Huong Thu Vu, Hung Trong Nguyen, Anh Trung Nguyen
INTRODUCTION: Behavioral and psychological symptoms of dementia (BPSD) substantially contribute to functional decline and caregiver burden, yet culturally validated assessment tools remain limited in Vietnam. This study aimed to translate, culturally adapt, and assess the reliability and selected aspects of construct validity of the Vietnamese version of the Neuropsychiatric Inventory (V-NPI). METHODS: A cross-sectional study was conducted among 399 individuals with dementia and their caregivers in Hai Duong province. The V-NPI was administered alongside the Clinical Dementia Rating (CDR), Geriatric Depression Scale-15 (GDS-15), and Pittsburgh Sleep Quality Index (PSQI). Internal consistency, domain-level associations, and convergent and discriminant validity were assessed. RESULTS: The V-NPI demonstrated excellent internal consistency for both the severity (Cronbach's α = 0.91) and caregiver distress (Cronbach's α = 0.93) subscales. Domain-total correlations ranged from 0.44 to 0.64, indicating moderate internal convergence alongside meaningful heterogeneity across symptom domains. The depression domain showed a modest correlation with the GDS-15, and the night-time disturbances domain showed a weak but statistically significant correlation with the PSQI, supporting domain-level construct validity. Neuropsychiatric symptoms were highly prevalent, with night-time disturbances (71.2%), apathy/indifference (60.2%), and depression/dysphoria (59.6%) being the most frequently reported domains. CONCLUSION: The V-NPI appears to be a reliable and culturally appropriate instrument for assessing BPSD and caregiver distress among older adults with dementia in Vietnam, supporting its use in both clinical practice and research.