1. Meneze AM, Perez-Padilla R, Jardim JR, et al. Chronic obstructive pulmonary disease in five Latin America cities (the PLATI-NO study):a prevalence study. Lancet, 2005, 366:1875-1881.
[2]
2. Zhong N, Wang C, Yao W, et al. Prevalence of chronic obstructive pulmonary disease in China: a large, population-based survey. Am J Respir Crit Care Med, 2007, 176:753-760.
4. Leidy NK, Vernon M. Perspectives on patient-reported outcomes: content validity and qualitative research in a changing clinical trial environment. Pharmacoeconomics, 2008, 26:363-370.
[5]
5. Guidance for industry:patient-reported outcome measures:use in medical product development to support labeling claims:draft guidance.Health Qual Life Outcomes, 2009, 4:79.