Alcohol and illicit drugs in drivers involved in road traffic crashes in Italy. An 8-year retrospective study

Prevalence of alcohol-impaired driving: a systematic review with a gender-driven approach and meta-analysis of gender differences

BACKGROUND

A growing number of studies investigated the factors that contribute to driving under the influence (DUI) of alcohol in relation to gender. However, a gendered approach of the scientific evidence is missing in the literature. To fill this gap, a gender-driven systematic review on real case studies of the last two decades was performed. In addition to the gender of the drivers involved, major independent variables such as the period of recruitment, the type of drivers recruited, and the geographical area where the study was conducted, were examined. Afterwards, a meta-analysis was performed comparing alcohol-positive rates (APR) between male and female drivers in three subgroups of drivers: those involved in road traffic accidents, those randomly tested on the road, and volunteers.

METHODS

Three databases were searched for eligible studies in October 2023. Real-case studies reporting APR in man and women convicted for DUI of alcohol worldwide were included. Univariate analysis by ANOVA with post-hoc tests identified the independent variables with a significant impact on the dependent variable APR, according to a relationship subsequently investigated by standard multiple linear regression. The meta-analysis of random effects estimates was performed to investigate the change in overall effect size (measured by Cohen's d standardized mean difference test) and 95% confidence interval (CI).

RESULTS

Among papers addressing driver gender, univariate analysis of independent variables revealed a higher Alcohol Positive Rate (APR) in men, particularly in drivers involved in crashes, with a noticeable decrease over time. Analyzing the gender of drivers involved in crashes, the meta-analysis showed that men had a significantly higher APR (30.7%; 95%CI 26.8-35.0) compared to women (13.2%; 95%CI 10.7-16.1). However, in drivers randomly tested, there was no significant difference in APR between genders (2.1% for men and 1.4% for women), while in volunteers, there was a statistically significant difference in APR with 3.4% (95%CI 1.5-7.6) for men and 1.1% (95%CI 0.5-2.7) for women.

CONCLUSION

Despite a progressive decrease in the epidemiological prevalence of alcohol-related DUI over time, this phenomenon remains at worryingly high levels among drivers involved in road traffic accidents in both genders, with a higher prevalence in men. It's important for policymakers, professionals, and scientists to consider gender when planning research, analysis, interventions, and policies related to psychoactive substances, such as alcohol or other licit drugs. Forensic sciences can play a vital role in this regard, enabling a thorough analysis of gender gaps in different populations.

What's in drugs freely used by Brazilian truck drivers - "Rebites"? Determination of target and nontarget compounds by high-resolution mass spectrometry and nuclear magnetic resonance

Highways, the lifeline of the Brazilian economy, transport approximately 75% of the country's economic activity, highlighting its importance. However, professional drivers, accustomed to long daily journeys, make use of tablets widely available in Gas Station, which are known as "Rebites," which could contain a mixture of legal and illegal compounds. Thus, this study aims at the chemical characterization of these through different analytical methods. Initially, we performed a comprehensive screening of compounds present in seven samples collected across the country using high-resolution mass spectrometry (HRMS). The findings revealed caffeine as the main compound, alongside theophylline, lidocaine, and clobenzorex, among others. In the next step, we employ quantitative nuclear magnetic resonance (qNMR) to quantify the caffeine content in the tablets. The results indicated a caffeine concentration ranging between 14% and 31% (m/m), which may imply a daily overdose of this compound from around four tablets. In summary, this investigation provides a chemical characterization of real samples of "Rebites" freely obtained along Brazilian highways. Caffeine emerged as the predominant active compound, with its concentration determined by qNMR analysis. The notable presence of caffeine, combined with other stimulants, depressants, and hallucinogens, underscores the need for strict quality control measures regarding "Rebites" to safeguard public health.

Drug driving in Italy. The results of the first roadside drug testing service utilizing on-site confirmatory analysis between 2019 and 2022

BACKGROUND

Drug driving represents a public safety concern, and the size of this issue in Italy is not fully known. Drug testing is composed of two steps: 1) screening and 2) confirmatory analysis. The second step, and the associate medical examination to assess the state of impairment, usually are not performed right after the screening as they require specialized personnel and instrumental equipment that are not historically available at roadblocks. These pitfalls make this process both complicated and time-consuming.

METHODS

A mobile laboratory was set up in 2019 by the Forensic Lab Service S.r.l. (limited liability company) to improve roadblock timing, planning, as well as to shed light on the extent of the drug driving issue in Italy. Drug screenings were performed using DrugWipe® Saliva testing. Confirmatory analysis was performed on oral fluids by liquid chromatography coupled with tandem mass spectrometry. A dedicated room of the mobile laboratory was also designed for drug driving medical assessment.

RESULT

2082 samples were collected during 88 road safety services held in different locations across Italy. In total, 9 % of the tested subjects were positive to both the screening and the confirmatory analysis. The most prevalent illicit drugs found in this study were THC (72 %), followed by cocaine (41 %). Drug drivers were mostly male (93 %) and younger than 30 years of age (58 %).

CONCLUSIONS

The prevalence of drivers testing positive for illicit drugs resulted to be higher compared to the results obtained in the DRUID project and to other surveys previously performed in Italy. These data demonstrate the need for control services to improve road safety in regards to drug driving.

Increase in driving after cocaine use in Spain: a cross-sectional dataset analysis for 2021

Objective

Driving under the influence of alcohol and/or drugs impairs skills essential for safe driving, increases the risk of being involved in a traffic accident and is particularly prevalent in Spain. The aim is to assess the prevalence of positive substance driving cases, what factors may be associated with driving after substance use, and the evolution of the progress in the prevalence of drug use among drivers in drivers based on the 2008, 2013, 2018, and 2021 studies.

Study design and setting

The present study was conducted in a representative sample of Spanish drivers in 2021 for alcohol (breath) and psychoactive substances [oral fluid (OF)]. The sample size was 2980 drivers, mostly males (76.5%) with a mean age of 41.35 ± 13.34 years.

Results

In 2021, 9.3% of drivers tested positive for alcohol and/or drugs. The presence of alcohol alone was observed in 4.2% of drivers, alcohol and another substance in 0.3%, a single drug in 4.4%, and two or drugs other than alcohol in 0.4%. Overall, cocaine cases were the highest registered in 2021 (2.4%), while cannabis (1.9%) and polydrug cases (0.7%) were the lowest, with respect to the 2008/2013/2018 studies.

Conclusions

According to our research, in 2021, 9 out of 100 drivers were detected to have some substance in their system. This prevalence remains unacceptably high in Spain, with a marked increase in the frequency of driving after cocaine use. Further interventions and measures must be taken to avoid driving under the influence of alcohol and/or drugs.

Modeling pedestrian injury severity in pedestrian-vehicle crashes considering different land use patterns: Mixed logit approach

OBJECTIVE

The objective of this study is to identify and compare the contributing factors to pedestrian injury severity in pedestrian-vehicle crashes considering different land use patterns.

METHODS

The pedestrian-vehicle crash data from 2007 to 2018 were collected from the North Carolina Department of Transportation (NCDOT). A total number of 15,807 observations with 72 categorical variables were included in the final dataset. Two mixed logit models were developed to analyze the crash dataset with segmentations of two dominant land use areas (i.e., residential and commercial). Fixed and random parameters were found in both models. Estimation results and marginal effects of significant explanatory variables were investigated.

RESULTS

In general, the residential model has 24 fixed parameters and 3 random parameters. The commercial model has 31 fixed parameters and 3 random parameters. According to the estimated results, elder or drunk factors are found to have more impacts on severe injuries in residential areas. Large and mid-size vehicles increase the probability of severe injuries in commercial areas. The marginal effect values for severe injury at non-intersections have opposite signs in the two models. Besides, speed limits between 40 and 45 mph and factors related to poor visibility are more likely to result in severe pedestrian injuries. Coarse asphalt pavement can reduce the probability of severe pedestrian injuries.

CONCLUSIONS

This study investigated the pedestrian injury severity in pedestrian-vehicle crashes considering two types of land use using a mixed logit approach. Based on the discussions of factors contributing to the pedestrian injury severity, policies and countermeasures to improve traffic safety are suggested. Above all, a mixed-use land development policy is recommended. Other suggestions are summarized below: (1) giving more considerations to older pedestrians when planning and designing residential areas; (2) strengthening laws and education against drunk driving and even drunk walking on/across the roadways; (3) increasing the frequency of the patrols and alcohol tests; (4) improving lighting conditions and road alignments; (5) establishing a limited-truck-passing-period policy especially in commercial areas; and (6) improving the pavement conditions wherever needed.

Driving under the influence of drugs: Correlation between blood psychoactive drug concentrations and cognitive impairment. A narrative review taking into account forensic issues

Driving under the influence of alcohol has been shown to increase the risk of involvement in road traffic collisions (RTCs) however, less is known about the effects of illicit drugs, and a clear correlation between drug concentrations and RTC risk is still debated. The goal of this narrative review is to assess the current literature regarding the most detected psychoactive drugs in RTC (ethanol, amphetamines, cannabis, opioids and cocaine), in relation to driving performance. Evidence on impaired driving due to psychoactive substances, forensic issues relating to the assessment of the impact of drugs, blood cut-off values proposed to date as well as scientific basis for proposed legislative limits are discussed. At present there is no unequivocal evidence demonstrating a clear dose/concentration dependent impairment in many substances. Per se and zero tolerance approaches seem to have negative effect on drugged driving fatalities. However, the weight of these approaches needs further investigation.

Prevalence and concentrations of sedative-hypnotic drugs in blood of drivers involved in road traffic crashes in the Padova region of Italy - not so easy to interpret

BACKGROUND & OBJECTIVES

This study reports the prevalence and concentrations of sedative-hypnotic drugs as exemplified by benzodiazepines (BZD) and zolpidem (Z-hypnotic) in blood samples from drivers involved in road traffic accidents (RTA) in the Padova region of Italy. Another aim of the study was to estimate the prevalence of these drugs with concentrations in blood above the therapeutic intervals and above specific per se limits.

METHODS

A total of 4066 blood samples collected from drivers involved in RTA were analysed for the presence of alcohol, drugs of abuse and medicinal drugs with sedative-hypnotic properties. Prevalence of drivers positive for BZDs and zolpidem were reported according to the reporting limit of our laboratory (1 ng/mL) in a sort of zero tolerance approach and compared with the prevalence according to analytical cut-offs used in the "European Union's research project on Driving Under the Influence of Drugs, Alcohol and Medicines" (DRUID). The impairment-based, per se limits adopted in Norway and in England and Wales and the values used to define "therapeutic ranges" in blood and in plasma/serum were also applied to the case study.

RESULTS

175 blood samples were positive for sedative-hypnotics above 1 ng/mL, with the following prevalence: diazepam 44%, nordazepam 41.8%, lorazepam 32.6%, zolpidem 28%, oxazepam 25.6%, alprazolam 16%, delorazepam 11,6%, lormetazepam 11,6%, temazepam 11.6%, clonazepam 11.6%, triazolam 6.9%, N-desalkylflurazepam 4.6%, bromazepam 2.3%. When applying DRUID analytical cut-offs, the prevalence of BZDs and zolpidem sharply decreases. Applying the impairing cut-offs used in Norway, 56% of positive samples were above the limits equivalent to a BAC of 0.2 g/L, 39% above the limits corresponding to 0.5 g/L, and 23% above the cut-off corresponding to 1.2 g/L. Only 1% of the drivers had drug concentrations above the per se concentration limits adopted in England and Wales [26]. When comparing blood levels with therapeutic ranges in plasma, bromazepam, lormetazepam and delorazepam were often found above the highest limits. The adjustment of the concentrations with the plasma-to-blood ratios causes a significant increase of cases above the therapeutic ranges in plasma.

CONCLUSIONS

Sedative-hypnotic drugs are medicinal substances frequently identified in drivers involved in RTA, commonly in concentrations associated with driving impairment. Besides the concentrations of drugs in blood, several factors have to be considered to conclude that a driver was impaired. The frequent association with alcohol, cocaine and other BZDs, confirms the abuse potential of these medications.

Role of Passengers in Single-Vehicle Drunk-Driving Crashes: An Injury-Severity Analysis

Background: Drunk-driving is a major crash risk factor, and crashes resulting from this risky behavior tend to be serious and have significant economic and societal impacts. The presence of passengers and their demographics and activities can influence risky driving behaviors such as drunk-driving. However, passengers could either be an “enabling” factor to take more risks or could be an “inhibiting” factor by ensuring safe driving by a drunk-driver. Objective: This study examines whether the presence of passengers affects the contributing factors of single-vehicle (SV) drunk-driving crashes, by presenting a severity analysis of single- and multi-occupant SV drunk-driving crashes, to identify risk factors that contribute to crash severity outcomes, for the effective implementation of relevant countermeasures. Method: A total of 7407 observations for 2012–2016 from the crash database of the State of Alabama was used for this study. The variables were divided into six classes: temporal, locational, driver, vehicle, roadway, and crash characteristics and injury severities into three: severe, minor, and no injury. Two latent class multinomial logit models—one each for single- and multi-occupant crashes—were developed, to analyze the effects of significant factors on injury severity outcomes using marginal effects. Results: The estimated results show that collision with a ditch, run-off road, intersection, winter season, wet roadway, and interstate decreased the probability of severe injuries in both single- and multi-occupant crashes, whereas rural area, road with downward grade, dark and unlit roadway, unemployed driver, and driver with invalid license increased the likelihood of severe injuries for both single- and multi-occupant crashes. Female drivers were more likely to be severely injured in single-occupant crashes, but less likely in multi-occupant crashes. A significant association was found between severe injuries and weekends, residential areas, and crash location close (<25 mi ≈40.23 km) to the residence of the at-fault driver in multi-occupant crashes. Sport utility vehicles were found to be safer when driving with passengers. Conclusions: The model findings show that, although many correlates are consistent between the single- and multi-occupant SV crashes that are associated with locational, roadway, vehicle, temporal, and driver characteristics, their effect can vary across the single- and multi-occupant driving population. The findings from this study can help in targeting interventions, developing countermeasures, and educating passengers to reduce drunk-driving crashes and consequent injuries. Such integrated efforts combined with engineering and emergency response may contribute in developing a true safe systems approach.

Optimization of cloned enzyme donor immunoassay cut-offs for drugs of abuse in post-mortem whole blood

INTRODUCTION

Immunoassay (IA) tests are not widely applied in post-mortem samples, since they are based on technologies requiring relatively non-viscous specimens, and compounds originating from the degradation of proteins and lipids during the post-mortem interval can alter the efficiency of the test. However, since the extraction techniques for IA tests are normally rapid and low-cost, IA could be used as near-body drug-screening for the classes of drugs most commonly found in Italy and Europe. In this study, semi-quantitative results on post-mortem whole blood samples obtained through CEDIA analysis (cannabinoids, cocaine, amphetamine compounds, opiates and methadone), were compared with results of confirmatory analysis obtained using GC-MS. Screening cut-offs for all drugs were retrospectively optimized.

METHODS

Post-mortem whole blood samples from autopsy cases of suspected fatal intoxication were collected over 3 years. Samples were initially analyzed through CEDIA (CEDIA, ILab 650, Werfen). Confirmatory analyses were then performed by GC-MS (QP 2010 Plus, Shimadzu). Screening cut-offs were retrospectively optimized using Receiver Operating Characteristic (ROC) analysis.

RESULTS

CEDIA results were available for 125 samples. Two-hundred-eighty-nine (289) positive screening results were found. Among these, 162 positive confirmation results were obtained. Optimized screening cut-offs were as follows: 6.5ng/ml for THC; 4.2ng/ml for THC-COOH; 12.0ng/ml for cocaine; 6.6ng/ml for benzoylecgonine; 6.4ng/ml for opiates; 2.0ng/ml for methadone. Analysis of ROC-curves showed a satisfying degree of separation in all tests except for amphetamine compounds, with areas under the curve (AUC) between 0.915 (THC) and 0.999 (for benzoylecgonine and methadone).

DISCUSSION

The results of the study showed that CEDIA screening at the optimized cut-offs exhibits a very high sensitivity and good specificity and positive predictive value (PPV) for cannabinoids, cocaine and metabolites, opiates and methadone. A high number of false positives (n=19) for amphetamine compounds was observed at the optimized cut-off, resulting in a very low PPV, which is also influenced by the very low number of TP (n=4).

CONCLUSION

The results of the study show that the CEDIA is a valuable screening test on post-mortem whole blood for cannabinoids, cocaine and metabolites, opiates and methadone, but it is not recommended for amphetamine compounds, due to the high number of false positives. The strengths of the study are the large sample size, the inclusion of post-mortem cases only and the high level of sensitivity and specificity obtained at the optimized cut-offs.