Receiver operating characteristic curve delineating discriminatory capacity of coagulation assays for detecting rivaroxaban use for (A) all patients (i.e., 80 rivaroxaban patients and 20 controls); (B) after excluding patients noted to be on prehospital rivaroxaban, but presenting with rivaroxaban concentrations more than 50 ng/ml (i.e., 52 rivaroxaban patients and 20 controls). AUC, area under curve; PT, prothrombin time; TEG, thromboelastography.