Validity of Transdermal Alcohol Monitoring: Fixed and Self‐Regulated Dosing

Abstract

Background: To study the validity of transdermal assessment of alcohol concentration measured by a lightweight, noninvasive device. Methods: Subjects wore a 227‐g anklet that sensed transdermal alcohol concentrations (TACs) every 15 to 30 minutes, downloading results to a remote computer each day. Twenty‐four subjects entered a laboratory and received a dose of 0, 0.28, or 0.56 g/kg of ethanol. Breath alcohol concentrations (BrAC) and TAC were measured every 15 to 30 minutes Twenty others [10 alcohol dependent (AD) and 10 not (NAD)] in the community who wore the anklet for 8 days kept a drinking log and provided a BrAC sample each day. Results: In the laboratory, no zero‐dose subject, and every subject receiving alcohol, had alcohol‐positive TACs. The device distinguished low‐ and high‐alcohol–dosing groups using peak (t₁₄=3.37; pt₁₄=3.42; pt₁₈=−3.77; pt_9.5=−3.56; pt_9.9=−3.35; p<0.01) all significantly distinguished the AD and NAD groups. However, individual transdermal readings were not reliably quantitatively equivalent to simultaneously obtained breath results. Conclusions: Within the limits of the laboratory study, the device consistently detected consumption of approximately 2 standard drinks. On average, the device shows discriminative validity as a semiquantitative measure of alcohol consumption but individual readings often are not equivalent to simultaneous BrACs.