Factors related to the low-risk perception of driving after cannabis use.

INTRODUCTION: Modifying risk perceptions related to driving after cannabis use (DACU) could deter individuals from enacting this behavior, as low-risk perception is associated with DACU engagement. This study identified sociodemographic characteristics, substance use, other driving behaviors, peer norms, and psychological characteristics that are associated with lower risk perception regarding DACU. METHODS: Canadian drivers aged 17-35 who have used cannabis in the past year (n = 1,467) completed an online questionnaire. A multivariate linear regression model allowed for identifying variables associated with the low-risk perception of DACU (i.e. believing it to be safe as one's driving ability is not impaired by cannabis or by being high). RESULTS: Lower risk perception of DACU was associated with identifying as male, weekly to daily cannabis use, engagement in DACU, general risky driving behaviors, being a passenger of a driver who engages in DACU, number of friends who engage in DACU, and peer approval of DACU. Having driven under the influence of alcohol, living in urban areas, having received traffic tickets in the past three years, and declaring past-week irritability and cognitive problems were associated with holding a higher risk perception related to DACU. DISCUSSION: Road education and prevention programs should target attitudes and perceptions regarding risks shaped by sociocultural norms and past risky driving experiences. They need to reach out more specifically to drivers with the identified characteristics associated with the low-risk perception of DACU. These interventions can potentially help reduce the rate of individuals who engage in this behavior.

Scheduling optimisation of alcohol test sites.

Drink driving is an infamous factor in road crashes and fatalities. Alcohol testing is a major countermeasure, and random breath tests (RBTs) deter tested drivers and passersby (observers who are not tested). We propose a genetic algorithm (GA)-based RBT scheduling optimisation method to achieve maximal deterrence of drink driving. The RBT schedule denotes the daily plan of where, when, and for how long tests should occur in the road network. The test results (positive and negative) and observing drivers are considered in the fitness function. The limited testing resource capacity is modeled by a number of constraints that consider the total duration of tests, the minimum and maximum duration of a single test site, and the total number of test sites during the day. Clustering of the alcohol-related crash data is used to estimate the matrix for drink driving on the scheduled day. The crash data and traffic flow data from Victoria, Australia are analysed and used to describe sober/drink driving. A detailed synthetic example is developed and a significant improvement with 150% more positive results and 59% more overall tests is observed using the proposed scheduling optimisation method.

Non-Invasive Alcohol Concentration Measurement Using a Spectroscopic Module: Outlook for the Development of a Drunk Driving Prevention System.

Alcohol acts as a central nervous system depressant and falls under the category of psychoactive drugs. It has the potential to impair vital bodily functions, including cognitive alertness, muscle coordination, and induce fatigue. Taking the wheel after consuming alcohol can lead to delayed responses in emergency situations and increases the likelihood of collisions with obstacles or suddenly appearing objects. Statistically, drivers under the influence of alcohol are seven times more likely to cause accidents compared to sober individuals. Various techniques and methods for alcohol measurement have been developed. The widely used breathalyzer, which requires direct contact with the mouth, raises concerns about hygiene. Methods like chromatography require skilled examiners, while semiconductor sensors exhibit instability in sensitivity over measurement time and has a short lifespan, posing structural challenges. Non-dispersive infrared analyzers face structural limitations, and in-vehicle air detection methods are susceptible to external influences, necessitating periodic calibration. Despite existing research and technologies, there remain several limitations, including sensitivity to external factors such as temperature, humidity, hygiene consideration, and the requirement for periodic calibration. Hence, there is a demand for a novel technology that can address these shortcomings. This study delved into the near-infrared wavelength range to investigate optimal wavelengths for non-invasively measuring blood alcohol concentration. Furthermore, we conducted an analysis of the optical characteristics of biological substances, integrated these data into a mathematical model, and demonstrated that alcohol concentration can be accurately sensed using the first-order modeling equation at the optimal wavelength. The goal is to minimize user infection and hygiene issues through a non-destructive and non-invasive method, while applying a compact spectrometer sensor suitable for button-type ignition devices in vehicles. Anticipated applications of this study encompass diverse industrial sectors, including the development of non-invasive ignition button-based alcohol prevention systems, surgeon's alcohol consumption status in the operating room, screening heavy equipment operators for alcohol use, and detecting alcohol use in close proximity to hazardous machinery within factories.

Do tougher drinking policies affect men's smoking behavior - Evidence from China.

In 2011, China implemented tougher driving-under-the-influence laws, which criminalized driving under the influence of alcohol for the first time and increased penalties. This paper provides the first comprehensive analysis of the effects of stricter drinking policies on men's smoking behavior by using data from the 2010 and 2012 waves of the China Family Panel Studies. The results show that stricter drinking policies reduced smoking initiation and the number of cigarettes smoked per day among men by reducing the frequency and quantity of alcohol consumption. Heterogeneity analyses show that the impact of the policy is more pronounced not only for men aged 41-55, but also for men who have higher educational qualifications, who are employed, or who are not members of the Communist Party.

Measurement uncertainty of ethyl alcohol concentration in the exhaled breath of drivers and determination of sobriety at the time of incident. / Niepewnosc pomiaru stezenia alkoholu etylowego w powietrzu wydychanym kierowców oraz ustalenia stanu trzezwosci w chwili zdarzenia.

The aim of the study was to determine the components of measurement uncertainty in the concentration of alcohol in exhaled breath and to determine the state of sobriety at the time of incident. Based on the literature review and the authors' experience in providing opinions for law enforcement and the judiciary, the influence of various factors on the final interpretation of sobriety state is described on the basis of measurement uncertainty of breath analyzers, uncertainty of retrospective and prospective calculations, and uncertainty related to the conversion of alcohol concentrations detected during breath and blood tests. The paper pays particular attention to interpreting the concentrations of ethanol in exhaled breath close to the legal limits of the state of sobriety and the state after alcohol use, or the state after alcohol use and the state of insobriety. Analyzing the results of an exhaled breath test concerning concentrations close to the values of 0.1 mg/dm3 and 0.25 mg/dm3, it is necessary to take into account the factors affecting the measurements obtained, including the measurement uncertainty of the determination of alcohol in exhaled breath, the processes of absorption, distribution and metabolism of ethyl alcohol, and the possibility of the presence of alcohol lingering in the oral cavity. The incorrect execution of measurements of the tested person's alcohol concentration is also a problematic issue. When determining sobriety state by means of retrospective and prospective calculations, it is important to remember that the uncertainty of the result is affected by a number of factors and depends, among other things, on the information provided by the suspect. Hence, the expert should draw conclusions particularly cautiously and any overestimation or underestimation of the components of uncertainty can lead to erroneous conclusions. Awareness of the uncertainties inherent in the results of a sobriety test or alcohol calculation allows for meaningful interpretation of test results and determination of the sobriety state of the person tested.

Quantitation of hexahydrocannabinol (HHC) and metabolites in blood from DUID cases.

Hexahydrocannabinol (HHC) was first reported in the EU in May 2022. HHC has three chiral carbon atoms, but only (6aR,9R,10aR)-HHC (9R-HHC) and (6aR,9S,10aR)-HHC (9S-HHC) have been encountered in HHC products. The aim of this study was to develop and validate a method for the quantitative analysis of 9R-HHC, 9S-HHC, 11-OH-9R-HHC, 9R-HHC-COOH, 9S-HHC-COOH and 8-OH-9R-HHC. In addition, an objective was to investigate the immunochemical cross-reactivity. Blood samples from driving under the influence of drugs (DUID) cases screened positive for cannabis using enzyme-linked immunoadsorbent assay (ELISA) and confirmed negative for tetrahydrocannabinol (THC), 11-hydroxy-THC and THC-COOH were reanalyzed with a newly validated HHC method to investigate the presence of HHC and metabolites. The LC-MS-MS method was validated for matrix effects, lower limit of quantification (LLOQ), calibration model, precision, bias and autosampler stability. Cross-reactivity on an ELISA method was investigated separately for 9R-HHC-COOH and 9S-HHC-COOH at a concentration range between 5 and 200 ng/mL. The cross-reactivity was found to be 120% for 9R-HHC-COOH and 48% for 9S-HHC-COOH. In the LC-MS-MS method, 9R-HHC-COOH, 9S-HHC-COOH and 11-OH-9R-HHC showed matrix effects <25% at both concentrations, while 8-OH-9R-HHC, 9R-HHC and 9S-HHC matrix effects exceeded 25% at both concentrations but showed good precision (<10% for both inter and intra day) and low bias (<6%) in the further validation. The LLOQ was investigated and established at 0.2 ng/mL for all analytes except the carboxylated metabolites that had an LLOQ of 2.0 ng/mL. The upper LOQ was 20 and 200 ng/mL, respectively. Reanalysis of cases (n = 145) confirmed HHC and metabolites in 32 cases (22%). It was determined that the major metabolite in blood after administration of HHC was 9R-HHC-COOH followed by 11-OH-9R-HHC and that presumptive positive cases are caught by the routine ELISA screening for cannabis.

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.

Prevalence and factors associated with driving under the influence of alcohol in Brazil.

OBJECTIVES: To estimate the prevalence and factors associated with Driving Under the Influence of Alcohol (DUIA) among car drivers and motorcyclists in Brazil and to evaluate the association between DUIA and self-reported Road Traffic Injuries (RTIs) in these groups. METHODS: A cross-sectional study was conducted using data from adults aged 18 or older who participated in the 2019 National Health Survey. Probability sampling was used to recruit participants, and data collection was carried out through home visits. Data from 31,246 car drivers and 21,896 motorcyclists were analyzed. Key indicators included the proportion (%) of car drivers who consumed alcohol and then drove in the past 12 months and the proportion (%) of motorcyclists who consumed alcohol and then drove in the past 12 months. Multiple Poisson regression was used to determine factors associated with DUIA and the association of this variable with RTIs in both groups. RESULTS: DUIA prevalence was 9.4% (95% Confidence Interval [95% CI] = 8.8-10.0) among car drivers and 11.2% (95% CI = 10.4-12.1) among motorcyclists. Among car drivers, DUIA prevalence was higher in men, young adults, those without a spouse/partner, and lower in individuals with lower income and education level. Among motorcyclists, DUIA prevalence was higher in men, young adults, those living outside the capitals and metropolitan regions, and lower in individuals with lower income. DUIA increased the prevalence of self-reported RTIs in the previous 12 months among car drivers and motorcyclists. CONCLUSIONS: A high prevalence of DUIA was evident among drivers, particularly motorcyclists. The DUIA was more prevalent among men and young adults. The DUIA was associated with an increased magnitude of self-reported RTIs among car drivers and motorcyclists. Despite the extensive legislation for zero tolerance toward DUIA in the country, actions need stricter enforcement.

Gabapentin in drugged driving investigations.

The increasing use and misuse of gabapentin pose a major risk to public health and traffic safety. Gabapentin has been approved by the Food and Drug Administration (FDA) since 1993 for adjunctive therapy in the treatment of epilepsy and neuralgia but is increasingly being prescribed for numerous off-label uses including insomnia, anxiety, depression, and migraine. Reported side effects include blurred vision, drowsiness, and loss of coordination. Driving behaviors such as exiting the lane of travel and crashes have been reported in connection to drugged driving investigations concerning gabapentin. To further assist with the toxicological interpretation of gabapentin in driving under the influence of drugs (DUID) scenarios, a review of approximately 108,000 gabapentin-positive DUID cases was conducted. Of those, 858 cases met inclusion criteria and underwent additional evaluation. Blood specimens were screened via enzyme-linked immunosorbent assay (ELISA) and confirmed by liquid chromatography tandem mass spectrometry (LC-MS/MS) for quantitation of gabapentin. This review found an overall DUID gabapentin positivity of 7.9% between January 2020 and December 2022; 17 states from various geographical regions had at least one positive gabapentin DUID case. Observations in six driving and human performance cases where gabapentin was the only drug reported were consistent with the known adverse effects of the medication. Half of the case histories reviewed involved crashes where the driver was determined to be at fault. Additionally, 94% of the cases in this review involved gabapentin in combination with other drugs. The most prevalent drug combinations were opioids and gabapentin present in 64% of cases.

Off-road vehicle crashes: dangers of alcohol and drug impairment.

BACKGROUND: Impaired driving is a public health issue, yet little is known concerning the prevalence of substance use in drivers involved in off-road vehicle crashes. The goal of the present study was to describe the demographics and prevalence of alcohol and drug use in drivers of off-road vehicle crashes. METHODS: In this observational substudy, we collected clinical and toxicological data on all moderately or severely injured off-road vehicle drivers who had blood samples obtained within 6 h of the crash. Clinical data were extracted from patients' medical charts and toxicology analyses were performed for blood alcohol, cannabinoids, recreational drugs, and impairing medications. RESULTS: Thirty-three injured drivers met the inclusion criteria. The mean age was 37.6 ± 13.4 years and 79% were male. Blood alcohol was detected in 58% of drivers and 42% of these were above the legal limit. Tetrahydrocannabinol was positive in 12% of drivers, and 18% were positive for recreational drugs. Opiates were detected in 21% of drivers. Overall, 85% were positive for at least one substance and 39% tested positive for multiple substances. CONCLUSION: This study presents the first evidence of alcohol and drug use in off-road vehicle drivers after cannabis legalization in Canada. Our results show that over half of drivers in off-road vehicle crashes test positive for alcohol and 30% tested positive for THC, cocaine, or amphetamines. Opiates are also commonly detected in off-road vehicle drivers. Emergency department (ED) visits resulting from drug driving of off-road vehicles serve as an opportunity for screening, initiating treatment, and connecting patients to interventions for substance use disorders.

ABSTRAIT: CONTEXTE: La conduite avec facultés affaiblies est un problème de santé publique, mais on sait peu de choses sur la prévalence de la toxicomanie chez les conducteurs impliqués dans des accidents de la route. L'objectif de la présente étude était de décrire la démographie et la prévalence de la consommation d'alcool et de drogues chez les conducteurs de véhicules hors route. MéTHODES: Dans le cadre de cette sous-étude observationnelle, nous avons recueilli des données cliniques et toxicologiques sur tous les conducteurs de véhicules hors route ayant subi des blessures modérées ou graves qui avaient reçu des échantillons de sang dans les 6 heures suivant l'accident. Les données cliniques ont été extraites des dossiers médicaux des patients et des analyses toxicologiques ont été effectuées pour l'alcool dans le sang, les cannabinoïdes, les drogues récréatives et les médicaments pour les facultés affaiblies. RéSULTATS: Trente-trois conducteurs blessés répondaient aux critères d'inclusion. L'âge moyen était de 37,6 13,4 ans et 79 % étaient des hommes. L'alcool dans le sang a été détecté chez 58 % des conducteurs et 42 % d'entre eux dépassaient la limite légale. Le tétrahydrocannabinol était positif chez 12 % des conducteurs et 18 % étaient positifs aux drogues récréatives. Des opiacés ont été détectés chez 21 % des conducteurs. Dans l'ensemble, 85 % étaient positifs pour au moins une substance et 39 % étaient positifs pour plusieurs substances. CONCLUSION: Cette étude présente les premières preuves de la consommation d'alcool et de drogues chez les conducteurs de véhicules hors route après la légalisation du cannabis au Canada. Nos résultats montrent que plus de la moitié des conducteurs de véhicules hors route ont un résultat positif au test de dépistage de l'alcool et 30 % ont un résultat positif au test de dépistage du THC, de la cocaïne ou des amphétamines. Les opiacés sont également couramment détectés chez les conducteurs de véhicules hors route. Les visites aux services d'urgence (SU) découlant de la conduite de véhicules hors route avec facultés affaiblies par la drogue constituent une occasion de dépistage, d'amorcer un traitement et de mettre les patients en contact avec des interventions pour les troubles liés à la consommation de substances.

Colorado drugged driving prevalence and impaired driving conviction rates: Effects of impaired driving definitions and a 5-nanogram limit for delta-9 tetrahydrocannabinol.

Objectives: How prevalent is drugged driving among Colorado drivers convicted of Driving Under the Influence (DUI)? What are the conviction rates of Colorado drivers charged with DUI, including impairment by marijuana's delta-9 tetrahydrocannabinol (THC)? Is Colorado's THC permissible inference law effective? To answer these questions, this report analyzes data published primarily in appendices of Colorado drugged driving reports.Methods: In 2017 Colorado began requiring annual analyses of Driving Under the Influence (DUI) offenses, including causes and judicial consequences of DUI offenses. These analyses are performed by the Division of Criminal Justice's Office of Research and Statistics (ORS) within the Department of Public Safety. Each analysis requires ORS to link toxicology and court data bases. Data linking enables reporting of charges and convictions by categories including alcohol only, THC only, and polydrug use (two or more drugs simultaneously). Reports have been published annually for 5 years, the latest published in 2023 which covers case filings for 2020.Results: A rough estimate of one-half of the state's DUI filings were attributed to drug use and half were attributed to alcohol only. The largest component of drugged driving was polydrug impairment, rather than impairment by a single drug like THC. Conviction rates in 2020 were 91% for alcohol only, 90% for polydrug cases, and 72% for THC only. Blood drug levels and law structure (per se, permissible inference, DUI definition) affected conviction rates significantly by defendant subsets. THC conviction rates in 2020 ranged from 11% to 100%, depending on blood drug levels and the legal charges.Conclusions: Efforts to educate the public about the dangers of drugged driving should emphasize polydrug impairment, not simply THC impairment. States should analyze data on causes and consequences of DUI arrests to understand what their drugged driving problems are and what they are not. Non-zero drug per se levels and defining DUI as "incapable of safe driving" can severely reduce the effectiveness of DUI laws.

Sales to Apparently Intoxicated Customers in Three States With Different Histories of Responsible Beverage Service Training.

OBJECTIVE: Most states prohibit sales of alcohol to customers who are apparently intoxicated, and many require training in responsible beverage service (RBS), with the aim of reducing driving while intoxicated (DWI) and other harms. Sales to apparently intoxicated patrons were assessed in onsite alcohol sales establishments and compared across three states. METHOD: A sample of 180 licensed onsite alcohol establishments was selected in California (n = 60), New Mexico (n = 60), and Washington State (n = 60). States had different RBS training histories, content, and procedures. Research confederates, trained to feign cues of intoxication, visited each establishment twice. The pseudo-intoxicated patron (PP) ordered an alcoholic beverage while displaying intoxication cues. Sale of alcohol was the primary outcome. RESULTS: At 179 establishments assessed, PPs were served alcohol during 56.5% of 356 visits (35.6% of establishments served and 22.6% did not serve at both visits). Alcohol sales were less frequent in New Mexico (47.9% of visits; odds ratio [OR] = 0.374, p = .008) and Washington State (49.6%; OR = 0.387, p = .012) than in California (72.0%). Servers less consistently refused service at both visits (6.8%) in California than New Mexico (33.9%) or Washington (27.1%), χ2(4, n = 177) = 16.72, p = .002. Alcohol sales were higher when intoxication cues were less obvious (p < .001). CONCLUSIONS: Overservice of alcohol to apparently intoxicated customers was frequent and likely elevated risk of DWI and other harms. The lower sales in New Mexico and Washington than California may show that a policy approach prohibiting sales to intoxicated customers combined with well-established RBS training can reduce overservice. Further efforts are needed to reduce overservice.

How do drunk-driving events escalate into drunk-driving crashes? An empirical analysis of Beijing from a spatiotemporal perspective.

Drunk-driving events often escalate into drunk-driving crashes, however, the contributing factors of this progression remain elusive. To mitigate the likelihood of crashes stemming from drunk-driving events, this paper introduces the notion of 'the severity of drunk-driving event' and examines the complex relationship between the severity and its contributing factors, considering spatiotemporal heterogeneity. The study utilizes a Geographically and Temporally Weighted Binary Logistic Regression (GTWBLR) model to conduct spatiotemporal analysis based on police-reported drunk-driving events in Beijing, China. The results show that most factors passed the non-stationary test, indicating their effects on the severity of drunk-driving event vary significantly across different spatial and temporal domains. Notably, during non-workday, drunk-driving events in northeast of Beijing are more likely to escalate into crashes. Furthermore, severe weather during winter in the northwest of Beijing is associated with high risk of drunk-driving crashes. Based on these insights, the authorities can strengthen drunk-driving checks in the northeast region of Beijing, particularly during non-workdays. And it is crucial to promptly clear accumulated snow on the roads during severe winter weather to improve road safety. These insights and recommendations are highly valuable for reducing the risk of drunk-driving crashes.

Drug driving: a secondary analysis of factors associated with driving under the influence of cannabis in Jamaica.

OBJECTIVES: To determine cannabis use patterns, the predictive sociodemographic correlates of driving under the influence of cannabis (DUIC) and the association between risk perception and cannabis dependence among vehicle drivers in Jamaica. DESIGN: Secondary data analysis. SETTING: Used the Jamaica National Drug Prevalence Survey 2016 dataset. PARTICIPANTS: 1060 vehicle drivers extracted from the population sample of 4623. PRIMARY AND SECONDARY OUTCOME MEASURES: Analysis used Pearson's χ2 test and logistic regression. ORs and 95% CIs were recorded. A p<0.05 was considered statistically significant. RESULTS: More than 10% of Jamaican drivers admitted to DUIC in the past year. Approximately 43.3% of drivers who currently use cannabis reported DUIC only. Evidently, 86.8% of drivers who DUIC were heavy cannabis users. Approximately 30% of drivers with moderate to high-risk perception of smoking cannabis sometimes or often were dependent on cannabis. Notwithstanding, drivers with no to low-risk perception of smoking cannabis sometimes or often were significantly likelier to be dependent (p<0.001 and p<0.001, respectively). Logistic regression highlighted male drivers (OR 4.14, 95% CI 1.59 to 14.20, p=0.009) that were 34 years and under (OR 2.97, 95% CI 1.71 to 5.29, p<0.001) and were the head of the household (OR 2.22, 95% CI 1.10 to 4.75, p=0.031) and operated a machine as part of their job (OR 1.87, 95% CI 1.09 to 3.24, p=0.023) were more likely to DUIC, while those who were married (OR 0.42, 95% CI 0.22 to 0.74, p=0.004) and had achieved a tertiary-level education (OR 0.26, 95% CI 0.06 to 0.76, p=0.031) were less likely. CONCLUSIONS: Two in five Jamaican drivers, who currently smoke cannabis, drive under its influence, with over 85% engaging in heavy use. Public health implications necessitate policy-makers consider mobile roadside drug testing and amending drug-driving laws to meet international standards.

Origin of the First Handheld Breath Alcohol Analyzer Incorporating an Electrochemical Sensor.

Historical events leading to the development of the first handheld instrument for breath alcohol analysis using an electrochemical sensor are reviewed. The first prototype instrument, known as the Alcolmeter Pocket Model, became available in 1972 and weighed only 180 g and was about the size of a cellphone. By the mid-1970s, the Alcolmeter instrument was used by police forces in several countries as a preliminary roadside test of driver sobriety. Positive results in a roadside breath test were considered sufficient evidence to arrest a suspect for further evaluation and testing. This might entail an evidential-quality breath alcohol test or taking a sample of the driver's blood for analysis at a forensic laboratory. The main advantages of breath testing over blood testing are the non-invasive nature of the sampling procedure compared with sticking a needle in a vein to draw blood, and obtaining immediate information whether or not a person is in breach of the drunk driving legislation.

Cannabis legalization and driving under the influence of cannabis and driving under the influence of alcohol among adult and adolescent drivers in Ontario, Canada (2001-2019).

BACKGROUND: The impacts of cannabis legalization on driving under the influence of cannabis and driving under the influence of alcohol among adults and adolescents were examined in Ontario, Canada. METHODS: Data were sourced from adult (N=38,479) and adolescent (N=23,216) populations-based surveys (2001-2019). The associations between cannabis legalization and driving within an hour of using cannabis and driving within an hour of drinking two or more drinks of alcohol were quantified using logistic regression, with testing of multiplicative interactions between cannabis legalization and age and sex. All analyses were conducted separately for adults and adolescents and restricted to participants with a valid driver's license. RESULTS: Cannabis legalization was not associated with driving within an hour of using cannabis among adults (OR, 95% CI: 1.21, 0.69-2.11). However, a multiplicative interaction indicated that there was an increased likelihood of driving within an hour of using cannabis among adults ≥55 years of age (4.23, 1.85-9.71) pre-post cannabis legalization. Cannabis legalization was not associated with driving within an hour of using cannabis among adolescents (0.92, 0.72-1.16), or with driving within an hour of consuming two or more drinks of alcohol among adults (0.78, 0.51-1.20) or adolescents (0.87, 0.42-1.82). CONCLUSIONS: An increased likelihood of driving under the influence of cannabis among adults ≥55 years of age was detected in the year following cannabis legalization, suggesting the need for greater public awareness and education and police monitoring and enforcement concerning driving under the influence of cannabis, particularly among older adults.

Perceptions and Attitudes Related to Driving after Cannabis Use in Canadian and US Adults.

BACKGROUND: This study examined the risk perceptions related to driving after cannabis use (DACU) among Canadian and US adults who used cannabis in the past six months. METHODS: Perceptions of danger, normative beliefs, perceived likelihood of negative consequences, and other driving-related variables were collected via online surveys in Canadian (n = 158; 50.0% female, 84.8% White, mean age = 32.73 years [SD = 10.61]) and US participants (n = 678; 50.9% female, 73.6% White, mean age = 33.85 years [SD = 10.12]). Driving cognitions and DACU quantity/frequency were compared between samples using univariate analyses of variance, and Spearman's (ρ) correlations were performed to examine associations between driving cognitions and DACU quantity/frequency. RESULTS: The two samples did not significantly differ in self-reported level of cannabis use, lifetime quantity of DACU, or the number of times they drove within two hours of cannabis use in the past three months (Ps > .12). Compared to US participants, Canadians perceived driving within two hours of cannabis use as more dangerous (P < 0.001, ηp2 = 0.013) and reported more of their friends would disapprove of DACU (P = 0.03, ηp2 = 0.006). There were no differences in the number of friends who would refuse to ride with a driver who had used cannabis (P = 0.15) or the perceived likelihood of negative consequences (Ps > 0.07). More favorable perceptions were significantly correlated with greater lifetime DACU and driving within two hours of use (ρ = 0.25-0.53, Ps < 0.01). CONCLUSIONS: These findings reveal differences in distal risk factors for DACU between Canada and the US and may inform prevention efforts focusing on perceptions of risk and social acceptance of DACU.

A retrospective study of traffic offenses associated with driving under the influence of drugs in China.

OBJECTIVE: This study aimed to investigate the prevalence and pattern of traffic offenses associated with driving under the influence of drugs (DUID) in 31 provinces of mainland China. METHODS: Traffic offenses were extracted from the nationally representative court file disclosure website. Drivers convicted of traffic offenses associated with DUID were included. The monthly percentage change (MPC) in rates was estimated by fitting negative binomial regression models to assess the time trends. Moran's I was used to determine the correlations of DUID-related rates among surrounding provinces. RESULTS: In total, 896 individuals convicted of DUID offenses were identified (April 2007 to March 2022). Of these, 769 individuals were involved in traffic crashes, and they killed 629 people. Regarding the types of drugs, 638 used amphetamine-type stimulants (ATS; methamphetamine, 3,4-methylenedioxymethamphetamine, amphetamine, and tenamfetamine), 104 used ketamine, 104 used opioids (heroin, morphine, methadone, codeine, and tramadol), 20 used caffeine, 4 used tetrahydrocannabinol, and 1 used gamma-hydroxybutyric acid. The offense trends among overall drug users (MPC, -1.1; p < .001) declined from 2014 to 2020. The trends also decreased for DUID-related traffic crashes (-1.5; p < .001) and deaths (-1.7; p < .001) during the same period. Except in three provinces, ATS-related offense rates were higher than opioid-related offense rates. Ketamine-related offense rates showed a significant positive correlation among the surrounding provinces (Moran's I, 0.22; p < .01), and South China had the highest ketamine-related offense rates. CONCLUSIONS: In the sample, the case fatality rate was 70.7%, which was a strong indicator of underreporting, and most minor DUID-related offenses could not be captured by Chinese court files. The frequency of drug screening tests for people should be increased. The traffic police in Qinghai, Tibet, and Xinjiang should always be equipped with fast screening test kits for drugs, which could increase the possibility of identifying DUID offenders.

Driving under the influence of nitrous oxide - A retrospective study of HS-GC-MS analysis in whole blood.

Since 2020, our lab has received blood samples from traffic cases involving suspicion of driving under the influence of nitrous oxide (N2O). While N2O analysis by gas chromatography (GC) has been around for decades, quantitative results in blood from drivers have been only scarcely reported. We present a three-year (2020-2022) retrospective study of N2O from traffic cases in Eastern Denmark with suspected involvement of N2O intake. Whole blood samples from traffic cases were analysed for N2O using headspace-GC-MS. Freshly made calibration curves and additions of xenon gas as an internal standard were used for calculation of N2O concentrations. Positive samples have been defined as having concentrations greater than 0.1 mL N2O/L blood. Over a three-year period, we have tested 62 traffic case blood samples for the presence of N2O. Despite the technical challenges associated with the analysis of N2O, we have found N2O in 52 of the samples. Calculated concentrations were in the range 0.1-48 mL N2O/L blood, which are similar to the few cases previously found in the literature.