1)Fukuchi Y, et al:COPD in Japan;The Nippon COPD epidemiology study. Respirology 9:458-465, 2004
2)Qaseem A, et al:Diagnosis and management of stable chronic obstructive pulmonary disease;A clinical practice guideline update from the American College of Physicians, American College of Chest Physicians, American Thoracic Society, and European Respiratory Society. Ann Intern Med 155:179-191, 2011
3)Nishimura K, et al:Dyspnea is a better predictor of 5-year survival than airway obstruction in patients with COPD. Chest 121:1434-1440, 2002
4)Onishi K, et al:Prevalence of airflow limitation in outpatients with cardiovascular diseases in Japan. Int J Chron Obstract Pulmol Dis 9:563-568, 2014
5)Samukawa T, et al:Development of a self-scored persistent airflow obstruction sreening questionnaire in a general Japanese population;The Hisayama study. Int J Chron Obstract Pulmol Dis 12:1469-1481, 2017