Validity of the COPD-6® Device for COPD Screening in the Primary Care Setting of China

Background: The use of simple and affordable screening tools for chronic obstructive pulmonary disease (COPD) is limited. We aimed to assess the validity of a handheld expiratory flow meter (COPD-6®, Vitalograph Ltd., Ireland) for COPD screening in Chinese primary care settings.Methods: In our cross-sectional study, subjects were randomly selected in eight primary care settings. Testing with the Vitalograph-COPD-6® and conventional spirometry were sequentially performed on subjects. The correlation between COPD-6® and conventional spirometry was determined. Validity was analyzed by the area under the receiver operator characteristic curve (AUC) of the forced expiratory volume in one second (FEV1) / forced expiratory volume in six seconds (FEV6) that used to detect airway obstruction. The sensitivity, specificity, predictive values, and likelihood ratio were calculated according to different FEV1/FEV6 cut-off points.Results: 229 subjects (15.4%) were diagnosed with airflow limitation by standard spirometry. FEV1, FEV6, and FEV1/FEV6 measured by COPD-6® were correlated with FEV1, FVC, and FEV1/FVC measured by spirometry (r=0.889, 0.835and 0.647, p1/FEV6 to determine airflow obstruction was 0.857 (95%CI: 0.826 to 0.888). No significant difference of AUC was observed between the symptomatic group and the asymptomatic population (AUC=0.869 vs. 0.843, P=0.425). A similar phenomenon was found in the AUC of smokers and never-smokers (AUC=0.862 vs.0.840; P=0.515). The value of AUC was largest (i.e., 0.80) when the cut-off point for FEV1/FEV6 was 0.77.Conclusions: The handheld COPD-6® could be used as a pre-screening device on early diagnosis of COPD in Chinese primary care settings.