Iceland has witnessed a dramatic decline in adolescent substance use that may be partly the result of efforts related to the Icelandic prevention model (IPM). We sought to test risk and protective factor assumptions of the IPM using a prospective cohort study with 12 months separating baseline from follow-up. Participants were students in grades 8 and 9 in the national Icelandic school system enrolled in the spring of 2018 and 2019 (N=2165). Participants self-reported their experiences of cigarette smoking, alcohol consumption, and cannabis use and seven risk and protective factors. Analyses were conducted with generalized linear modeling with extension to general estimating equations with correlated outcomes data. Both individual main-effects models and collective models including all main-effects were tested. Out of 28 individual main-effects models, 23 produced findings consistent with study premises (P<0.05). Multiple main-effects models largely sustained the findings of the individual main-effects models. Findings support the assumption that the risk and protective factors commonly emphasized in the IPM are associated with the four different substance use outcomes in the hypothesized direction. Communities that plan to implement the IPM among adolescents might consider these factors in their work.

中文翻译：

---

在冰岛青少年吸毒预防模型中测试风险和保护因素假设

冰岛见证了青少年药物使用的急剧下降，这可能部分是与冰岛预防模式 (IPM) 相关努力的结果。我们试图使用一项前瞻性队列研究来测试 IPM 的风险和保护因素假设，该研究将基线与随访间隔 12 个月。参与者是2018年和2019年春季入学的冰岛国家学校系统的8年级和9年级学生（N=2165）。参与者自我报告了他们吸烟、饮酒和使用大麻的经历以及七项风险和保护因素。使用广义线性模型进行分析，并扩展到具有相关结果数据的一般估计方程。测试了个体主效应模型和包含所有主效应的集体模型。在 28 个单独的主效应模型中，23 个产生了与研究前提一致的结果（P<0.05）。多个主效应模型在很大程度上支持了单个主效应模型的发现。调查结果支持这样一个假设，即 IPM 中通常强调的风险和保护因素与假设方向上的四种不同的物质使用结果相关。计划在青少年中实施 IPM 的社区可能会在他们的工作中考虑这些因素。