[1] Univ Malaya, Fac Med, UM eHlth Unit, Kuala Lumpur, Malaysia
[2] Univ Putra Malaysia, Fac Med & Hlth Sci, Dept Family Med, Serdang, Selangor, Malaysia
[3] Univ Edinburgh, Usher Inst, NIHR Global Hlth Res Unit Resp Hlth RESPIRE, Edinburgh, Midlothian, Scotland
[4] Univ Malaya, Fac Med, Dept Primary Care Med, Kuala Lumpur, Malaysia
[5] Minist Hlth Malaysia, Klin Kesihatan Lukut, Port Dickson, Negeri Sembilan, Malaysia
[6] Univ Malaya, Fac Med, Dept Med, Kuala Lumpur, Malaysia
[7] Taylors Univ, Fac Hlth & Med Sci, Sch Med, Subang Jaya, Selangor, Malaysia