Block,Level 10, Singapore 119228, Singapore
[2] Natl Univ Healthcare Syst, Natl Univ Hosp, Univ Med Cluster, Div Geriatr Med, Singapore, Singapore
[3] Natl Univ Singapore, Yong Loo Lin Sch Med, Biostat Unit, Singapore, Singapore
[4] Natl Univ Singapore, Yong Loo Lin Sch Med, Deans Off, Singapore, Singapore
[5] Natl Univ Singapore, Yong Loo Lin Sch Med, Dept Med, Singapore, Singapore
[6] Natl Univ Healthcare Syst, Natl Univ Hosp, Dept Nursing, Singapore, Singapore
[7] Natl Univ Healthcare Syst, Natl Univ Hosp, Management Informat Corp Planning & Dev, Singapore, Singapore