Evaluating the Protective Behavioral Strategies for Marijuana Scale (PBSM) short-form: Support for a two-factor structure and measurement invariance

Background: The present study evaluated the two-factor structure of the Protective Behavioral Strategies for Marijuana Scale (PBSM-SF) Short-Form, a 13-item measure of harm reduction behaviors related to cannabis use. Additionally, the PBSM was evaluated for measurement invariance based on sex and state cannabis legalization status.

Method: Participants were 1,048 college students (M_age = 19.00) reporting past 30-day cannabis use who primarily identified as White (75.5%) females (64.9%) recruited from 11 universities in 11 states representative of the United States. All participants provided demographic information and completed the PBSM-SF, Marijuana Use Grid assessing cannabis use frequency, Cannabis Use Disorder Identification Test-Revised assessing hazardous cannabis use, and Brief Marijuana Consequences Questionnaire evaluating negative consequences.

Results: The two-factor structure (i.e., Quantity and Context) of the PBSM-SF identified in Mian et al. (2021) was supported in the present study. Additionally, analyses demonstrated evidence of convergent and concurrent validity. Finally, the two-factor PBSM-SF demonstrated some degree of invariance by sex and state legalization status.

Conclusions: This study provides additional support for a two-factor model of PBSM-SF (i.e., Quantity and Context) that functions similarly for men and women college students as well as for students from states without legalized cannabis use and states with legalized cannabis use.