The potential for dementia prevention in Brazil: a population attributable fraction calculation for 14 modifiable risk factors.
Level 3 - non-randomized controlled study
Population-based cross-sectional epidemiological modeling using cohort prevalence data
PubMed 40823285 · doi:10.1016/j.lana.2025.101209
What was done
Researchers calculated the population attributable fraction (PAF) for 14 modifiable dementia risk factors using data from 9,949 participants aged 50 years or older from the nationally representative Brazilian Longitudinal Study of Aging (ELSI-Brazil, wave 2, 2019–2021). Principal component analysis accounted for risk factor overlap, and relative risks were obtained from the 2024 Lancet Commission update. Disparities were evaluated across sex, race, and geographic macro-regions.
What was found
The combined PAF for all 14 modifiable risk factors was 59.5% (95% CI = 58.5–60.5). The leading contributors were less education (9.5%, 95% CI = 8.9–10.1), untreated visual loss (9.2%, 95% CI = 8.6–9.8), and midlife depression (6.3%, 95% CI = 5.8–6.8). The PAF was higher in women (61.1%, 95% CI = 59.9–62.4) than in men (58.2%, 95% CI = 56.7–59.8), while estimates were comparable across racial groups and Brazilian regions.
Why it matters
This study provides the first Brazil-specific estimates using the updated 14-factor framework, demonstrating that nearly 60% of dementia cases in Brazil are potentially preventable, with education and vision care representing major targets for public health intervention.
Limits
The findings derive from theoretical population attributable fraction modeling, which assumes causal relationships and applies external meta-analytic relative risks to national prevalence data. Risk factors were assessed at a single wave rather than continuously across the life course.