Department of Respiratory Medicine, National Hospital Organization Wakayama Hospital, Wakayama, Japan. Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan. Clinical Research Unit of Respiratory Pathophysiology, Juntendo University Graduate School of Health Care and Nursing, Chiba, Japan. Division of Respiratory Medicine, Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan. Medical Division, Nippon Boehringer Ingelheim Co. Ltd., Tokyo, Japan. Clinical Information Division Data Science Center, Statistics Analysis Department 1, EPS Corporation, Tokyo, Japan. Department of Respiratory Medicine, Graduate School of Medicine, Osaka City University, Osaka, Japan. Department of Respiratory Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan.