Abstract：
The psychometric process used to establish a relationship between the scores of two (or more) instruments is generically referred to as linking. When two instruments with the same content and statistical test specifications are linked, these instruments are said to be equated. Linking and equating procedures have long been used for practical benefit in educational testing. In recent years, health outcome researchers have increasingly applied linking techniques to patient-reported outcome (PRO) data. However, these applications have some noteworthy purposes and associated methodological questions. Purposes for linking health outcomes include the harmonization of data across studies or settings (enabling increased power in hypothesis testing), the aggregation of summed score data by means of score crosswalk tables, and score conversion in clinical settings where new instruments are introduced, but an interpretable connection to historical data is needed. When two PRO instruments are linked, assumptions for equating are typically not met and the extent to which those assumptions are violated becomes a decision point around how (and whether) to proceed with linking. We demonstrate multiple linking procedures-equipercentile, unidimensional IRT calibration, and calibrated projection-with the Patient-Reported Outcomes Measurement Information System Depression bank and the Patient Health Questionnaire-9. We validate this link across two samples and simulate different instrument correlation levels to provide guidance around which linking method is preferred. Finally, we discuss some remaining issues and directions for psychometric research in linking PRO instruments.
摘要：
用于建立两个(或更多)仪器的分数之间的关系的心理测量过程通常被称为链接。当具有相同内容和统计测试规范的两个仪器链接时，据说这些工具是等同的。链接和等同程序长期以来一直用于教育测试中的实际利益。近年来,健康结局研究人员越来越多地将链接技术应用于患者报告的结局（PRO）数据。然而,这些应用程序有一些值得注意的目的和相关的方法论问题。联系健康结果的目的包括协调研究或设置之间的数据（提高假设检验的能力），通过得分人行横道表汇总得分数据，在引入新仪器的临床环境中进行评分转换，但需要与历史数据的可解释连接。当两个PRO仪器连接时，通常不满足等同的假设，并且违反这些假设的程度成为如何（以及是否）进行链接的决策点。我们演示了多个链接程序-等百分位数，一维IRT校准，并使用患者报告的结果测量信息系统抑郁库和患者健康问卷-9校准投影。我们在两个样本中验证此链接，并模拟不同的仪器相关性级别，以提供有关首选链接方法的指导。最后,我们讨论了连接PRO工具的心理测量学研究的一些剩余问题和方向。
