Strength together: examining risk and protective factors associated with dementia and cognitive impairment in Aboriginal and Torres Strait Islander peoples through harmonisation of landmark studies.

BACKGROUND: Rates of dementia for Aboriginal and Torres Strait Islander peoples are three to five times greater compared to non-Indigenous Australians, with earlier age of onset. However, the risk and protective factors that drive these higher rates vary across existing cohort studies, with minimal findings on the role of vascular risk factors beyond stroke. Harmonisation of data across studies may offer greater insights through enhanced diversity and strengthened statistical capabilities. This study aims to combine three landmark cohort studies of Aboriginal and Torres Strait Islander participants to better understand the determinants of cognitive health and dementia. METHODS/DESIGN: Three cohort studies - the Kimberley Healthy Adults Project (KHAP, N = 363), Koori Growing Old Well Study (KGOWS, N = 336) and Torres Strait Dementia Prevalence Study (TSDPS, N = 274) - share a similar research methodology with demographic, medical history, psychosocial factors, cognitive tests and consensus clinical diagnoses of cognitive impairment and dementia. Associations between risk and protective factors of interest and the presence of dementia and/or cognitive impairment diagnoses will be evaluated by univariable and multivariable logistic regression in a harmonised cross-sectional cohort of 898 participants. Factors associated with incident dementia and/or cognitive impairment will be assessed in a subset of KHAP (n = 189) and KGOWS participants (n = 165) who were available in longitudinal follow-up, after exclusion of those with baseline dementia or cognitive impairment. Analyses in relation to outcome measure of death or dementia will be conducted to account for the competing risk of death. Logistic regression will be used to evaluate the association between the individual components of the 16-component Kimberley Indigenous Cognitive Assessment (KICA) tool and the presence of dementia and cognitive impairment determined by independent consensus diagnoses. Multivariable binary logistic regression will be used to adjust for the effect of confounding variables. Results will be reported as odds ratios (OR) with 95% confidence intervals (95% CI). DISCUSSION: Greater understanding of risk and protective factors of dementia and cognitive impairment relevant to Aboriginal and Torres Strait Islander peoples may improve approaches across the life course to delay cognitive decline and reduce dementia risk.

Medications and cognitive risk in Aboriginal primary care: a cross-sectional study.

BACKGROUND: Aboriginal and Torres Strait Islander people are ageing with high rates of comorbidity, yet little is known about suboptimal prescribing in this population. AIM: The prevalence of potentially suboptimal prescribing and associated risk factors were investigated among older patients attending primary care through Aboriginal Community Controlled Health Services (ACCHSs). METHODS: Medical records of 420 systematically selected patients aged ≥50 years attending urban, rural and remote health services were audited. Polypharmacy (≥ 5 prescribed medications), potentially inappropriate medications (PIMs) as per Beers Criteria and anticholinergic burden (ACB) were estimated and associated risk factors were explored with logistic regression. RESULTS: The prevalence of polypharmacy, PIMs and ACB score ≥3 was 43%, 18% and 12% respectively. In multivariable logistic regression analyses, polypharmacy was less likely in rural (odds ratio (OR) = 0.43, 95% confidence interval (CI) = 0.24-0.77) compared to urban patients, and more likely in those with heart disease (OR = 2.62, 95% CI = 1.62-4.25), atrial fibrillation (OR = 4.25, 95% CI = 1.08-16.81), hypertension (OR = 2.14, 95% CI = 1.34-3.44), diabetes (OR = 2.72, 95% CI = 1.69-4.39) or depression (OR = 1.91, 95% CI = 1.19-3.06). PIMs were more frequent in females (OR = 1.88, 95% CI = 1.03-3.42) and less frequent in rural (OR = 0.41, 95% CI = 0.19-0.85) and remote (OR = 0.58, 95% CI = 0.29-1.18) patients. Factors associated with PIMs were kidney disease (OR = 2.60, 95% CI = 1.37-4.92), urinary incontinence (OR = 3.00, 95% CI = 1.02-8.83), depression (OR = 2.67, 95% CI = 1.50-4.77), heavy alcohol use (OR = 2.83, 95% CI = 1.39-5.75) and subjective cognitive concerns (OR = 2.69, 95% CI = 1.31-5.52). High ACB was less common in rural (OR = 0.10, 95% CI = 0.03-0.34) and remote (OR = 0.51, 95% CI = 0.25-1.04) patients and more common in those with kidney disease (OR = 3.07, 95% CI = 1.50-6.30) or depression (OR = 3.32, 95% CI = 1.70-6.47). CONCLUSION: Associations between potentially suboptimal prescribing and depression or cognitive concerns highlight the importance of considering medication review and deprescribing for these patients.

Prevalence of functional limitations in older remote-living Aboriginal Australians.

INTRODUCTION: To better tailor prevention and care strategies, there is a need to identify modifiable factors associated with functional impairment in older Aboriginal people, and related service needs. OBJECTIVE: To investigate the prevalence and associated factors for functional impairment in older Aboriginal people, and related service needs. DESIGN: Cross-sectional survey of 289 Aboriginal people aged ≥45 years living in the remote Kimberley region of Western Australia. Factors associated with functional impairment were explored with logistic regression. FINDINGS: 41.2% (95% CI 35.6%-47.0%) of participants required assistance with at least one I/ADL, and 26.0% (95% CI 21.2%-31.3%) required assistance with two or more I/ADLs. A core activity limitation (required assistance with showering, dressing or cooking) was reported by 15.9% (95% CI 12.1%-20.6%). In multivariable logistic regression analyses, older age, diabetes, difficulty walking, head injury, higher depression score and worse cognition were associated with needing help with two or more I/ADLs, while older age, history of stroke, higher depression score and worse cognition were associated with the presence of a core activity limitation. The proportion of participants receiving support with I/ADLs ranged from 71.2% to 97.6%. Support was generally provided by family and friends rather than service providers. DISCUSSION: The key modifiable factors associated with functional impairment in older Aboriginal people living in remote regions are diabetes, depression and cognitive impairment. Services required are transport and socio-cultural activities, and ensuring support for family providing the majority of care. CONCLUSIONS: This study highlights the need for holistic prevention strategies and care for older Aboriginal people with functional limitations and their families.

Difference in Severe Acute Respiratory Syndrome Coronavirus 2 Attack Rate Between Children and Adults May Reflect Bias.

The epidemiology of coronavirus disease 2019 in children has been challenging to establish, owing to the high prevalence of asymptomatic infection in this population. Lower secondary attack rates in children compared with adults have been observed in household contact studies, but there is evidence that this may reflect lower testing in children and reduced exposure, rather than a genuine difference in biological susceptibility. In addition, children may shed infectious virus for a shorter period than adults and their antibody response may be less broad, with implications for both polymerase chain reaction and serological testing. Improvements in study design, data collection, and data interpretation are required to better understand the epidemiology of coronavirus disease 2019 in children.

Prevalence and sites of pain in remote-living older Aboriginal Australians, and associations with depressive symptoms and disability.

BACKGROUND: Pain is a growing public health problem associated with significant health and functional implications. Limited data exist for Aboriginal Australians. AIMS: To describe the prevalence, severity and sites of pain, analgesic use and associated factors, including depression and disability, in remote-living Aboriginal Australians. METHODS: Cross-sectional study of 263 Aboriginal Australians aged ≥45 years from six remote Indigenous communities and the town of Derby in the Kimberley region of Western Australia between 2011 and 2013. Pain was assessed using a culturally adapted pain scale. Factors associated with pain were investigated with binary logistic regression. RESULTS: One hundred and seventy (64.6%) participants reported having pain and 53 (20.2%) reported persistent pain. Of those reporting pain, 61 (35.9%) rated it as moderate and 70 (41.2%) as severe. The most common sites of pain were back and knee, and 38 (22.4%) participants with pain indicated three or more sites of pain. Only 70 (41.2%) participants with pain were on some type of analgesic medication. After adjustment, poor vision (odds ratio (OR) = 2.21; 95% confidence interval (CI) 1.22-4.00), hypertension (OR = 1.89; 95% CI 1.03-3.45) and heart problems (OR = 2.05; 95% CI 1.01-4.14) were associated with pain. Higher depression scores were associated with more persistent pain, but pain was not significantly associated with clinically relevant depressive symptoms, or requiring assistance with two or more personal and/or instrumental activities of daily living. CONCLUSION: High levels of pain were reported, although the prevalence of persistent pain was comparable to the general population. Identifying risk factors, improving pain recognition and assessment and evaluating culturally tailored management approaches should be a priority.

Strong Carers, Strong Communities: a cluster randomised controlled trial to improve wellbeing of family carers of older people in remote Aboriginal communities.

INTRODUCTION: Unpaid carers have a crucial role in supporting older people with cognitive impairment and disability, but their own health and wellbeing are often impacted. There are limited data on how carer strain, depression and empowerment may be improved for carers. METHODS: This was a cluster randomised controlled trial to compare the effect of a carer support program developed with a community-based participatory action research (PAR) approach to the delivery of information sessions to 100 carers of people aged 45 years or more living in four remote Aboriginal communities in Western Australia. RESULTS: The mean age of carers was 38.3±14.9 years, 76% were female and 77% were children or grandchildren of the care recipient. Carer strain and empowerment measures did not change significantly between baseline and follow-up. A statistically significant decrease in depression scores was observed in the PAR group. However, decreases were observed in both the PAR and control groups, and the change in scores did not differ significantly between groups. Depression scores decreased most in those who had not attended high school. Overall, the proportion of participants meeting criteria for depression decreased from 18.8% at baseline to 8.3% at follow-up. CONCLUSION: A carer support program was of equivocal benefit, although this research demonstrates that the wellbeing of carers in remote Aboriginal communities can potentially be markedly improved by outreach strategies.

Potentially suboptimal prescribing of medicines for older Aboriginal Australians in remote areas.

OBJECTIVES: To investigate the prevalence of polypharmacy, under-prescribing and potentially inappropriate medicine use among Aboriginal Australians living in remote Western Australia. DESIGN: Cross-sectional study. SETTING: Six remote communities and the town of Derby in the Kimberley, Western Australia. PARTICIPANTS: Aboriginal people aged 45 years or more with complete medication histories. MAIN OUTCOME MEASURES: Proportions of patients with medicine histories indicating polypharmacy, potential under-prescribing of indicated medicines, or potentially inappropriate prescribing (including potential prescribing cascades or drug interactions). RESULTS: Complete medicine histories were available for 273 participants. The mean number of prescribed medicines was 5.1 (SD, 3.6). At least one form of suboptimal prescribing was identified for 166 participants (61%), including polypharmacy for 145 (53%), potential under-prescribing of at least one indicated medicine for 33 (12%), and potentially inappropriate prescribing for 54 participants (20%). Potential prescribing cascades or drug interactions were identified for 12 participants (4%). CONCLUSIONS: Potentially suboptimal prescribing affected more than half the participating older Aboriginal Australians from the Kimberley. If generalisable to other remote Indigenous Australians, the prevalence of polypharmacy, potentially inappropriate prescribing, and under-prescribing of indicated medicines is problematic, and suggests that older Indigenous people in remote areas are at risk of medicine-related harm.

Assessment, incidence and factors associated with urinary incontinence in older Aboriginal Australians.

BACKGROUND: Little is known about urinary incontinence in older Aboriginal Australians. AIM: To describe urinary incontinence assessment, prevalence, incidence and associated conditions in older Aboriginal Australians. METHODS: Wave 1 consisted of 363 Aboriginal participants aged ≥45 years from Western Australia; 289 participants participated in Wave 2, with 184 included at both time points. Urinary incontinence was assessed by self-report, family report and the modified International Consultation on Incontinence Questionnaire (ICIQ). We investigated factors associated with incontinence with binary logistic regression. Sensitivity and specificity analyses of incontinence measures were undertaken using the ICIQ score ≥2 as the reference standard. RESULTS: Participant mean age was 61.2 ± 11.2 years. Prevalence of incontinence at Wave 2 (n = 289) using self-report was 24.6%; using ICIQ ≥2 was 22.5%; and family report 14.2%. Incidence after follow-up of 6.7 years was 33 (23.6%), higher than estimates of 5-20% in other populations. Cross-sectional associations with incontinence include female sex (odds ratio (OR) = 6.82; 95% confidence interval (CI) 2.98-15.57), stroke (OR = 3.55; 95% CI 1.43-8.77), head injury (OR = 3.15; 95% CI 1.54-6.45) and depressive symptoms (OR = 1.07; 95% CI 1.01-1.14). Longitudinal associations were age (OR = 1.05; 95% CI 1.01-1.09) and female sex (OR = 2.37; 95% CI 0.99-5.67). Sensitivity (81.5%) and specificity (93.5%) of self-report were high. CONCLUSION: The prevalence and incidence of urinary incontinence in Aboriginal Australians is high with risk factors of older age and female sex. The modified ICIQ and self-report appear to be appropriate incontinence screens. Further research to understand causes and treatments within this population is urgently required.

Incidence and predictors of cognitive impairment and dementia in Aboriginal Australians: A follow-up study of 5 years.

INTRODUCTION: Aboriginal Australians are reported to develop dementia earlier than the general population. The causes remain unknown. METHODS: This was a longitudinal study of 363 participants aged ≥45 years. Consensus diagnoses were established for cognitive impairment or dementia. RESULTS: At follow-up, 189 people (mean ± standard deviation age, 65.4 ± 10.3 years) participated, as 109 (30%) had died and 65 (18%) were unavailable. The incidence of cognitive impairment or dementia was 52.6 (95% confidence interval 33.9, 81.5) per 1000 person-years (380.3 total person-years) and for dementia was 21.0 (10.5, 42.1) per 1000 person-years (380.3 person-years total) over the age 60 years. Longitudinal risk factors associated with a decline from normal cognition to impairment were age and head injury. Other associations with cognitive decline were stroke, head injury, nonaspirin analgesics, lower BMI, and higher systolic BP. DISCUSSION: Dementia incidence in Aboriginal Australians is among the highest in the world, and is associated with age and head injury.

Validity of self-reported versus hospital-coded diagnosis of stroke: a cross-sectional and longitudinal study.

BACKGROUND: Population-based studies, as well as clinicians, often rely on self-report and hospital records to obtain a history of stroke. This study aimed to compare the validity of the diagnosis of stroke by self-report and by hospital coding according to their cross-sectional association with prevalent vascular risk factors, and longitudinal association with recurrent stroke and major cardiovascular outcomes in a large cohort of older Australian men. METHODS: Between 1996 and 1999, 11,745 older men were surveyed for a self-reported history of stroke as part of the Health in Men Study (HIMS). Previous hospitalization for stroke was obtained with consent from linked medical records via the Western Australian Data Linkage System (WADLS). Subjects were followed by WADLS until December 31, 2010, for hospitalization for stroke, cardiovascular events, and all-cause mortality. The primary outcome was hospitalisation for stroke during follow-up. Secondary outcomes included incident vascular events and composite vascular endpoints. RESULTS: At baseline, a history of stroke was reported by 903 men (7.7%), previous hospitalisation for stroke was recorded in 717 (6.1%), both self-report and hospitalisation in 467 (4.0%), and no history of stroke in 10,696 men (91.1%). Prevalent cardiovascular disease and peripheral arterial disease were more common among men with previous hospitalisation for stroke than a history of self-reported stroke (p < 0.001). In longitudinal analyses, incident aortic aneurysm was also more common among men with baseline history of hospitalization for stroke (adjusted hazard ratio (HR) 1.71, 95% CI 1.12-2.60) than among men with self-reported stroke (HR 0.88, 95% CI 0.56-1.36) compared to men with no history of stroke. With regard to the primary outcome, the rate of hospitalisation for stroke during follow-up was significantly higher among men with self-reported stroke (HR 2.44, 95% CI 2.03-2.94), hospital-coded stroke (adjusted HR 3.02, 2.42-3.78) and both self-reported and hospital-coded stroke (adjusted HR 3.33, 2.82-3.92) compared to participants with no previous stroke. Time to recurrent stroke was similar among different methods of initial stroke diagnosis (p = 0.067). CONCLUSIONS: Self-reported stroke and hospital-coded stroke have a similar prognostic value for predicting the risk of recurrent stroke. This supports the use of these ways of assessing a history of stroke for the clinical purposes of secondary prevention and for further epidemiological studies.

Potentially modifiable dementia risk factors in all Australians and within population groups: an analysis using cross-sectional survey data.

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.