Study to evaluate the effectiveness and cost-effectiveness of different screening strategies for identifying undiagnosed COPD among residents (≥40 years) in four cities in China: Protocol for a mult

This paper described the design of a cross-sectional study that will evaluate the effectiveness and cost-effectiveness of different screening strategies for identifying undiagnosed COPD among approximately 2000 urban and rural residents aged ≥40 years in four cities in China. Screening strategies will include questionnaires and lung function testing. Measurement of FEV1 and FEV6 will be performed using the Vitalograph COPD-6 handheld device.