Psychometric properties of the French and English short form of the Protective Behavioural Strategies for Marijuana Scale in Canadian university students

BACKGROUND: The Protective Behavioural Strategies for Marijuana (PBSM-17) scale serves to identify and measure strategies employed by young adults before, during or after cannabis use. After the adaptation and translation of the PBSM-17 into French, a methodological study was conducted to evaluate the psychometric properties of this French version (FV) and of the original English version (EV) in a sample of bilingual Canadian university students. METHODS: A total of 211 cannabis users (mean age=22.1 years) completed a sociodemographic questionnaire, a question on frequency of cannabis use (four categories: 1–3 times a month, once a week, more than once a week, everyday) and both versions (FV and EV) of the PBSM-17. RESULTS: Both versions had similar internal reliability (α=0.91; α=0.88). The one-factor solution explained 36.46% of the variance for the FV and 42.26% for the EV. As hypothesised, greater use of protective behavioural strategies was related to lower frequency of cannabis use. One-way ANOVA test results revealed a statistically significant difference in use of strategies by frequency of cannabis use for both the FV (F(3, 207)=27.38, p<0.001) and EV (F(3, 207)=29.32, p<0.001). Post hoc comparisons showed that everyday users employed fewer strategies on average than lower-frequency users. CONCLUSION: The FV and EV of the PBSM-17 demonstrated satisfactory psychometric properties. The proposed FV of the PBSM-17 is a reliable instrument that could be used for research and clinical purposes. Protective behavioural strategies can serve as indicator of lower-risk cannabis use and could be targeted in prevention interventions.