Multilevel Predictors of Dementia Progression in Mild Cognitive Impairment: A Nationwide Case-Control Study

TL;DR

This study identifies personal and regional factors that influence dementia risk in people with mild cognitive impairment, suggesting combined clinical and community strategies for prevention.

Contribution

The study introduces a multilevel analysis combining individual and regional factors to predict dementia progression from MCI.

Findings

Individual risk factors include type 2 diabetes, depression, and Parkinson’s disease, while protective factors include dyslipidemia and physical activity.

Regionally, higher proportions of older adults increase dementia risk, but more elderly welfare facilities reduce it.

Integrated prevention strategies are needed to manage dementia risk in MCI patients.

Abstract

Mild cognitive impairment (MCI) represents an early stage of cognitive decline with a high risk of progression to dementia. Since no effective drug treatments exist for dementia, identifying modifiable risk factors is critical. This study examined individual- and regional-level factors associated with dementia diagnosis among patients with MCI.

A nested case-control study was conducted using nationwide health insurance claims data. The cohort included patients first diagnosed with MCI in 2017. Cases were individuals newly diagnosed with dementia in 2022 (n = 1,344), while controls were MCI patients without dementia (n = 5,376), matched 1:4 by age and sex. Individual-level variables included demographics, comorbidities, lifestyle, and medication use. Regional-level variables encompassed demographic aging indices, healthcare resources, and elderly welfare facilities. Conditional multivariate logistic regression was applied to individual-level factors, and multilevel logistic regression assessed regional-level influences.

Significant individual-level predictors of dementia included type 2 diabetes (OR = 1.14, 95%CI=1.00–1.31), depression (OR = 1.64, 95%CI=1.43–1.88), Parkinson’s disease (OR = 2.49, 95%CI=1.79–3.47), and hospitalization days (OR = 1.03, 95%CI=1.02–1.05). Protective factors included dyslipidemia (OR = 0.79, 95%CI=0.69–0.90), moderate physical activity (OR = 0.76, 95%CI=0.66–0.87), and adherence to dementia medications (OR = 0.71, 95%CI=0.58–0.87). At the regional level, a higher proportion of older adults increased dementia risk (OR = 1.01, 95%CI=1.00–1.02), while greater availability of elderly residential welfare facilities was protective (OR = 0.96, 95%CI=0.92–0.99).

Both individual and regional factors significantly influence dementia risk among MCI patients. These findings underscore the need for integrated prevention strategies that combine clinical risk management with community-level resource planning to delay dementia onset and reduce its societal burden.