Objective: The Strengths and Difficulties Questionnaire (SDQ) is a widely used mental health screening instrument among children and adolescents and increasingly used by welfare professionals in Denmark. However, the psychometric properties of the SDQ-self report (SDQ-S) among vocational education and training (VET) students are unknown. We assess the structural validity, internal consistency reliability, and test-retest reliability of the Danish SDQ-S among these students.

Method: The SDQ-S was tested twice in a sample of VET students (sample N = 486; mean age = 17 years) with 10 to 14 days in-between. Using separate analyses for men (n = 371) and women (n = 115), structural validity was assessed using confirmatory factor analysis; internal consistency was assessed using composite reliability (CR); and test-retest reliability using Pearson’s correlation.

Results: Overall, the results provide inconsistent support for the five-factor first-order model, especially among males. CR was acceptable for all five scales except for Peer problems (among females and males) and Conduct (among males only). Test-retest reliability was satisfactory for all scales among females but for only two of the five scales (Conduct, Hyperactivity) among men.

Conclusion: Overall, the SDQ-S is a more valid and reliable instrument among females. Results suggest caution in using the SDQ-S among VET students, in particular males.

目标：优势和困难问卷 (SDQ) 是一种在儿童和青少年中广泛使用的心理健康筛查工具，并且越来越多地被丹麦的福利专业人员使用。然而，职业教育和培训 (VET) 学生的 SDQ-自我报告 (SDQ-S) 的心理测量特性尚不清楚。我们在这些学生中评估丹麦 SDQ-S 的结构效度、内部一致性信度和重测信度。

方法： SDQ-S 在 VET 学生样本（样本N = 486；平均年龄 = 17 岁）中进行了两次测试，中间间隔 10 至 14 天。对男性 ( n = 371) 和女性 ( n = 115)进行单独分析，使用验证性因素分析评估结构有效性；使用复合信度 (CR) 评估内部一致性；和使用 Pearson 相关性的重测信度。

结果：总体而言，结果为五因素一阶模型提供了不一致的支持，尤其是在男性中。除了同伴问题（女性和男性）和行为（仅限男性）之外，所有五个量表的 CR 都是可以接受的。女性的所有量表的重测信度都令人满意，但男性的五个量表（行为、多动）中只有两个量表令人满意。

结论：总体而言，SDQ-S 在女性中是一种更有效和可靠的工具。结果表明，在 VET 学生（尤其是男性）中使用 SDQ-S 时要谨慎。