REALizing and improving management of stable COPD in China: a multi-center prospective observational study to realize the current situation of COPD patients in China (REAL) – rationale study design and protocol

摘要

Multi-stage, stratified, cluster sampling method. * All secondary and tertiary hospitals administered by NHFPC. Excluding traditional Chinese medicine hospitals; the actual hospital number and the ratio of tertiary to secondary hospitals in each region may be adjusted based on the hospital distribution in the region; subject numbers may be adjusted according to COPD outpatient numbers at the site