Fig. 2
From: Value of metalloproteinases in predicting COPD in heavy urban smokers
ROC Curves of Model 1 and Model 2, with the corresponding Youden Index (specificity, sensitivity). Optimal cutpoints and (sensitivity, specificity) for that cutpoint shown. The optimal cut point for the logistic score in Model 1 has sensitivity 0.789 and specificity 0.703 for the classification of emphysema . The optimal cut point for the logistic score in Model 2 has sensitivity 0.802 and specificity 0.674