1. Department of Respiratory Medicine, Hakodate Goryoukaku Hospital , Hokkaido, Japan , , Sapporo, Japan and , 38-3 Goryoukaku-cho, Hakodate-shi , Hokkaido 040-8611, Japan
2. Department of Respiratory Medicine and Allergology, Sapporo Medical University School of Medicine , Hokkaido, Japan , , Sapporo, Japan and , 38-3 Goryoukaku-cho, Hakodate-shi , Hokkaido 040-8611, Japan
3. Department of Pulmonary Medicine, Hakodate Goryoukaku Hospital , Hokkaido, Japan , , Sapporo, Japan and , 38-3 Goryoukaku-cho, Hakodate-shi , Hokkaido 040-8611, Japan
4. Department of Respiratory Medicine, Hakodate Goryoukaku Hospital , Hokkaido, Japan
5. Department of Respiratory Medicine and Allergology, Sapporo Medical University School of Medicine , Sapporo, Japan