OBJECTIVE To detect latent patterns of drug-related problems and their predictors among adolescents. METHODS A three-wave randomized controlled trial was conducted among 6,391 7th and 8th graders (51.02% girls) at 72 public schools in six Brazilian cities to evaluate the #Tamojunto school-based drug prevention program. Patterns of drug use and behavior problems were identified through latent class analysis, and logistic regression analyses were used to detect predictors of high-risk and low-risk groups. RESULTS Two groups were found that best explained the patterns of drug use and problem behaviors: high drug use/high problems and low drug use/low problems, representing 36.7 and 63.3% of the sample, respectively. No program effect was a determinant of the risk of belonging to these groups. Any reported problem behavior in the year preceding baseline assessment increased the likelihood of belonging to the high-risk group at the 21-month follow-up by 16 times. Alcohol use at baseline and female gender increased the likelihood of belonging to the high-risk group by 70%. CONCLUSION Previous behavior problems and alcohol use were the strongest predictors of higher risk, suggesting that effective earlier interventions and early screening for alcohol use and behavioral problems are needed at schools, particularly for girls. Clinical trial registration: Registro Brasileiro de Ensaios Clínicos (REBEC), RBR-4mnv5g.

中文翻译：

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预测青少年毒品相关问题的潜在类别：整群随机对照试验的二次分析

目的 检测青少年毒品相关问题的潜在模式及其预测因素。方法 在巴西 6 个城市的 72 所公立学校的 6,391 名 7 和 8 年级学生（51.02% 女生）中进行了一项三波随机对照试验，以评估#Tamojunto 基于学校的毒品预防计划。通过潜在类别分析确定药物使用和行为问题的模式，并使用逻辑回归分析检测高风险和低风险群体的预测因素。结果发现两组最能解释吸毒和问题行为的模式：高吸毒/高问题和低吸毒/低问题，分别占样本的36.7%和63.3%。没有计划效果是属于这些群体的风险的决定因素。在基线评估前一年报告的任何问题行为都会使 21 个月随访时属于高风险组的可能性增加 16 倍。基线和女性使用酒精会使属于高危组的可能性增加 70%。结论 以前的行为问题和饮酒是高风险的最强预测因子，这表明学校需要有效的早期干预和早期筛查酒精使用和行为问题，尤其是对女孩。临床试验注册：Registro Brasileiro de Ensaios Clínicos (REBEC)，RBR-4mnv5g。结论 以前的行为问题和饮酒是高风险的最强预测因子，这表明学校需要有效的早期干预和早期筛查酒精使用和行为问题，尤其是对女孩。临床试验注册：Registro Brasileiro de Ensaios Clínicos (REBEC)，RBR-4mnv5g。结论 以前的行为问题和饮酒是高风险的最强预测因子，这表明学校需要有效的早期干预和早期筛查酒精使用和行为问题，尤其是对女孩。临床试验注册：Registro Brasileiro de Ensaios Clínicos (REBEC)，RBR-4mnv5g。