[1] Univ Malaya, Fac Med, Dept Med, Kuala Lumpur, Malaysia
[2] Univ Malaya, Fac Med, Dept Primary Care Med, Kuala Lumpur, Malaysia
[3] Sunway Univ, Sch Med & Life Sci, Dept Med Sci, Bandar Sunway, Selangor, Malaysia
[4] Int Med Univ, Dept Med, Seremban, Negeri Sembilan, Malaysia
[5] Univ Malaysia Sarawak, Fac Med & Hlth Sci, Dept Med, Kota Samarahan, Sarawak, Malaysia
[6] Natl Univ Malaysia, Fac Med, Dept Med, Kuala Lumpur, Malaysia
[7] Univ Malaya, Fac Med, Dept Med, Kuala Lumpur 50603, Malaysia