Mantente Real (keepin' it REAL) in Mexico: Gender Differences in Effects of a Culturally Adapted Substance Use Prevention Program for Middle Schools

Background and Purpose: Despite increasing youth substance use rates and a disappearing gender gap in use, Mexico lacks school-based universal prevention programs that are culturally grounded and evidence-based. Our bi-national research team addressed this gap by culturally adapting the keepin’ it REAL (kiR) prevention intervention, and testing it in an RCT in Mexico’s largest cities. kiR is a prevention program for middle school students shown to be efficacious and cost-effective in reducing substance use among multi-ethnic and Mexican American USA samples, and several Latin American countries. The cultural program adaptation updated kiR’s core prevention elements and accompanying videos to address gender differences in exposure to substances in Mexico (e.g., sources of offers) and how substance use is connected to violence. This presentation reports tests of gender differences in intervention effects on substance use, drug resistance strategies, and violence.

Methods: Local research teams in Mexico City, Guadalajara and Monterrey recruited a probability sample of 12 public middle schools from each city, stratified by whether they met for morning or afternoon classes. We randomized schools to three conditions: Culturally adapted kiR (kiR-A), Original kiR translated into Spanish (kiR-O), and a treatment as usual Control condition. Regular teachers were trained to implement the manualized kiR-A and kiR-O curricula to their students over a 3-4 month period. Consented students in 7^th grade completed pretest and posttest questionnaires in the 2017-18 school year (pretest n=5,523). We tested the relative effectiveness of kiR-A versus both kiR-O and Controls with baseline adjusted regression models using FIML estimation to adjust for attrition (24%), accounting for school-level random effects (clustering). We estimated models separately by gender group, tested for significant gender differences in intervention effects using interactions, and also investigated whether intervention effects varied by the level of use of substances at pretest (risk moderation).

Results: Risk moderation interactions showed that females already using substances experienced relatively greater efficacy of kiR-A in reducing overall alcohol use, binge drinking and hard drug use. Males already experimenting with substances reported greater efficacy of kiR-A in constraining intoxication and cigarette use. Both males and females in kiR-A reported relatively more use of the central kiR drug resistance strategies from pretest to post-test (Explain why you decline a drug offer, Leave the situation, Avoid drug offers) as well as related alternatives commonly used in Mexico (Change the subject, make up an Excuse, Ignore the offer). Female and male kiR-A students reported an expanding repertoire of different drug resistance skills. kiR-A female and male students reported relative declines in violence victimization and perpetrating bullying, while kiR-A females reported less criminal violence.

Conclusions and Implications: Although there were some gender differences in the type of substance use impacted by the intervention, the culturally adapted version of kiR for Mexico produced desired effects on substance use, use of effective drug resistance strategies, and violence for both females and males. The cultural grounding of the intervention enhanced outcomes compared to the original version, showed applicability to both genders, and extended desired effects to the prevention of violence.