Implementation fidelity of a Brazilian drug use prevention program and its effect among adolescents: a mixed-methods study

BACKGROUND: Based on the US DARE-kiR, a version of the Keepin’ it REAL program, the Drug and Violence Resistance Educational Program (PROERD) is the most widely implemented Brazilian prevention program. It originates from the translation of the DARE-kiR, a version of the Keepin’ it REAL program. Previous results suggest its inefficiency in preventing drug use among Brazilian adolescents. Since kiR fidelity can impact program outcomes, this mixed-methods study evaluates the PROERD implementation fidelity and its effects on preventing drug use among adolescents. METHODS: Data from two cluster randomized controlled trials (cRCTs) with 4,030 students from 30 public schools in São Paulo (1,727 fifth graders and 2,303 seventh graders), assessed at two-time points, were analyzed quantitatively. After implementing each lesson during the cRCT, 19 PROERD instructors answered fidelity forms. The effect of PROERD fidelity on alcohol, cigarettes, marijuana, inhalant, and cocaine use (the last two only among seventh graders) in the six months prior to follow-up assessment was analyzed by logistic regressions for fifth grade and mixed effect models for seventh graders. For qualitative analysis, semi-structured interviews were conducted with PROERD instructors and investigated by thematic analysis. RESULTS: Quantitative analysis showed that PROERD implementation fidelity had no impact on drug use among fifth and seventh graders. Conversely, the qualitative analysis revealed important aspects that may influence implementation fidelity and consequently program effectiveness, such as adaptations made by instructors, school infrastructure, among others, besides program application. CONCLUSION: PROERD requires cultural adaptation to improve its implementation in Brazilian public schools. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13011-022-00496-w.