Driving and riding under the influence of recent marijuana use: Risk factors among a racially diverse sample of young adults

Driving under the influence of cannabis versus alcohol: A mixed-methods study examining perceptions and related risk behaviors among US and Israeli adults

BACKGROUND

Despite the dangers of driving under the influence (DUI), little is known about DUI substance-specific risk perceptions or risk factors for riding with drunk/drugged drivers (RDD).

METHODS

In this sequential exploratory mixed-methods study, we conducted: 1) multivariable analyses of cross-sectional survey data from 2222 US and Israeli adults to identify correlates of perceived cannabis- vs. alcohol-related DUI risks (linear regression) and past-month RDD involving alcohol-only, cannabis-only, or both (alcohol-cannabis) (multinomial logistic regression); and 2) deductive-inductive thematic analyses of qualitative interview data from 84 participants to identify themes elaborating on survey findings regarding DUI-related risk perceptions.

RESULTS

54.0 % reported past-month alcohol use, 16.7 % cannabis use, 4.2 % alcohol-only RDD, 5.5 % cannabis-only RDD, and 7.9 % alcohol-cannabis RDD. Being from the US, not having children at home, and cannabis non-use correlated with lower perceived cannabis vs. alcohol DUI risk. Lower perceived cannabis vs. alcohol DUI risk correlated with cannabis-only and alcohol-cannabis (vs. no) RDD, and with alcohol-cannabis (vs. cannabis-only) RDD. Alcohol use correlated with alcohol-only (vs. no) RDD and alcohol-cannabis (vs. cannabis-only) RDD. Cannabis use correlated with cannabis-only and alcohol-cannabis (vs. no) RDD, and with alcohol-cannabis (vs. alcohol-only) RDD. Being from the US correlated with alcohol-only (vs. alcohol-cannabis and none) RDD and cannabis-only (vs. alcohol-cannabis) RDD; being from Israel correlated with alcohol-cannabis (vs. no) RDD. Qualitative data indicated most participants perceived greater risk of DUI of alcohol vs. cannabis and desired more effective DUI-related prevention and regulatory efforts.

CONCLUSIONS

Prevention interventions targeting DUI- and RDD-related risk perceptions are needed, particularly for high-risk populations.

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.

Daily level predictors of impaired driving behaviors in young adults: Protocol design for utilizing daily assessments

Background

Motor vehicle crashes remain a leading cause of death among young adults (ages 18–25) in the United States. Many drivers implicated in these crashes are under the influence of alcohol, cannabis, or the simultaneous use of alcohol and cannabis. Extremely limited research has assessed impaired driving behaviors and their predictors at the daily level. Perceived norms and motives to use substances have empirical support suggesting they may impact impaired driving-related behavior. Novel approaches to assess these associations at the daily level are needed and may inform future intervention and prevention programs.

Objective

The goal of the current study is to utilize electronic daily assessments to assess driving under the influence of alcohol, cannabis, or simultaneous use and riding with a driver impaired by these substances to assess variability and predictors of these impaired driving-related behaviors at the daily level. This present manuscript details a protocol, measures, and a plan of analyses to assess how within-person differences in perceived norms and motives to use are associated with the likelihood of engaging in impaired driving-related behaviors.

Methods

Participants include young adults in Washington State who report simultaneous use in the past month and either driving under the influence of alcohol, cannabis, or simultaneous use, or riding with a driver under the influence of both substances in the past 6 months. Individuals who verify their identity and meet eligibility requirements will complete a baseline assessment after which they will be scheduled for training on the daily assessment procedure via Zoom. Next, they will be invited to complete daily surveys on Thursday, Friday, Saturday, and Sunday every other week for 6 months and a 6-month follow up assessment. Analyses will utilize multilevel models with days nested within individuals.

Results

The study is currently recruiting participants. A total of 192 participants have been recruited and 100 have completed the study protocol. Data collection is expected to be completed in Fall 2022.

Conclusions

This study utilizes a novel design to assess impaired driving and predictors at the daily level among young adults at high risk of impaired driving-related behaviors. Findings will provide unique data that will shape the knowledge base in the field of social science and public health substance use research and that may be helpful for future prevention and intervention efforts on impaired driving.

Typologies of Canadian young adults who drive after cannabis use: A two-step cluster analysis

Young adults that drive after cannabis use (DACU) may not share all the same characteristics. This study aimed to identify typologies of Canadians who engage in DACU. About 910 cannabis users with a driver's license (17-35 years old) who have engaged in DACU completed an online questionnaire. Two-step cluster analysis identified four subgroups, based on driving-related behaviors, cannabis use and related problems, and psychological distress. Complementary comparative analysis among the identified subgroups was performed as external validation. The identified subgroups were: (1) frequent cannabis users who regularly DACU; (2) individuals with generalized deviance with diverse risky road behaviors and high levels of psychological distress; (3) alcohol and drug-impaired drivers who were also heavy frequent drinkers; and (4) well-adjusted youths with mild depressive-anxious symptoms. Individuals who engaged in DACU were not a homogenous group. When required, prevention and treatment need to be tailored according to the different profiles.

Driving After Cannabis Use Among Young Adults in Michigan

Introduction: Driving after cannabis use is associated with a number of risks. Examination of driving after cannabis use among young adults is particularly important, as young adults have the highest rates of cannabis use and among the highest rates of traffic crashes. The current study examines rates and correlates of driving after cannabis use among young adults (aged 18-25) who reported past month cannabis use. Methods: Participants were from Michigan and recruited through paid Facebook and Instagram advertisements between February and March 2018 (n=461). Results: Nearly a third (31.9%) of the sample reported driving after cannabis use in the past month. Young adults who were employed (aOR=1.872, p=0.045), had medical cannabis cards (aOR=2.877, p<0.001), endorsed coping reasons for use (aOR=2.992, p=0.007), and endorsed social/recreational reasons for use (aOR=1.861, p=0.034) had greater odds of driving after cannabis use. Students had lower odds of driving after use (aOR=0.573, p=0.011). Conclusions: Employment and having a medical cannabis card may be important risk markers for identifying individuals more likely to drive after use of cannabis. Prevention efforts could provide psychoeducation at dispensaries to individuals with medical cannabis cards about the risks of driving after use. Coping motives for cannabis use may also be useful in identifying young adults at the greatest risk of driving after use of cannabis.

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.

Prevalence and Correlates of Driving Under the Influence of Cannabis in the U.S

INTRODUCTION

As cannabis use rises among adults in the U.S., driving under the influence of cannabis represents a public health concern.

METHODS

In 2020, public-use data from the National Survey on Drug Use and Health were examined, using an analytic sample of 128,205 adults interviewed between 2016 and 2018. The annual prevalence of driving under the influence of cannabis was computed overall, by state, by demographic group, and among cannabis users. Demographic, psychosocial, and behavioral correlates of driving under the influence were tested by multivariate logistic regression.

RESULTS

The self-reported annual prevalence of driving under the influence of cannabis was 4.5% (95% CI=4.3, 4.6) among U.S. adults, ranging from 3.0% (Texas) to 8.4% (Oregon) in individual U.S. states. Among cannabis users, 29.5% (95% CI=28.6, 30.3) reported driving under the influence of cannabis; the predicted probabilities of driving under the influence of cannabis were highest for those with more frequent use, with daily cannabis users evidencing a 57% predicted probability. Among individuals with symptoms suggestive of a cannabis use disorder, the prevalence of driving under the influence of cannabis was 63.8% (95% CI=60.8, 66.6). Among cannabis users, those reporting driving under the influence of cannabis had higher odds of driving under the influence of other illicit substances, using other illicit drugs, taking part in illegal behavior, and suffering from mental distress, after adjusting for demographic characteristics and psychosocial/behavioral correlates.

CONCLUSIONS

Findings suggest that prevention efforts should focus on frequent and problem cannabis users and should include content related to other illicit drug use and other drug-impaired driving.

Sex differences in driving under the influence of cannabis: The role of medical and recreational cannabis use

BACKGROUND

Existing evidence suggest that cannabis may impair driving and is the most prevalent drug identified in drivers. Males exhibit an excess risk for driving under the influence of drugs or alcohol compared to females. We assessed sex differences in the association between the reason for cannabis use (medical, recreational, or both) and driving under the influence of cannabis (DUIC).

METHODS

A sample of 17,405 past 12-month cannabis users (18 + years old) were analyzed from the 2016-17 National Survey on Drug Use and Health. Multivariable logistic regression was used to assess the interaction of sex and reason for cannabis use on DUIC using predicted probabilities.

RESULTS

Among cannabis users in the sample, 88.1% used for recreational reasons, 7.8% used for medical reasons, and 4.1% used for medical and recreational reasons. The probability of DUIC was as low as 20% among female medical only users, and as high as 40% among male combined medical and recreational users. Females showed more similar probabilities of DUIC across reasons of use (range 20% to 25%s) than males (range 28% to 40%). The difference in the probability of DUIC between combined medical and recreational users and recreational only users was significantly greater among males than among females (Δ 0.1, p < 0.05).

CONCLUSIONS

The observed effects of sex and reasons for cannabis use on DUIC suggests a need for targeted educational interventions, particularly among males reporting combined medical and recreational marijuana use.

Perceived safety of cannabis intoxication predicts frequency of driving while intoxicated

Driving under the influence of cannabis (DUIC) is a public health concern, and data are needed to develop screening and prevention tools. Measuring the level of intoxication that cannabis users perceive as safe for driving could help stratify DUIC risk. This study tested whether intoxication levels perceived as safe for driving predicted past-month DUIC frequency. Online survey data were collected in 2017 from a national sample of n = 3010 past-month cannabis users with lifetime DUIC (age 18+). Respondents indicated past-month DUIC frequency, typical cannabis intoxication level (1-10 scale), and cannabis intoxication level perceived as safe for driving (0-10 scale). Approximately 24%, 38%, 13%, and 24% of respondents engaged in DUIC on 0, 1-9, 10-19, and 20-30 days respectively in the past month. Among these four DUIC frequency groups, median typical intoxication varied little (5-6), but median intoxication perceived as safe for driving varied widely (3-8). Higher intoxication levels perceived as safe for driving corresponded to frequent DUIC (Spearman's rho: 0.46). For each unit increase in intoxication level perceived as safe for driving, the odds of past-month DUIC increased 18% to 68% (multinomial logistic regression odds ratio - MOR1-9 days: 1.18, 95% CI: 1.13-1.23; MOR10-19 days: 1.40, 95% CI: 1.30-1.50; MOR20-30 days: 1.68, 95% CI: 1.57-1.80). In this targeted sample of past-month cannabis users, DUIC frequency varied widely, but daily/near-daily DUIC was common (24%). Measuring intoxication levels perceived as safe for driving permits delineation of past-month DUIC frequency. This metric has potential as a component of public health prevention tools.