The potential for dementia prevention in Japan: a population attributable fraction calculation for 14 modifiable risk factors and estimates of the impact of risk factor reductions.
Level 4 - case-series / case-control
Epidemiological risk modeling using secondary survey prevalence data and meta-analytic relative risks
PubMed 41647885 · doi:10.1016/j.lanwpc.2025.101792
What was done
Researchers calculated population attributable fractions (PAFs) and potential impact fractions (PIFs) for 14 potentially modifiable dementia risk factors in older Japanese adults. The analysis combined Japanese prevalence data from national surveys and cohort studies with relative risk estimates and communality weights from the 2024 Lancet Commission report. The authors modeled the theoretical reduction in national dementia cases resulting from hypothetical 10% and 20% reductions in risk factor prevalence.
What was found
The weighted combined PAF across all 14 risk factors was 38.9%. The three largest individual contributors were hearing loss (6.7%), physical inactivity (6.0%), and high LDL cholesterol (4.5%). Modeling indicated that reducing all 14 risk factors by 10% could prevent approximately 208,000 dementia cases, while a 20% reduction could prevent approximately 407,000 cases.
Why it matters
This study provides country-specific prevention targets for Japan's super-aging population, highlighting hearing care, exercise, and lipid management as high-priority public health targets.
Limits
The abstract does not report the specific underlying sample sizes or confidence intervals. The findings rely on epidemiological modeling that assumes causal relationships derived from international meta-analytic relative risks rather than prospective intervention trials in Japan.
Cited by
- partial The Lancet report identified 14 modifiable risk factors for dementia.