Driving license regranting: Hair EtG, serum CDT, and the role of sociodemographic and medicolegal variables

Monitoring of phosphatidylethanol in dried blood spots and of ethyl glucuronide in hair over 6 months of alcohol consumption

The aim of this study was to monitor seven phosphatidylethanol (PEth) homologues in dried blood spots (DBS) and ethyl glucuronide in hair (EtGH) over a 6-month period of drinking while documenting the daily drinks (amount and type) of alcohol via app. A total of 23 volunteers (12 males and 11 females) aged 19-54 years were enrolled. At four-weekly intervals, capillary blood to create DBS and after 3 and 6 months, respectively, a strand of hair (proximal, 3 cm) was collected. Analyses of EtGH and PEth homologues were performed using liquid chromatography-tandem mass spectrometry. All participants consumed alcohol during the 6 months. Only one participant tested negative for both PEth and EtGH. Eight participants had PEth 16:0/18:1 concentrations between 20 and <210 ng/mL (mean: 45.6 ng/mL) but EtGH concentrations below 5 pg/mg. PEth 16:0/18:1 concentrations between 20 and <210 ng/mL and EtGH concentrations between 5 and <30 pg/mg were assigned to eight subjects, uniformly matching them in the category of socially accepted drinking behavior. Four test subjects exceeded the cutoff for social drinking behavior in both PEth 16:0/18:1 (mean: 528 ng/mL) and EtGH (mean: 84.5 pg/mg). Two participants exceeded the threshold for PEth 16:0/18:1 of 210 ng/mL in blood but remained below 30 pg EtG/mg hair. PEth showed a higher detection rate for alcohol consumption than EtGH did. Moreover, PEth concentrations reacted quickly to changes in drinking behavior, whereas EtGH concentrations remained similar over time.

Comparative analysis between CDT in serum and Ethyl glucuronide in hair to define the best reliable tool for the diagnosis of alcohol abuse

The increase in alcohol consumption in society has not only led to a number of medical issues but has also become a matter of considerable legal importance. Thus, there is both scientific interest and the necessity to diagnose alcohol abuse in the application of the provisions of the law through laboratory tests that ensure maximum objectivity. The purpose of this work is to study and compare the diagnostic performance of two of the main markers of alcohol abuse, serum carbohydrate-deficient transferrin (CDT) and Ethyl glucuronide (EtG) in a group of 336 driving under the influence (DUI) of alcohol offenders. Thus, it is possible to establish the best marker of alcohol consumption in order to assess the fitness to drive of DUI subjects.EtG was detected in 55 hair samples, while CDT was detected in 5 blood samples. Of the EtG-positive subjects 96,4% had CDT values below the cut-off. While CDT refers to an alcohol consumption of approximately the previous 10 days, EtG allows to detect an excessive alcohol consumption of the last few months. Because of these two different time-windows, EtG proves to be more reliable, since it is more difficult for subjects to change their drinking practice to test negative to toxicological analysis. The determination of Ethyl glucuronide on hair matrix is a valuable tool for the diagnosis of alcohol abuse, with high sensitivity and specificity and certainly greater reliability than traditional markers such as CDT, being a direct marker of alcohol consumption.

Sex differences and driving impairment related to psychoactive substances

OBJECTIVE

The first aim of the study was to identify sex differences in the use of psychoactive substances among subjects with a previous driving under the influence (DUI) episode. The secondary objective was to propose specific strategies for medico-legal improvements.

METHODS

This was a retrospective observational study that took place between June 1, 2019, and August 31, 2023. It was conducted on DUI subjects examined for reinstatement of their driver's license using an integrated medico-legal and toxicological approach. Ethyl glucuronide (EtG) and illicit psychoactive substances were determined from hair samples. We performed descriptive statistical analyses for the entire sample as well as separately by sex. Additionally, we conducted binary logistic regression analyses separately for males and females to identify protective/risk factors associated with previous road accidents and judgments of unfitness to drive due to excessive alcohol consumption (EtG ≥ 30 pg/mg).

RESULTS

The study included 2,221 subjects, comprising 1,970 men and 251 women. Men exhibited a higher prevalence of tobacco, alcohol, and illicit psychoactive substance use. Women were more frequently co-users of alcohol and psychoactive substances and involved in road accidents at the time of DUI. Among the men, being married or having a partner was found to be a protective factor concerning past traffic accidents. For both sexes, a DUI episode with a blood alcohol concentration (BAC) exceeding 1.5 g/L or the co-ingestion of alcohol and drugs was identified as a risk factor for road accident involvement. For men, smoking more than 20 cigarettes per day and, for women, having a DUI episode with a BAC over 1.5 g/L were the main factors indicating unfitness to drive, as determined through high hair EtG levels (> 30 pg/mg). Women with a previous history of road accidents were less likely to have EtG levels of 30 pg/mg or more.

CONCLUSIONS

The study confirmed sex differences in subjects with a previous DUI episode. A BAC exceeding 1.5 g/L or the simultaneous use of alcohol and drugs at the time of DUI necessitate careful assessment of both men and women seeking driver's license reinstatement. In women, a BAC exceeding 1.5 g/L is considered a risk factor for a subsequent judgment of unfitness to drive. The medico-legal assessment should also involve a thorough investigation of smoking habits in men, as these habits could be related to an increased risk of excessive alcohol consumption.

Driving impairment due to psychoactive substances and attention deficit disorder: A pilot study

Objective

Attention disorder and substance use disorder are linked to driving impairment and increased road crash involvement. This study explores attention deficits in a population of drivers found driving under the influence (DUI) of psychoactive substances.

Methods

A case-control study was conducted comparing subjects with a previous DUI episode (cases) to subjects who were negative for DUI offenses (controls). Personal, socio-demographic, and DUI data were collected for both groups. All subjects were administered the Continuous Performance Test-third edition (CPT-3), which measures dimensions of attention, including inattentiveness, impulsivity, sustained attention, and vigilance. Possible associations with a previous DUI episode, the use of illicit substances or excessive alcohol use, and road crash involvement were analyzed statistically.

Results

Overall, the study included 147 subjects (100 cases, 47 controls). The parameter distributions of detectability, probability of ADHD, and inattentiveness indicated statistical differences between the two groups. No attention deficits predicted substance use disorder or excessive alcohol consumption. Inattentiveness was an independent risk factor for previous road collision involvement.

Conclusions

The results suggest that alterations exist in some attention dimensions in a population of DUI subjects who were users of alcohol or other psychoactive substances and involved in road traffic crashes. The CPT-3 had successfully distinguished between the two study groups, and after validation, it could be useful in the process of reinstating a driver's license. Future research should expand the study sample to better understand the relevance of the proposed methodological approach in terms of prevention, rehabilitation, and the monitoring of subjects evaluated for driving eligibility requirements.