Wearable Transdermal Alcohol Monitors: A Systematic Review of Detection Validity, and Relationship Between Transdermal and Breath Alcohol Concentration and Influencing Factors

Abstract

Background: Research on alcohol consumption mostly relies on self-reported data, which are subject to recall bias. Wearable transdermal alcohol concentration (TAC) monitors address this limitation by continuously measuring the ethanol excreted via the skin. This systematic review aims to provide an overview of TAC monitors' reliability to detect alcohol consumption and methods to estimate breath alcohol concentration (BrAC) and number of standard drinks consumed in a given time frame. Methods: The databases MEDLINE, PsycINFO, SCOPUS, Engineering Village, and CINAHL were systematically searched to identify 1,048 empirical research papers published from 2013 onwards, of which 13 were included after full-text screening. The selected studies included 3 TAC monitors: SCRAM TM , WristTAS TM , and Skyn TM. Results: TAC measures of SCRAM, WrisTAS, and Skyn are found to be positively correlated with BrAC (r = 0.56 to 0.79) and/or self-reports (r = 0.62). Using the AMS criteria for detection results in low sensitivity, adjusted criteria can increase the sensitivity of the SCRAM from 39.9 to 68.5%. The WrisTAS and an early prototype of the Skyn showed high failure rates (17 to 38%). Recent advances toward transforming the TAC data into more clinically relevant measures have led to the development of mathematical models and the BrAC Estimator Software. Using TAC data, both approaches produce estimates explaining 70 to 82% of actual BrAC and self-reported drinking or to highly correlate with the actual BrAC measures (b = 0.90 to 0.91). Conclusions: Transdermal alcohol monitors offer an opportunity to measure alcohol consumption in a valid and continuous way with mathematical models and software estimating BrAC values improving interpretation of TAC data. However, the SCRAM seems unable to detect low-to-moderate drinking levels using the thresholds and criteria set by the manufacturer. Moreover, the WrisTAS and the Skyn prototype show a high failure rate, raising questions about reliability. Future studies will assess the validity of new-generation wristbands, including the next Skyn generations.

Ecological Momentary Assessment of Alcohol Consumption and Its Concordance with Transdermal Alcohol Detection and Timeline Follow‐Back Self‐report Among Adults Experiencing Homelessness

“…Similarly, for alcohol use intensity, day‐level correspondence between EMA and SCRAM ( r = 0.46) was modest, compared with person‐level correspondence ( r = 0.78). The person‐level correlation of 0.78 in alcohol use intensity between EMA and SCRAM slightly exceeds the reported correlation of 0.62 between TAC readings and self‐reports in a recent systematic review (van Egmond et al, 2020). In an alcohol administration study in a highly controlled laboratory setting, the correlation between transdermal and breath assessments of alcohol across 24 subjects was 0.84 (Sakai et al, 2006).…”

“…and TAC readings were correlated at 0.68 at the person-level (Rash et al, 2019). Similarly, a recent systematic review reported that TAC data from 3 biological detection methods (SCRAM, WristTAS, and Skyn) had a correlation of 0.62 with self-reported alcohol use (van Egmond et al, 2020).…”

“…For example, in a sample of soup kitchen attendees who reported heavy drinking, drinking days assessed by daily self‐report (e.g., “…since I saw you yesterday?”) and TAC readings were correlated at 0.68 at the person‐level (Rash et al, 2019). Similarly, a recent systematic review reported that TAC data from 3 biological detection methods (SCRAM, WristTAS, and Skyn) had a correlation of 0.62 with self‐reported alcohol use (van Egmond et al, 2020).…”

“…Although studies note a number of drawbacks to using the SCRAM, including equipment failures, equipment loss or tampering, discomfort, and challenges related to detecting lower‐level drinking and interpreting transdermal alcohol concentration (TAC) data (Barnett et al, 2014; Roache et al, 2015; Roache et al, 2019), correspondence between self‐reported alcohol use and SCRAM‐assessed TAC appears to be adequate, and the SCRAM tends to be reasonably well tolerated by participants (see van Egmond et al, 2020; Piasecki, 2019 for reviews). For example, in a sample of soup kitchen attendees who reported heavy drinking, drinking days assessed by daily self‐report (e.g., “…since I saw you yesterday?”) and TAC readings were correlated at 0.68 at the person‐level (Rash et al, 2019).…”

Combining transdermal and breath alcohol assessments, real‐time drink logs and retrospective self‐reports to measure alcohol consumption and intoxication across a multi‐day music festival

“…However, transdermal monitors surprisingly remain markedly underutilised in research investigating heavy drinking in public spaces, as well as in combination with other measures of intoxication and consumption. A recent systematic review by van Egmond et al [17] noted that ambulatory studies combining transdermal and EMA self-report measures have only assessed consumption amongst populations drinking a maximum of 12.4 standard drinks per week, the same amount an average festival patron will consume in a 24 h period [2]. Thus, there is a clear need to evaluate the combination of these measures among more heavydrinking populations and in a broader range of drinking contexts.…”