1. Department of Primary Care Medicine, University Malaya Primary Care Research Group (UMPCRG), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
2. Pharmacy Department, University Malaya Medical Centre, Kuala Lumpur, Malaysia
3. Department of Surgery, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
4. Department of Medicine, Faculty of Medicine, University Malaya, Kuala Lumpur, Malaysia