1. Division of Respiratory Medicine, Department of Internal Medicine Kobe University Graduate School of Medicine Kobe Japan
2. Department of Respiratory Medicine Kita‐Harima Medical Center Ono‐City Japan
3. Department of Respiratory Medicine Akashi Medical Center Akashi Japan
4. Department of Respiratory Medicine Hyogo Prefectural Awaji Medical Center Sumoto Japan
5. Department of Respiratory Medicine Takatsuki General Hospital Osaka Japan