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.

Prevalence, risk factors, and outcomes of secondary infections among hospitalized patients with COVID-19 or post-COVID-19 conditions in Victoria, 2020-2023.

OBJECTIVES: Estimates of secondary infections are variedly reported, with few studies done in Australia. We investigated the occurrence and impact of secondary infections complicating COVID-19 and post-COVID-19 admissions in Victoria, Australia, 2020-2023. METHODS: We used linked population-wide data sets and specific International Classification of Disease, 10th Revision codes to identify and estimate the occurrence of secondary infections. Using hospital/intensive care unit length of stay in negative binomial regression and mortality, we examined the impact of secondary infections. RESULTS: Secondary infections were identified in 6.9% (13,467 of 194,660) of COVID-19 and post-COVID-19 admissions: 6.0% (11,651 of 194,660) bacterial, 0.9% (1691 of 194,660) viral, and 0.2% (385 of 194,660) fungal. Prevalence was highest during the pre-Delta (10.4%) and Omicron-BA2 (8.1%) periods. Sepsis and pneumonia were the most reported syndromes; the occurrence of sepsis declined gradually over time. The odds of secondary infections were higher among the ≥70-year-olds (adjusted odds ratio (aOR) 3.76, 95% confidence interval [CI] 3.43-4.14, vs 20-29-year-olds), individuals with chronic conditions (aOR 3.15, 95% CI 2.88-3.45, vs those without), the unvaccinated (aOR 1.59, 95% CI 1.45-1.75), and the lowest socioeconomic group (aOR 1.12, 95% CI 1.05-1.19). Patients with secondary infections had 2.43 times longer hospital length of stay and 9.60 times longer intensive care unit length of stay than those without secondary infections. The mortality risk was 2.17 times higher in those with secondary infections. CONCLUSIONS: Secondary infections occurred in 69 per 1000 COVID-19-associated hospital admissions in Victoria, mostly in high-risk groups, and were associated with severe outcomes.

Shoulder dystocia in babies born to Aboriginal mothers with diabetes: a population-based cohort study, 1998-2015.

BACKGROUND: Australian Aboriginal and Torres Strait Islander women with diabetes in pregnancy (DIP) are more likely to have glycaemic levels above the target range, and their babies are thus at higher risk of excessive fetal growth. Shoulder dystocia, defined by failure of spontaneous birth of fetal shoulder after birth of the head requiring obstetric maneuvers, is an obstetric emergency that is strongly associated with DIP and fetal size. The aim of this study was to investigate the epidemiology of shoulder dystocia in Aboriginal babies born to mothers with DIP. METHODS: Stratifying by Aboriginal status, characteristics of births complicated by shoulder dystocia in women with and without DIP were compared and incidence and time-trends of shoulder dystocia were described. Compliance with guidelines aiming at preventing shoulder dystocia in women with DIP were compared. Post-logistic regression estimation was used to calculate the population attributable fractions (PAFs) for shoulder dystocia associated with DIP and to estimate probabilities of shoulder dystocia in babies born to mothers with DIP at birthweights > 3 kg. RESULTS: Rates of shoulder dystocia from vaginal births in Aboriginal babies born to mothers with DIP were double that of their non-Aboriginal counterparts (6.3% vs 3.2%, p < 0.001), with no improvement over time. Aboriginal mothers with diabetes whose pregnancies were complicated by shoulder dystocia were more likely to have a history of shoulder dystocia (13.1% vs 6.3%, p = 0.032). Rates of guideline-recommended elective caesarean section in pregnancies with diabetes and birthweight > 4.5 kg were lower in the Aboriginal women (28.6% vs 43.1%, p = 0.004). PAFs indicated that 13.4% (95% CI: 9.7%-16.9%) of shoulder dystocia cases in Aboriginal (2.7% (95% CI: 2.1%-3.4%) in non-Aboriginal) women were attributable to DIP. Probability of shoulder dystocia among babies born to Aboriginal mothers with DIP was higher at birthweights > 3 kg. CONCLUSIONS: Aboriginal mothers with DIP had a higher risk of shoulder dystocia and a stronger association between birthweight and shoulder dystocia. Many cases were recurrent. These factors should be considered in clinical practice and when counselling women.

Cardiometabolic health markers among Aboriginal adolescents from the Next Generation Youth Wellbeing Cohort Study.

OBJECTIVE: The objective of this study was to investigate cardiometabolic health markers among Aboriginal adolescents aged 10-24 years and relationships with age, gender, and body composition. METHODS: Baseline data (2018-2020) from the Next Generation Youth Wellbeing Cohort Study (Western Australia, New South Wales, and Central Australia) on clinically assessed body mass index, waist/height ratio, blood pressure, glycated haemoglobin (HbA1c), total and high-density lipoprotein cholesterol, total/high-density lipoprotein cholesterol ratio, and triglycerides were analysed. RESULTS: Among 1100 participants, the proportion with individual health markers within the ideal range ranged from 59% for total cholesterol to 91% for HbA1c. Four percent had high blood pressure, which was more common with increasing age and among males; 1% had HbA1c indicative of diabetes. Healthier body composition (body mass index and waist/height ratio) was associated with having individual health markers in the ideal range and with an ideal cardiometabolic profile. CONCLUSIONS: Most Aboriginal adolescents in this study had cardiometabolic markers within the ideal range, though markers of high risk were present from early adolescence. Ideal health markers were more prevalent among those with healthy body composition. IMPLICATIONS FOR PUBLIC HEALTH: Specific screening and management guidelines for Aboriginal adolescents and population health initiatives that support maintenance of healthy body composition could help improve cardiometabolic health in this population.

Use of targeted SMS messaging to encourage COVID-19 oral antiviral uptake in South West Victoria.

OBJECTIVES: During winter 2022, as part of a multifaceted approach to optimise oral antiviral uptake in the Barwon South West region in Victoria, Australia, the Barwon South West Public Health Unit (BSWPHU) implemented an innovative, targeted SMS messaging program that encouraged people with coronavirus disease 2019 (COVID-19) to be assessed for antiviral treatment. In this study, we investigated patterns of antiviral uptake, identified barriers and facilitators to accessing antivirals, and examined the potential impact of targeted SMS messaging on oral antiviral uptake. METHODS: We conducted a cross-sectional study of notified COVID-19 cases aged 50 years and older, and Aboriginal and Torres Strait Islander people aged 30-49 years, in the BSWPHU catchment area over a 6-week period commencing 21 July 2022. We analysed survey data using descriptive statistics and generalised linear models. RESULTS: Of the 3829 survey respondents, 36.7% (95% confidence interval (CI) 35.2, 38.2) reported being prescribed oral antivirals, with 75.4% (95% CI 72.8, 77.9) of these aged ≥70. Antiviral prescriptions increased significantly over the 6-week survey period. Most prescriptions (87.5%; 95% CI 85.7, 89.2) were provided by the respondents' usual general practitioners (GPs). Barriers to receiving antivirals included respondents being unable to get a medical appointment in time (3.7%; 95% CI 3.1, 4.2), testing too late in their illness (2.3%; 95% CI 1.8, 2.8) and being unable to access medications in time after receiving a prescription (0.2%; 95% CI 0.1, 0.6). Facilitators to receiving antivirals included respondents first hearing about antivirals from a trusted source such as a family member, friend or usual doctor. Nearly one in eight people who were prescribed antivirals reported first hearing about them from the SMS message sent by BSWPHU. CONCLUSIONS: Oral antiviral treatment uptake in south-west Victoria in July-August 2022 was high among survey respondents and increased over time. GPs were the key prescribers in the community. Targeted SMS messaging to COVID-19 cases is a simple, low-cost intervention that potentially increases antiviral uptake.

Risk, protective, and biomarkers of dementia in Indigenous peoples: A systematic review.

INTRODUCTION: Dementia is an emergent health priority for Indigenous peoples worldwide, yet little is known about disease drivers and protective factors. METHODS: Database searches were conducted in March 2022 to identify original publications on risk, protective, genetic, neuroradiological, and biological factors related to dementia and cognitive impairment involving Indigenous peoples. RESULTS: Modifiable risk factors featured across multiple studies include childhood adversity, hearing loss, low education attainment, unskilled work history, stroke, head injury, epilepsy, diabetes, hypertension, hyperlipidemia, depression, low BMI, poor mobility, and continence issues. Non-modifiable risk factors included increasing age, sex, and genetic polymorphisms. Education, ex-smoking, physical and social activity, and engagement with cultural or religious practices were highlighted as potential protective factors. There is a paucity of research on dementia biomarkers involving Indigenous peoples. DISCUSSION: Greater understanding of modifiable factors and biomarkers of dementia can assist in strength-based models to promote healthy ageing and cognition for Indigenous peoples.

Demographic Characteristics of Unvaccinated Asymptomatic and Symptomatic SARS-CoV-2 Cases in Barwon South West, Victoria, Australia.

We investigated 328 SARS-CoV-2 cases in Barwon South West, Victoria, Australia, in the 2020 pre-vaccination period, comparing infections with symptoms to those that remained asymptomatic. De-identified self-reported data on case characteristics and symptom progression from three sequential questionnaires were examined. Multivariable logistic regression was used to model associations between demographic profiles and symptoms. Asymptomatic infections were more than three times as likely to be seen in ethnic minority groups than the Caucasian population after adjusting for gender and age [OR 3.2, 95% CI 1.5-6.7, p < 0.01] and were more common among cases of Asian background [OR 2.8, 95%CI 1.2-6.4]. Asymptomatic infections were also more common in youth and younger adults, but cases were approximately seven times more likely to be in seniors (≥65 years) compared with those 24 years of age or younger after adjusting for sex and ethnicity [OR 6.9, 95% CI 1.3-35.8]. The overrepresentation of ethnic minority groups among asymptomatic infections is suggestive of genetic haplotype variability by ethnic group, conferring greater cross-protection from other coronaviruses in the initial phase of the COVID-19 pandemic. Replication of this analysis in the post-vaccination era and reassessment of symptom expression according to ethnicity in a community with established vaccine and infection-induced immunity would determine whether this is a sustained association or one confined to the early stages of a pandemic in an immunologically naive population. These findings may, in part, reflect differences in testing patterns by ethnicity and true differences in disease expression, both of which are important to understand in order to inform transmission prevention strategies and tailored risk messaging according to ethnic background.

Comprehensive Case-Control Study of Protective and Risk Factors for Buruli Ulcer, Southeastern Australia.

To examine protective and risk factors for Buruli ulcer (BU), we conducted a case-control study of 245 adult BU cases and 481 postcode-matched controls across BU-endemic areas of Victoria, Australia. We calculated age- and sex-adjusted odds ratios for socio-environmental, host, and behavioral factors associated with BU by using conditional logistic regression. Odds of BU were >2-fold for persons with diabetes mellitus and persons working outdoors who had soil contact in BU-endemic areas (compared with indoor work) but were lower among persons who had bacillus Calmette-Guérin vaccinations. BU was associated with increasing numbers of possums and with ponds and bore water use at residences. Using insect repellent, covering arms and legs outdoors, and immediately washing wounds were protective; undertaking multiple protective behaviors was associated with the lowest odds of BU. Skin hygiene/protection behaviors and previous bacillus Calmette-Guérin vaccination might provide protection against BU in BU-endemic areas.

Health behaviours associated with healthy body composition among Aboriginal adolescents in Australia in the 'Next Generation: Youth Well-being study'.

This study described the distribution of healthy body composition among Aboriginal adolescents in Australia aged 10-24 years and examined associations with health behaviours and self-rated health. Data were cross-sectional from the 'Next Generation: Youth Well-being study' baseline (N = 1294). We used robust Poisson regression to quantify associations of self-reported health behaviours (physical activity, screen time, sleep, consumption of vegetables, fruit, soft drinks and fast food, and tobacco smoking and alcohol) and self-rated health to healthy body mass index (BMI) and waist/height ratio (WHtR). Overall, 48% of participants had healthy BMI and 64% healthy WHtR, with healthy body composition more common among younger adolescents. Higher physical activity was associated with healthy body composition (5-7 days last week vs none; adjusted prevalence ratio (aPR) healthy BMI 1.31 [95% CI 1.05-1.64], and healthy WHtR 1.30 [1.10-1.54]), as was recommended sleep duration (vs not; aPR healthy BMI 1.56 [1.19-2.05], and healthy WHtR 1.37 [1.13-1.67]). There was a trend for higher proportion of healthy body composition with more frequent fast food consumption. Healthy body composition was also associated with higher self-rated health ('very good/excellent' vs 'poor/fair'; aPR healthy BMI 1.87 [1.45-2.42], and healthy WHtR 1.71 [1.40-2.10]). Culturally appropriate community health interventions with a focus on physical activity and sleep may hold promise for improving body composition among Aboriginal adolescents.

The impact of diabetes during pregnancy on neonatal outcomes among the Aboriginal population in Western Australia: a whole-population study.

BACKGROUND: Aboriginal and Torres Strait Islander (hereafter Aboriginal) women have a high prevalence of diabetes in pregnancy (DIP), which includes pre-gestational diabetes mellitus (PGDM) and gestational diabetes mellitus (GDM). We aimed to characterize the impact of DIP in babies born to Aboriginal mothers. METHODS: A retrospective cohort study, using routinely collected linked health data that included all singleton births (N = 510 761) in Western Australia between 1998 and 2015. Stratified by Aboriginal status, generalized linear mixed models quantified the impact of DIP on neonatal outcomes, estimating relative risks (RRs) with 95% CIs. Ratio of RRs (RRRs) examined whether RRs differed between Aboriginal and non-Aboriginal populations. RESULTS: Exposure to DIP increased the risk of adverse outcomes to a greater extent in Aboriginal babies. PGDM heightened the risk of large for gestational age (LGA) (RR: 4.10, 95% CI: 3.56-4.72; RRR: 1.25, 95% CI: 1.09-1.43), macrosomia (RR: 2.03, 95% CI: 1.67-2.48; RRR: 1.39, 95% CI: 1.14-1.69), shoulder dystocia (RR: 4.51, 95% CI: 3.14-6.49; RRR: 2.19, 95% CI: 1.44-3.33) and major congenital anomalies (RR: 2.14, 95% CI: 1.68-2.74; RRR: 1.62, 95% CI: 1.24-2.10). GDM increased the risk of LGA (RR: 2.63, 95% CI: 2.36-2.94; RRR: 2.00, 95% CI: 1.80-2.22), macrosomia (RR: 1.95, 95% CI: 1.72-2.21; RRR: 2.27, 95% CI: 2.01-2.56) and shoulder dystocia (RR: 2.78, 95% CI: 2.12-3.63; RRR: 2.11, 95% CI: 1.61-2.77). Birthweight mediated about half of the DIP effect on shoulder dystocia only in the Aboriginal babies. CONCLUSIONS: DIP differentially increased the risks of fetal overgrowth, shoulder dystocia and congenital anomalies in Aboriginal babies. Improving care for Aboriginal women with diabetes and further research on preventing shoulder dystocia among these women can reduce the disparities.

Severity of COVID-19 among Residents in Aged Care Facilities in Victoria, Australia: A Retrospective Cohort Study Comparing the Delta and Omicron Epidemic Periods.

OBJECTIVES: During the COVID-19 pandemic, no country with widespread community transmission has avoided outbreaks or deaths in residential aged care facilities (RACFs). As RACF residents are at high risk of morbidity and mortality from COVID-19, understanding disease severity risk factors is imperative. DESIGN: This retrospective cohort study aimed to compare COVID-19 disease severity (hospitalization and deaths) and associated risk factors among RACF residents in Victoria, Australia, across Delta and Omicron epidemic periods. SETTINGS AND PARTICIPANTS: Resident case hospitalization risk (HR) and case fatality risk (CFR) were assessed using Victorian RACFs COVID-19 outbreaks data across 2 epidemic periods; Delta, 994 resident cases linked to 86 outbreaks; and Omicron, 1882 resident cases linked to 209 outbreaks. METHODS: Adjusting for outbreak-level clustering, age, sex, up-to-date vaccination status, and time since last vaccination, the odds of hospitalization and death were compared using mixed effects logistic regression. RESULTS: The HR and CFR was lower during the Omicron period compared with the Delta period [HR 8.2% vs 24.6%, odds ratio (OR) 0.17, 95% CI 0.11-0.26, and CFR: 11.4% vs 18.7%, OR 0.40, 95% CI 0.28-0.56]. During both periods, males had higher odds of hospitalization and odds of death; being up to date with vaccination reduced odds of hospitalization by 40% (excluding nonemergency patient transfers) and odds of death by 43%; and for each month since last vaccination, odds of hospitalization increased by 9% and odds of death by 16%. CONCLUSIONS AND IMPLICATIONS: This study provides empirical evidence of lower COVID-19 severity among RACF residents in the Omicron period and highlights the importance of up-to-date and timely vaccination to reduce disease severity in this cohort.

Area-level social and economic factors and the local incidence of SARS-CoV-2 infections in Victoria during 2020.

OBJECTIVE: To examine associations between area-level socio-economic factors and the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in Victoria during 2020. DESIGN, SETTING: Population-level ecological study of the incidence of SARS-CoV-2 infections in Victoria, by postcode, 1 March - 13 August 2020. MAIN OUTCOME MEASURES: Relationships between the incidence of SARS-CoV-2 infections by postcode (Department of Health and Human Services data published on The Age website), and demographic, education level, ethnic background, economic and employment-related factors, housing-related factors, and social disadvantage (Australian Bureau of Statistics data for 2014-19), expressed as incidence rate ratios (IRRs). RESULTS: During the study period, 15 482 SARS-CoV-2 infections with associated postcodes were recorded in Victoria. Incidence was higher for metropolitan than regional postcodes (418.3 v 62 infections per 100 000 population; IRR, 6.2; 95% CI, 4.6-8.2). In regional postcodes, incidence rose with mean household size (per person: IRR, 7.30; 95% CI, 4.37-12.2), unemployment proportion (per percentage point: IRR, 1.50; 95% CI, 1.33-1.69), and proportions for whom rent (IRR, 1.15; 95% CI, 1.07-1.22) or mortgage repayments (IRR, 1.22; 95% CI, 1.15-1.28) exceeded 30% of household income. In metropolitan areas, incidence increased with unemployment proportion (IRR, 1.14; 95% CI, 1.05-1.23) and proportion without paid leave (IRR, 1.22; 95% CI, 1.02-1.45). Incidence also increased with proportion speaking languages other than English at home (regional: IRR, 1.08; 95% CI, 1.06-1.11; metropolitan: IRR, 1.01; 95% CI, 1.002-1.02) and with Indigenous Australian proportion (metropolitan only: IRR, 1.91; 95% CI, 1.10-2.73). CONCLUSIONS: Socio-economic factors may have contributed to the non-homogeneous incidence of SARS-CoV-2 infections across Victoria during 2020.

Pregnancy and birth characteristics of Aboriginal twins in two Australian states: a data linkage study.

INTRODUCTION: Perinatal outcomes for singleton pregnancies are poorer, on average, for Aboriginal people than non-Aboriginal people, but little is known about Aboriginal multifetal pregnancies. Yet multifetal pregnancies and births are often more complicated and have poorer outcomes than singleton pregnancies. We describe the pregnancies, births and perinatal outcomes for Aboriginal twins born in Western Australia (WA) and New South Wales (NSW) with comparisons to Aboriginal singletons in both states and to non-Aboriginal births in NSW. MATERIALS AND METHODS: Whole-population birth records and birth and death registrations were linked for all births during 2000-2013 (WA) and 2002-2008 (NSW). Hospital records and the WA Register of Developmental Anomalies - Cerebral Palsy were linked for all WA births and hospital records for a subset of NSW births. Descriptive statistics are reported for maternal and child demographics, maternal health, pregnancy complications, births and perinatal outcomes. RESULTS: Thirty-four thousand one hundred twenty-seven WA Aboriginal, 32,352 NSW Aboriginal and 601,233 NSW non-Aboriginal births were included. Pregnancy complications were more common among mothers of Aboriginal twins than Aboriginal singletons (e.g. 17% of mothers of WA twins had hypertension/pre-eclampsia/eclampsia vs 8% of mothers of singletons) but similar to mothers of NSW non-Aboriginal twins. Most Aboriginal twins were born in a principal referral, women's or large public hospital. The hospitals were often far from the mother's home (e.g. 31% of mothers of WA Aboriginal twins gave birth at hospitals located more than 3 h by road from their home). Outcomes were worse for Aboriginal liveborn twins than Aboriginal singletons and non-Aboriginal twins (e.g. 58% of NSW Aboriginal twins were preterm compared to 9% of Aboriginal singletons and 49% non-Aboriginal twins). CONCLUSIONS: Mothers of Aboriginal twins faced significant challenges during the pregnancy, birth and the postnatal period in hospital and, in addition to accessible specialist medical care, these mothers may need extra practical and psychosocial support throughout their journey.

Maternal fetal programming of birthweight among Australian Aboriginal infants: a population-based data linkage study.

BACKGROUND: Low birthweight, which is common among Australian Aboriginal infants, has been found to persist across generations because of shared genetic and environmental factors and possibly fetal programming. Fetal programming refers to the response of a fetus to hostile uterine conditions with lifelong effects and possibly, in turn, providing a poorer uterine environment for future offspring. Fetal programming might have a greater effect in populations that have undergone rapid lifestyle transitions-for example, Indigenous populations. Disentangling causal effects is difficult, but family-based approaches could provide insights. We explored whether poor maternal fetal growth caused low birthweight in Aboriginal infants. METHODS: In this data linkage study, we used linked administrative health records of 12 865 singleton Aboriginal infants born in Western Australia between 1980 and 2010 and their relatives (including siblings born in 2011). Electronic birth records included all births since 1980 with at least 20 weeks completed gestation or a birthweight of 400 g. We compared parental-offspring birthweight associations using three approaches-a regression analysis of the complete sample, adjusting for confounding variables; a comparison of the maternal-offspring and paternal-offspring associations; and a within-cousin group comparison. We used binary and continuous measures of birthweight. We categorised infants and their parents as small for gestational age (SGA) if their birthweight was below the first decile of birthweights for all singleton livebirths of the same sex and gestational age in Australia between 1998 and 2007. FINDINGS: The relative risk (RR) of SGA birth was higher for infants with SGA mothers than for those with non-SGA mothers (RR 1·65, 95% CI 1·49 to 1·83), after adjusting for grandmaternal parity. After additional adjustment for maternal height, the risk remained higher for those with non-SGA mothers (RR 1·51, 1·36 to 1·68). The maternal birthweight Z score coefficient was 0·17 (95% CI 0·14 to 0·20), compared with 0·13 (0·10 to 0·16) for paternal birthweight, a difference of 0·03 (-0·01 to 0·08). In the cousin analysis, the maternal-offspring association was fully attenuated (0·00, 95% CI -0·05 to 0·06). Conditions in the current pregnancy were strongly associated with offspring birthweight Z score. Smoking was associated with a mean decrease of 0·39 (95% CI -0·45 to -0·34) in offspring birthweight Z score, drug misuse with a decrease of 0·31 (-0·43 to -0·20), and diabetes with an increase of 0·58 (0·39 to 0·77). INTERPRETATION: We found little support for maternal fetal programming causing low offspring birthweight. The similar maternal and paternal influence on birthweight and our cousin analysis suggested transmission of genetic and environmental factors could explain much of the maternal-offspring birthweight association. Compared with other risk factors in the current pregnancy, fetal programming appears to have little or no role in the high numbers of infants with low birthweight among Aboriginal populations. FUNDING: National Health and Medical Research Council of Australia and Bellberry Ltd.

Factors relating to high psychological distress in Indigenous Australians and their contribution to Indigenous-non-Indigenous disparities.

OBJECTIVE: To explore factors associated with high psychological distress among Aboriginal and non-Aboriginal Australians and their contribution to the elevated distress prevalence among Aboriginal people. METHODS: Questionnaire data from 1,631 Aboriginal and 233,405 non-Aboriginal 45 and Up Study (NSW, Australia) participants aged ≥45 years were used to calculate adjusted prevalence ratios for high psychological distress (Kessler-10 score ≥22) for socio-demographic, health and disability-related factors, and to quantify contributions to differences in distress prevalence. RESULTS: While high-distress prevalence was increased around three-fold in Aboriginal versus non-Aboriginal participants, distress-related risk factors were similar. Morbidity and physical disability had the strongest associations; high distress affected 43.8% of Aboriginal and 20.9% of non-Aboriginal participants with severe physical limitations and 9.5% and 3.9% of those without limitations, respectively. Differences in distress prevalence between Aboriginal and non-Aboriginal participants were essentially attributable to differences in SES, morbidity, disability/functional limitations and social support (fully-adjusted PR 1.19 [95% 1.08, 1.30]); physical morbidity and disability explained the bulk. CONCLUSIONS: The markedly elevated prevalence of high distress among older Aboriginal Australians appears largely attributable to greater physical morbidity and disability. Implications for public health: Addressing upstream determinants of physical morbidity and improved integration of social and emotional wellbeing care into primary care and chronic disease management are essential.

Factors relating to participation in follow-up to the 45 and up study in Aboriginal and non-Aboriginal individuals.

BACKGROUND: This study aimed to characterise the factors relating to participation in a postal follow-up study in Aboriginal and non-Aboriginal individuals, given the need to quantify potential biases from loss to follow-up and the lack of evidence regarding postal surveys among Aboriginal people. METHODS: The first 100,000 participants from the Sax Institute's 45 and Up Study, a large scale cohort study, were posted a follow-up questionnaire gathering general demographic, health and risk factor data, emphasising Social, Economic and Environmental Factors ("The SEEF Study"). For each variable of interest, percentages of those invited who went on to participate in follow-up were tabulated separately for Aboriginal and non-Aboriginal participants and age- and sex-adjusted participation rate ratios (aPRR) were calculated. RESULTS: Of the 692 Aboriginal and 97,178 non-Aboriginal invitees to the study, 314 Aboriginal (45 %) and 59,175 non-Aboriginal (61 %) individuals responded. While Aboriginal people were less likely to respond than non-Aboriginal people (aPRR 0.72, 95 % CI 0.66-0.78), factors related to response were similar. Follow-up study participants were more likely than non-participants to have university versus no educational qualifications (1.6, 1.3-2.0 [Aboriginal]; 1.5, 1.5-1.5 [non-Aboriginal]) and an annual income of ≥70,000 versus < $20,000 (1.6, 1.3-2.0; 1.2, 1.2-1.3 [χ (2) = 7.7; p = 0.001]). Current smokers (0.55, 0.42-0.72; 0.76, 0.74-0.77 [χ (2) = 7.14; p = 0.03]), those reporting poor self-rated health (0.68, 0.47-0.99; 0.65, 0.61-0.69), poor quality of life (0.63, 0.41-0.97; 0.61, 0.57-0.66) and very high psychological distress (0.71, 0.68-0.75 [non-Aboriginal]) were less likely than other cohort members to respond. CONCLUSIONS: Relatively large numbers of Aboriginal and non-Aboriginal individuals participated in the first 45 and Up Study follow-up suggesting that postal surveys can be used to follow Aboriginal participants in cohort studies. Despite somewhat greater loss to follow-up in Aboriginal people (after considering socio-demographic and health characteristics), factors related to follow-up participation were similar in both groups: greater loss was observed in those experiencing disadvantage, ill-health and health risk, with implications for interpretation of future findings. Aboriginal low income earners and current regular smokers had a particularly elevated likelihood of non-participation compared to non-Aboriginal people. These findings highlight the importance of identifying and addressing barriers to participation among hard-to-reach population groups.

Physical Functional Limitations among Aboriginal and Non-Aboriginal Older Adults: Associations with Socio-Demographic Factors and Health.

BACKGROUND: Australian Aboriginal people are disproportionately affected by physical disability; the reasons for this are unclear. This study aimed to quantify associations between severe physical functional limitations and socio-demographic and health-related factors among older Aboriginal and non-Aboriginal adults. METHODS: Questionnaire data from 1,563 Aboriginal and 226,802 non-Aboriginal participants aged ≥45 years from the Sax Institute's 45 and Up Study (New South Wales, Australia) were used to calculate age- and sex-adjusted prevalence ratios (aPRs) for severe limitation [MOS-PF score <60] according to socio-demographic and health-related factors. RESULTS: Overall, 26% (410/1563) of Aboriginal participants and 13% (29,569/226,802) of non-Aboriginal participants had severe limitations (aPR 2.8, 95%CI 2.5-3.0). In both Aboriginal and non-Aboriginal participants, severe limitation was significantly associated with: being ≥70 vs <70 years old (aPRs 1.8, 1.3-2.4 and 5.3, 5.0-5.5, within Aboriginal and non-Aboriginal participants, respectively), none vs tertiary educational qualifications (aPRs 2.4, 1.7-3.3 and 3.1, 3.0-3.2), lower vs higher income (aPRs 6.6, 4.2-10.5 and 5.5, 5.2-5.8), current vs never-smoking (aPRs 2.0, 1.6-2.5 and 2.2, 2.1-2.3), obese vs normal weight (aPRs 1.7, 1.3-2.2 and 2.7, 2.7-2.8) and sitting for ≥7 vs <7 hours/day (aPRs 1.6, 1.2-2.0 and 1.6, 1.6-1.7). Severe limitations increased with increasing ill-health, with aPRs rising to 5-6 for ≥5 versus no chronic conditions. It was significantly higher in those with few vs many social contacts (aPRs 1.7, 1.4-2.0 and 1.4, 1.4-1.4) and with very high vs low psychological distress (aPRs 4.4, 3.6-5.4 and 5.7, 5.5-5.9). CONCLUSIONS: Although the prevalence of severe physical limitation among Aboriginal people in this study is around three-fold that of non-Aboriginal people, the factors related to it are similar, indicating that Aboriginal people have higher levels of risk factors for and consequences of severe limitations. Effective management of chronic disease and reducing the prevalence of obesity and smoking are important areas for attention.

Measuring psychological distress in older Aboriginal and Torres Strait Islanders Australians: a comparison of the K-10 and K-5.

OBJECTIVES: To assess the cross-cultural validity of two Kessler psychological distress scales (K-10 and K-5) by examining their measurement properties among older Aboriginal and Torres Strait Islanders and comparing them to those in non-Aboriginal individuals from NSW Australia. METHODS: Self-reported questionnaire data from the 45 and Up Study for 1,631 Aboriginal and 231,774 non-Aboriginal people were used to examine the factor structure, convergent validity, internal consistency and levels of missing data of K-10 and K-5. RESULTS: We found excellent agreement in classification of distress of Aboriginal participants by K-10 and K-5 (weighted kappa=0.87), high internal consistency (Cronbach's alpha K-10: 0.93, K-5: 0.88), and factor structures consistent with those for the total Australian population. Convergent validity was evidenced by a strong graded relationship between the level of distress and the odds of: problems with daily activities due to emotional problems; current treatment for depression or anxiety; and poor quality of life. CONCLUSIONS AND IMPLICATIONS: K-10 and K-5 scales are promising tools for measuring psychological distress among Aboriginal and Torres Strait Islanders aged 45 and over in research and clinical settings.

Design-based stereological methods for estimating numbers of glomerular podocytes.

The podocyte depletion hypothesis has emerged as a unifying concept in glomerular pathology. According to this hypothesis podocyte depletion may be absolute (decrease in number of healthy mature podocytes), relative (fewer podocytes per unit of glomerular volume) or involve alterations to the specialized podocyte architecture (such as foot process effacement). To study and understand podocyte depletion it is important to be able to accurately and precisely count these cells. Here we present new design-based stereological methods for estimating podocyte number in individual glomeruli of known volume, and in average glomeruli. Both methods involve serial histological sectioning, triple label immunohistochemistry, laser confocal microscopy and cell counting with the optical disector/fractionator.

The overall health and risk factor profile of Australian Aboriginal and Torres Strait Islander participants from the 45 and up study.

BACKGROUND: Despite large disparities in health outcomes between Aboriginal and non-Aboriginal Australians, detailed evidence on the health and lifestyle characteristics of older Aboriginal Australians is lacking. The aim of this study is to quantify socio-demographic and health risk factors and mental and physical health status among Aboriginal participants from the 45 and Up Study and to compare these with non-Aboriginal participants from the study. METHODS: The 45 and Up Study is a large-scale study of individuals aged 45 years and older from the general population of New South Wales, Australia responding to a baseline questionnaire distributed from 2006-2008. Odds ratios (OR) and 95% confidence intervals (CI) of self-reported responses from the baseline questionnaire for Aboriginal versus non-Aboriginal participants relating to socio-demographic factors, health risk factors, current and past medical and surgical history, physical disability, functional health limitations and levels of current psychological distress were calculated using unconditional logistic regression, with adjustments for age and sex. RESULTS: Overall, 1939 of 266,661 45 and Up Study participants examined in this study identified as Aboriginal and/or Torres Strait Islander (0.7%). Compared to non-Aboriginal participants, Aboriginal participants were significantly more likely to be: younger (mean age 58 versus 63 years); without formal educational qualifications (age- and sex- adjusted OR=6.2, 95% CI 5.3-7.3); of unemployed (3.7, 2.9-4.6) or disabled (4.6, 3.9-5.3) work status; and with a household income< $20,000/year versus ≥$70,000/year (5.8, 5.0-6.9). Following additional adjustment for income and education, Aboriginal participants were significantly more likely than non-Aboriginal participants to: be current smokers (2.4, 2.0-2.8), be obese (2.1, 1.8-2.5), have ever been diagnosed with certain medical conditions (especially: diabetes [2.1, 1.8-2.4]; depression [1.6, 1.4-1.8] and stroke [1.8, 1.4-2.3]), have care-giving responsibilities (1.8, 1.5-2.2); have a major physical disability (2.6, 2.2-3.1); have severe physical functional limitation (2.9, 2.4-3.4) and have very high levels of psychological distress (2.4, 2.0-3.0). CONCLUSIONS: Aboriginal participants from the 45 and Up Study experience greater levels of disadvantage and have greater health needs (including physical disability and psychological distress) compared to non-Aboriginal participants. The study highlights the need to address the social determinants of health in Australia and to provide appropriate mental health services and disability support for older Aboriginal people.