How accurate are blood (or breath) tests for identifying self-reported heavy drinking among people with alcohol dependence?

Screening for alcohol use in primary care: assessing French general practitioner practices

Alcohol use is a leading risk factor for premature death and disability. To tackle this issue, more systematic and accurate screening for at-risk consumption is needed in healthcare systems, especially by general practitioners (GPs). We assessed the frequency of at-risk consumption screening by GPs in France. We also identified characteristics associated with more frequent screening and greater use of validated screening tools by these healthcare providers. A cross-sectional survey was conducted among a representative sample of French GPs. Multinomial logistic regressions were used to identify factors associated with more frequent screening and greater use of validated screening tools. Response rate was of 73%. Of the 2412 participants, 42.8% screened all their patients systematically and repeatedly, while 48.0% never used standardized tools to screen potentially at-risk patients. Among other characteristics, being aware of and using the "early identification and brief intervention" screening strategy, and feeling absolutely comfortable talking with patients about reducing or stopping their alcohol use, were both associated with more frequent screening and use of standardized tools. Our results on at-risk alcohol use screening highlight an improvement over data from previous studies. Nevertheless, better training of French GPs in good alcohol screening practices-specifically, increased screening frequency and greater use of standardized tools-may improve identification of at-risk patients.

Accuracy of carbohydrate-deficient transferrin as a biomarker of chronic alcohol abuse during treatment for alcoholism

AIM

Clinical evaluations are generally used to verify the effectiveness of detoxification treatments for alcohol dependence, but new objective biomarkers are essential for accurate diagnosis. We aim to assess the accuracy of carbohydrate-deficient transferrin (%CDT) in a cohort of Japanese patients admitted to a psychiatric hospital specializing in alcohol dependence. In addition, we investigated the kinetics of %CDT during alcohol moderation or cessation.

METHODS

The study cohort consisted of 126 alcohol-dependent patients. The levels of serum %CDT were assessed by the N Latex CDT direct immunonephelometric assay.

RESULTS

Alcohol consumption was significantly correlated with %CDT. The only independent predictive factor of alcohol consumption was %CDT, with glutamyltranspeptidase (GGT) and albumin-bilirubin score proving insufficient. The cut-off value of %CDT was 1.9% with high sensitivity and specificity in detecting alcohol abstinence beyond 30 days (68.6% sensitivity, 91.8% specificity) and excessive alcohol drinking (77.9% sensitivity, 77.1% specificity). The %CDT levels were significantly decreased at 30 days of abstinence when compared with baseline. Notably, %CDT values were significantly changed even in the light alcohol drinking cohort (p = 0.0009), whereas GGT levels were not significantly changed.

CONCLUSIONS

Our results indicate that %CDT is an accurate and specific biomarker of alcohol consumption and is useful in detecting alcohol abstinence even in a low alcohol intake patient cohort. These results suggest that %CDT could be a useful objective biomarker of chronic alcohol abuse during clinical treatment for alcoholism.

Embedded Transdermal Alcohol Detection via a Finger Using SnO2 Gas Sensors

In this paper, we report the fabrication and characterization of a portable transdermal alcohol sensing device via a human finger, using tin dioxide (SnO₂) chemoresistive gas sensors. Compared to conventional detectors, this non-invasive technique allowed us the continuous monitoring of alcohol with low cost and simple fabrication process. The sensing layers used in this work were fabricated by using the reactive radio frequency (RF) magnetron sputtering technique. Their structure and morphology were investigated by means of X-ray spectroscopy (XRD) and scanning electron microscopy (SEM), respectively. The results indicated that the annealing time has an important impact on the sensor sensitivity. Before performing the transdermal measurements, the sensors were exposed to a wide range of ethanol concentrations and the results displayed good responses with high sensitivity, stability, and a rapid detection time. Moreover, against high relative humidity (50% and 70%), the sensors remained resistant by showing a slight change in their gas sensing performances. A volunteer (an adult researcher from our volunteer group) drank 50 mL of tequila in order to realize the transdermal alcohol monitoring. Fifteen minutes later, the volunteer's skin started to evacuate alcohol and the sensor resistance began to decline. Simultaneously, breath alcohol measurements were attained using a DRAGER 6820 certified breathalyzer. The results demonstrated a clear correlation between the alcohol concentration in the blood, breath, and via perspiration, which validated the embedded transdermal alcohol device reported in this work.

Evaluation of the diagnostic utility of carbohydrate-deficient transferrin in chronic alcoholism: Results from Southwest China

Although recent gathered evidence indicates that obtaining the diagnostic value of serum carbohydrate-deficient transferrin might be more useful for identifying alcohol abuse than other widely available biochemical tests; however, its precise value as an indicator of chronic alcoholism is unclear. The main objective is to investigate the diagnostic significance of carbohydrate-deficient transferrin in chronic alcoholism in the Chinese population.In this study, we enrolled (1) 52 physically healthy subjects, (2) 20 patients with nonalcoholic liver disease, and (3) 70 alcoholics. Patients with liver injuries and a history of liver surgery were excluded. Serum gamma-glutamyltransferase, aspartate aminotransferase, alanine aminotransferase, and mean corpuscular volume were determined by standard biochemical assays, and serum carbohydrate-deficient transferrin was estimated in each group using capillary electrophoresis. Subsequently, the diagnostic value of carbohydrate-deficient transferrin (CDT) in chronic alcoholism was determined based on differences between each indicator among the three groups.The CDT level in the alcoholic group was significantly higher than that of the non-alcoholic liver disease and healthy control groups (P < .05). The area under the curve for alcoholism diagnosis was the highest for CDT, at 0.922, whereas those for gamma-glutamyltransferase, aspartate aminotransferase, alanine aminotransferase, and mean corpuscular volume were 0.860, 0.744, 0.615, and 0.754, respectively. When the cutoff value of CDT was set at 1.25%, the sensitivity and specificity were 85.5% and 89.6%, respectively. However, the correlation between CDT and daily alcohol consumption was weak (r = 0.175; P = .16).Compared with the other parameters evaluated, CDT was a better indicator of alcoholism. It should, therefore, be actively promoted in clinical practice. However, the correlation between CDT and daily alcohol consumption needs further evaluation.

Nerve Growth Factor in Alcohol Use Disorders

The nerve growth factor (NGF) belongs to the family of neurotrophic factors. Initially discovered as a signaling molecule involved in the survival, protection, differentiation, and proliferation of sympathetic and peripheral sensory neurons, it also participates in the regulation of the immune system and endocrine system. NGF biological activity is due to the binding of two classes of receptors: the tropomyosin-related kinase A (TrkA) and the low-affinity NGF pan-neurotrophin receptor p75. Alcohol Use Disorders (AUD) are one of the most frequent mental disorders in developed countries, characterized by heavy drinking, despite the negative effects of alcohol on brain development and cognitive functions that cause individual’s work, medical, legal, educational, and social life problems. In addition, alcohol consumption during pregnancy disrupts the development of the fetal brain causing a wide range of neurobehavioral outcomes collectively known as fetal alcohol spectrum disorders (FASD). The rationale of this review is to describe crucial findings on the role of NGF in humans and animals, when exposed to prenatal, chronic alcohol consumption, and on binge drinking.

A Comparison of the Predictive Power of DNA Methylation with Carbohydrate Deficient Transferrin for Heavy Alcohol Consumption

Currently, the most commonly used biomarker of alcohol consumption patterns is carbohydrate-deficient transferrin (CDT). However, the CDT has limited sensitivity and requires the use of blood. Recently, we have shown that digital DNA methylation techniques can both sensitively and specifically detect heavy alcohol consumption (HAC) using DNA from blood or saliva. In order to better understand the relative performance characteristics of these two tests, we compared an Alcohol T-Score (ATS) derived from our prior study and serum CDT levels in 313 (182 controls and 131 HAC cases) subjects discordant for HAC. Overall, the Receiver Operating Characteristic (ROC) area under the curve (AUC) analyses showed that DNA methylation predicted HAC status better than CDT with AUCs of 0.96 and 0.87, respectively (p < 0.0001). The performance of the CDT was affected by gender while the ATS was not, while both were affected by age. We conclude that DNA methylation is a promising method for quantifying HAC and that further studies to better refine its strengths and limitations are in order.

Craving mediates the effect of impulsivity on lapse-risk during alcohol use disorder treatment

Rash impulsiveness, the propensity for approach behaviour despite potential negative consequences, is associated with stronger alcohol craving in patients with Alcohol Use Disorder (AUD). This relationship is poorly understood and implications for treatment response are unexamined. This study explored the relationship between rash impulsiveness, craving, and treatment response among 304 outpatients enrolled in a 12-week abstinence-based Cognitive-Behavioural Therapy (CBT) program for AUD. Assessments were completed pre-and-post treatment, with craving and alcohol consumption monitored at each treatment session. Higher rash impulsiveness predicted more frequent craving over treatment (b = 0.95, 95% CI = 0.40, 1.50). Higher craving was associated with greater lapse-risk (b = 0.04, 95% CI = 0.03, 0.05), with the association between craving and lapse-risk increasing as treatment progressed (b = 0.01, 95% CI = 0.01, 0.02). Craving positively mediated the relationship between rash impulsiveness and lapse-risk (µ = 0.38, 95% CI = 0.10, 0.70). Contrary to hypotheses, the risk of lapse in response to craving was not moderated by rash-impulsiveness. These results suggest that AUD patients with a predisposition for rash impulsiveness are more vulnerable to alcohol craving, and subsequently, poorer treatment outcomes.

The Cochrane 2018 Review on Brief Interventions in Primary Care for Hazardous and Harmful Alcohol Consumption: A Distillation for Clinicians and Policy Makers

AIMS

An updated Cochrane systematic review assessed effectiveness of screening and brief intervention to reduce hazardous or harmful alcohol consumption in general practice or emergency care settings. This paper summarises the implications of the review for clinicians.

METHODS

Cochrane methods were followed. Reporting accords with PRISMA guidance. We searched multiple resources to September 2017, seeking randomised controlled trials of brief interventions to reduce hazardous or harmful alcohol consumption in people attending general practice, emergency care or other primary care settings for reasons other than alcohol treatment. Brief intervention was defined as a conversation comprising five or fewer sessions of brief advice or brief lifestyle counselling and a total duration of less than 60 min. Our primary outcome was alcohol consumption, measured as or convertible to grams per week. We conducted meta-analyses to assess change in consumption, and subgroup analyses to explore the impact of participant and intervention characteristics.

RESULTS

We included 69 studies, of which 42 were added for this update. Most studies (88%) compared brief intervention to control. The primary meta-analysis included 34 studies and provided moderate-quality evidence that brief intervention reduced consumption compared to control after one year (mean difference -20 g/wk, 95% confidence interval -28 to -12). Subgroup analysis showed a similar effect for men and women.

CONCLUSIONS

Brief interventions can reduce harmful and hazardous alcohol consumption in men and women. Short, advice-based interventions may be as effective as extended, counselling-based interventions for patients with harmful levels of alcohol use who are presenting for the first time in a primary care setting.

Design of a randomized controlled trial examining the efficacy of oxytocin to enhance alcohol behavioral couple therapy

Combining pharmacological interventions with evidence-based behavioral interventions may help optimize treatment outcomes for alcohol use disorder (AUD). While several effective behavioral interventions for AUD have been developed, the vast majority target individual patients, despite evidence that behavioral interventions for couples have the ability to outperform individual treatments for AUD. Alcohol Behavioral Couples Therapy (ABCT) is an evidence-based behavioral intervention for couples that has been shown to significantly reduce AUD severity as well as improve relationship functioning. Accumulating evidence suggests that the neuropeptide oxytocin has the ability to reduce alcohol craving and consumption, symptoms of tolerance and withdrawal, and ameliorate neurobiological deficits associated with AUD. Furthermore, oxytocin has demonstrated the ability to increase prosocial behavior and cognition, and restore sensitivity to natural rewards such as interpersonal relationships. No study to date has examined the ability of oxytocin to enhance ABCT. Thus, the primary objective of this Phase II study is to examine the effects of oxytocin versus placebo in combination with ABCT in reducing AUD severity and improving relationship functioning. We also will utilize neuroimaging techniques before and after treatment to investigate the underlying pathophysiology of AUD among couples and identify prognostic indicators of treatment outcome. The findings from this study might provide critical new information to help inform clinical practice and accelerate research on the pharmacological treatment of AUD.

Alcohol expectancies pre-and post-alcohol use disorder treatment: Clinical implications

BACKGROUND AND AIMS

Modification of elevated positive expectations of alcohol consumption (alcohol outcome expectancies; AOEs) is a key feature of Cognitive Behaviour Therapy (CBT) approaches to Alcohol Use Disorders (AUDs). Despite extensive research supporting the efficacy of CBT for AUD, few studies have examined AOE change. This study aimed to assess AOE change following completion of CBT for AUD and its association with drinking behaviour.

METHOD

One-hundred and seventy-five patients who completed a 12-week CBT program for AUD were administered the Drinking Expectancy Questionnaire (DEQ) at pre-treatment assessment and upon completion of treatment. Abstinence was achieved by 108 (61.7%) of completing patients. For patients who lapsed, the mean proportion of abstinent days was 93%.

RESULTS

DEQ scales assessing expectations of positive alcohol effects on tension reduction, assertiveness, and cognitive enhancement were significantly lower post-treatment (p<0.001). Expectations of negative effects on mood were higher post-treatment (p<0.001). The largest AOE change occurred on the tension reduction scale. Greater percentage of abstinent days over treatment was associated with lower pre-and post-treatment tension reduction expectancy scores (p<0.05). Drinking during treatment was associated with smaller changes in expectations of negative effects of alcohol on mood (p<0.05).

CONCLUSIONS

Individuals who completed CBT treatment for AUD showed significant AOE change. Tension reduction and affective change expectancies may be particularly important for abstinence and useful markers of lapse risk.

Monitoring people at risk of drinking by a rapid urinary ethyl glucuronide test

Alcohol and illicit drug abuse are major public health problems worldwide. Since alcohol is the predominant substance of choice in polydrug abusers, monitoring its use, along with urinary drug screening in patients in rehabilitation programs, appeared to be crucial in identifying patients at risk of alcohol disorders leading to impaired quality of life. Ethyl β-D-6-glucuronide, a non-oxidative, non-volatile, stable and minor direct ethanol metabolite, has a 6h to 4 day window of detection in urine after the last alcohol intake. Each of the 119 subjects (85 males, 34 females) registered with the Public Health Service for Drug Dependence Treatment provided a urine sample for ethylglucoronide (EtG) determination in an immunochemical test with a 500 ng/ml cutoff. All results were evaluated with confirmation criteria of a fully validated gas chromatography/mass spectrometry assay. The diagnostic performance of the EtG immunochemical test was assessed using Receiver Operating Characteristic Curve analysis. The immunochemical test specificity was 100% for EtG urinary values above 500 ng/ml. No false positive results were found. With levels below 500 ng/ml, 12% of the samples were classified as negative. The average consumption of the incorrectly classified subjects was 171 ng/ml, with a misclassification error of 6.5% to 18.5%. High agreement between EtG as determined in an immunochemical test and gas chromatography/mass spectrometry, suggests that the rapid EtG test is a reliable, cost-effective alcohol monitoring assay for patient management in many non-forensic settings, such as drug rehabilitation programs.

Analytical and diagnostic aspects of carbohydrate deficient transferrin (CDT): A critical review over years 2007-2017

The need for investigating alcohol abuse by means of objective tools is worldwide accepted. Among the currently available biomarkers of chronic alcohol abuse, carbohydrate-deficient transferrin (CDT) is one of the most used indicator, mainly because of its high specificity. However, some CDT analytical and interpretation aspects are still under discussion, as witnessed by numerous research papers and reviews. The present article presents a critical review of the literature on CDT appeared in the period from 2007 to 2017 (included). The article is organized in the following sections: (1) introduction, (2) pre-analytical aspects (3) analytical aspects (4) diagnostic aspects (5) concluding remarks. As many as 139 papers appeared in the international literature and retrieved by the search engines PubMed, Web of Science and Scopus are quoted.

Alcohol use disorders in Australia

Alcohol use disorders are common in Australia and are often unrecognised. Alcohol places a significant burden on our healthcare system by increasing the risk of injuries as well as many chronic medical conditions. Diagnosis requires a high index of suspicion and can be aided by the use of specific questionnaires, such as the Alcohol Use Disorder Identification Test-C. The current available laboratory tests are of limited sensitivity and specificity, but can nevertheless aid in the diagnosis in some circumstances. Newer tests, such as ethyl-glucuronide and phosphatidylethanol, are more sensitive and specific but are costly and not widely available. The effective management of alcohol use disorder entails psychosocial or pharmacological treatments or a combination of both. In those who cannot reduce alcohol consumption, harm reduction strategies can be applied to reduce the burden of harm to the drinkers as well as the community at large.

Why measure carbohydrate deficient transferrin?

The acute or chronic harmful use of alcohol is among the top five risk factors for disease, disability and death worldwide.1 Monitoring alcohol consumption is an important aspect of the management of alcohol-use disorders and may include subjective self-reported questionnaires or objective tests.1,2-6 Such tests include measuring alcohol or alcohol metabolite levels or biomarkers such as liver enzymes or red cell indices.2-6 Carbohydrate deficient transferrin (CDT) is a biomarker used for assessing chronic alcohol misuse.6 Here, we review CDT and its place in the assessment of chronic alcohol use.

Phosphatidylethanol is superior to carbohydrate-deficient transferrin and γ-glutamyltransferase as an alcohol marker and is a reliable estimate of alcohol consumption level

BACKGROUND

In clinical practice as well as research situations, it is of great importance to get reliable information about a patient's alcohol consumption. The aim of the study was to investigate the correlation of alcohol biomarkers (phosphatidylethanol [PEth], carbohydrate-deficient transferrin [CDT], γ-glutamyltransferase, aspartate aminotransferase, and alanine aminotransferase) to retrospective as well as diary-based alcohol self-reports and to examine whether it is possible to correlate a biomarker result to a more precise level of alcohol consumption.

METHODS

One hundred and sixty alcohol-dependent patients were included in a randomized, placebo-controlled clinical trial of pharmacotherapy for alcohol dependence, of which 115 (76 men and 39 women) completed the study. Retrospective alcohol consumption data were collected at baseline, and alcohol diaries were used during the study. Blood samples for determination of alcohol biomarkers were collected on 5 occasions during the study.

RESULTS

PEth and CDT showed a better correlation with alcohol consumption documented in the diary (PEth rs = 0.56 and CDT rs = 0.35) than with retrospective consumption data (PEth rs = 0.23 and CDT rs = 0.22). An even higher correlation (rs = 0.63) was seen between the 2 alcohol biomarkers PEth and CDT. At all consumption levels, PEth had the highest sensitivity of all biomarkers studied.

CONCLUSIONS

PEth was the biomarker with the best correlation to self-reported alcohol consumption. PEth was superior to CDT owing to its substantially higher sensitivity but also due to its closer correlation to self-report. PEth values can be translated into an approximate level of alcohol consumption and PEth appears to be a more reliable measure of alcohol consumption than self-reports.

Alcohol use disorders

Alcohol use disorders are common in developed countries, where alcohol is cheap, readily available, and heavily promoted. Common, mild disorders often remit in young adulthood, but more severe disorders can become chronic and need long-term medical and psychological management. Doctors are uniquely placed to opportunistically assess and manage alcohol use disorders, but in practice diagnosis and treatment are often delayed. Brief behavioural intervention is effective in primary care for hazardous drinkers and individuals with mild disorders. Brief interventions could also encourage early entry to treatment for people with more-severe illness who are underdiagnosed and undertreated. Sustained abstinence is the optimum outcome for severe disorder. The stigma that discourages treatment seeking needs to be reduced, and pragmatic approaches adopted for patients who initially reject abstinence as a goal. To engage people in one or more psychological and pharmacological treatments of equivalent effectiveness is more important than to advocate a specific treatment. A key research priority is to improve the diagnosis and treatment of most affected people who have comorbid mental and other drug use disorders.

Baclofen for alcohol dependence: Relationships between baclofen and alcohol dosing and the occurrence of major sedation

High-dose baclofen, i.e., 300 mg/d or more, has recently emerged as a strategy for treating alcohol dependence. The impact that the co-exposure of large amounts of alcohol and baclofen has on sedation is unclear. In a prospective cohort of 253 subjects with alcohol dependence, we collected daily alcohol and baclofen doses across the first year of baclofen treatment and the monthly maximum subjective sedation experienced by each patient (0-10 visual analog scale). For each patient-month, we determined the average weekly alcohol consumption (AWAC; standard-drinks/week) and the maximum daily dose of baclofen (DDB; mg/d). The occurrence of an episode of major sedation (EMS) during a patient-month was defined as a sedation score ≥7. The relationship between the EMS occurrence and the concurrent AWAC and DDB was investigated using a generalized estimating equation model. In total, 1528 patient-months were compiled (70 with an EMS). Univariate analyses demonstrated that the rate of patient-month to EMS increased gradually with AWAC (p<0.001), from 0.9% for AWAC=0 to 9.4% for AWAC >35. There was also a significant gradual risk for EMS associated with DDB (<0.001). Multivariate analysis demonstrated a significant interaction between DDB and AWAC on EMS risk (p=0.047). Each 20mg/d increase in DDB was associated with an OR of EMS in AWAC >35 of 1.22 (95%CI, 1.08-1.38) versus 1.11 (95%CI, 0.96-1.29) in AWAC=1-35, and 0.95 (95%CI, 0.76-1.19) in AWAC=0. The level of sedation observed in patients using baclofen for alcohol dependence appears to directly depend on the immediate doses of both the baclofen and the alcohol.

Pain as a predictor of heavy drinking and any drinking lapses in the COMBINE study and the UK Alcohol Treatment Trial

AIMS

To test the association between pain and heavy drinking lapses during and following treatment for alcohol use disorders (AUD).

DESIGN

Secondary data analysis of data from two clinical trials for AUD.

SETTING AND PARTICIPANTS

Participants included 1383 individuals from the Combined Pharmacotherapies and Behavioral Interventions (COMBINE) Study in the United States [69.0% male, 76.8% non-Hispanic White average age=44.4, standard deviation (SD) = 10.2] and 742 individuals from the UK Alcohol Treatment Trial (UKATT) in the United Kingdom [74.1% male, 95.6% White, average age=41.6 (SD=10.1)].

MEASUREMENTS

Form-90 (a structured assessment interview) was used to assess the primary outcome: time to first heavy drinking day. The Short Form Health Survey and Quality of Life measures were used to assess pain interference and pain intensity.

FINDINGS

Pain was a significant predictor of heavy drinking lapses during treatment in UKATT [odds ratio (OR)=1.19, 95% confidence interval (CI)=1.08, 1.32, P=0.0003] and COMBINE (OR=1.12, 95% CI=1.03, 1.21, P=0.009), and was a significant predictor of heavy drinking lapses following treatment in COMBINE (OR=1.163, 95% CI=1.15, 1.17, P<0.00001). After controlling for other relapse risk factors (e.g. dependence severity, self-efficacy, temptation, psychiatric distress), pain remained a significant predictor of heavy drinking lapses during treatment in UKATT (OR=1.19, 95% CI=1.06, 1.34, P=0.004) and following treatment in COMBINE (OR=1.44, 95% CI=1.07, 1.92, P=0.01).

CONCLUSIONS

Among people treated for alcohol use disorder, being in physical pain appears to predict heavy drinking lapses during or after treatment.

Biomolecules and Biomarkers Used in Diagnosis of Alcohol Drinking and in Monitoring Therapeutic Interventions

BACKGROUND

The quantitative, measurable detection of drinking is important for the successful treatment of alcohol misuse in transplantation of patients with alcohol disorders, people living with human immunodeficiency virus that need to adhere to medication, and special occupational hazard offenders, many of whom continually deny drinking. Their initial misconduct usually leads to medical problems associated with drinking, impulsive social behavior, and drunk driving. The accurate identification of alcohol consumption via biochemical tests contributes significantly to the monitoring of drinking behavior.

METHODS

A systematic review of the current methods used to measure biomarkers of alcohol consumption was conducted using PubMed and Google Scholar databases (2010-2015). The names of the tests have been identified. The methods and publications that correlate between the social instruments and the biochemical tests were further investigated. There is a clear need for assays standardization to ensure the use of these biochemical tests as routine biomarkers.

FINDINGS

Alcohol ingestion can be measured using a breath test. Because alcohol is rapidly eliminated from the circulation, the time for detection by this analysis is in the range of hours. Alcohol consumption can alternatively be detected by direct measurement of ethanol concentration in blood or urine. Several markers have been proposed to extend the interval and sensitivities of detection, including ethyl glucuronide and ethyl sulfate in urine, phosphatidylethanol in blood, and ethyl glucuronide and fatty acid ethyl esters in hair, among others. Moreover, there is a need to correlate the indirect biomarker carbohydrate deficient transferrin, which reflects longer lasting consumption of higher amounts of alcohol, with serum γ-glutamyl transpeptidase, another long term indirect biomarker that is routinely used and standardized in laboratory medicine.

Determining ethyl glucuronide cutoffs when detecting self-reported alcohol use in addiction treatment patients

BACKGROUND

Ethyl glucuronide (EtG) is an alcohol biomarker with potential utility as a clinical research and alcohol treatment outcome. Debate exists regarding the appropriate cutoff level for determining alcohol use, particularly with the EtG immunoassay. This study determined the EtG immunoassay cutoff levels that most closely correspond to self-reported drinking in alcohol-dependent outpatients.

METHODS

Eighty adults with alcohol dependence and mental illness, taking part in an alcohol treatment study, provided urine samples 3 times per week for up to 16 weeks (1,589 samples). Self-reported drinking during 120 hours prior to each sample collection was assessed. Receiver operating characteristic analyses were conducted to assess the ability of the EtG immunoassay to detect self-reported alcohol use across 24- to 120-hour time periods. Sensitivity and specificity of EtG immunoassay cutoff levels was compared in 100 ng/ml increments (100 to 500 ng/ml) across 24 to 120 hours.

RESULTS

Over half (57%) of the 1,589 samples indicated recent alcohol consumption. The EtG immunoassay closely corresponded to self-reported drinking from 24 (area under the curve [AUC] = 0.90, 95% confidence interval [CI]: 0.88, 0.92) to 120 hours (AUC = 0.88, 95% CI: 0.87, 0.90). When cutoff levels were compared across 24 to 120 hours, 100 ng/ml had the highest sensitivity (0.93 to 0.78) and lowest specificity (0.67 to 0.85). Relative to 100 ng/ml, the 200 ng/ml cutoff demonstrated a reduction in sensitivity (0.89 to 0.67), but improved specificity (0.78 to 0.94). The 300, 400, and 500 ng/ml cutoffs demonstrated the lowest sensitivity (0.86 to 0.33) and highest specificity (0.86 to 0.97) over 24 to 120 hours.

CONCLUSIONS

For detecting alcohol use for >24 hours, the 200 ng/ml cutoff level is recommended for use as a research and clinical outcome.