China Case Finding Project

A study to evaluate the test accuracy of different screening strategies for identifying undiagnosed COPD in China, amongst patients (≥40 years) attending community health centres.

Research question:

What are the most cost effective screening strategies for identifying undiagnosed COPD in the general population in China?

Study design

Cross-sectional study (screening test accuracy)


General population, aged ≥40 years, living in four cities in China: Beijing (North), Chengdu (South West), Guangzhou (South), Shenyang (North East).


Eligible patients attending community centers will be invited to attend a study assessment session. Consented patients will undertake study measures including screening tests (questionnaires, peak flow and microspirometry) and diagnostic quality spirometry.

Sample size:

The study will aim to recruit approximately 2,600 patients.


Test performance (sensitivity, specificity, positive predictive value, negative predictive value, area under the curve) of all screening tests and strategies will be compared against quality diagnostic spirometry. A diagnosis of COPD (the reference standard) will be defined as airflow obstruction based on the lower limit of normal using the Global Lung Initiative (GLI) equations, according to post-bronchodilator quality diagnostic spirometry.