1. Department of Preventive Medicine, School of Medicine, and Institute of Health Sciences, Gyeongsang National University, JinJu, Korea.
2. Department of Preventive Medicine, School of Medicine, Kyungpook National University, Daegu, Korea.
3. Department of Pediatrics, Keimyung University School of Medicine, Daegu, Korea.
4. Han-Young Pediatric Hospital, Daegu, Korea.