PROJECT SUMMARY/ABSTRACT
Driving after cannabis use (DACU) and driving after simultaneous alcohol and cannabis use represent
significant public health concerns. Rates of substance-impaired driving remain especially high among
emerging adults, and traffic accidents remain the leading cause of substance-related death among this
population. Brief Interventions (BIs) have been shown to reduce alcohol and cannabis use in emerging adults,
but to date no study has selected emerging adults on the basis of recent DACU and evaluated the efficacy of a
mobile-based substance-impaired driving BI. The present study will be the first to examine whether a mobile
phone-based substance-impaired driving BI, including interactive text-messaging, significantly decreases
DACU among emerging adult substance users compared to personalized feedback only. Research participants
will be 160 emerging adults (ages 18-25) who endorse driving after cannabis use and/or simultaneous
cannabis and alcohol use at least three times in the past 3 months. After completing baseline measures,
participants will be randomly assigned to receive either: a) substance-impaired driving personalized feedback
or b) a substance-impaired driving personalized feedback intervention plus interactive text messages.
Participants will complete comprehensive follow-ups 3- and 6-months post-intervention. Repeated measures
mixed modeling analyses will be used to determine whether the intervention significantly reduces DACU over
time. The project has two specific aims: 1) to evaluate a mobile phone-based substance-impaired driving
intervention in a randomized clinical trial, and 2) to determine whether cognitive factors identified in previous
research (e.g. perceived dangerousness and consequences, peer norms, expectancies) mediate intervention
outcomes. This study is innovative because it utilizes cutting-edge technology to deliver the entire intervention,
enabling the study to reach a large number of emerging adults in a short time period in a cost-effective
manner. The study is significant because it will contribute substantially to the substance-impaired driving
literature by identifying an intervention that can decrease substance-impaired driving among this high-risk
population. Additionally, this study will add to the rapidly growing technology-based intervention literature by
including mobile-based assessment, personalized feedback, and interactive text-messaging.
