Wada-Isoe Kenji, Kikuchi Takashi, Umeda-Kameyama Yumi, Mori Takahiro, Akishita Masahiro, Nakamura Yu
Department of Dementia Research, Kawasaki Medical School, Kita-ku, Okayama, Japan.
Translational Research Informatics Center for Medical Innovation, Foundation for Biomedical Research and Innovation at Kobe, Chuo-ku Kobe, Hyogo, Japan.
J Alzheimers Dis Rep. 2020 May 20;4(1):151-159. doi: 10.3233/ADR-200172.
The Neuropsychiatric Inventory (NPI) is a widely used scale for the assessment of the behavioral and psychological symptoms of dementia (BPSD). We previously developed a novel dementia scale, the ABC dementia scale, in the TRIAD1412 trial and we compared the BPSD domain scores with the NPI scores. We, therefore, considered that we should investigate the quality of the NPI items using statistical approaches.
We investigated the statistical characteristics of the 12 questions or items in the Japanese version of the NPI using the item response theory. This theory is the standard approach for the development of a new assessment scale and we used it to evaluate the quality of the items in the NPI.
First, we performed factor analysis with Promax rotation to identify latent constructs in the data from 312 patients obtained in TRIAD1412. Second, following the result of the factor analysis, we divided the 12 items into domains and then investigated the characteristics of the sub-syndromes in each domain using item response category characteristic curves.
We found three latent constructs or domains: "hyperactivity," "psychosis and apathy," and "affect" (Cronbach's = 0.68) in the 12 items. Further, the items on euphoria, apathy, and appetite and eating abnormalities did not provide sufficient information to estimate BPSD severity.
The NPI item characteristics indicate that while the scale can distinguish whether patients have severe BPSD or not, it cannot estimate the degree of severity in a suspected case with a mild or unknown level of BPSD.
神经精神科问卷（NPI）是一种广泛用于评估痴呆行为和心理症状（BPSD）的量表。我们先前在TRIAD1412试验中开发了一种新型痴呆量表——ABC痴呆量表，并将BPSD领域得分与NPI得分进行了比较。因此，我们认为应该使用统计方法来研究NPI项目的质量。
我们使用项目反应理论研究了日语版NPI中12个问题或项目的统计特征。该理论是开发新评估量表的标准方法，我们用它来评估NPI中项目的质量。
首先，我们进行了Promax旋转因子分析，以识别在TRIAD1412中获得的312例患者数据中的潜在结构。其次，根据因子分析结果，我们将12个项目划分为不同领域，然后使用项目反应类别特征曲线研究每个领域中亚综合征的特征。
我们在12个项目中发现了三个潜在结构或领域：“多动”、“精神病和冷漠”以及“情感”（克朗巴哈系数=0.68）。此外，关于欣快、冷漠以及食欲和饮食异常的项目没有提供足够信息来估计BPSD的严重程度。
NPI项目特征表明，虽然该量表可以区分患者是否患有严重BPSD，但对于疑似轻度或BPSD程度未知的病例，它无法估计其严重程度。
