Fig. 2
From: Accuracy of the COPD diagnostic questionnaire as a screening tool in primary care
Receiver operating characteristic (ROC) curve comparing CDQ score to COPD diagnosis using GOLD spirometry criteria for obstruction (post-bronchodilator FEV1/FVC < 0.70) as the reference standard. Area under the ROC curve (ROCAUC) = 0.59 ± 0.50. A ROCAUC of 0.5 is indicated by the solid diagonal line. Cut point 16.5 is indicated by the black star>