1. Department of Primary Care Medicine, Faculty of Medicine University of Malaya Kuala Lumpur Malaysia
2. Rawang Health Clinic Ministry of Health of Malaysia Malaysia
3. NIHR Global Health Research Unit on Respiratory Health (RESPIRE), Usher Institute University of Edinburgh Edinburgh UK
4. Department of Medicine, Faculty of Medicine University of Malaya Kuala Lumpur Malaysia
5. Bandar Botanic Health Clinic, Ministry of Health Malaysia Malaysia