1. Department of Pre-Clinical Sciences, Faculty of Medicine and Health Sciences, Universiti Tunku Abdul Rahman, Kajang, Malaysia
2. Klinik Kesihatan Pelabuhan Klang, Ministry of Health Malaysia, Klang, Malaysia
3. National Institute of Health, Ministry of Health Malaysia, Setia Alam, Malaysia
4. Family Health Development Division, Ministry of Health Malaysia, Setia Alam, Malaysia
5. Department of Family Medicine, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
6. Malaysian Research Institute on Ageing, Universiti Putra Malaysia, Serdang, Malaysia
7. Klinik Kesihatan Seksyen 7, Ministry of Health Malaysia, Shah Alam, Malaysia
8. Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Cheras, Malaysia
9. Klinik Kesihatan Selayang Baru, Ministry of Health Malaysia, Batu Caves, Malaysia
10. Klinik Kesihatan Cheras Batu 9, Ministry of Health Malaysia, Cheras, Malaysia
11. Klinik Kesihatan Teluk Panglima Garang, Ministry of Health Malaysia, Teluk Panglima Garang, Malaysia