Potential for cannabis adaptation among participants in a drunk driving intervention.

BACKGROUND: Some alcohol interventions have been found to have the adverse outcome of increasing non-alcohol-related substance use. It is unknown, however, how changes in alcohol use over the course of alcohol ignition interlocks - a common DUI intervention - may impact other substance use. METHODS: Alcohol and cannabis use were measured using hair ethylglucuronide and Delta-9-Tetrahydrocannabinol concentrations in blood, respectively. Participants (N = 69) were measured at the interlock installation period and again 6-months later while the interlock was installed. A mixed ANOVA was conducted to examine changes in levels of ethanol and THC over time. RESULTS: On measures of marijuana use, there was a significant interaction effect between the group that increased alcohol use and time F(2, 66) = 7.863, p =.001; partial η 2 =.192; as well as a main effect for time F(2, 66) = 21.106, p <.001; partial η 2 =.242. CONCLUSIONS: Installing interlocks may inadvertently increase cannabis use among those who decrease alcohol use. Crash risk associated with cannabis use is notably less than that of alcohol use, however, continued cannabis use may be problematic when the device is removed and alcohol use is expected to return to the higher pre-interlock levels.

Mandating Treatment Based on Interlock Performance: Evidence for Effectiveness.

BACKGROUND: Vehicle alcohol ignition interlocks reduce alcohol-impaired driving recidivism while installed, but recidivism reduction does not continue after removal. It has been suggested that integrating alcohol use disorder (AUD) treatment with interlock programs might extend the effectiveness of interlocks in reducing recidivism beyond their removal. This study evaluated the first implementation of a Florida policy mandating AUD treatment for driving under the influence (DUI) offenders on interlocks. Treatment was required when the offender accumulated 3 violations (defined as 2 "lockouts" within 4 hours; a lockout occurs when the device prevents a drinking driver from starting the vehicle). METHODS: Cox regression was used to compare alcohol-impaired driving recidivism during the 48 months following the interlock removal between 2 groups: (i) 640 multiple DUI offenders who received AUD treatment while interlocks were installed; and (ii) 806 matched offenders not mandated to treatment while interlocks were installed. RESULTS: The ignition interlock plus treatment group experienced 32% lower recidivism, 95% confidence interval [9, 49], following the removal of the interlock during the 12 to 48 months in which they were compared with the nontreatment group. We estimated that this decline in recidivism would have prevented 41 rearrests, 13 crashes, and almost 9 injuries in crashes involving the 640 treated offenders over the period following interlock removal. CONCLUSIONS: This study provides strong support for the inclusion of AUD treatment for offenders in interlock programs based on the number of times they are "locked out." The offenders required to attend treatment demonstrated a one-third lower DUI recidivism following their time on the interlock compared to similar untreated offenders.

Characterization of sialic acid index of plasma apolipoprotein J and phosphatidylethanol during alcohol detoxification--a pilot study.

BACKGROUND: Apolipoprotein J (ApoJ) is a component of plasma high-density lipoproteins. Previous studies have shown progressive recovery of ApoJ sialic acid content with increased duration of alcohol abstinence. Therefore, the sialic acid index of plasma apolipoprotein J (SIJ) seems to be a promising alcohol biomarker. Phosphatidylethanol (PEth) is a direct ethanol metabolite and has recently attracted attention as a biomarker of prolonged intake of higher amounts of alcohol. The aim of the pilot study was to explore sensitivity, specificity, and normalization of SIJ and PEth in comparison with traditional and emerging biomarkers. METHODS: Five male alcohol-dependent patients (International Classification of Diseases 10, F 10.25) were included (median: 40 years old; Alcohol Use Disorders Identification Test value, 30; alcohol consumption in the previous 7 days, 1,680 g). SIJ, PEth, urinary ethyl glucuronide (UEtG), urinary ethyl sulfate (UEtS), and gamma glutamyl-transpeptidase (GGT) were determined at days 1, 3, 7, 10, 14, 21, and 28. RESULTS: At study entry, SIJ, PEth, UEtG, and UEtS were positive in all subjects, whereas GGT and mean corpuscular volume were positive in 3 of 5 (60%) of the subjects. Individual SIJ levels increased between day 1 and 28 between 13.7 and 44.3%, respectively. For SIJ and PEth, the ANOVA (p < 0.005) showed a significant trend with the average subject's SIJ and PEth changing 1.22 and 1.02, respectively, per week. CONCLUSIONS: Our preliminary data suggest that SIJ and PEth might hold potential as markers of heavy ethanol intake.

Cannabis Adaptation During and After Alcohol Ignition Interlock Device Installation: A Longitudinal Study.

OBJECTIVE: A common intervention to prevent alcohol-impaired driving are alcohol ignition interlock devices (IIDs), which prevent drivers with a blood alcohol concentration greater than .025% from starting the car. These devices force drivers to adapt their drinking to accommodate the device. Prior studies indicated a transfer of risk as some drivers with an IID may increase cannabis use as they decrease alcohol use. This study examines whether this increase in cannabis use persists after IID removal when alcohol use reverts to pre-IID levels. METHOD: The data are from the Managing Heavy Drinking (MHD) study of drivers in New York State. The MHD is a comprehensive three-wave study of drivers convicted of driving under the influence from 2015 to 2020. Participants (N = 189) completed all waves, and provided oral fluid/blood and hair samples to measure cannabis and alcohol use, respectively. Mixed between-within analysis of variance was conducted to assess cannabis use at IID installation (Time 1), removal (Time 2), and at 6-month follow-up (Time 3). RESULTS: In aggregate, participants increased their cannabis use over the course of the study. Drivers who decreased their alcohol use while the IID was installed on their car significantly increased their cannabis use while the IID was in place and further increased cannabis use after the device's removal. CONCLUSIONS: IIDs are efficacious in preventing alcohol-impaired driving. However, in some cases, they may have the unintended effect of increasing other substance use. The current study outlines the need for supplemental treatment interventions while on IID to prevent a transfer of risk to other substances, or polysubstance use after the device is removed.

Field and laboratory alcohol detection with 2 types of transdermal devices.

BACKGROUND: Two types of transdermal electrochemical sensors that detect alcohol at the skin surface were evaluated. One, the AMS SCRAM device, is locked onto the ankle and is based on a fuel cell sensor; the other, a Giner WrisTAS device, worn on the wrist, is based on a proton exchange membrane. SCRAM is used by several court systems in the United States to monitor alcohol offenders, WrisTAS, a research prototype, is not commercially available. METHODS: The 2 devices were worn concurrently by 22 paid research subjects (15 men, 7 women), for a combined total of 96 weeks. Subjects participated in both laboratory-dosed drinking to a target of 0.08 g/dl blood alcohol concentration (BAC), and normal drinking on their own; all subjects were trained to use and carry a portable fuel-cell breath tester for BAC determinations. Overall 271 drinking episodes with BAC > or = 0.02 g/dl formed the signal for detection-60 from laboratory dosing, and 211 from self-dosed drinking, with BAC ranging from 0.02 to 0.230 g/dl (mean 0.077 g/dl). RESULTS: False negatives were defined as a transdermal alcohol concentration response equivalent <0.02 g/dl when BAC > or = 0.02 g/dl. The overall true-positive hit rate detected by WrisTAS was 24%. The low detection rate was due to erratic output and not recording during nearly 67% of all episodes; reportedly a chipset, not a sensor problem. SCRAM correctly detected 57% across all BAC events, with another 22% (total 79%) detected, but as <0.02 g/dl. When subjects dosed themselves to BAC > or = 0.08 g/dl, SCRAM correctly detected 88% of these events. SCRAM devices lost accuracy over time likely due to water accumulation in the sensor housing. Neither unit had false-positive problems when true BAC was <0.02 g/dl. CONCLUSIONS: Each device had peculiarities that reduced performance, but both types are able to detect alcohol at the skin surface. With product improvements, transdermal sensing may become a valuable way to monitor the alcohol consumption of those who should be abstaining.

A Swedish alcohol ignition interlock programme for drink-drivers: effects on hospital care utilization and sick leave.

AIMS: This project evaluates health outcomes following an alcohol ignition interlock programme (AIIP) by assessing hospital care utilization and sick-leave register data relative to controls with revoked licences, but with no comparable opportunity to participate in an AIIP. SETTING: In Sweden, driving while impaired (DWI) offenders can now select voluntarily a 2-year AIIP in lieu of 12 months' licence revocation. The AIIP includes regular medical check-ups designed to alter alcohol use. DESIGN: The study is a quasi-experimental intent-to-treat design; accordingly, the intervention group includes 48% of the participants who were dismissed from the AIIP before completion. FINDING: The control group (865 individuals) showed increased hospital care and sick leave after licence revocation following the DWI. Among the 1266 people in the AIIP, however, significantly fewer needed hospital care relative to controls, and relative to their own care utilization before the DWI offence. This occurred whether care reflected all diagnosis or only alcohol-related diagnosis. Also, sick-leave data showed significantly fewer AIIP group individuals using sick leave relative to the control group, and relative to their own pre-treatment period. These significant health benefits disappear in the post-treatment period. However, among those who actually do complete the entire AIIP, sustained positive health effects are observed 3 and 4 years after the DWI offence. CONCLUSIONS: Voluntary participation in an AIIP has favourable effects with less need for hospital care or sick leave. This is probably linked to reduced alcohol consumption during the programme and to the ability to continue driving.

Mandating interlocks for fully revoked offenders: the New Mexico experience.

OBJECTIVE: In New Mexico, between July 1999 and December 2002, the installation of an ignition interlock was an optional judicial sanction for second and third driving-while-impaired (DWI) offenders. This is a study of the recidivism of 437 offenders who were convicted and installed interlocks for an average of 322 days during that period. METHODS: The comparison group was a stratified random sample (N = 12,554) of the 20,949 offenders who were convicted during the same period but did not install interlocks. DWI arrest and conviction data for all study participants were received from the Motor Vehicle Department's Citation Tracking System. RESULTS: Only 11 (2.5%) of the interlock offender group were rearrested for DWI while interlocks were installed, whereas 1,017 (8.1%) of the comparison group were rearrested during an equivalent 322-day period. Survival graphs and Cox proportional hazard regression analyses were used to compare the interlock and noninterlock groups during installation, after installation, and for the entire period up to December 2004. Results indicate a reduction in recidivism of 65% during installation. After removal, there was no significant difference in recidivism rates in a 3-year follow-up period. Following all offenders for 4 years, including both the period while the interlock was installed and the period after its removal, indicates that the difference in recidivism achieved during installation, though not increased, is maintained, so at the end of 4 years, interlock users still have lower total recidivism than nonusers. CONCLUSIONS: The magnitude of interlock effectiveness reported here is similar to those in other published studies with comparable samples.

Interlocks for first offenders: effective?

OBJECTIVE: Vehicle interlocks have been shown to effectively reduce the recidivism of multiple driving-while-impaired (DWI) offenders; however, the evidence for their effectiveness with first offenders has been mixed. Two Canadian studies found that the installation of an interlock reduced first DWI recidivism, but U.S. studies in West Virginia and California failed to find a significant reduction in recidivism for first DWI offenders in interlock programs. The objective of this study was to determine the extent to which such devices were effective with first offenders in New Mexico. METHODS: This study compared 1,461 first offenders, who installed interlocks in New Mexico between January 1, 2003, and December 1, 2005, with 17,562 first offenders convicted during the same period who did not install the units. Cox multivariate proportional hazards regression (CMVPHR) was used to compare recidivism rates during three periods: while the interlock was on the vehicles of offenders who installed them, after those offenders removed the units until the end of the study period (approximately 2 years), and for the combined period (both while the interlock was installed and after it was removed). RESULTS: While the device was on the vehicles of the interlock group, their recidivism rate, 2.6% per year of exposure, was significantly less than the 7.1% per year rate of the comparison group (CMVPHR hazard ratio = 0.39, p < 0.0001). After the device was removed, the annualized recidivism rate of the interlock group increased to 4.9% per year of exposure, which was less than the 6.7% rate of the comparison group, but the hazard ratio was not statistically significant (CMVPHR hazard ratio = 0.82, p = 0.16). When the combined periods (interlock on and off) were considered, the interlock group had a recidivism rate of 3.9% per year, which again was significantly lower than the 6.8% rate for the comparison group (CMVPHR hazard ratio = 0.61, p < 0.0001). CONCLUSION: The study provides evidence that interlocks are as effective with first offenders (approximately 60% reduction in recidivism when on the vehicle) as they are for multiple offenders. In addition, the benefits of requiring an interlock for first offenders exceed the costs by a factor of three.

Preference-weighted health status associated with substance use-disorders treatment.

OBJECTIVE: Cost-effectiveness analyses using preference-weighted health status as the measure of effectiveness allow for the direct comparison of cost-effectiveness ratios for physical and mental health interventions. However, these analyses are not commonly used for substance use-disorders interventions. We conducted a methodological evaluation of the relationship between preference-weighted health status and 6-month substance use-disorders treatment outcomes. METHOD: The design was an observational study of clients receiving substance use-disorders treatment. Fifteen high-volume treatment centers within a regional managed behavioral health care organization participated. There were 165 subjects (117 men, 48 women) diagnosed with current Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, substance dependence in the analysis. Baseline and 6-month data included substance-use quantity, frequency, and diagnostic criteria and preference-weighted Medical Outcomes Study Short Form-36 scores based on visual analog scale (VAS) and standard gamble (SG) conversion formulas. RESULTS: Controlling for sociodemographic variables, VAS change for early remission at 6 months was 0.107 (p = .0002) (reference category continued dependence). SG change for early remission at 6 months was 0.041 (p < .0004). Using heavy drinkers as the reference category, VAS preference-weighted change was 0.062 (p = .10) for abstinent and 0.112 (p = .01) for moderate drinkers. SG preference-weighted change was 0.027 (p = .08) for abstinent and 0.046 (p = .01) for moderate drinkers. CONCLUSIONS: These findings support the construct validity of preference-weighted health status in substance use-disorders treatment. Direct comparisons of the cost-effectiveness of substance use-disorders treatment with other mental or physical health interventions are critical during times of limited health care resources.

Behavioral measures of drinking: patterns from the Alcohol Interlock Record.

AIMS: This report reviews breath test data captured by the alcohol ignition interlock, a device that prevents a car from starting when BAC (breath alcohol concentration) is elevated. DESIGN: The predictors were elevated BAC test rates from ignition interlock equipped cars of traffic offenders convicted of DUI (driving under the influence of alcohol) and who used interlocks for 6-18 months. Outcome data were future DUI convictions. SETTINGS: Québec and Alberta, Canada. PARTICIPANTS: Approximately 10000 interlock users from these two culturally distinctive English- and French-speaking Provinces. MEASUREMENT: Predictor patterns were analyzed from among 23 million breath tests. Repeat DUI convictions accumulated up to several years after interlock removal were studied as an outcome to be predicted by the rate of BAC tests > or = 20 mg/dl (0.02%) while the interlock was installed. Data were analyzed with sensitivity and survival methods. FINDINGS: A median of eight interlock breath tests per day per driver were logged (a rate of 3000 tests/year). Less than 1% of all tests were over 0.02%, but the rate of elevated BAC tests, particularly those taken at 7-9 a.m., strongly predicts repeat DUI offenses 2 years hence. The interlock record is an unobtrusive measure of drinking behavior and can be used to profile driver risk. CONCLUSIONS: With new legal mandates, North American use of these DUI control devices is increasing rapidly from the current 5% penetration rate. Interlock data may eventually come to serve as a useful adjunct for patient monitoring by alcohol counselors as well as by courts and motor vehicle authorities.

Comparative and joint prediction of DUI recidivism from alcohol ignition interlock and driver records.

OBJECTIVE: This work was conducted to find practical predictors that anticipate which driving under the influence (DUI) offenders will continue to drink and drive after a period of alcohol ignition interlock-controlled driving ends. The interlock prevents impaired driving by requiring a low blood alcohol concentration (BAC) breath sample before allowing an engine to start. Each breath test is recorded. The study evaluated the interlock record as a predictor of future DUI offenses relative to driver records and self-report items. METHOD: Subjects were 2,273 DUI offenders in Alberta, Canada, who used an interlock to gain full reinstatement of driving privileges; for 2,134, the installed periods ranged from 5 to 30 months. A median of 8.1 breath tests was logged for each installed day; 9.9 tests were taken on each day of vehicle use (4.3 starts plus 5.6 running retests). Predictors of postinterlock repeat DUI were compared by sensitivity and survival analyses. RESULTS: Although 69% of all interlock users had at least one BAC test > or = .04% (a "fail" test) within the first 5 months, only 9% were reconvicted up to 4 years after interlock removal. Failed interlock tests proportional to all BAC tests taken was the best predictor of driver recidivism risk during the years following interlock removal. CONCLUSION: The interlock record provides new information, particularly about drivers with no prior DUI offenses. Prior moving violations and driving while suspended convictions, although better predictors than questionnaire data, were poorer than interlock records and prior DUI offenses. The alcohol interlock, already recognized as a useful control device, warrants attention for DUI prediction as well.

Evaluation of a program to motivate impaired driving offenders to install ignition interlocks.

Approximately 30,000 alcohol ignition interlocks, which are designed to prevent the operation of a vehicle if the driver has been drinking, are in use in the US and Canada. Ignition interlock programs are also being initiated in Sweden and Australia. The best-controlled studies that are currently available suggest that ignition interlocks are effective in reducing impaired driving recidivism while on the vehicle. However, in the US, the practical effectiveness of these devices is limited because only a small number of offenders are willing to install them in order to drive legally. This paper reports on a study of a court policy that created a strong incentive for impaired driving offenders to install interlocks by making traditional penalties, such as jail or electronically monitored house arrest, the alternative to participation in an interlock program. Comparison of the recidivism rates of offenders subject to this policy with offenders in similar, nearby courts, not using interlocks, indicated that the policy was producing substantial reductions in DUI recidivism.

Barriers to interlock implementation.

This commentary reviews current and past vehicle interlock programs for impaired driving offenders with a focus on the challenges that courts and motor vehicle departments face in attempting to implement mandatory programs as required by current federal legislation. There are few offenders in interlock programs compared to the large number of impaired drivers arrested each year. This suggests that, to increase participation, courts will have to threaten more severe sanctions for those offenders who reject interlock programs. A combination of electronic house arrest with interlock programs is suggested as a method of maximizing interlock use.

Emerging technological approaches for controlling the hard core DUI offender in the U.S.

Drivers convicted of impaired driving are substantially overrepresented in alcohol-related fatal crashes. Because many such offenders continue to drive with suspended operators' licenses, monitoring their postconviction driving is a significant problem for the criminal justice system. Technology for tracking the location and drinking of such offenders is a rapidly developing field, which promises to provide methods for monitoring offenders on a 24/7 basis. The status of traditional monitoring methods is reviewed and contrasted with the new technologies that are being implemented. Although those technologies offer considerable promise, they have not yet been evaluated in programs for impaired driving offenders. Eight issues related to the probability of rapid implementation of the new technologies are discussed.

The alcohol interlock: an underutilized resource for predicting and controlling drunk drivers.

This report summarizes evidence presented during the Third Annual Ignition Interlock Symposium at Vero Beach, Florida, 29 October 2002. The ignition interlock prevents a car from starting when blood alcohol concentration (BAC) is elevated. We review some of our prior work as well as introduce previously unpublished results to demonstrate the manner in which the data recorded by the alcohol ignition interlock device can serve as an advance predictor of future driving under the influence (DUI) of alcohol risks. Data used in this current report represent approximately 2,200 ignition interlock users from Alberta, Canada, and about 8,000 interlock users from Quebec, Canada; the Alberta data set contained 5.5 million breath tests and the Quebec data 18.8 million breath tests. All tests are time and date stamped and this information was used to characterize patterns of BAC and vehicle use, and the relationship between BAC elevations and DUI offenses that accumulated after the interlock was removed from the vehicles. Findings from Cox regression show that BAC elevations >.02-.04% are more potent predictors of repeat DUI (p<.0001) than even prior DUI (p<.006), usually found to be the strongest indicator of driver risk. Prior DUI obviously has no use for scaling the risk of first-time offenders. Drivers who are both multiple offenders and who have more than a few elevated interlock BAC tests are much more likely to repeat DUI. The timing and pattern of elevated BAC tests provided during the time drivers were required to use an alcohol ignition interlock device are remarkably similar on both a daily basis and an hourly basis when the interlock programs from the two provinces are compared directly. Both provinces had higher rates of elevated tests on Saturday and Sunday, and the fewest elevated tests on Tuesdays. The absolute rate of elevated tests is similar despite the two provinces adhering to different interlock lockout points (.02% Quebec;.04% Alberta). Charts tracking the Monday-Friday timing of elevated BAC tests by hour are nearly identical for both provinces. The most elevated BAC tests occurred between 7 and 9 A.M. Monday to Friday, even though most vehicle start attempts occurred much later in the day. This higher rate of elevated morning BAC likely represents drinking from the prior evening with alcohol not yet cleared from circulation; those with elevated BAC in the early morning were more likely to have a repeat offense even after accounting for prior DUI and the higher overall rate of elevated BAC tests. This is viewed as evidence of a drinking problem that will lead to impaired driving after the controlling function of the interlock is removed. Policy changes are discussed that might take better advantage of interlock information to improve the public response to drunk driving.

Ethylglucuronide in hair is a top predictor of impaired driving recidivism, alcohol dependence, and a key marker of the highest BAC interlock tests.

OBJECTIVES: This study focuses on the predictive and comparative significance of ethyl glucuronide measured in head hair (hEtG) for estimating risks associated with alcohol-impaired driving offenders. Earlier work compared different alcohol biomarkers for estimating rates of failed blood alcohol concentration (BAC) tests logged during 8 months of interlock participation. These analyses evaluate the comparative performance of several alcohol markers including hEtG and other markers, past driver records, and psychometric assessment predictors for the detection of 4 criteria: new driving under the influence (DUI) recidivism, alcohol dependence, and interlock record variables including fail rates and maximal interlock BACs logged. METHODS: Drivers charged with alcohol impairment (DUI) in Alberta, Canada (n = 534; 64% first offenders, 36% multiple offenders) installed ignition interlock devices and consented to participate in research to evaluate blood-, hair-, and urine-derived alcohol biomarkers; sit for interviews; take psychometric assessments; and permit analyses of driving records and interlock log files. Subject variables included demographics, alcohol dependence at program entry, preprogram prior DUI convictions, postenrollment new DUI convictions, self-reported drinking assessments, morning and overall rates of failed interlock BAC tests, and maximal interlock BAC readings. Recidivism, dependence, high BAC, and combined fail rates were set as criteria; other variables were set as predictors. Area under the receiver operating characteristics (ROC) curve (A') estimates of sensitivity and specificity were calculated. Additional analyses were conducted on baseline hEtG levels. Driver performance and drinking indicators were evaluated against the standard hEtG cutoff for excessive drinking at (30 pg/mg) and a higher criterion of 50 pg/mg. HEtG splits were evaluated with the Mann-Whitney rank statistic. RESULTS: HEtG emerged as a top overall predictor for discriminating new recidivism events that occur after interlock installation, for entry alcohol dependence, and for the highest interlock BACs recorded. Together, hEtG and phosphatidylethanol (PEth) were the top predictors of all criterion measures. By contrast, the hair-derived alcohol biomarkers hEtG and hFAEE (fatty acid ethyl esters) were poorer than other alcohol biomarkers as detectors of interlock BAC test fail rates. CONCLUSIONS: This study showed that hEtG, an objective alternative to often unreliable self-reported past representation of drinking levels, yields crucial insight into driver alcohol-related risks early in an interlock program and is a top predictor of new recidivist events. Together with PEth, these markers would be excellent anchors in a panel for detecting alcohol consumption.

Levels and types of alcohol biomarkers in DUI and clinic samples for estimating workplace alcohol problems.

Widespread concern about illicit drugs as an aspect of workplace performance potentially diminishes attention on employee alcohol use. Alcohol is the dominant drug contributing to poor job performance; it also accounts for a third of the worldwide public health burden. Evidence from public roadways--a workplace for many--provides an example of work-related risk exposure and performance lapses. In most developed countries, alcohol is involved in 20-35% of fatal crashes; drugs other than alcohol are less prominently involved in fatalities. Alcohol biomarkers can improve detection by extending the timeframe for estimating problematic exposure levels and thereby provide better information for managers. But what levels and which markers are right for the workplace? In this paper, an established high-sensitivity proxy for alcohol-driving risk proclivity is used: an average eight months of failed blood alcohol concentration (BAC) breath tests from alcohol ignition interlock devices. Higher BAC test fail rates are known to presage higher rates of future impaired-driving convictions (driving under the influence; DUI). Drivers in alcohol interlock programmes log 5-7 daily BAC tests; in 12 months, this yields thousands of samples. Also, higher programme entry levels of alcohol biomarkers predict a higher likelihood of failed interlock BAC tests during subsequent months. This paper summarizes the potential of selected biomarkers for workplace screening. Markers include phosphatidylethanol (PEth), percent carbohydrate deficient transferrin (%CDT), gammaglutamyltransferase (GGT), gamma %CDT (γ%CDT), and ethylglucuronide (EtG) in hair. Clinical cut-off levels and median/mean levels of these markers in abstinent people, the general population, DUI drivers, and rehabilitation clinics are summarized for context.

Detection of phosphatidylethanol (PEth) in the blood of drivers in an alcohol ignition interlock program.

OBJECTIVE: The rate of failed interlock blood alcohol content (BAC) tests is a strong predictor of recidivism post-interlock and a partial proxy for alcohol use. Alcohol biomarkers measured at the start of an interlock program are known to correlate well with rates of failed BAC tests over months of interlock use. This study evaluates 2 methods of measuring low blood levels of the biomarker phosphatidylethanol (PEth). PEth is a 100 percent alcohol-specific biomarker and strongly intercorrelated with several independent indicators of drinking driving risk, including 8 other biomarkers, 3 psychometric assessments, and the rate of failed interlock BAC tests during many months of interlock use. Does a more sensitive method of measuring PEth at program entry detect drinking even among those who subsequently log no failed interlock tests? METHODS: In a sample of 281 driver blood samples, PEth was measured by both high-performance liquid chromatography (HPLC) and liquid chromatography tandem mass spectrometry (LCMSMS) in order to compare sensitivity and accuracy. The average rate of failed interlock BAC tests was the criterion measure for marker sensitivity. LCMSMS, calibrated to detect low levels of drinking as a possible measure of abstinence violation, was judged relative to the standard HPLC assay for PEth measured up to 4 µmol/L. RESULTS: The 2 methods showed a good quantitative relationship (r(2)> .86). LCMSMS detected positive PEth levels in samples that were below the limit of detection of the HPLC method. PEth measured by LCMSMS was positive for a higher proportion of driving under the influence (DUI) offenders who logged zero failed interlock BAC tests than were detected by HPLC. CONCLUSION: Although HPLC is the widely used standard for measuring PEth in clinical alcoholism samples, the LCMSMS method, when calibrated to detect trace amounts of the major component of PEth, can detect abstinence levels of alcohol near zero intake and still correlate strongly with other indicators related to alcohol use and road safety.

Estimating driver risk using alcohol biomarkers, interlock blood alcohol concentration tests and psychometric assessments: initial descriptives.

AIM: To identify alcohol biomarker and psychometric measures that relate to drivers' blood alcohol concentration (BAC) patterns from ignition interlock devices (IIDs). DESIGN, SETTING, PARTICIPANTS, MEASUREMENTS: In Alberta, Canada, 534 drivers, convicted of driving under the influence of alcohol (DUI), installed IIDs and agreed to participate in a research study. IID BAC tests are an established proxy for predicting future DUI convictions. Three risk groups were defined by rates of failed BAC tests. Program entry and follow-up blood samples (n = 302, 171) were used to measure phosphatidyl ethanol (PETH), carbohydrate deficient transferrin (%CDT), gamma glutamyltransferase (GGT) and other biomarkers. Program entry urine (n = 130) was analyzed for ethyl glucuronide (ETG) and ethyl sulphate (ETS). Entry hair samples were tested for fatty acid ethyl esters (FAEE) (n = 92) and ETG (n = 146). Psychometric measures included the DSM-4 Diagnostic Interview Schedule Alcohol Module, Alcohol Use Disorders Identification Test (AUDIT), the time-line follow-back (TLFB), the Drinker Inventory of Consequences (DRINC) and the Temptation and Restraint Inventory (TRI). FINDINGS: Except for FAEE, all alcohol biomarkers were related significantly to the interlock BAC test profiles; higher marker levels predicted higher rates of interlock BAC test failures. PETH, the strongest with an overall analysis of variance F ratio of 35.5, had significant correlations with all nine of the other alcohol biomarkers and with 16 of 19 psychometric variables. Urine ETG and ETS were correlated strongly with the IID BAC tests. CONCLUSIONS: The findings suggest that several alcohol biomarkers and assessments could play an important role in the prediction and control of driver alcohol risk when re-licensing.