This report is an evaluation study of two types of transdermal devices that detect alcohol at the skin surface representing two types of electrochemical sensing technology. The AMS SCRAM™ ankle device and the Giner WrisTAS™ wrist device were worn concurrently for the evaluation by 22 paid research subjects (15 males, 7 females), for a combined total of 96 weeks. Each subject participated in both laboratory drinking to .08 grams per deciliter (g/dL) BAC and normal drinking on their own. A total of 271 drinking episodes with BAC =.02 g/dL were logged: 60 were from laboratory dosing, and 211 were from self-dosed drinking. Both devices detected alcohol at the skin surface. The SCRAM™ unit has security features and automated reporting protocols that make it suitable for the offender market, whereas the WrisTAS™ unit is a research prototype that has had trials as an aid to detection for alcohol treatment settings. Neither unit had falsepositive problems when true BAC was <.02 g/dL. False negatives were defined as TAC (transdermal alcohol concentration) response <.02 g/dL when true BAC =.02 g/dL. Overall, the true-positive hit rate detected by WrisTAS™ was 24 percent. The low detection rate for the WrisTAS™ was largely due to those devices’ erratic output or not recording during nearly 67 percent of all episodes. SCRAM™ correctly detected 57 percent across all BAC events, with another 22 percent (total 79%) detected, but as <.02 g/dL. SCRAM™ devices were more accurate earlier than later in the trials and may have had problems with water accumulation that reduced sensitivity. When subjects dosed themselves to BAC = .08 g/dL, SCRAM™ correctly detected 88 percent of these events. The report summarizes comments from research subjects, offenders, and vendors who manage transdermal detection programs. (Author/publisher)
Abstract