Abstract
BACKGROUND: We aimed to evaluate differences in dementia risk profiles according to age, birthplace and First Nations status. METHODS: The sample included 6171 (62% female, < 1% non-binary/other) middle-aged and older adults who self-administered the CogDrisk assessment online and consented to their data being used for research from May 2023 to May 2024. The majority were aged 40–64 (‘midlife’; 67.9%) or aged 65–96 (‘later-life’; 25.8%); 6.3% were aged 18–40. More than a third (36.2%) were born overseas, 95% resided in Australia, and 66.0% had a university degree. RESULTS: Key midlife risk factors were hypertension 27.7%, pesticide exposure 24.6%, high cholesterol 25.1%, head injury 15.3%, diabetes 7.6%, and atrial fibrillation (AFib) 7.3%. Key later-life risk factors were hypertension 45.4%, pesticide exposure 33.0%, AFib 18.3% head injury 16.4%, and diabetes 11.7%. Midlife respondents born in the Pacific and New Zealand (NZ) had high rates of vascular risk factors and those born in NZ reported high rates of head injury and depression. The highest rates of heavy drinking and insufficient physical activity were reported by respondents born in the UK and Asia respectively. Using published estimates from validation studies, 20% of those aged 65 + had a high dementia risk (CogDrisk score > 12). CONCLUSIONS: High rates of multiple risk factors were identified and varied according to age group and birthplace. This study provides evidence for tailoring risk reduction intervention and advice by age and birthplace. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-025-25943-8.