1. Department of Pulmonary Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan
2. Department of Pulmonary Medicine, Kyoto Chubu Medical Center, Kyoto, Japan
3. Department of Pulmonary Medicine, Kyoto Kuramaguchi Medical Center, Kyoto, Japan
4. Department of Pulmonary Medicine, Nishijin Hospital, Kyoto, Japan
5. Kyoto Industrial Health Association, Kyoto, Japan
6. Department of Pulmonary Medicine, Showa General Hospital, Tokyo, Japan