Functional–behavioral profiles and clinical characteristics among hospitalized patients with Alzheimer’s disease: a real-world clustering analysis

Abstract

Alzheimer’s disease (AD) exhibits substantial heterogeneity in functional impairment and behavioral symptoms beyond cognitive decline. However, clinically interpretable approaches for characterizing functional–behavioral heterogeneity in real-world inpatient settings remain limited. This retrospective cross-sectional study included 118 hospitalized patients with clinically diagnosed AD. Functional ability and behavioral symptoms were assessed using the Barthel Index (BI) and the Nurses’ Observation Scale for Inpatient Evaluation (NOSIE), respectively. Spearman correlation analysis and k-means clustering were performed to explore the relationship between functional and behavioral characteristics and identify exploratory functional–behavioral profiles. Functional ability showed a weak inverse correlation with behavioral symptom burden (Spearman ρ = −0.30), suggesting heterogeneous relationships between functional impairment and behavioral symptoms. Three exploratory functional–behavioral profiles were identified: Profile 1 characterized by severe functional impairment and increased psychomotor retardation; Profile 2 characterized by relatively preserved functional ability and lower behavioral symptom burden; and Profile 3 characterized by intermediate functional impairment with more prominent psychotic symptoms. Profiles differed significantly in specific functional domains (including feeding, toileting, and walking) and behavioral dimensions, whereas demographic characteristics and comorbidities showed no significant differences. Hospitalized patients with AD demonstrate heterogeneity in functional and behavioral characteristics. Exploratory functional–behavioral profiles may help organize this clinical heterogeneity and support individualized assessment and care planning. Further external and longitudinal validation is required to determine their stability and clinical relevance.