Dementia risk reduction in China: Country-specific estimates of modifiable risk factors and population attributable fractions (PAFs).

INTRODUCTION

This study updates the population attributable fractions (PAFs) for 12 dementia risk factors in China, categorized as early life (education), midlife (obesity, hypertension, hearing loss, alcohol abuse, and traumatic brain injury), and later life (smoking, depression, social isolation, physical inactivity, air pollution, and diabetes).

METHOD

Relative risks and communality were calculated from literature. The prevalence was estimated using the latest Chinese Health and Retirement Longitudinal Study (CHARLS); other nationwide surveys substitute for lacking CHARLS factors.

RESULTS

The 12 risk factors account for 60.3% of dementia cases in China, including 14.0% in early life, 8.8% in midlife, and 37.5% in later life. Some factors (e.g., alcohol abuse, depression) showed wide confidence intervals indicating lack of evidence.

DISCUSSION

This study highlights the potential for dementia prevention in China, but more evidence is needed to estimate PAFs for specific risk factors (e.g., midlife factors).

HIGHLIGHTS

We used the most recent and nationally representative data to calculate population attributable fractions (PAFs) for dementia risk factors in China. In China, 60.3% of dementia cases were attributed to the 12 modifiable risk factors. Education was estimated to contribute 14.0% of dementia cases, and 37.5% was attributed to later-life lifestyle and health factors in China. It is necessary to consider incorporating China-specific factors and updating the PAF calculation method.