Potentially modifiable dementia risk factors in all Australians and within population groups: an analysis using cross-sectional survey data.
Level 4 - case-series / case-control
Cross-sectional survey data and epidemiological population attributable fraction modeling
PubMed 37633680 · doi:10.1016/S2468-2667(23)00146-9
What was done
The authors calculated population attributable fractions (PAFs) adjusted for communality for 11 potentially modifiable dementia risk factors (low education, hearing loss, hypertension, obesity, smoking, depression, social isolation, physical inactivity, diabetes, alcohol excess, and air pollution) using cross-sectional data from four Australian Bureau of Statistics surveys (National Aboriginal and Torres Strait Islander Health Survey 2018–19, National Aboriginal and Torres Strait Islander Social Survey 2014–15, National Health Survey 2017–18, and General Social Survey 2014). Analyses evaluated Australians overall and across three population groups (First Nations, European, and Asian ancestries), with sensitivity analyses using proxy estimates for traumatic brain injury.
What was found
The 11 modifiable risk factors accounted for a theoretical PAF of 38.2% (95% CI 37.2–39.2) of dementia in Australia, which rose to 40.6% (95% CI 39.6–41.6) when including traumatic brain injury. PAFs varied across groups: 44.9% (95% CI 43.1–46.7) for First Nations Australians, 36.4% (95% CI 34.8–38.1) for European ancestry, and 33.6% (95% CI 30.1–37.2) for Asian ancestry. Physical inactivity (8.3%, 95% CI 7.5–9.2), hearing loss (7.0%, 95% CI 6.4–7.6), and obesity (6.6%, 95% CI 6.0–7.3) contributed roughly half of the total PAF across Australia and within all three ancestry groups.
Why it matters
Approximately 40% of dementia risk in Australia is theoretically attributable to modifiable factors, identifying specific lifestyle and health targets with the highest preventable fraction observed among First Nations Australians.
Limits
The analysis relies on cross-sectional survey data and epidemiological risk modeling rather than prospective longitudinal data. Sample size is not reported in the abstract. Traumatic brain injury data were unavailable nationally and required proxy estimates, and PAF calculations assume direct causal reversibility.
Cited by
- supports Modifiable lifestyle factors studied by Gill Livingston and colleagues, including poverty, childhood obesity, lower education, smoking, and excessive alcohol use, substantially influence the risk of developing dementia and Alzheimer's disease.