Research Abstract: Advanced Trainee - Oral Presentation Australian and New Zealand Society for Geriatric Medicine Annual Scientific Meeting 2023

Potentially modifiable dementia risk factors in all Australians and within ethnic subgroups       (#31)

Rhiann Sue See 1 , Fintan Thompson 2 3 4 , Sarah Russell 4 5 , Rachel Quigley 4 5 , Adrian Easterman 3 , Linton Harriss 2 4 , Zoe Hyde 6 , Sean Taylor 7 , Kylie Radford 8 9 , Dina LoGiudice 10 11 , Robyn McDermott 2 3 , Gill Livingston 12 13 , Edward Strivens 4 5
  1. Queensland Health, Metro South Health Service, Brisbane
  2. Australian Institute of Tropical Health and Medicine, College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns
  3. University of South Australia, Adelaide
  4. Queensland Health, Cairns and Hinterland Hospital and Health Service, Cairns
  5. College of Medicine and Dentistry, James Cook University, Cairns
  6. Western Australian Centre for Health and Ageing, The University of Western Australia, Perth
  7. Northern Territory Health, Top End, Northern Territory Government, Darwin
  8. Neuroscience Research Australia, Randwick
  9. School of Psychology, University of New South Wales, Sydney
  10. Department Medicine and Aged Care, Royal Melbourne Hospital, Parkville
  11. Department of Medicine, University of Melbourne, Parkville
  12. Division of Psychiatry, University College London, London
  13. Camden and Islington NHS Foundation Trust, London

Background: Dementia is the leading cause of disease burden in Australia. We aimed to calculate the population attributable fractions (PAF) of dementia attributable to 11 potentially modifiable risk factors, for Australians overall and three ethnic subgroups (First Nations Australian, European, Asian). The risk factors examined were less education, hearing loss, hypertension, obesity, smoking, depression, social isolation, physical inactivity, diabetes, alcohol excess, traumatic brain injury.

Methods: We calculated the prevalence of dementia risk factors and PAF risks adjusted for communality from National Australian surveys.

Findings: Half (49.8%) of dementia in Australia was theoretically attributable to 11 risk factors; respectively, 58.5% for First Nations Australians, 47.9% for European ancestry, and 44.5% for Australians of Asian ancestry. The commonest three, physical inactivity (10.9%), hearing loss (9.1%), and obesity (8.6%) accounted for more than half of cases across Australia, and for all ethnic subgroups. For First Nations Australians, the PAF was lowest for air pollution (1.4%) and social isolation (1.0%) and these risks were lower or comparable to those for Australians overall. However, the aPAF for smoking, less education, diabetes, and hypertension were higher among First Nations Australians. For Australians of Asian ancestry, the contribution of physical inactivity (11.8%) and diabetes (5.1%) were higher than all Australians, while obesity (4.9%), depression (1.7%) and alcohol consumption (0.1%) were lower.

Interpretation: The highest potential for dementia prevention is in First Nations Australians. The variation in risk factor contribution between ethnic subgroups should inform tailoring of dementia prevention strategies for Australia.