Drivers under the influence of drugs of abuse: quantification of cocaine and impaired driving

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.

Drug use and driving behaviors among drivers with and without alcohol-related infractions

INTRODUCTION

Brazil is one of the countries with the highest rates of alcohol-related traffic infractions, but little is known about the profile of the drivers who commit them. Identifying the characteristics of impaired drivers is essential for planning preventive actions.

OBJECTIVE

To compare drug use and driving behavior profiles of drivers with and without alcohol-related infractions.

METHODS

178 drivers stopped at routine roadblocks were assessed by traffic agents who conducted standard roadblock procedures (document verification; request of a breathalyzer test [BT]). Drug use and driving behavior data were collected through semi-structured interviews. Subjects were divided into three groups: drivers who refused the BT (RDs, n = 72), drivers who tested positive on the BT (PDs, n = 34), and drivers who had committed other infractions (ODs, n = 72).

RESULTS

The proportion of alcohol use in the last year was higher among RDs (100%) than in the PD and OD groups (97.1% and 72.2% respectively, p < 0.001). Lifetime prevalence of cannabis and cocaine use for the overall sample was 44.3% and 18.2%, respectively. Fewer individuals in the OD group (31.5%) reported having been stopped at roadblocks in the previous year compared to the PDs (55.9%) and RDs (48.6%, p = 0.03). However, a higher proportion of RDs reported drunk driving in the same period (87.5%; PD 69.7%; OD 26.9%; p < 0.001).

CONCLUSION

Essential differences among groups were observed. RDs had a higher proportion of alcohol use and drunk driving in the previous year; drivers who fit into this particular group may be unresponsive or less responsive to social deterrence and enforcement actions.

User experience and operational feasibility of four point-of-collection oral fluid drug-testing devices according to Brazilian traffic agents

OBJECTIVE

Traffic fatalities in Brazil still rank among the highest worldwide, with an overall rate of 23.4 deaths/100,000 inhabitants/year. Although alcohol and drug use play an important role in traffic accidents, national data about their relative influence are scarce. Drug screening is not routinely performed by traffic agents because alcohol is the only substance regularly investigated in roadblocks. Therefore, we aimed to describe the initial traffic agent user experience for 4 handheld point-of-collection oral fluid drug testing devices used in routine roadblocks in Brazil, focusing on usage perceptions in hopes of generalizing this approach for other developing countries.

METHODS

Four different oral fluid collection devices were evaluated: The DDS2, the DOA MultiScreen, the Dräger DrugTest 5000, and the Multi-Drug Multi-Line Twist Screen Device. Fourteen trained traffic agents obtained oral fluid from 164 drivers and performed 37 qualitative evaluations of the devices. Traffic agents filled out a questionnaire focusing on 9 feasibility criteria: Overall simplicity for roadside operation; operational success; saliva sample collection time; sample analysis time; ease of sample preparation and analysis; agreement with observed clinical signs; overall hygiene and safety; sufficient operating instructions; and hygiene of saliva collection. These were weighted based on an expert panel and yielded an overall composite device experience score that ranged from 1 (poor) to 100 (excellent).

RESULTS

Ease of use, operational success, and acceptable collection and analysis time were considered the most important criteria by the expert panel. The results ranged from 27.3 to 88.9% for simplicity of use; 45.5 to 100.0% for operational success; 27.3 to 100% for acceptable collection time; and 36.4 to 100.0% for acceptable analysis time. The final device scores, based on the agents' user experiences, ranked as follows: DOA MultiScreen: 49.3/100; Dräger DrugTest 5000: 82.4/100; Multi-Drug Multi-Line Twist Screen Device: 84.3/100; DDS2: 88.4/100.

CONCLUSION

Based on the selected criteria, 3 of the 4 devices were considered useful by traffic agents in routine roadblock operations. The weighted evaluations suggest that their ease of use (handling, sampling analysis, and reliability), as well as their agreement with findings obtained by other means, defined their utility to traffic agents, although such appraisals must be further analyzed in future studies.

Correlation between Blood and Oral Fluid Psychoactive Drug Concentrations and Cognitive Impairment in Driving under the Influence of Drugs

BACKGROUND

The effects of drugs on driving performance should be checked with drug concentration in the brain and at the same time with the evaluation of both the behavioural and neurophysiological effects. The best accessible indicator of this information is the concentration of the drug and/or metabolites in blood and, to a certain extent, oral fluid. We sought to review international studies on correlation between blood and oral fluid drug concentrations, neurological correlates and cognitive impairment in driving under the influence of drugs.

METHODS

Relevant scientific articles were identified from PubMed, Cochrane Central, Scopus, Web of Science, Science Direct, EMBASE up to April 2017.

RESULTS

Up to 2010, no epidemiological studies were available on this matter and International scientists suggested that even minimal amounts of parent drugs in blood and oral fluid could affect driving impairment. More recently, epidemiological data, systematic reviews and meta-analysis on drugged drivers allowed the suggestion of impairment concentration limits for the most common illicit drugs. These values were obtained comparing driving disability induced by psychotropic drugs with that of established blood alcohol limits. Differently from ethyl alcohol where both detection methods and concentration limits have been well established even with inhomogeneity of ranges within different countries, in case of drugs of abuse no official cut-offs have yet been established, nor any standardized analytical protocols.

CONCLUSION

Multiple aspects of driving performance can be differently affected by illicit drugs, and even if for few of them some dose/concentration dependent impairment has been reported, a wider knowledge on concentration/impairment relationship is still missing.

Psychopathology and traffic violations in subjects who have lost their driving license

BACKGROUND

The persistence of risky behaviors while driving and traffic accidents despite campaigns to increase awareness suggest that there may be underlying causes that maintain proneness to traffic violations. The aim of the current study was to assess: a) the prevalence of psychopathology in a sample of people who have lost their driving license due to former traffic violations and b) the discriminatory capacity of each psychopathological disorder to differentiate among people with high and low proneness to perform risky behaviors while driving.

METHODS

383 participants in a course to recover their driving license after its loss due to previous traffic violations were included. The International Neuropsychiatric Interview (M.I.N.I.) according to DSM-IV was used to assess psychopathology.

RESULTS

Between 67% and 76.2% of the participants had been affected by a lifetime psychopathological disorder until the moment of assessment. The most prevalent diagnoses were substance abuse including alcohol (52.5-62.7%), ADHD (19.7-28.5%), depression (7.9-14.4%) and anxiety (3.6-12.4%). Substance abuse and ADHD also showed the strongest set of associations with specific risk behaviors, but ADHD emerged as the most discriminant disorder to distinguish between those people at high and low risk of while driving.

CONCLUSIONS

The results of the current study suggest that addressing psychopathology explicitly to prevent risky behaviors and recidivism while driving would provide benefits in this area.