Predictors of Nicotine and Cannabis Vaping Among Middle School Youth: A Routine Activity Theory Analysis

Background and Purpose:
Electronic vapor product (EVP) use remains a persistent concern among middle school youth, particularly as early initiation increases risk for long-term substance use and related harms. Although prior research has identified key predictors such as peer use and parental monitoring, fewer studies have examined how these factors operate together within a unified theoretical framework. Guided by Routine Activity Theory (RAT), which posits that risky behavior emerges from the convergence of the absence of a capable guardian, the presence of suitable targets, and a motivated actor, this study examines how parental monitoring, friends’ EVP use, and unstructured socializing (delinquency, school attachment, and binge drinking) influence youth EVP use. This study builds on prior research by applying a theory-driven, multi-model approach to understand how opportunity structures shape both e-cigarette and e-marijuana use in a diverse middle school sample, with the goal of informing prevention strategies.

Methods:
Data were drawn from 1,331 students enrolled in middle schools participating in a five-year substance use prevention program in a racially and ethnically diverse southeastern U.S. region. Measures included past 30-day e-cigarette and e-cannabis use (dichotomized), parental monitoring, friends’ EVP use, delinquency, school attachment, and binge drinking, assessed using validated survey items. Demographic variables included age, sex, race/ethnicity, parental education, family structure, and neighborhood safety. Four multivariable logistic regression models were estimated to examine predictors of posttest EVP use, with parallel models including and excluding pretest measures of each outcome. Intervention condition (LST vs. mindfulness comparison) was included as a covariate to account for potential program effects. Missing data were handled using multiple imputation.

Results:
The sample was racially diverse (47% Black, 22% White, 17% Latinx, Others <8%) and evenly split by sex (~50% female). Mean age was 12.6 years. Across models, friends’ EVP use and delinquency emerged as consistent and significant predictors of both outcomes. In fully adjusted models, friends’ EVP use (OR = 1.41) and delinquency (OR = 2.12) were significantly associated with higher odds of posttest e-cigarette use, while pretest e-cigarette use was the strongest predictor (OR = 7.26). Similarly, for e-cannabis use, friends’ EVP use (OR = 1.50) and delinquency (OR = 2.46) were significant predictors, with pretest e-cannabis use also strongly associated with posttest use (OR = 5.40). Parental monitoring, school attachment, and binge drinking were not consistently significant in fully adjusted models.

Conclusions and Implications:
Findings support Routine Activity Theory, highlighting peer accessibility and delinquent behavior contexts as key drivers of early adolescent EVP use. Youth embedded in peer networks where EVP use is present, and who engage in unstructured or delinquent activities, are at significantly greater risk. While guardianship factors such as parental monitoring are important, they may be insufficient in the presence of strong peer opportunity structures. Prevention efforts should prioritize reducing peer-based access, targeting high-risk social environments, and addressing delinquent behavior patterns. These findings underscore the importance of multi-level, theory-driven interventions and support the need for longitudinal research to further examine opportunity-based mechanisms influencing youth substance use.