1. Department of Community Health, Faculty of Medicine, Universiti Kebangsaan Malaysia, Selangor, Malaysia.
2. Faculty of Business and Management, Universiti Teknologi MARA Selangor, Selangor, Malaysia.
3. Department of Community Health, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Malaysia.
4. Medical Department, Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Malaysia.