1. Division of Hematology and Oncology, Department of Pediatrics, Faculty of Medicine, Prince of Songkla University, Hat Yai, Thailand
2. Division of Rheumatology, Department of Pediatrics, Faculty of Medicine, Prince of Songkla University, Hat Yai, Thailand
3. Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, Hat Yai, Thailand