BACKGROUND As a consequence of biological, psychological and social changes during puberty, youth is a period characterized by impulsiveness and risk-taking. Members of this population often feel invulnerable and have a strong motivation to explore their identity. A good level of knowledge is necessary to allow young people to experience their sexuality in a healthy way, without associated risks. In our environment there is currently no valid Spanish-language tool to measure the level of knowledge about sexuality and contraception. This study sought to develop and test the psychometric properties of a new sexuality and contraception knowledge instrument. METHODS This is a cross-sectional study to validate the sexuality and contraception knowledge instrument. The validation process followed four phases: (1) development of the instrument, (2) content validation by an expert panel, (3) pilot test and (4) psychometric analysis of the instrument using item response theory according to the Rasch model. The validation process took place from September 2017 to February 2018. RESULTS The sample included 387 students enrolled at the Nursing and Law degrees from the University of Jaen. The final instrument was made up of 15 items. All of the items presented good adaptation values with respect to the model. The scale showed good fit and reliability: 0.99 for items and 0.74 for people. The temporal stability of the scale was calculated using test-retest, obtaining a value of 0.81 (CI 0.692-0.888). The construct validity showed the one-dimensionality of the construct, while the discriminant validity obtained good results, so the scale appears to be able to differentiate between participants with low or high levels of knowledge. CONCLUSION The results suggest the Sexuality and Contraception Knowledge Instrument is psychometrically valid and reliable for measuring the knowledge level concerning sexuality and contraceptive methods in young university students.

中文翻译：

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大学生中的性和避孕知识：使用项目反应理论的仪器开发和心理计量分析。

背景技术由于青春期期间的生物学，心理和社会变化，青年时期是一个以冲动和冒险为特征的时期。该人群的成员经常感到无敌，并具有强烈​​的动力去探索自己的身份。必须具备足够的知识水平，才能使年轻人以健康的方式体验其性生活，而没有相关的风险。在我们的环境中，目前没有有效的西班牙语工具来衡量有关性和避孕的知识水平。这项研究试图开发和测试一种新的性行为和避孕知识工具的心理测量特性。方法这是一项横断面研究，旨在验证性和避孕知识工具。验证过程分为四个阶段：（1）仪器的开发，（2）由专家小组进行内容验证，（3）试行测试，以及（4）根据项目表述理论根据Rasch模型对仪器进行心理分析。验证过程于2017年9月至2018年2月进行。结果样本包括来自哈恩大学护理和法律学位的387名学生。最终乐器由15个项目组成。所有项目都相对于模型具有良好的适应性值。量表显示出良好的拟合度和可靠性：项为0.99，人员为0.74。使用重新测试计算量表的时间稳定性，得出的值为0.81（CI 0.692-0.888）。构造效度显示了构造的一维性，而判别效度获得了良好的结果，因此该量表似乎能够区分知识水平低或高的参与者。结论结果表明，性行为和避孕知识工具在心理学上是有效的，可用于测量年轻大学生有关性行为和避孕方法的知识水平。