Institute of Medical Psychology and Medical Sociology, University Medical Center, Georg-August-University, Waldweg 37, Eingang A, 37073 Göttingen, Germany.
Institute of Medical Psychology and Medical Sociology, University Medical Center, Georg-August-University, Waldweg 37, Eingang A, 37073 Göttingen, Germany.
J Affect Disord. 2020 Feb 1;262:278-285. doi: 10.1016/j.jad.2019.10.035. Epub 2019 Oct 31.
The Patient Health Questionnaire-9 (PHQ-9) and the Generalized Anxiety Disorder (GAD-7) are two widely used instruments to screen patients for depression and anxiety. Comparable psychometric properties across different demographic and linguistic groups are necessary for multiple group comparison and international research on depression and anxiety.
We examine measurement invariance for the PHQ-9 and GAD-7 by: (a) the sex of the participants, (b) recruitment stratum, and (c) linguistic background. This study is based on non-randomized observational data six months after Traumatic Brain Injury (TBI) that were collected in 18 countries. We used multiple methods to detect Differential Item Functioning (DIF) including Item Response Theory, logistic regression, and the Mantel-Haenszel method.
At the 6-month post-injury, 2137 (738 [34.5%] women) participants completed the PHQ-9 and GAD-7 questionnaires: 885 [41.4%] patients were primarily admitted to the Intensive Care Unit (ICU), 805 [37.7%] were admitted to hospital ward, and 447 [20.9%] were evaluated in the Emergency Room and discharged. Results supported the invariance of PHQ-9 and GAD-7 across sex, patient strata and linguistic background. For different strata three PHQ-9 items and one GAD-7 item and for different linguistic groups only two GAD-7 items were flagged as showing differences in two out of four DIF tests. However, the magnitude of the DIF effect was negligible.
Despite high number of participants from ICU, patients have mostly mild TBI.
The findings demonstrate adequate psychometric properties for PHQ-9 and GAD-7, allowing direct multigroup comparison across sex, strata, and linguistic background.
患者健康问卷-9（PHQ-9）和广泛性焦虑症（GAD-7）是两种广泛用于筛查抑郁和焦虑患者的工具。在不同的人口统计学和语言群体中具有可比的心理测量特性，对于抑郁和焦虑的多组比较和国际研究是必要的。
我们通过以下方式检查 PHQ-9 和 GAD-7 的测量不变性：（a）参与者的性别，（b）招募层，和（c）语言背景。本研究基于颅脑损伤（TBI）后 6 个月的非随机观察性数据，这些数据是在 18 个国家收集的。我们使用多种方法来检测差异项目功能（DIF），包括项目反应理论、逻辑回归和 Mantel-Haenszel 方法。
在受伤后 6 个月时，2137 名（738 名[34.5%]女性）参与者完成了 PHQ-9 和 GAD-7 问卷：885 名[41.4%]患者主要被收入重症监护病房（ICU），805 名[37.7%]被收入病房，447 名[20.9%]在急诊室接受评估并出院。结果支持 PHQ-9 和 GAD-7 在性别、患者层和语言背景方面的不变性。对于不同的层有三个 PHQ-9 项目和一个 GAD-7 项目，对于不同的语言群体只有两个 GAD-7 项目在四个 DIF 测试中的两个测试中被标记为存在差异。然而，DIF 效应的幅度是微不足道的。
尽管 ICU 的参与者人数众多，但患者大多患有轻度 TBI。
这些发现表明 PHQ-9 和 GAD-7 具有足够的心理测量特性，允许在性别、层和语言背景方面进行直接的多组比较。
