Feasibility and reliability of continuously monitoring alcohol use among female adolescents and young adults

Abstract

Introduction and aims: Transdermal alcohol sensors allow objective, continuous monitoring and have potential to expand current research on adolescent and young adult alcohol use. The purpose of this manuscript is to evaluate the feasibility and reliability of transdermal alcohol sensor use among female adolescents as compared to female young adults.

Design and methods: This trial included 59 female adolescents and young adults aged 14-24 years who reported drinking during the previous month. All participants were asked to wear a Giner Wrist Transdermal Alcohol Sensor (WrisTAS)-7 over a 1 month prospective study. Participants came to the research lab weekly to complete a detailed self-report of behaviours, including day of drinking events, amounts and types of alcohol use and length of drinking events. Estimates of blood alcohol concentration (eBAC) were computed from self-report data using the Matthew and Miller, NHTSA and Zhang equations. Daily transdermal alcohol concentration (TAC) peaks and calculated eBAC peak data were analysed with paired-samples t-tests and repeated measures correlations for validity comparisons.

Results: All participants (100%, n = 59) completed the trial, however, two participants were removed due to greater than 50% of missing transdermal alcohol sensor data. Of the 57 participants, the data included 1,722 days of continuous alcohol monitoring. Missing data was recorded more frequently among female adolescents at about (11.78%) as compared to female young adults (8.59%; χ² = -18.40, P < 0.001). Participant self-report of drinking occurred with greater frequency (374 events) than detected by the WrisTAS transdermal alcohol sensors (243 events). On days when self-report and sensor data indicated a drinking event, participants' eBAC was moderately correlated with TAC, after accounting for repeated measures.

Discussion and conclusions: This study finds that transdermal alcohol sensors are moderately reliable when sensor data is paired with self-report. This objective data collection method may improve the ability to collect alcohol curves among adolescents.

Keywords: estimates of blood alcohol concentration; female adolescent; female young adult; transdermal alcohol concentration; transdermal alcohol sensor.

Figure 1.

Transdermal alcohol sensor curves, showing adjustment for baseline and locally estimated scatterplot smoothing and prediction in blue and raw data points in red.

Figure 2.

One week of transdermal alcohol data, assessed by coders as noisy sensor data, therefore, coded as missing data. As with Figure 1, adjustment for baseline and locally estimated scatterplot smoothing and prediction in blue and raw data points in red.

Figure 3.

(a) Bland–Altman plot for estimated blood alcohol concentration (eBAC) and transdermal alcohol concentration (TAC) measures. The Bland–Altman plot shows the difference between measures of TAC and eBAC means. This figure uses all daily-recorded measures of TAC and eBAC, which shows little change with increased alcohol measures. (b) Bland–Altman plot showing the difference between measures of TAC and eBAC means. This figure shows only matched events where the sensors detected alcohol concentration in addition to the participant reporting alcohol consumption. This plot shows that the agreement between methods lessened when blood alcohol concentration rose above ~0.2.