Department of Internal Medicine, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, CAN, Canada; Department of Community Health Sciences, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, CAN, Canada.
Department of Community Health Sciences, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, CAN, Canada.
J Psychosom Res. 2023 Sep;172:111415. doi: 10.1016/j.jpsychores.2023.111415. Epub 2023 Jun 15.
We tested for the presence of differential item functioning (DIF) in commonly used measures of depressive symptoms, in people with multiple sclerosis (MS) versus people with a psychiatric disorder without MS.
Participants included individuals with MS, or with a lifetime history of a depressive or anxiety disorder (Dep/Anx) but no immune-mediated inflammatory disease. Participants completed the Patient Health Questionnaire (PHQ-9), Hospital Anxiety and Depression Scale (HADS), and the Patient Reported Outcome Measurement Information System (PROMIS)-Depression. We assessed unidimensionality of the measures using factor analysis. We evaluated DIF using logistic regression, with and without adjustment for age, gender and body mass index (BMI).
We included 555 participants (MS: 252, Dep/Anx: 303). Factor analysis showed that each depression symptom measure had acceptable evidence of unidimensionality. In unadjusted analyses comparing the MS versus Dep/Anx groups we identified multiple items with evidence of DIF, but few items showed DIF effects that were large enough to be clinically meaningful. We observed non-uniform DIF for one PHQ-9 item, and three HADS-D items. We also observed DIF with respect to gender (one HADS-D item), and BMI (one PHQ-9 item). For the MS versus Dep/Anx groups, we no longer observed DIF post-adjustment for age, gender and BMI. On unadjusted and adjusted analyses, we did not observe DIF for any PROMIS-D item.
Our findings suggest that DIF exists for the PHQ-9 and HADS-D with respect to gender and BMI in clinical samples that include people with MS whereas DIF was not observed for the PROMIS-Depression scale.
我们在多发性硬化症（MS）患者与无 MS 的精神障碍性抑郁或焦虑障碍（Dep/Anx）病史患者中，测试了常用抑郁症状评估工具中是否存在项目功能差异（DIF）。
参与者包括 MS 患者或有抑郁或焦虑障碍（Dep/Anx）病史但无免疫介导炎症性疾病的患者。参与者完成了患者健康问卷（PHQ-9）、医院焦虑抑郁量表（HADS）和患者报告结局测量信息系统（PROMIS）抑郁量表。我们使用因子分析评估了这些工具的单维性。我们使用逻辑回归评估了 DIF，并在调整年龄、性别和体重指数（BMI）后进行了评估。
我们纳入了 555 名参与者（MS：252 名，Dep/Anx：303 名）。因子分析显示，每种抑郁症状评估工具都有可接受的单维性证据。在比较 MS 组与 Dep/Anx 组的未调整分析中，我们发现了多个具有 DIF 证据的项目，但很少有项目的 DIF 效应大到具有临床意义。我们观察到一个 PHQ-9 项目和三个 HADS-D 项目存在非均匀 DIF。我们还观察到了性别（一个 HADS-D 项目）和 BMI（一个 PHQ-9 项目）的 DIF。对于 MS 组与 Dep/Anx 组，在调整年龄、性别和 BMI 后，我们不再观察到 DIF。在未调整和调整分析中，我们均未观察到任何 PROMIS-Depression 项目的 DIF。
我们的研究结果表明，在包括 MS 患者在内的临床样本中，PHQ-9 和 HADS-D 存在与性别和 BMI 相关的 DIF，而 PROMIS-Depression 量表则不存在 DIF。
