1. Department of Family Medicine, Faculty of Medicine and Health, National Defense, University of Malaysia, Sg. Besi 57000, Malaysia
2. Sector for Biostatistics and Data Repository, National Institutes of Health, Ministry of Health Malaysia, Shah Alam 40170, Malaysia
3. Department of Psychiatry, Faculty of Medicine, Universiti Teknologi MARA (UiTM), Sg. Buloh 47000, Malaysia
4. Family Health Development Division, Ministry of Health Malaysia, Putrajaya 62590, Malaysia
5. Klinik Kesihatan Bandar Botanik, Ministry of Health Malaysia, Klang 42000, Malaysia
6. Department of Family Medicine, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang 43400, Malaysia
7. Laboratory of Medical Gerontology, Malaysian Research Institute on Ageing (MyAgeing), Universiti Putra Malaysia, Serdang 43400, Malaysia
8. Department of Family Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia