1. Division of Pulmonary and Critical Care Medicine, Daegu Fatima Hospital, Daegu, Korea.
2. Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea.
3. Department of Internal Medicine, Catholic University of Daegu School of Medicine, Daegu, Korea.
4. Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Korea.
5. Department of Internal Medicine, Dongguk University College of Medicine, Gyeongju, Korea.
6. Department of Internal Medicine, Sunlin Hospital, Handong Global University, Pohang, Korea.