[1] Univ Malaya, Fac Med, Dept Primary Care Med, Primary Care Res Grp, Kuala Lumpur 50603, Malaysia
[2] Univ Malaya, Fac Med, Dept Pediat, Kuala Lumpur 50603, Malaysia
[3] Univ Malaya, Fac Med, Deans Off, Kuala Lumpur 50603, Malaysia
[4] Univ Malaya, Fac Med, Dept Med, Kuala Lumpur 50603, Malaysia
[5] Monash Univ Malaysia, Jeffrey Cheah Sch Med & Hlth Sci, Subang Jaya 47500, Selangor, Malaysia
[6] Hosp Kuala Lumpur, Inst Pediat, Kuala Lumpur 50586, Malaysia