4Fang X C,Wang C,Bai C X.COPD in China:the burden and importance of proper management[J].Chest,2011,139(4):920.
5GOLD Executive Committee.Global strategy for the diagnosis,managemntand prevention of chronic obstructive pulmonary disease(updated 2013)EB/OL.http://www.goldcopd org,2013,11:20.
6Cazzola M,Calzetta L,Page C,et al.Influence of N-acetylcysteine on chronic bronchitis or COPD exacerbations:a metaanalysis[J].Eur Respir Rev,2015,24(137):451-461.
7Wang F,Liu J,Zhang Y,et al.Association of Helicobacter pylori infection with chronic obstructive pulmonary disease and chronic bronchitis:a meta-analysis of 16 studies[J].Infect Dis,2015,47(9):597-603.
8Fayers P,Bottomley A,EORTC Quality of life group,et al.Qality of life research within the EORTC-the EORTC QLQC30:European Organisation for Research and Treatment of Cancer[J].Eur J Cancer,2002,38(4):125-133.
9Goren A,Gupta S,Dong P,et al.Burden of smoking among adults with COPD,chronic bronchitis,and emphysema in urban China[J].Int J Clin Pract,2015,69(9):1015-1028.