Distribution of dementia severity and its functional correlates in community-dwelling older adults in Vietnam

BACKGROUND: Dementia is a growing public health concern in low- and middle-income countries (LMICs), where population aging is accelerating and evidence on disease severity remains limited. Vietnam is undergoing a rapid demographic transition, yet community-based evidence on dementia severity and its associated factors remains limited. METHODS: We conducted a cross-sectional study among 399 community-dwelling older adults (≥ 60 years) diagnosed with dementia in Hai Duong province, Vietnam. Dementia severity was assessed using the Clinical Dementia Rating (CDR) scale. Sociodemographic characteristics, physical activity, social engagement, depressive symptoms, neuropsychiatric symptoms, instrumental activities of daily living (IADL), and quality of life (EQ-5D-5L) were collected. Multivariable Poisson regression with robust variance was used to identify factors associated with dementia severity. RESULTS: Overall, 43.3% of participants had very mild and mild dementia, 30.1% had moderate dementia, and 26.6% had severe dementia. In univariate analyses, several sociodemographic, clinical, and behavioral factors were associated with severe dementia. However, after adjustment in the multivariable model, higher IADL scores (PR = 0.69; 95% CI: 0.56-0.84) and higher EQ-5D-5 L scores (PR = 0.92; 95% CI: 0.87-0.97 per 0.1 increase) were associated with a lower prevalence of severe dementia. CONCLUSION: This study provides community-based evidence on dementia severity among older adults in two districts of Hai Duong province, Vietnam, showing that more than half of participants had moderate-to-severe dementia. Functional independence and quality of life were associated with dementia severity and may represent important considerations when designing community-based dementia care strategies.