Objective: The Amsterdam Instrumental Activities of Daily Living Questionnaire (A-IADL-Q) is well validated and commonly used to assess difficulties in everyday functioning regarding dementia. To facilitate interpretation and clinical implementation across different European countries, we aim to provide normative data and a diagnostic cutoff for dementia. Methods: Cross-sectional data from Dutch Brain Research Registry (N = 1,064; mean (M) age = 62 ± 11 year; 69.5% female), European Medial Information Framework-Alzheimer’s Disease 90 + (N = 63; Mage = 92 ± 2 year; 52.4% female), and European Prevention of Alzheimer’s Dementia Longitudinal Cohort Study (N = 247; Mage = 63 ± 7 year; 72.1% female) were used. The generalized additive models for location, scale, and shape framework were used to obtain normative values (Z-scores). The beta distribution was applied, and combinations of age, sex, and educational attainment were modeled. The optimal cutoff for dementia was calculated using area under receiver operating curves (AUC-ROC) and Youden Index, using data from Amsterdam Dementia Cohort (N = 2,511, Mage = 64 ± 8 year, 44.4% female). Results: The best normative model accounted for a cubic-like decrease of IADL performance with age that was more pronounced in low compared to medium/high educational attainment. The cutoff for dementia was 1.85 standard deviation below the population mean (AUC = 0.97; 95% CI [0.97–0.98]). Conclusion: We provide regression-based norms for A-IADL-Q and a diagnostic cutoff for dementia, which help improve clinical assessment of IADL performance across European countries.

中文翻译：

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促进阿姆斯特丹日常生活工具活动问卷的临床使用：规范数据和诊断临界值

目的：阿姆斯特丹工具性日常生活问卷（A-IADL-Q）经过充分验证，通常用于评估与痴呆症相关的日常功能困难。为了促进欧洲不同国家的解释和临床实施，我们的目标是提供痴呆症的规范数据和诊断界限。方法：来自荷兰脑研究登记处的横截面数据（氮= 1,064；意思是 （中号) 年龄 = 62 ± 11 岁；69.5% 女性），欧洲媒体信息框架-阿尔茨海默病 90 +（氮= 63；法师 = 92 ± 2 年；52.4% 女性），以及欧洲预防阿尔茨海默氏症痴呆纵向队列研究（氮= 247；法师 = 63 ± 7 岁；72.1% 女性）被使用。使用位置、尺度和形状框架的广义加性模型来获得规范值（Z-分数）。应用贝塔分布，并对年龄、性别和教育程度的组合进行建模。使用来自阿姆斯特丹痴呆队列的数据，使用受试者工作曲线下面积 (AUC-ROC) 和约登指数计算痴呆的最佳截止值（氮= 2,511，法师 = 64 ± 8 岁，44.4% 女性）。结果：最佳规范模型解释了 IADL 表现随年龄呈三次方下降的情况，与中/高教育程度相比，低教育程度的情况更为明显。痴呆症的临界值比总体平均值低 1.85 个标准差（AUC = 0.97；95% CI [0.97–0.98]）。结论：我们提供基于回归的 A-IADL-Q 规范和痴呆症的诊断临界值，这有助于改善欧洲国家 IADL 表现的临床评估。