ABC Dementia Scale Classifies Alzheimer's Disease Patients into Subgroups Characterized by Activities of Daily Living, Behavioral and Psychological Symptoms of Dementia, and Cognitive Function.

Kenji Wada-Isoe,Yu Nakamura,Takahiro Mori,Masahiro Akishita,On Behalf Of The Abc Dementia Scale Research Group ,Takashi Kikuchi,Yumi Umeda-Kameyama

doi:10.3233/jad-190767

Abstract

The course of Alzheimer’s disease (AD) varies between individuals, and the relationship between cognitive and functional decline and the deterioration of behavioral and psychological symptoms of dementia (BPSD) is still poorly understood. Until recently, it was challenging to monitor subsequent changes in these symptoms because there was no single composite scale available that could simultaneously evaluate activities of daily living (ADL), BPSD, and cognitive function (CF) states. The present authors developed a new, brief assessment scale, the “ABC Dementia Scale” (ABC-DS), which is based on item response theory and facilitates concurrent measurement of ADL, BPSD, and CF states. We previously presented the reliability, construct validity, concurrent validity, and responsiveness of the ABC-DS. We obtained the evidence through three clinical trials featuring 1,400 subjects in total. In the present study, we performed a secondary analysis of the data obtained in the previous study. We conducted hierarchical cluster analyses that allowed us to classify 197 AD patients in terms of similarities regarding ADL, BPSD, and CF domain scores, as measured by the ABC-DS. Consequently, the scale identified subgroups of patients with global clinical dementia ratings of 1, 2, and 3. Considering our results in conjunction with the clinical experiences of the AD expert among the present authors regarding longitudinal changes in ADL, BPSD, and CF, we were able to propose potential progression pathways of AD in the form of a hypothetical roadmap.

Highlights

Patients with Alzheimer’s disease (AD) are very heterogeneous regarding their profiles of activities of daily living (ADL), their behavioral and psychological symptoms of dementia (BPSD), and their cognitive function (CF).K
Previous researchers classified subtypes of AD using various methods such as clinical subtypes defined by diagnostic criteria [1,2,3,4,5]; atrophy subtypes assessed using magnetic resonance imaging [6,7,8,9,10,11]; etiological subtypes or molecular subtypes characterized by pathological levels of cerebrospinal fluid A␤1-42, total tau, and phosphorylated tau [12, 13]; and subtypes based on statistical analyses, such as latent class analysis of Mini-Mental Examination (MMSE) scores [14] and principal component analysis and cluster analysis of the distribution and abundance of senile plaques and neurofibrillary tangles in the brain [15, 16]
CF score did not hit a floor at the early stages of AD, there is variability of the score at Clinical Dementia Rating (CDR) 0/0.5; CF rapidly declined at CDR 3

Summary

Introduction

Patients with Alzheimer’s disease (AD) are very heterogeneous regarding their profiles of activities of daily living (ADL), their behavioral and psychological symptoms of dementia (BPSD), and their cognitive function (CF). K. Wada-Isoe et al / ABC-DS classifies AD patients into subgroups. Staging using assessment scales is another method of understanding AD pathology [17, 18] Identifying subtypes through these methods may successfully uncover some aspects of AD and help categorize their severity. Such approaches do not provide enough information regarding the heterogeneity of changes in ADL, BPSD, and CF as the disease progresses because these approaches do not focus on the combined changes in ADL, BPSD, and CF

Methods

Results

Discussion

Conclusion