Lastly, we calculated sensitivity (the proportion of individuals with a substance-specific SUD according to the DSM-IV Checklist who had a positive response to the item), specificity (the proportion of individuals without a substance-specific SUD according to the DSM-IV Checklist who had a negative response to the item), and the ROC-AUC for each item. A high ROC-AUC value indicates a high level of accuracy in classifying cases versus non-cases of a SUD according to the DSM-IV Checklist (1.0=perfect classification; <0.7=poor discrimination) (Hanley and McNeil, 1982).
