Transdermal Alcohol Concentration Research Articles

Transdermal alcohol concentration features predict alcohol-induced blackouts in college students.

Alcohol-induced blackouts (AIBs) are common in college students. Individuals with AIBs alsoexperienceacute and chronic alcohol-related consequences. Research suggests that how students drink is an important predictor ofAIBs. We used transdermal alcohol concentration (TAC) sensors to measure biomarkers of increasing alcohol intoxication (rise rate, peak, and rise duration) in a sample of college students. We hypothesized that the TAC biomarkers would be positively associated with AIBs. Students were eligible to participate if they were aged 18-22 years, in their second or third year of college, reported drinking 4+ drinks on a typical Friday or Saturday, experienced ≥1 AIB in the past semester, owned an iPhone, and were willing to wear a sensor for 3 days each weekend. Students (N = 79, 55.7% female, 86.1% White, Mage = 20.1) wore TAC sensors and completed daily diaries over four consecutive weekends (89.9% completion rate). AIBs were assessed using the Alcohol-Induced Blackout Measure-2. Logistic multilevel models were conducted to test for main effects. Days with faster TAC rise rates (OR = 2.69, 95% CI: 1.56, 5.90), higher peak TACs (OR = 2.93, 95% CI: 1.64, 7.11), and longer rise TAC durations (OR = 4.16, 95% CI: 2.08, 10.62) were associated with greater odds of experiencing an AIB. In a sample of "risky" drinking college students, three TAC drinking features identified as being related to rising intoxication independently predicted the risk for daily AIBs. Our findings suggest that considering how an individual drinks (assessed using TAC biomarkers), rather than quantity alone, is important for assessing risk and has implications for efforts to reduce risk. Not only is speed of intoxication important for predicting AIBs, but the height of the peak intoxication and the time spent reaching the peak are important predictors, each with different implications for prevention.

Subjective intoxication predicts alcohol-related consequences at equivalent alcohol concentrations in young adults using ecological momentary assessment and alcohol sensors.

Subjective intoxication (SI) when drinking may serve as an internal barometer of whether to continue drinking or engage in potentially unsafe behavior. Mobile assessments offer the potential to use SI as a prospective risk indicator during drinking episodes; little evidence exists for the validity of real-time SI measures. We test the correspondence of SI with estimated blood alcohol concentration and transdermal alcohol concentration (TAC) in young adults' natural settings. We provide a novel test of whether SI features (peak and mean SI) uniquely predict consequences adjusting for alcohol concentration. Two hundred twenty-two heavy-drinking young adults (Mage = 22.3, 64% female, 79% non-Hispanic White, 84% undergraduates) participated in a 6-day study that used ecological momentary assessment of drinking and TAC sensors. SI was assessed every 30 min during drinking episodes. Multilevel modeling was used to test hypotheses. Momentary SI and estimated blood alcohol concentration had moderate associations at the moment and day levels (standardized βs = 0.5-0.6); SI was moderately associated with TAC at the day level (βs = 0.5). Associations between SI and alcohol concentration varied widely between persons and across days. Day-level SI features predicted consequences when adjusting for alcohol concentration (incidence rate ratios, IRRs = 1.29-1.70). Our two-item SI measure shows evidence of validity in real-world settings with heavy-drinking young adults. SI was significantly correlated with alcohol concentration and was a unique predictor of consequences. The strength of these associations varied greatly across persons and days. Real-time SI measurement may be useful in preventive interventions, but continued research is needed into when and for whom momentary SI is most predictive of risk. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Signal processing and machine learning with transdermal alcohol concentration to predict natural environment alcohol consumption.

Wrist-worn alcohol biosensors continuously and discreetly record transdermal alcohol concentration (TAC) and may allow alcohol researchers to monitor alcohol consumption in participants' natural environments. However, the field lacks established methods for signal processing and detecting alcohol events using these devices. We developed software that streamlines analysis of raw data (TAC, temperature, and motion) from a wrist-worn alcohol biosensor (BACtrack Skyn) through a signal processing and machine learning pipeline: biologically implausible skin surface temperature readings (< 28°C) were screened for potential device removal and TAC artifacts were corrected, features that describe TAC (e.g., rise duration) were calculated and used to train models (random forest and logistic regression) that predict self-reported alcohol consumption, and model performances were measured and summarized in autogenerated reports. The software was tested using 60 Skyn data sets recorded during 30 alcohol drinking episodes and 30 nonalcohol drinking episodes. Participants (N = 36; 13 with alcohol use disorder) wore the Skyn during one alcohol drinking episode and one nonalcohol drinking episode in their natural environment. In terms of distinguishing alcohol from nonalcohol drinking, correcting artifacts in the data resulted in 10% improvement in model accuracy relative to using raw data. Random forest and logistic regression models were both accurate, correctly predicting 97% (58/60; AUC-ROCs = 0.98, 0.96) of episodes. Area under TAC curve, rise duration of TAC curve, and peak TAC were the most important features for predictive accuracy. With promising model performance, this protocol will enhance the efficiency and reliability of TAC sensors for future alcohol monitoring research. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Comparison of transdermal alcohol concentration and self-reported alcohol consumption in people with alcohol dependence attending community alcohol treatment services

AimWe aimed to assess the accuracy and wearability of a transdermal alcohol sensor (TAS) (BACtrack Skyn) with people currently receiving treatment at alcohol services. MethodA mixed methods observational study involving three NHS alcohol services in south London was conducted. All participants (7=male, 9=female) wore a TAS for 1 week and met with the researcher every other weekday to complete the TAS data download and a TimeLine Follow Back (TLFB). At the end of the week, a post-wear survey was completed. Transdermal Alcohol Concentration (TAC) from the TAS was compared to the TLFB. Post-wear survey responses, attendance voucher incentives and descriptive TAS data (removals, missing and skin temperature data) were analysed. We investigated different drinking event thresholds changing the criteria of TAC level and length of time TAC was increased and analysed each drinking threshold sensitivity, specificity, positive and negative predicative values, and percentage accuracy classification. ResultsThe TAS recorded the number of alcohol-drinking days with a high degree of accuracy compared to the TLFB as gold-standard. However, of the participation time of the 16 participants, 14.5% of the TAS data was missing in output and 16.4% of the recorded data suggests the TAS was not currently being worn. Of the data recorded, in line with the drinking event threshold of >15 ug/l TAC, >15minutes, we found that sensitivity = 93%, specificity = 84% and a Pearson correlation of r(16) =.926, p = <.001, BCa 95% CI [.855 −.981]. The threshold with the highest accuracy was TAC>15 ug/l, >60minutes which classified alcohol events with 90% accuracy, AUC =.910, sensitivity = 90%, specificity = 96%. The post-wear survey reported that most participants found it comfortable and that wearing it did not interfere with daily activities. Six participants reported side effects, including itching and a rash, but these would not deter them from wearing it again with all six reporting they would wear the TAS again and for longer than one week. ConclusionsThe TAS did not capture every drinking event that was self-reported but maintained a high correlation. There were instances of missing TAS data and TAS removals. Overall, our findings would support the acceptability and feasibility of TAS as a tool that could be used in clinical settings for objective alcohol monitoring with patients being responsible for the TAS.

Using alcohol biosensors and biomarkers to measure changes in drinking: Associations between transdermal alcohol concentration, phosphatidylethanol, and self-report in a contingency management study of persons with and without HIV.

Alcohol use can be measured in many ways, including objectively through transdermal alcohol biosensors (e.g., transdermal alcohol concentration; TAC) or blood biomarkers (e.g., phosphatidylethanol; PEth), or subjectively through self-report (e.g., with the timeline followback; TLFB). However, it is unclear which measures best indicate changes in alcohol use within individuals following intervention, and if they have concurrent validity. In the context of contingency management (CM) with a goal of 30-day abstinence (n = 45, 60% male, 80% Black; Mage = 56.7; 58% with HIV), we examined relationships among changes in TAC-AUC (area under the curve, reflecting volume consumed), PEth, and self-reported number of drinks. The Secure Continuous Remote Alcohol Monitor Continuous Alcohol Monitoring (SCRAM-CAM) biosensor was used to collect TAC-AUC during a pre-CM period (∼7 days) and over a 30-day CM period. PEth was collected at baseline and 30-day follow-up. Number of drinks was self-reported through a 30-day TLFB at baseline and follow-up. Daily TAC-AUC and number of self-reported drinks were calculated for the pre-CM period and for the last 7 days of the CM period. Linear regression models controlling for baseline values revealed that change in TAC-AUC was significantly associated with change in PEth (β = 0.33, p < .0001) and with change in number of self-reported drinks (β = 0.34, p < .0001). Change in PEth was significantly associated with change in number of self-reported drinks (β = 0.85, p < .0001). We conclude that all three measures may be appropriate for measuring within-person change in alcohol use, while controlling for baseline values, in the context of a study testing an intervention such as CM. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

College Students' Day-to-Day Maladaptive Drinking Responses to Stress Severity and Stressor-Related Guilt and Anger.

Stress is a common part of college students' daily lives that may influence their physical activity (PA) and alcohol use. Understanding features of daily stress processes that predict health behaviors could help identify targets for just-in-time interventions. This study used intensive longitudinal data to examine whether prior day stress processes predict current day PA or alcohol use. Participants (N=58, Mage=20.5, 59% women, 70% White) were 18-to-25-year-old students who engaged in binge drinking at least twice monthly and used cannabis or tobacco in the past year. They wore activity (activPAL4) and alcohol (Secure Continuous Remote Alcohol Monitor) monitors for 11 days to assess daily PA (e.g., step counts) and alcohol use (e.g., drinking day), and completed daily surveys about yesterday's stress, including number of stressors (i.e., frequency), stressor intensity (i.e., severity), and frequency of affective states (e.g., guilt). Multilevel models examined prior day stress predicting current day PA or alcohol use. Participants had higher odds of current day drinking (odds ratio=1.21) and greater area under the curve (B=0.08) when they experienced greater than usual stress severity the prior day. Participants had higher current day peak transdermal alcohol concentration (B=0.12) and area under the curve (B=0.11) when they more frequently experienced guilt due to stressors the prior day. College students' unhealthy response of increasing alcohol use due to stress could adversely impact health outcomes. There is a critical need for interventions addressing students' ability to effectively manage and respond to the stress-inducing, daily demands of student life.

Effectiveness of contingency management using transdermal alcohol monitoring to reduce heavy drinking among driving while intoxicated (DWI) arrestees: A randomized controlled trial.

Driving while intoxicated (DWI) is a serious public health problem. However, treatment for DWI arrestees is not readily available. This study examines the effectiveness of a contingency management (CM) procedure using transdermal alcohol concentration (TAC) monitoring to reduce drinking among DWI arrestees. The study participants were 216 DWI arrestees under pretrial and included both Mandated participants undergoing court-ordered TAC monitoring and Non-Mandated participants wearing a study-provided TAC monitor. Participants were randomly assigned to either a CM (Mandated = 35; Non-Mandated = 74) or a Control condition (Mandated = 37; Non-Mandated = 70) and completed the 8-week intervention. CM participants received $50/week for not exceeding a TAC of 0.02 g/dL during the previous week. Payments to Controls were yoked to the CM group. Among Non-Mandated participants, the probability of meeting the contingency was higher and remained stable (about 65%) over time in the CM group, whereas the probability was lower and declined in the Control group, widening the gaps in the probability between the study conditions (16.7%-24.1% greater in the CM group from visit 4 to 8, all p < 0.05). Among Mandated participants, the probability was not significantly different between conditions (p = 0.06-0.95). Furthermore, among Non-Mandated participants, the percentage of heavy drinking days remained low (9.16%-11.37%) in the CM group, whereas it was greater and increased over time (17.43%-26.59%) in the Control group. In Mandated participants, no significant differences in percent heavy drinking days were observed between conditions (p = 0.07-0.10). We found that contingency effects on alcohol use are more pronounced among frequent and heavy alcohol users, i.e., Non-Mandated DWI arrestees. However, for individuals whose drinking was already suppressed by existing contingencies (i.e., court-mandated TAC monitoring), our CM procedure did notproduce additional reductions in drinking.

Acceptability and anklet user experience with the SCRAM-CAM transdermal alcohol concentration sensor in regularly drinking young adults' natural environments.

Recent developments in wearable technologies have allowed for device-based capture of alcohol concentration among participants in their natural environments. Currently, the Continuous Alcohol Monitor from SCRAM systems (SCRAM-CAM) is the most extensively studied and validated transdermal alcohol concentration (TAC) sensor. However, there has been relatively little work focusing on its acceptability from the participants' perspective. In the current study, we assess the user experience of the SCRAM-CAM anklet in a sample of 222 regularly heavy drinking young adults (mean age=22.3) who wore the anklet in their natural environments for five 24-h periods spanning 6 consecutive days. Differences in the anklet user experience were measured along a number of dimensions, and differences were tested by sex at birth, white/non-white racial/ethnic group membership, and alcohol use disorder (AUD) risk (measured through Alcohol Use Disorder Identification Test [AUDIT] scores). Males and females differed significantly on six of the eight acceptability items, with males showing more positive responses toward the anklet than females. No differences were found by white/non-white racial/ethnic groups nor AUD risk. Results suggest positive levels of acceptability toward the device overall while in natural environments, further validating the usage of the device in studies that measure alcohol consumption among different groups, including those with high levels of alcohol consumption. Researchers should take into consideration the different levels of burden or discomfort in male versus female participants when using the device.

Flux-Type versus Concentration-Type Sensors in Transdermal Measurements.

New transdermal biosensors measure analytes that diffuse from the bloodstream through the skin, making it important to reduce the system response time and understand measurement output. While highly customized models have been created for specific sensors, a generalized model for transdermal sensor systems is lacking. Here, a simple one-dimensional diffusion model was used to characterize the measurement system and classify biosensors as either flux types or concentration types. Results showed that flux-type sensors have significantly faster response times than concentration sensors. Furthermore, flux sensors do not measure concentration, but rather have an output measurement that is proportional to skin permeability. These findings should lead to an improved understanding of transdermal measurements and their relation to blood analyte concentration. In the realm of alcohol research, where the majority of commercially available sensors are flux types, our work advocates toward moving away from transdermal alcohol concentration as a metric, and instead suggests embracing transdermal alcohol flux as a more suitable alternative.

Abstinence-contingent wage supplements for adults experiencing homelessness and alcohol use disorder: A randomized clinical trial

This study evaluated the effectiveness of abstinence-contingent wage supplements in promoting alcohol abstinence and employment in adults experiencing homelessness and alcohol use disorder. A randomized clinical trial was conducted from 2019 to 2022. After a 1-month Induction period, 119 participants were randomly assigned to a Usual Care Control group (n = 57) or an Abstinence-Contingent Wage Supplement group (n = 62). Usual Care participants were offered counseling and referrals to employment and treatment programs. Abstinence-Contingent Wage Supplement participants could earn stipends for working with an employment specialist and wage supplements for working in a community job but had to maintain abstinence from alcohol as determined by transdermal alcohol concentration monitoring devices to maximize pay. Abstinence-Contingent Wage Supplement participants reported significantly higher rates of alcohol abstinence than Usual Care participants during the 6-month intervention (82.8% vs. 60.2% of months, OR = 3.4, 95% CI 1.8 to 6.3, p < .001). Abstinence-Contingent Wage Supplement participants were also significantly more likely to obtain employment (51.3% vs. 31.6% of months, OR = 2.6, 95% CI 1.5 to 4.4, p < .001) and live out of poverty (38.2% vs. 16.7% of months, OR = 3.7, 95% CI 2.0 to 7.1, p < .001) than Usual Care participants. These findings suggest that Abstinence-Contingent Wage Supplements can promote alcohol abstinence and employment in adults experiencing homelessness and alcohol use disorder. ClinicalTrials.gov Identifier: NCT03519009

Measurement of transdermal alcohol concentration using a wrist-wornenzymatic transdermal monitor.

New-generation transdermal monitors such as the ION Research Alpha Prototypes (ION RAP) hold promise for real-time alcohol measurement, with improvements in design features such as sampling frequency, size, and comfort. This paper aims to provide the first comparisons of the wrist-worn enzyme-based ION RAP and the fuel cell-based SCRAM-CAM against breath alcohol concentration (BrAC) readings. Participants (N=23) completed a total of 69 laboratory alcohol administration sessions while wearing both a prototype of the ION RAP wristband and a SCRAM-CAM ankle monitor; they also gave breath samples each 10min. Analyses focused on latencies of transdermal alcohol concentration (TAC) after alcohol ingestion, correlations, and cross-correlations between BrAC and TAC measurements. A high failure rate of the ION RAP was observed (61.5% of the sessions were excluded due to the sessions not containing enough valid data). On average, the SCRAM-CAM and ION RAP detected alcohol 43 (SD=21) and 50 (SD=27) minutes after the first drink, with peak values reached after 138 (SD=47) and 154 (SD=56) minutes, respectively. SCRAM-CAM TAC peak (r=0.185, p=0.375) and area under the curve (AUC; r=0.320, p=0.118) showed small- and medium-sized correlations to BrAC. ION RAP TAC peak (r=-0.082, p=0.698) and AUC (r=0.040, p=0.852) correlations to BrAC were close to zero. In this study, the new-generation ION RAP and the traditionally used SCRAM-CAM show similar delays in detection and similar TAC curves over time, despite using either enzyme- or fuel cell-based technologies, respectively. Due to high failure rates of the ION RAP prototypes and close to zero correlations to BrAC, further developments and improvements of these TAC wristbands are required for reliable and valid use in real-time alcohol measurement.

Baseline protective behavioral strategy use predicts more moderate transdermal alcohol concentration dynamics and fewer negative consequences of drinking in young adults' natural settings.

Test whether frequent protective behavioral strategies (PBS) users report (a) fewer alcohol-related consequences and (b) less risky alcohol intoxication dynamics (measured via transdermal alcohol concentration [TAC] sensor "features") in daily life. Two hundred twenty-two frequently heavy-drinking young adults (Mage = 22.3 years) wore TAC sensors for 6 consecutive days. TAC features peak (maximum TAC), rise rate (speed of TAC increase), and area under the curve (AUC) were derived for each day. Negative alcohol-related consequences were measured in the morning after each self-reported drinking day. Past-year PBS use was measured at baseline. Young adults reporting more frequent baseline PBS use showed (a) fewer alcohol-related consequences and (b) lower intoxication dynamics on average (less AUC, lower peaks, and slower rise rates). Limiting/stopping and manner of drinking PBS showed the same pattern of findings as the total score. Serious harm reduction PBS predicted fewer negative alcohol-related consequences, but not TAC features. Multilevel path models showed that TAC features peak and rise rate partially explained associations between PBS (total, limiting/stopping, and manner of drinking) and consequences. Independent contributions of PBS subscales were small and nonsignificant, suggesting that total PBS use was a more important predictor of risk/protection than the specific types of PBS used. Young adults using more total PBS may experience fewer alcohol-related consequences during real-world drinking episodes in part through less risky intoxication dynamics (TAC features). Future research measuring PBS at the daily level is needed to formally test TAC features as day-level mechanisms of protection from acute alcohol-related consequences. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Supplemental Material for Baseline Protective Behavioral Strategy Use Predicts More Moderate Transdermal Alcohol Concentration Dynamics and Fewer Negative Consequences of Drinking in Young Adults’ Natural Settings

Supplemental Material for Baseline Protective Behavioral Strategy Use Predicts More Moderate Transdermal Alcohol Concentration Dynamics and Fewer Negative Consequences of Drinking in Young Adults’ Natural Settings

Resting state connectivity in people living with HIV before and after stopping heavy drinking.

Heavy alcohol use in people living with HIV (PLWH) has widespread negative effects on neural functioning. It remains unclear whether experimentally-induced reduction in alcohol use could reverse these effects. We sought to determine the effects of 30-days drinking cessation/reduction on resting state functional connectivity in people with and without HIV. Thirty-five participants (48.6% PLWH) demonstrating heavy alcohol use attempted to stop drinking for 30 days via contingency management (CM). MRI was acquired at baseline and after thirty days, and functional connectivity across five resting-state fMRI (rsfMRI) networks was calculated with the Conn toolbox for Matlab and examined in relation to transdermal alcohol concentration (TAC) recorded by the ankle-worn secure continuous remote alcohol monitor (SCRAM) and self-reported alcohol use (timeline follow-back; TLFB). Associations between alcohol use and reduction, HIV status, functional connectivity, and change in functional connectivity across five major rsfMRI networks were determined relative to the pre- and post-CM timepoints. Baseline resting-state functional connectivity was not significantly associated with average TAC-AUC during the pre-CM period, though higher self-reported alcohol use over the preceding 30 days was significantly associated with higher baseline connectivity within the Dorsal Attention Network (DAN; p-FDR < 0.05). Baseline connectivity within the Salience network was significantly negatively related to objective drinking reduction after intervention (DAN; p-FDR < 0.05), whereas baseline connectivity within the Limbic network was positively associated with self-reported drinking reduction (p-FDR < 0.05). Change in between-networks functional connectivity after intervention was significantly positively associated with biosensor-confirmed drinking reduction such that higher reduction was associated with stronger connectivity between the limbic and fronto-parietal control networks (p-FDR < 0.05). PLWH with lower DAN connectivity at baseline demonstrated poorer alcohol reduction than those with higher DAN connectivity at baseline. Lower resting-state functional connectivity of the Salience network significantly predicted stronger drinking reduction across all participants, suggesting a potential biomarker for reduced susceptibility to the environmental and social cues that often make alcohol use reduction attempts unsuccessful. Increased between-networks connectivity was observed in participants with higher alcohol reduction after CM, suggesting a positive benefit to brain connectivity associated with reduced drinking. PLWH with lower baseline DAN connectivity may not benefit as greatly from CM for alcohol reduction.

Acceptability and validity of using the BACtrack skyn wrist-worn transdermal alcohol concentration sensor to capture alcohol use across 28 days under naturalistic conditions - A pilot study.

Wrist-worn transdermal alcohol concentration (TAC) sensors have the potential to provide detailed information about day-level features of alcohol use but have rarely been used in field-based research or in early adulthood (i.e., 26-40 years) alcohol users. This pilot study assessed the acceptability, user burden, and validity of using the BACtrack Skyn across 28 days in individuals' natural settings. Adults aged 26-37 (N=11, Mage=31.2, 55% female, 73% non-Hispanic white) participated in a study including retrospective surveys, a 28-day field protocol wearing Skyn and SCRAM sensors and completing ecological momentary assessments (EMA) of alcohol use and duration (daily morning reports and participant-initiated start/stop drinking EMAs), and follow-up interviews. Day-level features of alcohol use extracted from self-reports and/or sensors included drinks consumed, estimated Blood Alcohol Concentration (eBAC), drinking duration, peak TAC, area under the curve (AUC), rise rate, and fall rate. Repeated-measures correlations (rrm) tested within-person associations between day-level features of alcohol use from the Skyn versus self-report or the SCRAM. Participants preferred wearing the Skyn over the SCRAM [t (10)=-6.79, p<.001, d=2.74]. Skyn data were available for 5614 (74.2%) out of 7566h, with 20.7% of data lost due to syncing/charging issues and 5.1% lost due to device removal. Skyn agreement for detecting drinking days was 55.5% and 70.3% when compared to self-report and the SCRAM, respectively. Correlations for drinking intensity between self-report and the Skyn were 0.35 for peak TAC, 0.52 for AUC, and 0.30 for eBAC, which were smaller than correlations between self-report and SCRAM, at 0.78 for peak TAC, 0.79 for AUC, and 0.61 for eBAC. Correlations for drinking duration were larger when comparing self-report to the Skyn (rrm=0.36) versus comparing self-report to the SCRAM (rrm=0.31). The Skyn showed moderate-to-large, significant correlations with the SCRAM for peak TAC (rrm=0.54), AUC (rrm=0.80), and drinking duration (rrm=0.63). Our findings support the acceptability and validity of using the Skyn for assessing alcohol use across an extended time frame (i.e., 28 days) in individuals' natural settings, and for providing useful information about day-level features of alcohol use.

Measuring alcohol consumption while watching sport events: a feasibility and validity study comparing ecological momentary assessments and transdermal alcohol monitors

ABSTRACT Background This feasibility and validity study aimed to evaluate and compare ecological momentary assessment (EMA) surveys and transdermal SCRAM-CAM monitors to measure drinking while watching Australian Rules Football (AFL). Methods During 29 events, 13 participants wore a SCRAM-CAM monitor while completing EMA surveys. Correspondence in the alcohol levels detected and correlation between the self-reported drinks and transdermal alcohol concentration (TAC) were measured. An exit survey assessed participant experiences. Results Alcohol consumption was self-reported on 24 (83.3%) of 29 events, with an average of 5.0 standard drinks consumed over 2.3 hours. Correspondence in the levels of alcohol detected was good at 0.62. TAC curves showed large-sized correlations to the number of self-reported drinks (r = 0.55–0.67). Some participants noted discomfort from the SCRAM-CAM, whilst others reported annoyance completing EMA surveys during a match. Conclusions EMA surveys are a cost effective method for collecting information on drinking as well as contexts and other factors such as harms. A clear benefit of the SCRAM-CAM is the ability to provide detailed information on intoxication trajectories. We suggest that a combination of the two methods will inform the most meaningful approaches for prevention and intervention strategies to reduce harmful drinking among sport spectators.

Perception of transdermal alcohol concentration monitoring system by polish prison officers

Perception of transdermal alcohol concentration monitoring system by polish prison officers

Correspondence between alcohol use measured by a wrist-worn alcohol biosensor and self-report via ecological momentary assessment over a 2-week period.

Transdermal alcohol biosensors measure alcohol use continuously, passively, and non-invasively. There is little field research on the Skyn biosensor, a new-generation, wrist-worn transdermal alcohol biosensor, and little evaluation of its sensitivity and specificity and the day-level correspondence between transdermal alcohol concentration (TAC) and number of self-reported drinks. Participants (N=36; 61% male, M age =34.3) wore the Skyn biosensor and completed ecological momentary assessment (EMA) surveys about their alcohol use over 2 weeks. A total of 497 days of biosensor and EMA data were collected. Skyn-measured drinking episodes were defined by TAC > 5 μg/L. Skyn data were compared to self-reported drinking to calculate sensitivity and specificity (for drinking day vs. nondrinking day). Generalized estimating equations models were used to evaluate the correspondence between TAC features (peak TAC and TAC-area under the curve (AUC)) and number of drinks. Individual-level factors (sex, age, race/ethnicity, body mass index, human immunodeficiency virus status, and hazardous drinking) were examined to explore associations with TAC controlling for number of drinks. Using a minimum TAC threshold of 5 μg/L plus coder review, the biosensor had sensitivity of 54.7% and specificity of 94.6% for distinguishing drinking from nondrinking days. Without coder review, the sensitivity was 78.1% and the specificity was 55.2%. Peak TAC (β=0.92, p < 0.0001) and TAC-AUC (β=1.60, p < 0.0001) were significantly associated with number of drinks. Females had significantly higher TAC levels than males for the same number of drinks. Skyn-derived TAC can be used to measure alcohol use under naturalistic drinking conditions, additional research is needed to accurately identify drinking episodes based on Skyn TAC readings.

Examining new-generation transdermal alcohol biosensor performance across laboratory and field contexts.

Wrist-worn transdermal alcohol sensors have the potential to change how alcohol consumption is measured. However, hardware and data analytic challenges associated with transdermal sensor data have kept these devices from widespread use. Given recent technological and analytic advances, this study provides an updated account of the performance of a new-generation wrist-worn transdermal sensor in both laboratory and field settings. This work leverages machine learning models to convert transdermal alcohol concentration data into estimates of Breath Alcohol Concentration (BrAC) in a large-scale laboratory sample (N=256, study 1) and a pilot field sample (N=27, study 2). Specifically, in both studies, the accuracy of the translation is evaluated by comparing BAC estimates yielded by BACtrack Skyn to real-time breathalyzer measurements collected in the laboratory and in the field. The newest version of the Skyn device demonstrates a substantially lower error rate than older hand-assembled prototypes (0% to 7% vs. 29% to 53%, respectively). On average, real-time estimates of BrAC yielded by these transdermal sensors are within 0.007 of true BAC readings in the laboratory context and within 0.019 of true BrAC readings in the field. In both contexts, the distance between true and estimated BrAC was larger when only alcohol episodes were examined (laboratory = 0.017; field = 0.041). Finally, results of power-law-curve projections indicate that, given their accuracy, transdermal BrAC estimates in real-world contexts have the potential to improve markedly (>25%) with adequately sized datasets for model training. Findings from this study indicate that the latest version of the transdermal wrist sensor holds promise for the accurate assessment of alcohol consumption in field contexts. A great deal of additional work is needed to provide a full picture of the utility of these devices, including research with large participant samples in field contexts.

To Drink or Not to Drink: Is That the Question? Examining Correspondence and Predictive Validity of Morning Drinking Intentions for Young Adults' Drinking Behaviors and Consequences.

The Theory of Planned Behavior suggests that intentions are significant and proximal determinants of behavior. The purpose of this study was to test the predictive validity of drinking intentions for subsequent same-day drinking behaviors and negative consequences. Regularly drinking young adults (N = 222, 21-29years, 84% undergraduates) completed an ecological momentary assessment (EMA) protocol and wore an alcohol monitor for five consecutive 24-h periods spanning 6days (Wednesday-Monday). Each morning, participants reported their drinking intentions for the day and their previous day's alcohol consumption and the number of negative drinking consequences. Multilevel models showed that, at the within-person level, on days when people reported intending to drink, to get drunk, or to drink more than usual, they had higher odds of drinking, consumed more drinks, and had higher peak transdermal alcohol concentrations later that day. However, drinking occurred on 28% of days without drinking intentions, suggesting intentions were an imperfect signal for future drinking behavior. Morning drinking intentions also predicted experiencing more negative consequences, even after controlling for alcohol consumption. On average, young adults' morning-reported drinking-related intentions predicted increased odds of same-day drinking behavior and alcohol-related consequences. However, drinking frequently occurred on days participants did not intend to drink, suggesting that focusing only on drinking intention days will result in many missed prevention opportunities. Together, these results suggest the need for additional research to increase the predictive value of drinking intention assessments and for prevention interventions aimed at helping individuals follow through on their intentions not to drink.