Search

Background: Dementia is the second leading cause of disease burden in Australia. We aimed to calculate the population attributable fractions (PAFs) of dementia attributable to 11 of 12 previously identified potentially modifiable health and social risk factors (less education, hearing loss, hypertension, obesity, smoking, depression, social isolation, physical inactivity, diabetes, alcohol excess, air pollution, and traumatic brain injury), for Australians overall and three population groups (First Nations, and those of European and Asian ancestry)., Methods: We calculated the prevalence of dementia risk factors (excluding traumatic brain injury) and PAFs, adjusted for communality, from the cross-sectional 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) conducted by the Australian Bureau of Statistics. We conducted sensitivity analyses using proxy estimates for traumatic brain injury (12th known risk factor) for which national data were not available., Findings: A large proportion (38·2%, 95% CI 37·2-39·2) of dementia in Australia was theoretically attributable to the 11 risk factors; 44·9% (43·1-46·7) for First Nations Australians, 36·4% (34·8-38·1) for European ancestry, and 33·6% (30·1-37·2) for Asian ancestry. Including traumatic brain injury increased the PAF to 40·6% (39·6-41·6) for all Australians. Physical inactivity (8·3%, 7·5-9·2), hearing loss (7·0%, 6·4-7·6), and obesity (6·6%, 6·0-7·3) accounted for approximately half of the total PAF estimates across Australia, and for all three population groups., Interpretation: Our PAF estimates indicate a substantial proportion of dementia in Australia is potentially preventable, which is broadly consistent with global trends and results from other countries. The highest potential for dementia prevention was among First Nations Australians, reflecting the enduring effect of upstream social, political, environmental, and economic disadvantage, leading to greater life-course exposure to dementia risk factors. Although there were common dementia risk factors across different population groups, prevention strategies should be informed by community consultation and be culturally and linguistically appropriate., Funding: Australian National Health and Medical Research Council and University College London Hospitals' National Institute for Health Research (NIHR) Biomedical Research Centre, and North Thames NIHR Applied Research Collaboration., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Objective: Dementia disproportionately affects First Nations populations. Biomarkers collected in primary care may assist with determining dementia risk. Our previous underpowered study showed some suggestive associations between baseline biomarkers with follow-up dementia or cognitive impairment. The current study extended this work with a larger linked dataset., Study Design and Setting: Probabilistic data linkage was used to combine four baseline datasets with one follow-up assessment of dementia status 0-20 years later in a First Nations population in Australia. Mixed Effects Generalized Linear Regression models were used to test associations between baseline measures and follow-up status, accounting for repeated measures within individuals., Results: Linked data were available for 88 individuals, with 101-279 baseline observations, depending on the type of measure. Higher urinary albumin to creatine ratio was associated with greater risk of cognitive impairment/dementia, whereas body weight and key lipid markers were negatively associated. There was no clear trend when these associations were examined by timing of measurement (i.e., ≤10 years or >10 years before a dementia assessment)., Conclusions: The results of this study support findings from our previous work and indicate that microalbuminuria can be an early indicator of dementia risk in this population. The weight and lipid profile findings reflect the mixed results in the published literature and require further investigation and interpretation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Thompson, Russell, Quigley, McDonald, Sagigi, Taylor, Campbell, Schmidt, Esterman, Harriss, Miller, Mills, Strivens and McDermott.)

Background: Reducing the burden of dementia in First Nations populations may be addressed through developing population specific methods to quantify future risk of dementia., Objective: To adapt existing dementia risk models to cross-sectional dementia prevalence data from a First Nations population in the Torres Strait region of Australia in preparation for follow-up of participants. To explore the diagnostic utility of these dementia risk models at detecting dementia., Methods: A literature review to identify existing externally validated dementia risk models. Adapting these models to cross-sectional data and assessing their diagnostic utility through area under the receiver operating characteristic curve (AUROC) analyses and calibration using Hosmer-Lemeshow Chi 2 ., Results: Seven risk models could be adapted to the study data. The Aging, Cognition and Dementia (AgeCoDe) study, the Framingham Heart Study (FHS), and the Brief Dementia Screening Indicator (BDSI) had moderate diagnostic utility in identifying dementia (i.e., AUROC >0.70) before and after points for older age were removed., Conclusion: Seven existing dementia risk models could be adapted to this First Nations population, and three had some cross-sectional diagnostic utility. These models were designed to predict dementia incidence, so their applicability to identify prevalent cases would be limited. The risk scores derived in this study may have prognostic utility as participants are followed up over time. In the interim, this study highlights considerations when transporting and developing dementia risk models for First Nations populations., Competing Interests: The authors have no conflict of interest to declare., (© 2023 – The authors. Published by IOS Press.)

Background: Dementia is highly prevalent among Australia's First Nations peoples, including Torres Strait Islander and Aboriginal peoples in Far North Queensland (FNQ). It is likely that historically recent exposure to modifiable risk factors underlies these rates, and a large proportion of dementia may be potentially preventable., Methods: Data from two adult community health checks (2015-2018) were analyzed to determine the prevalence of 11 modifiable dementia risk factors among the First Nations residents of the Torres Strait and Northern Peninsula Area of FNQ. Population attributable fractions (PAF%) for dementia were calculated using age-standardized prevalence estimates derived from these health checks and relative risks obtained from previous meta-analyses in other populations. PAF% estimates were weighted for communality to account for overlap of risk factors., Findings: Half (52·1%) of the dementia burden in this population may be attributed to 11 potentially modifiable risk factors. Hypertension (9·4%), diabetes mellitus (9·0%), obesity (8·0%), and smoking (5·3%) were the highest contributing risk factors. The contribution of depression (2·0%) and alcohol (0·3%) was lower than other global and national estimates. While the adjusted PAF% for social isolation was low based on the adult community health check data (1·6%), it was higher (4·2%) when official census data were analyzed., Interpretation: These results suggest that a substantial proportion of dementia in FNQ First Nations peoples could potentially be prevented. Government investment in preventative health now is essential to reduce the future burden of dementia., Funding: National Health and Medical Research Council (NHMRC, GNT1107140, GNT1191144, GNT1106175, GNT0631947)., Competing Interests: The authors have no conflict of interest to declare., (© 2022 The Authors.)

Objective: High rates of dementia are evident in First Nations populations, and modifiable risk factors may be contributing to this increased risk. This study aimed to use a longitudinal dataset to gain insights into the long-term risk and protective factors for dementia and cognitive impairment not dementia (CIND) in a Torres Strait Islander and Aboriginal population in Far North Queensland, Australia., Study Design and Setting: Probabilistic data linkage was used to combine baseline health check data obtained in 1998/2000 and 2006/2007 for 64 residents in remote communities with their results on a single dementia assessment 10-20 years later (2015-2018). The relationship between earlier measures and later CIND/dementia status was examined using generalized linear modeling with risk ratios (RRs). Due to the small sample size, bootstrapping was used to inform variable selection during multivariable modeling., Results: One third of participants ( n = 21, 32.8%) were diagnosed with dementia ( n = 6) or CIND ( n = 15) at follow-up. Secondary school or further education (RR = 0.38, 95% CI 0.19-0.76, p = 0.006) and adequate levels of self-reported physical activity (RR = 0.26, 95% CI 0.13-0.52, p < 0.001) were repeatedly selected in bootstrapping and showed some evidence of protection against later CIND/dementia in final multivariate models, although these had moderate collinearity. Vascular risk measures showed inconclusive or unexpected associations with later CIND/dementia risk., Conclusions: The preliminary findings from this small study highlighted two potential protective factors for dementia that may be present in this population. A tentative risk profile for later CIND/dementia risk is suggested, although the small sample size limits the applicability of these findings., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Thompson, Russell, Harriss, Esterman, Taylor, Quigley, Strivens and McDermott.)