The estimation of blood alcohol concentration : Widmark revisited

A physiologically-based digital twin for alcohol consumption-predicting real-life drinking responses and long-term plasma PEth

Alcohol consumption is associated with a wide variety of preventable health complications and is a major risk factor for all-cause mortality in the age group 15-47 years. To reduce dangerous drinking behavior, eHealth applications have shown promise. A particularly interesting potential lies in the combination of eHealth apps with mathematical models. However, existing mathematical models do not consider real-life situations, such as combined intake of meals and beverages, and do not connect drinking to clinical markers, such as phosphatidylethanol (PEth). Herein, we present such a model which can simulate real-life situations and connect drinking to long-term markers. The new model can accurately describe both estimation data according to a χ2 -test (187.0 < Tχ2 = 226.4) and independent validation data (70.8 < Tχ2 = 93.5). The model can also be personalized using anthropometric data from a specific individual and can thus be used as a physiologically-based digital twin. This twin is also able to connect short-term consumption of alcohol to the long-term dynamics of PEth levels in the blood, a clinical biomarker of alcohol consumption. Here we illustrate how connecting short-term consumption to long-term markers allows for a new way to determine patient alcohol consumption from measured PEth levels. An additional use case of the twin could include the combined evaluation of patient-reported AUDIT forms and measured PEth levels. Finally, we integrated the new model into an eHealth application, which could help guide individual users or clinicians to help reduce dangerous drinking.

Measurement uncertainty of ethyl alcohol concentration in the exhaled breath of drivers and determination of sobriety at the time of incident

The aim of the study was to determine the components of measurement uncertainty in the concentration of alcohol in exhaled breath and to determine the state of sobriety at the time of incident. Based on the literature review and the authors' experience in providing opinions for law enforcement and the judiciary, the influence of various factors on the final interpretation of sobriety state is described on the basis of measurement uncertainty of breath analyzers, uncertainty of retrospective and prospective calculations, and uncertainty related to the conversion of alcohol concentrations detected during breath and blood tests. The paper pays particular attention to interpreting the concentrations of ethanol in exhaled breath close to the legal limits of the state of sobriety and the state after alcohol use, or the state after alcohol use and the state of insobriety. Analyzing the results of an exhaled breath test concerning concentrations close to the values of 0.1 mg/dm3 and 0.25 mg/dm3, it is necessary to take into account the factors affecting the measurements obtained, including the measurement uncertainty of the determination of alcohol in exhaled breath, the processes of absorption, distribution and metabolism of ethyl alcohol, and the possibility of the presence of alcohol lingering in the oral cavity. The incorrect execution of measurements of the tested person's alcohol concentration is also a problematic issue. When determining sobriety state by means of retrospective and prospective calculations, it is important to remember that the uncertainty of the result is affected by a number of factors and depends, among other things, on the information provided by the suspect. Hence, the expert should draw conclusions particularly cautiously and any overestimation or underestimation of the components of uncertainty can lead to erroneous conclusions. Awareness of the uncertainties inherent in the results of a sobriety test or alcohol calculation allows for meaningful interpretation of test results and determination of the sobriety state of the person tested.

Validation of hair ethyl glucuronide using transdermal monitoring and self-reported alcohol use in women of childbearing potential

Aim

The present study aimed to evaluate the validity of hair ethyl glucuronide concentrations compared with transdermal alcohol concentration and self‐reported alcohol use.

Methods

This trial included 25 adolescent and young adult females, aged 16‐24, who reported at least one heavy drinking episode (≥4 drinks) in the two weeks prior to baseline. All participants were asked to wear an alcohol biosensor over a one‐month prospective study. Detailed self‐report of drinking behaviors was assessed weekly. Estimates of blood alcohol concentration were computed from self‐report data using the National Highway and Transportation Safety Administration equation. Transdermal alcohol concentration and estimated blood alcohol concentration data were categorized into at‐risk (>0.05 g/dL alcohol) and high‐risk (>0.08 g/dL alcohol) drinking events. Hair ethyl glucuronide concentration, total number of drinking events, moderate (>0.05 g/dL) and high level (>0.08 g/dL) of transdermal alcohol concentration, and estimated blood alcohol concentration drinking events were analyzed with Spearman's rank correlation test for validity comparisons.

Results

No significant correlations were found between hair ethyl glucuronide values and total number, and moderate or high levels of detected drinking events by estimated blood alcohol concentration or transdermal alcohol concentration. Total number of drinking events detected and number of drinking events >0.08 g/dL using estimated blood alcohol concentration and transdermal alcohol concentration methods were significantly correlated with each other (respectively, R = .33, P < .05; R = .42, P < .05).

Conclusion

Our findings indicate that, due to the number of false negatives, hair ethyl glucuronide concentrations should be used with caution for monitoring abstinence from alcohol use.

The catechol-O-methyltransferase inhibitor tolcapone modulates alcohol consumption and impulsive choice in alcohol use disorder

RATIONALE

Individuals suffering from alcohol use disorder (AUD) demonstrate difficulty with decision-making and impulsivity that may be associated with impaired frontal cortical function. Therapeutics that enhance frontal dopamine tone could decrease impulsivity and in turn reduce alcohol consumption in individuals with AUD.

OBJECTIVES

To determine if the catechol-O-methyltransferase (COMT) inhibitor tolcapone can attenuate alcohol consumption in individuals with AUD and whether this attenuation correlates with tolcapone-induced changes in laboratory-based decision-making tasks.

METHODS

We used daily self-report and a novel group laboratory bar task to assess the effects of randomized double-blind crossover administration of tolcapone (100 mg TID for 5 days) on alcohol consumption and laboratory tasks assessing impulsivity in 55 non-treatment-seeking subjects with AUD.

RESULTS

Tolcapone significantly reduced self-reported alcohol consumption (t (54) = 2.05, p = 0.045). The effects of tolcapone on drinking significantly correlated with changes in impulsive decision-making, such that subjects with the greatest decrease in impulsive choice on tolcapone also reported the greatest decrease in alcohol consumption (r (45) = 0.40, p = 0.0053). We did not see effects of tolcapone on laboratory bar consumption. Adverse event (AE) reporting was low, with no significant difference in frequency or severity of AEs on tolcapone versus placebo.

CONCLUSIONS

These data demonstrate that COMT inhibitors such as tolcapone may be useful therapeutics for AUD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02740582.

Wearable Enzymatic Alcohol Biosensor

Transdermal alcohol biosensors have the ability to detect the alcohol that emanates from the bloodstream and diffuses through the skin. However, previous biosensors have suffered from long-term fouling of the sensor element and drift in the resulting sensor readings over time. Here, we report a wearable alcohol sensor platform that solves the problem of sensor fouling by enabling drift-free signals in vivo for up to 24 h and an interchangeable cartridge connection that enables consecutive days of measurement. We demonstrate how alcohol oxidase enzyme and Prussian Blue can be combined to prevent baseline drift above 25 nA, enabling sensitive detection of transdermal alcohol. Laboratory characterization of the enzymatic alcohol sensor demonstrates that the sensor is mass-transfer-limited by a diffusion-limiting membrane of lower permeability than human skin and a linear sensor range between 0 mM and 50 mM. Further, we show continuous transdermal alcohol data recorded with a human subject for two consecutive days. The non-invasive sensor presented here is an objective alternative to the self-reports used commonly to quantify alcohol consumption in research studies.

Relationship between heavy drinking, binge drinking, and metabolic syndrome in obese and non-obese Korean male adults

BACKGROUND/OBJECTIVES

Obesity and alcohol drinking are associated with metabolic syndrome. However, few studies show the relationship between alcohol drinking and metabolic syndrome according to varying degrees of obesity. This study aimed to determine the association between alcohol drinking and metabolic syndrome in obese and non-obese Korean male adults.

SUBJECTS/METHODS

This cross-sectional study included 5,867 males aged ≥ 20 years who were examined at the Soonchunhyang University health promotion center during June 2008–December 2010. The subjects were divided into non-obese (body mass index [BMI] < 25 kg/m²) and obese (BMI ≥ 25 kg/m²) groups and further divided according to weekly alcohol consumption into nondrinking (0 drinks/week), moderate drinking (≤ 14 drinks/week), and heavy drinking (> 14 drinks/week) groups. The subjects were also categorized into binge drinking and non-binge drinking groups. To obtain odds ratios (ORs) for metabolic syndrome, binary logistic regression analysis was performed.

RESULTS

The overall metabolic syndrome prevalence was 27.3% (12.8%, non-obese group; 50.4%, obese group). After adjusting for age, physical activity, and smoking, in the non-obese group, the OR for heavy drinking with binge drinking (reference: nondrinking) was 1.56 (95% confidence interval [CI] = 1.12–2.18), with a significant increase in metabolic syndrome prevalence. In the obese group, the OR for heavy drinking with binge drinking was 1.42 (95% CI = 1.07–1.88), showing a significant increase in metabolic syndrome prevalence (P < 0.05).

CONCLUSIONS

In both non-obese and obese Korean males, heavy drinking with binge drinking was associated with increased risk of metabolic syndrome. Thus, both non-obese and obese males should restrict their alcohol intake and not indulge in binge drinking.

Outpatient treatment of alcohol use disorders among subjects 60+ years: design of a randomized clinical trial conducted in three countries (Elderly Study)

BACKGROUND

The proportion of 60+ years with excessive alcohol intake varies in western countries between 6-16 % among men and 2-7 % among women. Specific events related to aging (e.g. loss of job, physical and mental capacity, or spouse) may contribute to onset or continuation of alcohol use disorders (AUD). We present the rationale and design of a multisite, multinational AUD treatment study for subjects aged 60+ years.

METHODS/DESIGN

1,000 subjects seeking treatment for AUD according to DSM-5 in outpatient clinics in Denmark, Germany, and New Mexico (USA) are invited to participate in a RCT. Participants are randomly assigned to four sessions of Motivational Enhancement Treatment (MET) or to MET plus an add-on with eight sessions based on the Community Reinforcement Approach (CRA), which include a new module targeting specific problems of older adults. A series of assessment instruments is applied, including the Form-90, Alcohol Dependence Scale, Penn Alcohol Craving Scale, Brief Symptom Inventory and WHO Quality of Life. Enrolment will be completed by April 2016 and data collection by April 2017. The primary outcome is the proportion in each group who are abstinent or have a controlled use of alcohol six months after treatment initiation. Controlled use is defined as maximum blood alcohol content not exceeding 0.05 % during the last month. Total abstinence is a secondary outcome, together with quality of life andcompliance with treatment.

DISCUSSION

The study will provide new knowledge about brief treatment of AUD for older subjects. As the treatment is manualized and applied in routine treatment facilities, barriers for implementation in the health care system are relatively low. Finally, as the study is being conducted in three different countries it will also provide significant insight into the possible interaction of service system differences and related patient characteristics in predictionof treatment outcome.

TRIAL REGISTRATION

Clinical Trials.gov NCT02084173 , March 7, 2014.

A neuropsychological instrument measuring age-related cerebral decline in older drivers: development, reliability, and validity of MedDrive

When facing age-related cerebral decline, older adults are unequally affected by cognitive impairment without us knowing why. To explore underlying mechanisms and find possible solutions to maintain life-space mobility, there is a need for a standardized behavioral test that relates to behaviors in natural environments. The aim of the project described in this paper was therefore to provide a free, reliable, transparent, computer-based instrument capable of detecting age-related changes on visual processing and cortical functions for the purposes of research into human behavior in computational transportation science. After obtaining content validity, exploring psychometric properties of the developed tasks, we derived (Study 1) the scoring method for measuring cerebral decline on 106 older drivers aged ≥70 years attending a driving refresher course organized by the Swiss Automobile Association to test the instrument's validity against on-road driving performance (106 older drivers). We then validated the derived method on a new sample of 182 drivers (Study 2). We then measured the instrument's reliability having 17 healthy, young volunteers repeat all tests included in the instrument five times (Study 3) and explored the instrument's psychophysical underlying functions on 47 older drivers (Study 4). Finally, we tested the instrument's responsiveness to alcohol and effects on performance on a driving simulator in a randomized, double-blinded, placebo, crossover, dose-response, validation trial including 20 healthy, young volunteers (Study 5). The developed instrument revealed good psychometric properties related to processing speed. It was reliable (ICC = 0.853) and showed reasonable association to driving performance (R (2) = 0.053), and responded to blood alcohol concentrations of 0.5 g/L (p = 0.008). Our results suggest that MedDrive is capable of detecting age-related changes that affect processing speed. These changes nevertheless do not necessarily affect driving behavior.

Sex differences in alcohol misuse and estimated blood alcohol concentrations among emergency department patients: implications for brief interventions

OBJECTIVES

The objective was to assess the relationship between alcohol use and misuse and patient sex among emergency department (ED) patients by comparing self-reported estimates of quantity and frequency of alcohol use, estimated blood alcohol concentrations (eBACs) when typically drinking and during heavy episodic drinking (binging), and alcohol misuse severity, to understand sex differences in alcohol use and misuse for this population.

METHODS

The authors surveyed a random sample of nonintoxicated, subcritically ill or injured, 18- to 64-year-old English- or Spanish-speaking patients on randomly selected dates and times at two EDs during July 2009 and August 2009. Participants self-administered a questionnaire about their self-reported alcohol use during a typical month within the past 12 months and the Alcohol Use Disorders Identification Test (AUDIT). Using the formulae by Matthews and Miller, sex-specific eBACs were calculated for participants according to their reported weight and the number of reported alcoholic drinks consumed on days when typically drinking and on days of heavy episodic (binge) drinking (five or more drinks/occasion for men, four or more drinks for women). Sex-specific alcohol misuse severity levels (low-risk, harmful, hazardous, and dependence) were calculated using AUDIT scores. Wilcoxon rank-sum and Pearson's chi-square tests were used to compare outcomes by sex. Negative binomial regression was used to assess the relationship between sex and the number of drinks consumed on a typical day, the number of days spent drinking and binging, and estimated AUDIT scores. Logistic regression was used to assess the outcome of the presence of binging according to sex. Multinomial logistic regression was used to compare by sex the percentage of days spent drinking and binging in 1 month, eBACs when typically drinking and when binging, and AUDIT at-risk drinking levels. Incidence rate ratios (IRRs) and adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were estimated. All models were adjusted for patient demographic characteristics.

RESULTS

Of the 513 participants, 52.1% were women, 55.8% were white non-Hispanic, and their median age was 34 years (interquartile range [IQR] = 25 to 46 years). Men reported greater mean alcohol consumption than women when typically drinking (4.3 vs. 3.3 drinks/day; p < 0.001) and during heavy episodic drinking (8.6 vs. 5.3 drinks/occasion; p < 0.001). Men spent more days drinking (IRR = 1.41, 95% CI = 1.19 to 1.65) and engaging in heavy episodic drinking (IRR = 1.68, 95% CI = 1.31 to 2.17) than women. Additionally, men were more likely to engage in heavy episodic drinking (AOR = 1.72, 95% CI = 1.16 to 2.56) than women. However, the mean eBACs for men and women were similar when typically drinking (0.05 vs. 0.06; p < 0.13) and during heavy episodic drinking (0.13 vs. 0.12; p < 0.13). Mean AUDIT scores were greater for men than women (7.5 vs. 5.3; p < 0.001), although alcohol misuse severity levels were similar between men and women (24.4% vs. 26.6% for hazardous, 2.8% vs. 2.2% for harmful, and 6.5% vs. 3.4% for dependence; p < 0.38).

CONCLUSIONS

Although men drink more than women, women have similar eBACs with comparable levels of alcohol misuse. Women may benefit from recognizing that they are reaching similar levels of intoxication compared to men. Addressing these differences and possible health implications in future ED brief interventions may induce changes in problematic alcohol use among women.

Cross-sectional measures and modelled estimates of blood alcohol levels in UK nightlife and their relationships with drinking behaviours and observed signs of inebriation

BACKGROUND

Management of nightlife in UK cities focuses on creating safe places for individuals to drink. Little is known about intoxication levels as measuring total alcohol consumption on nights out is complicated by early evening interviews missing subsequent consumption and later interviews risking individuals being too drunk to recall consumption or participate at all. Here we assess mixed survey and modelling techniques as a methodological approach to examining these issues.

METHODS

Interviews with a cross sectional sample of nightlife patrons (n = 214) recruited at different locations in three cities established alcohol consumption patterns up to the point of interview, self-assessed drunkenness and intended drinking patterns throughout the remaining night out. Researchers observed individuals' behaviours to independently assess drunkenness. Breath alcohol tests and general linear modelling were used to model blood alcohol levels at participants' expected time of leaving nightlife settings.

RESULTS

At interview 49.53% of individuals regarded themselves as drunk and 79.43% intended to consume more alcohol before returning home, with around one in ten individuals (15.38% males; 4.35% females) intending to consume >40 units (equal to 400 mls of pure alcohol). Self-assessed drunkenness, researcher observed measures of sobriety and blood alcohol levels all correlated well. Modelled estimates for blood alcohol at time of going home suggested that 71.68% of males would be over 0.15%BAC (gms alcohol/100 mls blood). Higher blood alcohol levels were related to drinking later into the night.

CONCLUSIONS

UK nightlife has used substantive health and judicial resources with the aim of creating safer and later drinking environments. Survey and modelling techniques together can help characterise the condition of drinkers when using and leaving these settings. Here such methods identified patrons as routinely getting drunk, with risks of drunkenness increasing over later nights. Without preventing drunkenness and sales to intoxicated individuals, extended drinking hours can simply act as havens for drunks. A public health approach to nightlife is needed to better understand and take into account the chronic effects of drunkenness, the damages arising after drunk individuals leave city centres and the costs of people avoiding drunken city centres at night.