Objective Characterize three functional living scales under item response theory and examine these scales for evidence of differential item functioning (DIF) by participant and/or informant ethnicity and education. Method Baseline data from 3155 participants [Mage = 70.59(9.55); Medu = 13.3(4.26); 61.72%female] enrolled in the Texas Alzheimer’s Research and Care Consortium with data from the Clinical Dementia Rating Scale (CDR; functional items), Physical Self-Maintenance Scale (PSMS), and Instrumental Activities of Daily Living Scale (IADL) were used. The sample was predominately white (93.94%) and 35.97% identified as Hispanic. Graded response models fit all three tests best. DIF was examined by iteratively dropping item-by-item constraints and then testing model fit. Results The CDR demonstrated overall good item functioning with clear separation between all of the rating categories for each item, while the PSMS and IADL did not, suggesting the item ratings should be reconsidered. DIF was observed by ethnicity (Hispanic v. non-Hispanic) and education (separated into low, average, high) for every item on all three scales (all ps ≤ .01 after adjustment for multiple observations). Hispanic ethnicity and higher education subjects were more likely to be rated as more impaired. Conclusions Results suggest these three commonly used functional scales have DIF depending on the ethnicity and education of the patient. This finding has implications for understanding functional change in certain populations, particularly the potential for mischaracterization of impairment in minority samples. The finding that individuals with higher education tended to be rated as more functionally impaired warrants further investigation.

中文翻译：

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A-08 在混合样本中使用项目反应理论建模检查三个功能性生活量表

目标根据项目反应理论描述三个功能性生活量表，并通过参与者和/或线人种族和教育检查这些量表以获取差异项目功能 (DIF) 的证据。方法 来自 3155 名参与者的基线数据 [Mage = 70.59(9.55); 美杜 = 13.3(4.26); 61.72% 的女性] 加入了德克萨斯阿尔茨海默氏症研究和护理联盟，其数据来自临床痴呆症评定量表（CDR；功能项目）、身体自我维护量表（PSMS）和日常生活工具活动量表（IADL）。样本主要是白人 (93.94%)，35.97% 被确定为西班牙裔。分级响应模型最适合所有三个测试。通过迭代地删除逐项约束然后测试模型拟合来检查 DIF。结果 CDR 展示了总体良好的项目功能，每个项目的所有评级类别之间都有明确的分离，而 PSMS 和 IADL 则没有，这表明应该重新考虑项目评级。DIF 是通过种族（西班牙裔与非西班牙裔）和教育（分为低、平均、高）来观察所有三个量表中的每个项目（在对多次观察进行调整后，所有 ps ≤ .01）。西班牙裔和高等教育科目更有可能被评为更弱。结论 结果表明，这三种常用的功能量表具有 DIF，具体取决于患者的种族和教育程度。这一发现对理解某些人群的功能变化具有重要意义，特别是对少数样本中损伤的错误表征的可能性。