1. Clinical Surgical Research Center, Chiang Mai University, Chiang Mai 50200, Thailand
2. Department of Surgery, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
3. Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
4. Department of Pathology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
5. Department of Radiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
6. Clinical Epidemiology and Clinical Statistics Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand