1. Department of Pulmonology, Yokohama City University Graduate School of Medicine, Yokohama 236-0004, Japan
2. Department of Respiratory Medicine, Yokohama Sakae Kyosai Hospital, Yokohama 247-8581, Japan
3. Department of Pulmonology, Yokohama City University Medical Center, Yokohama 232-0024, Japan
4. Department of Respiratory Medicine, Kanto Rosai Hospital, Kawasaki 211-8510, Japan
5. Department of Respiratory Medicine, Yokohama Minami Kyosai Hospital, Yokohama 236-0037, Japan
6. Department of Respiratory Medicine, Chigasaki Municipal Hospital, Chigasaki 253-0042, Japan
7. Department of Respiratory Medicine, Fujisawa Municipal Hospital, Fujisawa 251-8550, Japan
8. Department of Respiratory Medicine, Yokohama Nanbu Hospital, Yokohama 234-0054, Japan