[1] Natl Univ Singapore, Yong Loo Lin Sch Med, 10 Med Dr, Singapore 117597, Singapore
[2] Singapore Gen Hosp, Dept Rheumatol & Immunol, Singapore, Singapore
[3] Duke NUS Med Sch, Program Hlth Sci & Syst Res, Singapore, Singapore
[4] Natl Univ Sch, Fac Sci, Dept Pharm, Singapore, Singapore
[5] Duke NUS Med Sch, Singapore, Singapore
[6] Natl Univ Singapore, Yong Loo Lin Sch Med, Dept Med, Singapore, Singapore