Modelling the impact of modifying lifestyle risk factors on dementia prevalence in Australian population aged 45 years and over, 2006–2051

Aim: To model impact of modifiable risk behaviour on dementia prevalence among the Australian population aged 45 years and over.

Methods: A group-based computer model was constructed to estimate the impact of modifying risk behaviour on dementia prevalence.

Results: Based on population ageing, the number of people aged 45 years and over living with dementia is expected to triple from 187 000 in 2006 to 650 000 by 2051. A drop in proportion ever smokers by 5% every 5 years would lower population with dementia by 2% in 2051. If obesity rate drops by 5%, dementia prevalence would be lower by 6%. A decline in physical inactivity rate by 5% would reduce dementia by 11%. Persistence of the growing trend in obesity and physical inactivity would result in a larger than expected dementia epidemic.

Conclusion: Improving the risk behaviours has potential to make a substantial reduction in the number of people with dementia.