1. Department of Respiratory Medicine, Yokohama Minami Kyosai Hospital, Yokohama, Japan
2. Department of Respiratory Medicine, Seirei Yokohama Hospital, Yokohama, Japan
3. Department of Respiratory Medicine, Isehara Kyodo Hospital, Isehara, Japan
4. Department of Respiratory Medicine, Yokohama City University Hospital, Yokohama, Japan