An Interactive Personalized Feedback and Text-Messaging Intervention is Associated with Reductions in Substance-Impaired Driving

Background: Substance-impaired driving continues to be a national public health concern and data suggests that up to one-third of college students report driving after drinking and/or cannabis use in the past year. To date, little research has investigated whether brief, technology-based interventions can be used to reduce substance-impaired driving among young adults. Recent research indicates that interventions that incorporate personal contact lead to larger effect sizes than fully automated interventions. The present study compared an interactive text-messaging intervention to an automated text-messaging intervention in the context of a brief, mobile-phone based substance-impaired driving intervention. Method: Participants were recruited through the university’s subject pool (n = 46) and completed measures that assessed impaired driving at baseline and three-month follow-up. In order to be eligible, students had to be at least 18 years or older, have access to a motor vehicle, and report driving after drinking two or more drinks and/or driving after cannabis use at least three times in the past three months. Participants were randomly assigned into four conditions: personalized feedback plus text-messaging (n = 12), personalized feedback plus automated text messaging (n = 11), an active control condition- (substance use information, n = 12), and an assessment only control condition (n = 11). Results: Repeated measures ANOVAs were run to compare the number of times driving while impaired over time across conditions. Analyses revealed the personalized feedback plus text-messaging led to significantly greater reductions over time in the number of times driving while impaired compared to participants in the assessment-only condition (p = .022). Additionally, participants in the personalized feedback plus text-messaging condition reported a greater reduction over time in the number of times driving while impaired than those in the personalized feedback plus automated text messaging condition, though this difference was not significantly significant (p = .066). Surprisingly, the text-messaging conditions did not result in significantly greater reductions in substance-impaired driving compared to the active control condition (p = .227). Discussion: Overall, these findings provide preliminary support for the short-term efficacy of a mobile-delivered personalized feedback intervention with interactive text-messaging in reducing substance-impaired driving among young adults. Due to Covid-19, three-month follow-up data could not be collected from half of the originally enrolled sample, resulting in underpowered analyses. Additional data will be collected as part of this pilot trial in the coming year.