[Study on the situation of drug use in patients with chronic obstructive pulmonary diseases in the Chinese communities of large cities]. 
Objectives: To understand the medication being used among patients with chronic obstructive pulmonary diseases (COPD) in Chinese communities of large cities.  Methods: A cross-sectional survey was carried out in Beijing, Shanghai, Chengdu and Guangzhou with the total number as 678 COPD cases who were continuously recruited.  Subjects were face-to-face interviewed using a structured questionnaire and with medical records checked at the same time.  All data were double entered into a database under EpiData 3.1, and analyzed by SAS 9.2.  Results: One quarter of all the subjects did not receive any clinical treatment.  The top three drugs for COPD were expectorant (50.74%), phosphodiesterase inhibitors (49.56%), and leukotriene (49.12%).  Totally, there were 36 different types combination of drugs used for COPD and the proportions of drugs being used as one, two, and three or more at the same time were 29.5%(200 cases), 39.7%(269 cases) and 30.8%(209 cases) respectively.  In addition 36.6% (248 cases) of them used oxygen.  There were statistical correlations between drug-use patterns and the severity of COPD.  Conclusion: The patterns of medication varied over COPD cases in communities from Chinese large cities and appeared differently under the recommendations in the clinical guidelines set for COPD.  Guidance and surveillance programs on drugs use for COPD should be improved on patients with COPD in the Chinese communities.