Students who saw less risk in cannabis were far more likely to drive or ride high

Among Canadian high school students, those who perceived regular cannabis use as high-risk were 94% less likely to drive under the influence and 91% less likely to ride with an impaired driver.

Carpino, Melissa et al.·CMAJ open·2020·Moderate EvidenceCross-Sectional
RTHC-02453Cross SectionalModerate Evidence2020RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Cross-Sectional
Evidence
Moderate Evidence
Sample
N=12

What This Study Found

Greater perceived risk of regular cannabis use was associated with reduced driving under the influence (DUIC) and riding with a cannabis-impaired driver (RWCD) in a dose-response pattern. Students perceiving great risk had adjusted RR of 0.06 (95% CI: 0.04-0.10) for DUIC and 0.09 (95% CI: 0.07-0.12) for RWCD, compared to those perceiving no risk.

Key Numbers

Survey response rate: 76.2% (52,103 of 68,415 students grades 7-12). 14,520 in grades 11-12 analyzed. Great perceived risk vs. no risk: adjusted RR 0.06 for DUIC, 0.09 for RWCD. Associations consistent across sexes and urban/rural settings.

How They Did This

Cross-sectional analysis of 14,520 grade 11-12 students from the 2016-2017 Canadian Student Tobacco, Alcohol and Drugs Survey across 9 provinces. Multinomial logistic regression examined associations between perceived risk and cannabis-related driving behaviors.

Why This Research Matters

With cannabis legalization, understanding what drives risky driving decisions in young people can inform public health messaging and prevention campaigns.

The Bigger Picture

The strong dose-response relationship between risk perception and behavior suggests that changing how young people perceive cannabis-related driving risks could reduce dangerous driving decisions.

What This Study Doesn't Tell Us

Cross-sectional design; self-reported behaviors and perceptions; New Brunswick and territories excluded; risk perception and behavior measured at same time point so direction cannot be determined.

Questions This Raises

  • ?Can educational campaigns effectively shift risk perceptions?
  • ?Do these associations hold after legalization changes the cultural context?

Trust & Context

Key Stat:
Students seeing great risk were 94% less likely to drive under the influence of cannabis
Evidence Grade:
Large national survey with strong response rate, though cross-sectional design limits causal inference.
Study Age:
Published in 2020.
Original Title:
Cannabis-related driving and passenger behaviours among high school students: a cross-sectional study using survey data.
Published In:
CMAJ open, 8(4), E754-E761 (2020)
Database ID:
RTHC-02453

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

A snapshot of a population at one point in time.

What do these levels mean? →

Frequently Asked Questions

Were there differences between male and female students?

The associations between perceived risk and cannabis-related driving behaviors were consistent for both male and female students, as well as for those in urban and rural areas.

Could changing risk perceptions actually reduce impaired driving?

The strong dose-response pattern suggests perceptions matter, but the cross-sectional design means this study cannot prove that shifting perceptions would change behavior. Longitudinal studies and intervention trials are needed.

Read More on RethinkTHC

Cite This Study

RTHC-02453·https://rethinkthc.com/research/RTHC-02453

APA

Carpino, Melissa; Langille, Donald; Ilie, Gabriela; Asbridge, Mark. (2020). Cannabis-related driving and passenger behaviours among high school students: a cross-sectional study using survey data.. CMAJ open, 8(4), E754-E761. https://doi.org/10.9778/cmajo.20200081

MLA

Carpino, Melissa, et al. "Cannabis-related driving and passenger behaviours among high school students: a cross-sectional study using survey data.." CMAJ open, 2020. https://doi.org/10.9778/cmajo.20200081

RethinkTHC

RethinkTHC Research Database. "Cannabis-related driving and passenger behaviours among high..." RTHC-02453. Retrieved from https://rethinkthc.com/research/carpino-2020-cannabisrelated-driving-and-passenger

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.