Emerging Adults Riding With Marijuana-, Alcohol-, or Illicit Drug-Impaired Peer and Older Drivers

A randomized pilot trial of a mobile phone-based brief intervention with personalized feedback and interactive text messaging to reduce driving after cannabis use and riding with a cannabis impaired driver

INTRODUCTION

Driving after cannabis use (DACU) and riding with a cannabis-impaired driver (RWCD) are national public health concerns. Though driving impairments and increased crash risk make DACU and RWCD two of the riskiest cannabis-related behaviors, many continue to drive after use and ride with others who are under the influence and do not view DACU or RWCD as dangerous. The current study examined the efficacy of an accessible, low-cost, mobile phone-based brief intervention aimed at reducing DACU and RWCD among college cannabis users in the context of a randomized three-group pilot trial.

METHOD

Participants were 97 college cannabis users (67.4 % women; average age = 21.34; 80.4 % Caucasian) who endorsed DACU at least three times in the past three months. After completing baseline measures, the study randomly assigned participants to one of three conditions: a) a substance impaired-driving personalized feedback plus MI-style interactive text messaging intervention (PF + MIT); b) a substance impaired-driving personalized feedback only intervention (PF); and c) a substance information control condition (IC). All conditions completed outcome measures three months postintervention.

RESULTS

Generalized linear mixed models (GLMM) analyses indicated that after controlling for sex, cannabis users in the PF + MIT condition significantly reduced DACU and RWCD over time compared to those in the IC condition.

CONCLUSIONS

These findings provide preliminary support for the short-term efficacy of a mobile phone-based intervention in decreasing DACU and RWCD among college cannabis users. Future research should determine whether these reductions in driving behaviors persist past three months.

Alcohol-related deaths among young passengers: An analysis of national alcohol-related fatal crashes

INTRODUCTION

There is consensus that riding with an impaired driver (RWI) constitutes a major threat to public health. The aim of this study was to characterize the factors contributing to the motor-vehicle deaths of 15-20 year-old (y/o) passengers that RWI with a peer.

METHOD

Secondary analyses of the 2010-2018 Fatality Analysis Reporting System. 5,673 passengers aged 15-20 y/o killed while riding in passenger cars with a driver aged 21 or older, 3,542 of these drivers also aged 15-20 y/o. Analyses were conducted between October 2019 and December 2020.

RESULTS

Sixty-three percent of the young passengers were killed while riding with a driver 15-20 y/o. Of these drivers, 26.8% had a blood alcohol concentration (BAC) >0.00 g/dL and 77.1% had a BAC ≥0.08 g/dL. Compared with those occurring during the day on weekdays, fatalities of young passengers who RWI with a peer driver with a BAC ≥ 0.08 g/dL often occurred on weekend nights (OR = 8.2) and weekday nights (OR = 5.2), and when the passenger and driver were both male (OR = 1.8). Race/ethnicity was not a significant contributor to RWI fatalities.

CONCLUSIONS

Most 15-20 y/o RWI fatalities occurred on weekends, at night, when the driver was a young peer with a high BAC, and the passenger and driver were male. The high prevalence of fatalities in these high-risk situations suggests that young driver-passenger dynamics may contribute to alcohol-related fatalities. Practical Applications: To curb RWI fatalities among underage passengers, countermeasures should focus not only on underage drinking drivers and riders, but also on drinking drivers of all ages. Prevention should increase focus on situations in which both the young passenger and young driver are males.

Intoxicated driving and riding with impaired drivers: Comparing days with alcohol, marijuana, and simultaneous use

BACKGROUND

Young adults who engage in simultaneous alcohol and marijuana (SAM) use may be more likely to engage in unsafe behaviors including riding with impaired drivers and driving after alcohol and/or marijuana use.

METHODS

Young adult SAM users (N = 408) self-reported their behavior for five 14-day bursts, yielding daily-level responses on a total of 14,675 substance use days. Adjusted odds ratios (AOR) estimated the likelihood of riding with an impaired driver and of driving after use on SAM use days compared to alcohol- or marijuana-only use days.

RESULTS

More frequent SAM users were more likely to ride with an impaired driver and to drive after use than less frequent SAM users (between-persons). On SAM use days, there were greater odds of riding with an impaired driver, compared to alcohol-only days (AOR = 1.28) and marijuana-only days (AOR = 2.22), and of driving after use, compared to marijuana-only days (AOR = 1.25). Driving after use was more likely on days with non-simultaneous alcohol and marijuana use compared to SAM use (AOR = 1.59).

CONCLUSIONS

Riding with an impaired driver is common among young adult substance users, and more likely following simultaneous use of alcohol and marijuana compared to other types of alcohol and marijuana use. Driving after use is more likely after SAM use than marijuana-only use days, but most likely on days when both alcohol and marijuana were used but not simultaneously. Future research on situation-level predictors of riding and driving-related risks among young adults is warranted.

Complexities of Young Driver Injury and Fatal Motor Vehicle Crashes

We offer a perspective on the literature discussing the importance of driving for youth, the complexities of learning to drive, and the risks of driving which lead to motor vehicle crashes (MVCs). Specifically, we discuss important underlying reasons why some adolescents and young adults may be more susceptible to engaging in driving behaviors which result in fatal MVCs; the leading cause of death among 15 to 20 y/o. Some of the factors known to lead to crash fatalities span the domains of cognitive development, distraction, alcohol/drug use, psychosocial development and peer influence, and young driver inexperience. While advancements in driver training, traffic safety legislation, vehicle safety engineering, and emergency/trauma care have helped reduce the prevalence of crashes, we suggest that natural brain maturation which occurs during adolescence and young adulthood may hold unique susceptibilities for young driver crashes. As such, we discuss the importance in using a multidisciplinary research approach, and specifically neuroscience methods, to develop a more compressive understanding of crash risk factors among young drivers. By using a multidisciplinary approach when studying young drivers, we can advance the injury and prevention science as well as inform relevant policies, innovative technologies, comprehensive training and intervention programs which will develop safer young drivers sooner.

Advancing the Health of Populations Across the Life Course: 50 Years of Discoveries in the Division of Intramural Population Health Research

In 2017, the Division of Intramural Population Health Research (DIPHR), within the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), reached a significant milestone: 50 years in existence. DIPHR celebrated this anniversary with a scientific program that reviewed past accomplishments and reflected on future directions in support of promoting the health of populations across the life course. Extending from the scientific program, the impetus of this article is to contribute to archiving and consolidating the legacy of intramural population health research at NICHD over the past 50 years. We present a brief history of the origin and evolution of intramural population health research at NICHD. Next, we conduct an empirical assessment of the scientific impact and evolving scope of this research over the past five decades and present specific key discoveries emerging from topics spanning the life course: (1) reproductive health, (2) the health of pregnant women and fetuses, (3) the health of children, and (4) associated methodologies. We also explore the Division's service to the profession in the form of mentorship of the next generation of scientists in population health research. Finally, we conclude with thoughts about future directions of population health research and reaffirm the DIPHR's commitment to promoting the health and well-being of the many populations we serve, both locally and globally.

Driving/riding after alcohol and marijuana use among young adults: Is residing with family protective?

Objective: Driving while impaired by alcohol or drugs increases the risk of motor vehicle fatalities, the leading cause of death among young adults. The current study documented the prevalence of driving after alcohol and marijuana use in the past 2 weeks as well as the prevalence of riding with a driver who had used each substance during that time frame. We tested whether young adults who lived with family members (i.e., their parents or their children) were less likely to engage in these behaviors. Methods: Participants aged 18-25 who resided in nonmetropolitan areas in the United States (N = 1,131; 55% female, M_age = 22.6) completed an online survey. Multivariate logistic regressions examined alcohol- and marijuana-related driving and riding behaviors adjusting for demographic factors. Interactions tested whether associations varied by gender. Results: In the 2 weeks prior to the survey, 17% of participants drove after drinking alcohol and 21% had ridden with a driver who had been drinking. The prevalence of driving after marijuana use was 11%, and 16% of the sample had ridden with a driver who had been using marijuana. Participants who lived with their parents were less likely to ride with a driver who had been using alcohol or marijuana (adjusted odds ratios [AORs] = 0.71 and 0.55, respectively). Living with parents was also associated negatively with driving after both substances, but these associations were no longer significant when controlling for substance use frequency and driving frequency. Surprisingly, the odds of driving after marijuana use were over 2 times larger for young adults who lived with their children. For women, but not men, residing with children decreased the odds of driving and riding after alcohol use. Conclusions: Living with parents protects against riding after substance use among young adults. Prevention programs should target young adults who live independently or those transitioning away from the parental home. Furthermore, given the higher rates of driving after marijuana use among young adult parents, this group should be educated about the risks associated with this behavior.

A Longitudinal Examination of Decisions to Ride and Decline Rides with Drinking Drivers

BACKGROUND

Riding with a drinking driver (RWDD) is a serious concern that leads to numerous preventable deaths every year. There is a significant gap in research on empirically tested predictors of RWDD that could be implemented in prevention efforts. College students are in need of such prevention efforts, as they have some of the highest rates of alcohol-related crash fatalities and may engage in RWDD more than their noncollege peers. This study utilized behavioral decision-making approach to examine predictors of RWDD and declining a ride from a drinking driver (Decline) in older college students.

METHODS

Students (n = 791) in their third year of college were enrolled from 3 large and diverse universities. Psychosocial (e.g., expectancies, norms) and decision-making variables (willingness to RWDD and intentions to use alternatives) were assessed in the fall of their third year. One year later, RWDD and Decline behaviors were assessed. Zero-inflated Poisson analyses were used to assess how decision-making variables predicted RWDD and Decline behavior. Associations between psychosocial and decision-making variables were also assessed.

RESULTS

Thirteen percent of students reported RWDD and ~28% reported Decline behavior. Willingness to RWDD and typical weekly drinking were both associated with increases in RWDD (odds ratio [OR] = 1.58 and 1.40, respectively), whereas intentions to use alternatives, sex, and ethnicity were not associated with RWDD. Only weekly drinking was associated with Decline, with an increase in drinking associated with increased Decline (OR = 1.48). All psychosocial variables were significantly associated with the decision-making variables except positive expectancies.

CONCLUSIONS

Results provide evidence that willingness to RWDD is a predictor of future RWDD, even if students intend to use safe alternatives. Future research is needed to better understand decision-making factors that influence Decline. Results also suggest prevention and interventions efforts, such as brief motivational intervention, Parent-Based Interventions, and normative feedback interventions could be adapted to reduce RWDD.