An examination of the relationships between cannabis use, driving under the influence of cannabis and risk-taking on the road

Risk-Taking, Social Support, and Belongingness Contribute to the Risk for Cannabis Use Frequency in University Students

Background: Cannabis use and misuse is known to be associated with a variety of negative health, academic, and work-related outcomes; therefore, it is important to study the factors that contribute to or moderate its use. Objectives: The aim of this study was to determine whether risky behavior, belongingness and social support as clustering variables play a role in cannabis use frequency. Method: In a university student sample, participant data on risky behavior, belongingness and social support were used to generate vulnerability profiles through cluster analysis (low vulnerability with low risk, low vulnerability with high belonging, moderate vulnerability, and high vulnerability). Using an analysis of variance, the vulnerability profiles were compared with respect to cannabis use frequency and quantity. Through chi-square tests we assessed whether these profiles are overrepresented in certain demographics. Results: The cluster analysis yielded four groups, which differed in their vulnerability for cannabis use. The most vulnerable cluster group had higher cannabis use frequency relative to the two least vulnerable groups. Low income vs. high income was also associated with high vulnerability group membership. International students were overrepresented in the low vulnerability with high belonging group relative to the low vulnerability with low-risk group. The opposite was observed for domestic students. Conclusions: This research adds to the expanding body of literature on cannabis use and misuse in Canada, which may contribute to public health policy and the prevention and treatment of cannabis addiction by providing new insight on who may be at risk.

Australian daily cannabis users' use of police avoidance strategies and compensatory behaviours to manage the risks of drug driving

INTRODUCTION

Daily use of cannabis is increasing in Australia, yet there is limited understanding of the driving behaviours within this cohort, including how they perceive and manage the risks of being apprehended for drug driving and involved in a crash after consumption.

METHODS

An online survey was completed by 487 Australians who reported daily cannabis use (30% medically prescribed patients, 58% male).

RESULTS

Current drug driving (i.e., driving within 4 h of consuming cannabis each week) was reported by 86% of participants. Future drug driving was anticipated by 92% of the sample. While most participants (93%) disagreed that their risk of crash increased following cannabis use, participants reported that they would drive more carefully (89%), leave greater headway (79%) and/or drive slower (51%) following cannabis consumption. Half of the sample (53%) perceived the risk of apprehension for drug driving to be likely to some extent. Strategies to reduce the likelihood of being detected were used by 25% of participants, and included using Facebook police location sites (16%), driving on back roads (6%) and/or consuming substances to mask the presence of drugs (13%). The regression analysis revealed that individuals who reported more occasions of cannabis use per day, and who perceived that cannabis does not reduce driving ability, reported a greater extent of current drug driving.

DISCUSSION AND CONCLUSIONS

Interventions and education which aim to challenge this perception that 'cannabis does not reduce driving ability' may prove important for reducing drug driving among the most frequent consumers of cannabis.

Preliminary study of the interactive effects of THC and ethanol on self-reported ability and simulated driving, subjective effects, and cardiovascular responses

RATIONALE

Drug- and alcohol-related motor vehicle accidents are a leading cause of morbidity and mortality worldwide. Compared to alcohol, less is known about the effects of cannabis on driving and even less about their combined effects.

OBJECTIVE

To characterize the combined and separate effects of ethanol and tetrahydrocannabinol (THC) on perceived ability to drive, subjective effects, and simulated driving.

METHODS

In a within-subject (crossover), randomized, placebo-controlled, double-blind, 2 × 2 design, the effects of oral THC (10 mg [dronabinol] or placebo) and low-dose intravenous ethanol (clamped at BAC 0.04% or placebo) on perceived ability to drive, simulated driving (standard deviation of lateral position [SDLP]), subjective effects (e.g., "high"), and physiological effects (e.g., heart rate) were studied in healthy humans (n = 18).

RESULTS

Subjects reported reductions in perceived ability to drive (THC < ethanol < combination) which persisted for ~ 6 h (placebo = ethanol, THC < combination). Ethanol and THC produced synergistic effects on heart rate, significant differences compared to either drug alone on perceived ability to drive and feeling states of intoxication (e.g., high), as well increases in SDLP compared to placebo.

CONCLUSIONS

Perceived ability to drive is reduced under the influence of THC against the backdrop of blood alcohol levels that are below the legal limit. People should be aware that the effects of oral THC on driving may persist for up to six hours from administration. Findings are relevant to the increasingly common practice of combining alcohol and cannabinoids and the effects on driving.

Risk Perception of Traffic Accidents Due to Alcohol and Marijuana Use in Mexican College Students

Driving under the influence (DUI) of alcohol and other drugs is a common occurrence in Western societies. Alcohol consumption is related to 15% of fatal injuries in traffic accidents worldwide, with those DUI of alcohol being up to 18 times more likely to be involved in a fatal accident. Evidence for DUI of alcohol or marijuana among the college population in Mexico is scarce. This research estimates the proportion of use of alcohol and marijuana, describes the risk perception of DUI, and evaluates the relationship between risk perception and DUI behaviors in a sample of Mexican college students aged 18 to 29. The study was cross-sectional with a non-probabilistic sample. Risk perception of suffering traffic accidents when DUI or riding with someone DUI of alcohol, marijuana, or both, was high, unlike the risk perception of being detected or sanctioned for a DUI of marijuana. The study provided valuable information on the risk perception of engaging in behaviors related to DUI of alcohol and/or marijuana. It is necessary to undertake research on the subject with probabilistic and representative samples of this population of Mexico.

Self-reported impacts of recreational and medicinal cannabis use on driving ability and amount of wait time before driving

OBJECTIVE

Past research indicates that driving after cannabis use is relatively common. However, not all cannabis users are equally likely to drive after use; frequent cannabis users and frequent drivers are most at risk. It has been suggested that this is due to a perceived lack of impact of cannabis on driving ability.

METHODS

The current study sought to better understand the motivation to drive after recent cannabis use. A survey was used to examine the self-reported impact of cannabis use on driving ability and, further, the amount of time cannabis users wait before driving after use. A total of 562 participants were recruited. Of these, 424 completed the survey and were included for analysis. Purposive sampling was used to screen for cannabis users who were over the age of 18 and residents of Connecticut.

RESULTS

Cannabis use frequency was found to predict the self-reported impact of both recreational and medicinal cannabis on driving ability, such that more frequent cannabis users reported less impairment. Additionally, cannabis use frequency was predictive of wait time before driving, where more frequent users reported waiting less time before driving after cannabis use. A plurality of participants reported not waiting at all before driving after using cannabis. Notably, the self-reported impact of cannabis on driving ability was not associated with wait time before driving.

CONCLUSIONS

Cannabis users may not wait before driving even if they think it has a negative impact on their driving ability. Other factors that potentially impact driving after using cannabis warrant investigation.

Driving under the influence of cannabis: perceptions from Canadian youth

BACKGROUND

Cannabis legalization is intended to protect the public from potential harm by restricting access and promoting greater awareness of cannabis-related risks. Youth are at a greater risk for experiencing road-related harms due to their own or others' use of cannabis. This qualitative research explored youths' perceptions about cannabis and road safety.

METHODS

A qualitative study using focus groups (FG) was conducted with youth (age 13-18) and young adults (age 19-25) who resided in Newfoundland and Labrador. Using semi-structured interview questions, the facilitator asked participants to share their opinions about cannabis and road safety. All sessions were hosted virtually using Zoom with recruitment until saturation was met. All sessions were audio recorded, de-identified, and transcribed. Analysis utilized an inductive thematic approach informed by Braun and Clarke's (2006) method and inductive coding was facilitated using NVivo.

RESULTS

Six youth (n = 38) and five young adult (n = 53) FG were conducted. Five prominent themes emerged throughout discussions across both age groups including: a) normalization of driving under the influence of cannabis, b) knowledge and awareness, c) perceptions of risk, d) modes of transportation, and e) detection. Variation in perceptions appeared to be influenced by lack of awareness of the impact of cannabis on driving ability, residence in urban versus rural locations, type of vehicle driven (e.g., car vs. off-road vehicles), and gender.

CONCLUSION

The themes uncovered from this research will help inform future enhancement of cannabis policy to ensure the safety of all citizens. These findings will also support the inclusion of youth-focused education that will equip youth with informed decision-making strategies regarding road safety. Furthermore, these findings can be utilized to inform the refinement of cannabis driving policies to ensure the safety of all citizens on or off the road.

A systematic review of factors associated with illegal drug driving

Drug driving is a serious problem worldwide that can increase the risk of road crashes. This systematic review seeks to identify factors associated with drug driving (i.e., driving after consuming drugs other than alcohol) to highlight gaps in existing knowledge and inform the design of more effective countermeasures. A search of the literature was conducted for the period January 1, 2005 to July 31, 2021 using six different databases. The search protocol followed PRISMA guidelines and was registered in PROSPERO (#CRD42021234616). Studies that met inclusion criteria compared drug drivers with either non-drug drivers, alcohol-only drivers or drug drivers from an earlier time period, to identify factors specifically associated with drug driving, rather than common to all drivers. Two hundred and nineteen publications met the inclusion criteria and were included within the review. Based on the findings, a logic model was developed that presents the factors associated with drug driving. Various sociodemographic, psychosocial and legal factors emerged as the main factors associated with illegal drug driving. At the sociodemographic and psychological levels, drug drivers were more likely to be single, young males who often drive after using cannabis and who score high on sensation-seeking and impulsivity scales. The key social factor found to be associated with drug driving was peer acceptance/disapproval of the behaviour. At the legal level, the review suggested that the effectiveness of current enforcement approaches to drug driving vary among jurisdictions around the world due to differences in the level of perceived certainty of apprehension and the chances of punishment avoidance. Future research into the anticipated and actual rewards for drug driving is needed to inform the development of more effective countermeasures.

Risk Factors Associated With Driving After Cannabis Use Among Canadian Young Adults

This study identifid the most prominent risk factors associated with driving after cannabis use (DACU). 1,126 Canadian drivers (17–35 years old) who have used cannabis in the past 12 months completed an online questionnaire about sociodemographic information, substance use habits, cannabis effect expectancies, driving behaviours and peers’ behaviours and attitudes concerning DACU. A hierarchical logistic regression allowed identifying variables that were associated with DACU. Income (CA$30,000–CA$69,000), weekly-to-daily cannabis use, higher level of cannabis-related problems, expectation that cannabis facilitates social interactions, drunk driving, belief that DACU is safe, general risky driving behaviours, having a few friends who had DACU and injunctive norms predicted past 12-month DACU. Older age, holding negative expectations concerning cannabis, driving aggressively and perceived accessibility of public transportation decreased the probability of DACU. With restricted resources, programmes will be more efficient by targeting Canadian young adults most inclined to DACU by focussing on these risk factors.

Medicinal cannabis and driving: the intersection of health and road safety policy

BACKGROUND

Recent shifting attitudes towards the medical use of cannabis has seen legal access pathways established in many jurisdictions in North America, Europe and Australasia. However, the positioning of cannabis as a legitimate medical product produces some tensions with other regulatory frameworks. A notable example of this is the so-called 'zero tolerance' drug driving legal frameworks, which criminalise the presence of THC (tetrahydrocannabinol) in a driver's bodily fluids irrespective of impairment. Here we undertake an analysis of this policy issue based on a case study of the introduction of medicinal cannabis in Australia.

METHODS

We examine the regulatory approaches used for managing road safety risks associated with potentially impairing prescription medicines and illicit drugs in Australian jurisdictions, as well as providing an overview of evidence relating to cannabis and road safety risk, unintended impacts of the 'zero-tolerance' approach on patients, and the regulation of medicinal cannabis and driving in comparable jurisdictions.

RESULTS

Road safety risks associated with medicinal cannabis appear similar or lower than numerous other potentially impairing prescription medications. The application of presence-based offences to medicinal cannabis patients appears to derive from the historical status of cannabis as a prohibited drug with no legitimate medical application. This approach is resulting in patient harms including criminal sanctions when not impaired and using the drug as directed by their doctor, or the forfeiting of car use and related mobility. Others who need to drive are excluded from accessing a needed medication and associated therapeutic benefit. 'Medical exemptions' for medicinal cannabis in comparable jurisdictions and other drugs included in presence offences in Australia (e.g. methadone) demonstrate a feasible alternative approach.

CONCLUSION

We conclude that in medical-only access models there is little evidence to justify the differential treatment of medicinal cannabis patients, compared with those taking other prescription medications with potentially impairing effects.

Recreational cannabis use impairs driving performance in the absence of acute intoxication

BACKGROUND

Across the nation, growing numbers of individuals are exploring the use of cannabis for medical or recreational purposes, and the proportion of cannabis-positive drivers involved in fatal crashes increased from 8 percent in 2013 to 17 percent in 2014, raising concerns about the impact of cannabis use on driving. Previous studies have demonstrated that cannabis use is associated with impaired driving performance, but thus far, research has primarily focused on the effects of acute intoxication.

METHODS

The current study assessed the potential impact of cannabis use on driving performance using a customized driving simulator in non-intoxicated, heavy, recreational cannabis users and healthy controls (HCs) without a history of cannabis use.

RESULTS

Overall, cannabis users demonstrated impaired driving relative to HC participants with increased accidents, speed, and lateral movement, and reduced rule-following. Interestingly, however, when cannabis users were divided into groups based on age of onset of regular cannabis use, significant driving impairment was detected and completely localized to those with early onset (onset before age 16) relative to the late onset group (onset ≥16 years old). Further, covariate analyses suggest that impulsivity had a significant impact on performance differences.

CONCLUSIONS

Chronic, heavy, recreational cannabis use was associated with worse driving performance in non-intoxicated drivers, and earlier onset of use was associated with greater impairment. These results may be related to other factors associated with early exposure such as increased impulsivity.

A meta-analysis of the crash risk of cannabis-positive drivers in culpability studies-Avoiding interpretational bias

BACKGROUND

Culpability studies, a common study design in the cannabis crash risk literature, typically report odds-ratios (OR) indicating the raised risks of a culpable accident. This parameter is of unclear policy relevance, and is frequently misinterpreted as an estimate of the increased crash risk, a practice that introduces a substantial "interpretational bias".

METHODS

A Bayesian statistical model for culpability study counts is developed to provide inference for both culpable and total crash risks, with a hierarchical effect specification to allow for meta-analysis across studies with potentially heterogeneous risk parameter values. The model is assessed in a bootstrap study and applied to data from 13 published culpability studies.

RESULTS

The model outperforms the culpability OR in bootstrap analyses. Used on actual study data, the average increase in crash risk is estimated at 1.28 (1.16-1.40). The pooled increased risk of a culpable crash is estimated as 1.42 (95% credibility interval 1.11-1.75), which is similar to pooled estimates using traditional ORs (1.46, 95% CI: 1.24-1.72). The attributable risk fraction of cannabis impaired driving is estimated to lie below 2% for all but two of the included studies.

CONCLUSIONS

Culpability ORs exaggerate risk increases and parameter uncertainty when misinterpreted as total crash ORs. The increased crash risk associated with THC-positive drivers in culpability studies is low.

PERCEPTION OF RISK AND DRIVING UNDER THE EFFECTS OF ALCOHOL AND MARIJUANA ON UNIVERSITY STUDENTS IN A MULTICENTER STUDY: COLOMBIA

ABSTRACT Objective: analyze the relationship between the perception of risk and the behavior of driving under the influence of alcohol or marijuana or getting into a vehicle driven by someone under the effects of these substances in order to identify risk factors and protective factors. Method: multicenter study cross sectional survey with students from a University in Colombia (n = 493) completed a survey prepared during the International Program of Training in Research for Health Professionals and Related Areas to Study the Drug Phenomenon in Latin America and the Caribbean. Results: an inverse relationship was observed between each of the three levels of risk perception: detection (p<.001), punishment (p<.05) and harm (p<.001), and driving behaviors with alcohol. This same type of relationship is observed with marijuana in terms of perceived risk of being involved in an accident (p<.05). However, regarding to marijuana, there is not enough evidence of an association with the perceived risk of being arrested or punished. The results show that there is an inverse relationship between what the students' relatives and friends think and do and the perception of risk of being arrested (p<.001), punished (p<.001) or of being involved in an accident (p<.001) for driving under the influence of alcohol and marijuana at the same time. Conclusion: the results suggest that there are risk factors and protective factors that can be intervened to prevent injuries or fatal events associated with driving under the influence of alcohol or marijuana.

RISK PERCEPTION AND DRIVING A MOTOR VEHICLE UNDER THE INFLUENCE OF CANNABIS: A STUDY WITH COLLEGE STUDENTS OF A PRIVATE INSTITUTION

ABSTRACT Objective: to analyze the relationship between risk perception and behaviors related to driving a motor vehicle under the influence of cannabis. Method: The research was carried out through a cross-sectional survey. 382 undergraduate students between the ages of 17 and 29 were interviewed at a private higher educational institution in the Federal District, Brazil. Descriptive and inferential statistics (cross tabulations and chi-square) were used to analyze the data. Results: they indicate that more than 1/3 of the participants used cannabis in the past 12 months, and 36.4% reported problematic use. It was possible to establish a relationship between the behaviors of perception of risk and driving a motor vehicle under the influence of cannabis: 1) the perception of being sanctioned as a driver and driving a motor vehicle under the influence of cannabis (χ2(1) = 3.96, p=≤0); 2) to perceive damages as driver and driving a motor vehicle under the influence of cannabis (χ2(1)=3.96, p = ≤05); 3) perception of damages as passenger and driving a motor vehicle under the influence of cannabis (χ2(1)=3.96, p=≤5.0). Conclusion: damages caused by cannabis are underestimated by university students, since they have a very low risk perception, especially when compared to alcohol. In Brazil, there is also a lack of regulation and sanctions with respect to driving a motor vehicle under the influence of cannabis, which may contribute to an important risk among this population.

PERCEPTION OF RISK AND BEHAVIORS ASSOCIATED WITH DRIVING UNDER THE EFFECTS OF ALCOHOL AND MARIJUANA ON UNIVERSITY STUDENTS OF VENEZUELA

ABSTRACT Objective: to evaluate the relationship between risk perception and the behaviors associated with driving under the influence of drugs. Method: quantitative cross-sectional study. The sample is composed by university students (n=383, average age 21.2 years). To evaluate the behaviors, items from Ontario Student Drug Use and Health were adapted, and two other instruments were used to measure alcohol and marijuana consumption. Results: it indicates a low risk perception when driving under the influence of drugs. There are no differences between the risk perception of being stopped by the police or being penalized for driving under effects of alcohol and/or marijuana among the students whose report the behavior called driving-under-influence and those without such behavior. However, there were differences between the perception of the risk of involvement in a vehicle accident and the behaviors called driving-under-influence, showing that those who report driving under the influence of alcohol and/or marijuana perceive a lower risk of accidents due to the effects of alcohol X2 (1, N=292)=7,999, p=.005 and of both substances X2 (1, N=35)=6.386, p=.012. Likewise, a lower perception of the risk of accidents was found among the subjects who board a vehicle driven by someone who uses marijuana X2 (1, N=67)=15,087, p=.000 and those who do not report being a passenger of a driver under influence; as well as when under the simultaneous effect of alcohol and marijuana X2 (1, N=366)=8,849, p=.003. Conclusion: it is concluded that the development of preventive programs in the university environment, as well as public policies that include the component of education and compliance with legal regulations, is important.

PERCEPTION OF HARM AND BENEFITS OF CANNABIS USE AMONG ADOLESCENTS FROM LATIN AMERICA AND CARIBE

ABSTRACT Objective: to investigate the perception of harms and benefits associated with cannabis use among adolescents and how regulatory changes might affect their intention to use marijuana. Method: this multi-centric cross-sectional survey study. participants included 2717 students aged 15-17 from 10 cities in Belize, Brazil, Chile, Colombia, Dominican Republic, Jamaica, Mexico, St. Kitts and Nevis, and Trinidad and Tobago. Results: an average lifetime prevalence of cannabis use of 30.6% (25.8% past year, 15.8% past 30 days). Most participants reported that their closest friends use cannabis (60%); many (55%) stated that they would not use marijuana, even if it were legally available. Conclusion: statistics revealed that a strong perception of benefits, a low perception of risk, and friends’ use of cannabis were associated with individual use as well as intention to use within a hypothetical context of regulatory change.

The effects of cannabis intoxication on motor vehicle collision revisited and revised

AIMS

To determine whether and to what extent acute cannabis intoxication increases motor vehicle crash risk.

DESIGN

Study 1 replicates two published meta-analyses, correcting for methodological shortcomings. Study 2 is an updated meta-analysis using 28 estimates from 21 observational studies. These included studies from three earlier reviews, supplemented by results from a structured search in Web of Science and Google Scholar, and by the personal libraries of the research team. Risk estimates were combined using random-effects models and meta-regression techniques.

SETTING

Study 1 replicates the analysis of Asbridge et al., based on nine studies from five countries, published 1982-2007; and Li et al., based on nine studies from six countries, published 2001-10. Study 2 involves studies from 13 countries published in the period 1982-2015.

PARTICIPANTS

In study 1, total counts extracted totalled 50 877 (27 967 cases, 22 910 controls) for Asbridge et al. and 93 229 (4236 cases and 88 993 controls) for Li et al. Study 2 used confounder-adjusted estimates where available (combined sample size of 222 511) and crude counts from the remainder (17 228 total counts), giving a combined sample count of 239 739.

MEASUREMENTS

Odds ratios (OR) were used from case-control studies and adjusted OR analogues from culpability studies. The impact of the substantial variation in confounder adjustment was explored in subsample analyses.

FINDINGS

Study 1 substantially revises previous risk estimates downwards, with both the originally reported point estimates lying outside the revised confidence interval. Revised estimates were similar to those of study 2, which found cannabis-impaired driving associated with a statistically significant risk increase of low-to-moderate magnitude [random-effects model OR 1.36 (1.15-1.61), meta-regression OR 1.22 (1.1-1.36)]. Subsample analyses found higher OR estimates for case-control studies, low study quality, limited control of confounders, medium-quality use data and not controlling for alcohol intoxication.

CONCLUSIONS

Acute cannabis intoxication is associated with a statistically significant increase in motor vehicle crash risk. The increase is of low to medium magnitude. Remaining selection effects in the studies used may limit causal interpretation of the pooled estimates.