1. Department of Respiratory Medicine Hiroshima University Hospital Hiroshima Japan
2. Department of Respiratory Internal Medicine JA Onomichi General Hospital Hiroshima Japan
3. Department of Respiratory Medicine Hiroshima Prefectural Hospital Hiroshima Japan
4. Department of Respiratory Internal Medicine Hiroshima Red Cross Hospital & Atomic‐bomb Survivors Hospital Hiroshima Japan
5. Department of Respiratory Internal Medicine Kure Medical Center Hiroshima Japan
6. Department of Clinical Research Center in Hiroshima Hiroshima University Hospital Hiroshima Japan
7. Department of Respiratory Internal Medicine Hiroshima City Hiroshima Citizens Hospital Hiroshima Japan
8. Department of Respiratory Internal Medicine Hiroshima City Asa Citizens Hospital Hiroshima Japan