4GOLD Executive Committee. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease ( Revised 2011 ). www. goldeopd, com.
5GOLD Executive Committee[DB/OL].Guidelines:Global Strategy for Diagnosis,Management,and Prevention of COPD,November 2006[2006-11-18].http://www.goldcopd.com/Guidelineitem.asp? l1 =2-12 = 1&intId =989.
6Celli BR,MacNee W,Committee members.Standard for the diagnosis and treatment of patients with COPD:a summary of the ATS/ERS position paper.Eur Respir J,2004,23:932-946.
7Celli BR,Cote CG,Marin JM,ct al.The body mass index,airflow obstruction,dyspnea and exercise capacity index in chronic obstructive pulmonary disease.N Engl J Med,2004,350:1005-1012.