Aims: Factors contributing to the higher rates of dementia in Aboriginal and Torres Strait Islander communities vary across existing studies. The aim of this study was to elucidate cross-sectional and longitudinal factors associated with dementia and Cognitive Impairment Not Dementia (CIND) in a harmonised dataset of Aboriginal and Torres Strait Islander participants.
Methods: Univariable and multivariable logistic regression was used to assess the associations between risk and protective factors of interest and dementia and/or CIND diagnoses in a cross-sectional harmonised dataset of three cohort studies (n=898), with multinomial logistic regression used to account for the competing risk of death in a subset of participants followed up longitudinally (n=319).
Results: 13% of 898 participants had a diagnosis of dementia and 15% had CIND. Important factors associated with dementia and CIND included age (OR 1.09; 95% CI 1.07-1.12), higher educational attainment (OR 0.49; 95% CI 0.26-0.93), stroke (OR 2.35; 95% CI 1.45-3.83), head injury with loss of consciousness (OR 1.96; 95% CI 1.31-2.93), epilepsy (OR 3.56; 95% CI 1.59-7.95), obesity (OR 0.53; 95% CI 0.36-0.78) and antidepressant use (OR 1.95; 95% CI 1.05-3.61). Living in urban compared to remote areas, hearing impairment, urinary incontinence, mobility impairment and difficulties with certain activities of daily living were associated with a greater risk of incident dementia/CIND.
Conclusions: This study reinforced important risk factors associated with dementia and CIND for Aboriginal and Torres Strait Islander peoples that may be clinically important for prevention and risk reduction but further validation is required.