Specifically, here we 1) examine prevalences of substance dependence and substance-specific symptoms across multiple substances, 2) determine the unidimensionality of dependence criteria and item-level discrimination and severity estimates, and 3) calculate sensitivity, specificity, and area under the receiver operating characteristic curve (ROC-AUC) for each dependence criterion in opioid-dependent adults. ROC-AUC considers the trade-off between sensitivity and specificity values and indicates the level of accuracy in classifying cases and non-cases of a SUD according to the DSM-IV checklist (1.0=perfect classification). We hypothesize that items showing low discrimination and high severity estimates (low relevancy to the underlying trait of a disorder) will have comparatively low sensitivity/specificity (ROC-AUC) values in identifying cases of a SUD.
