Factor analysis of a short form of the Protective Behavioral Strategies for Marijuana scale

Objective: The Protective Behavioral Strategies for Marijuana Scale (PBSM), a 17-item scale targeting strategies for mitigating the negative consequences of cannabis use, highlights a range of behaviors that can reduce harm beyond straightforward decreases in quantity or frequency. The 17-item scale's factor structure remains under-examined but could reveal meaningful distinctions among strategies. This study aimed to confirm the factor structure of the short form of the PBSM. Methods: This study recruited cannabis-using undergraduates (N = 454, M_age = 19.6, 68.8% female, 39% White), who reported using cannabis approximately 2.3 days per week with mild cannabis-related consequences (CAPQ; M = 9.74). Results: A confirmatory factor analysis demonstrated poor fit for the one-factor model of the PBSM, prompting an exploratory factor analysis. Analyses revealed two internally reliable factors: a “Quantity” factor, strategies specific to mitigating overuse and limiting amounts consumed and an “Context” factor loosely related to troubles with others. This two-factor model accounted for over half of the total variance; invariance testing indicated reduced fit as models became more restrictive. Though each of the factors covaried negatively with both days of use and problems, Context had a stronger relation to both variables compared to Quantity. Only Context predicted fewer cannabis problems and use. Conclusions: The two-factor solution suggests further work on the psychometric properties of the scale could provide heuristic information to allow for more nuanced approaches in clinical and research settings. Theoretically, each factor might have novel links to some constructs but not others in ways that could assist harm-reduction strategies and treatment.