Methods: To test effectiveness, the research team relied heavily on a community partner to deliver the interventions under “real world” conditions in a large urban center in the USA with high numbers of immigrant families. Parent-adolescent dyads (N=532) from 19 middle schools were randomized into three intervention conditions: Parent-Youth (PY), Parent Only (PO) and Comntrol (C). Data were collected through four surveys: baseline (T1), 4 months (T2), 8 months (T3), and 20 months (T4). The interventions occurred between T1 and T2. Generalized estimating equations (GEE) were used to estimate the effectiveness of the interventions on the use of different substances. Multiple imputations were used to handle attrition and missing data. The final analytic sample included 508 youth.
Results: The results indicate that between T1 and T4, adolescents in the C condition had significantly higher probabilities of overall substance use, while adolescents in the PO condition had marginally lower probabilities of overall substance use between T2 and T4. Adolescents in the PY condition remained stable over time with no significant increases or decreases in substance use. At T4, adolescents in the PO condition were significantly less likely to report overall substance use compared to adolescents in the C condition. The same pattern of results were seen separately for alcohol use. There were no significant differences between the intervention groups over time in inhalant, cigarette, or marijuana use.
Discussion & implications: The parent only (PO) conditions yielded the strongest effects. This finding has important implications for prevention with this population. It highlights the importance of involving families in any prevention efforts for youth. Future research includes the replication and adaptation of the intervention in partnership with European countries with high numbers of immigrants. Additional implications for prevention and cultural adaptation science as well as translational research will be discussed.