Association between maternal mental health-related hospitalisation in the 5 years prior to or during pregnancy and adverse birth outcomes: a population-based retrospective cohort data linkage study in the Northern Territory of Australia

Background

Mental health conditions prior to or during pregnancy that are not addressed can have adverse consequences for pregnancy and birth outcomes. This study aimed to determine the extent to which women's mental health-related hospitalisation (MHrH) prior to or during pregnancy was associated with a risk of adverse birth outcomes.

Methods

We linked the perinatal data register for all births in the Northern Territory, Australia, from the year 1999 to 2017, to hospital admissions records to create a cohort of births to women aged 15-44 years with and without MHrH prior to or during pregnancy. We used Modified Poisson Regression and Latent Class Analysis to assess the association between maternal MHrH and adverse birth outcomes (i.e., stillbirth, preterm birth, low birth weight, and short birth length). We explored a mediation effect of covariates on theoretical causal paths. We calculated the adjusted Population Attributable Fraction (PAF) and Preventive Fractions for the Population (PFP) for valid associations.

Findings

From 72,518 births, 70,425 births (36.4% for Aboriginal women) were included in the analysis. The Latent Class Analys identified two classes: high (membership probability of 10.5%) and low adverse birth outcomes. Births to Aboriginal women with MHrH were around two times more likely to be in the class of high adverse birth outcomes. MHrH prior to or during pregnancy increased the risk of all adverse birth outcomes in both populations with risk ranging from 1.19 (95% CI: 1.05, 1.35) to 7.89 (1.17, 53.37). Eight or more antenatal care visits and intrauterine growth restriction mostly played a significant mediation role between maternal MHrH and adverse birth outcomes with mediation effects ranging from 1.04 (1.01, 1.08) to 1.39 (1.14, 1.69). MHrH had a low to high population impact with a PAF ranging from 16.1% (5.1%, 25.7%) to 87.3% (14.3%, 98.1%). Eight or above antenatal care visits avert extra adverse birth outcomes that range from 723 (332-765) stillbirths to 3003 (1972-4434) preterm births.

Interpretation

Maternal MHrH is a modifiable risk factor that explained a low to moderate risk of adverse birth outcomes in the Northern Territory. The knowledge highlights the need for the development and implementation of preconception mental health care into routine health services.

Funding

The Child and Youth Development Research Partnership (CYDRP) data repository is supported by a grant from the Northern Territory Government.

Determining the Optimal Methodology for Identifying Incident Stroke Deaths Using Administrative Datasets Within Australia

BACKGROUND AND AIM

Quantifying stroke incidence and mortality is crucial for disease surveillance and health system planning. Administrative data offer a cost-effective alternative to "gold standard" population-based studies. However, the optimal methodology for establishing stroke deaths from administrative data remains unclear. We aimed to determine the optimal method for identifying stroke-related deaths in administrative datasets as the fatal component of stroke incidence, comparing counts derived using underlying and all causes of death (CoD).

METHOD

Using whole-population multijurisdictional person-level linked data from hospital and death datasets from South Australia, the Northern Territory, and Western Australia, we identified first-ever stroke events between 2012 and 2015, using underlying CoD and all CoD to identify fatal stroke counts. We determined the 28-day case fatality for both counts and compared results with gold standard Australian population-based stroke incidence studies.

RESULTS

The total number of incident stroke events was 16,150 using underlying CoD and 18,074 using all CoD. Case fatality was 24.7% and 32.7% using underlying and all CoD, respectively. Case fatality using underlying CoD was similar to that observed in four Australian "gold standard" population-based studies (20%-24%).

CONCLUSIONS

Underlying CoD generates fatal incident stroke estimates more consistent with population-based studies than estimates based on stroke deaths identified from all-cause fields in death registers.

Predicting child development and school readiness, at age 5, for Aboriginal and non-Aboriginal children in Australia's Northern Territory

BACKGROUND

Positive early development is critical in shaping children's lifelong health and wellbeing. Identifying children at risk of poor development is important in targeting early interventions to children and families most in need of support. We aimed to develop a predictive model that could inform early support for vulnerable children.

METHODS

We analysed linked administrative records for a birth cohort of 2,380 Northern Territory children (including 1,222 Aboriginal children) who were in their first year of school in 2015 and had a completed record from the Australian Early Development Census (AEDC). The AEDC measures early child development (school readiness) across five domains of development. We fitted prediction models, for AEDC weighted summary scores, using a Partial Least Square Structural Equation Model (PLS-SEM) considering four groups of factors-pre-pregnancy, pregnancy, known at birth, and child-related factors. We first assessed the models' internal validity and then the out-of-sample predictive power (external validity) using the PLSpredict procedure.

RESULT

We identified separate predictive models, with a good fit, for Aboriginal and non-Aboriginal children. For Aboriginal children, a significant pre-pregnancy predictor of better outcomes was higher socioeconomic status (direct, β = 0.22 and indirect, β = 0.16). Pregnancy factors (gestational diabetes and maternal smoking (indirect, β = -0.09) and child-related factors (English as a second language and not attending preschool (direct, β = -0.28) predicted poorer outcomes. Further, pregnancy and child-related factors partially mediated the effects of pre-pregnancy factors; and child-related factors fully mediated the effects of pregnancy factors on AEDC weighted scores. For non-Aboriginal children, pre-pregnancy factors (increasing maternal age, socioeconomic status, parity, and occupation of the primary carer) directly predicted better outcomes (β = 0.29). A technical observation was that variance in AEDC weighted scores was not equally captured across all five AEDC domains; for Aboriginal children results were based on only three domains (emotional maturity; social competence, and language and cognitive skills (school-based)) and for non-Aboriginal children, on a single domain (language and cognitive skills (school-based)).

CONCLUSION

The models give insight into the interplay of multiple factors at different stages of a child's development and inform service and policy responses. Recruiting children and their families for early support programs should consider both the direct effects of the predictors and their interactions. The content and application of the AEDC measurement need to be strengthened to ensure all domains of a child's development are captured equally.

Incidence of Stroke in the Aboriginal and Non-Aboriginal Populations of Australia: A Data Linkage Study

BACKGROUND

Most estimates of stroke incidence among Aboriginal and Torres Strait Islander (hereinafter Aboriginal) Australians are confined to single regions and include small sample sizes. We aimed to measure and compare stroke incidence in Aboriginal and non-Aboriginal residents across central and western Australia.

METHODS

Whole-population multijurisdictional person-linked data from hospital and death datasets were used to identify stroke admissions and stroke-related deaths (2001-2015) in Western Australia, South Australia, and the Northern Territory. Fatal (including out-of-hospital deaths) and nonfatal incident (first-ever) strokes in patients aged 20-84 years were identified during the 4-year study period (2012-2015), using a 10-year lookback period to exclude people with prior stroke. Incidence rates per 100 000 population/year were estimated for Aboriginal and non-Aboriginal populations, age-standardized to the World Health Organization World Standard population.

RESULTS

In a population of 3 223 711 people (3.7% Aboriginal), 11 740 incident (first-ever) strokes (20.6% regional/remote location of residence; 15.6% fatal) were identified from 2012 to 2015, 675 (5.7%) in Aboriginal people (73.6% regional/remote; 17.0% fatal). Median age of Aboriginal cases (54.5 years; 50.1% female) was 16 years younger than non-Aboriginal cases (70.3 years; 44.1% female; P<0.001), with significantly greater prevalence of comorbidities. Age-standardized stroke incidence in Aboriginal people (192/100 000 [95% CI, 177-208]) was 2.9-fold greater than in non-Aboriginal people (66/100 000 [95% CI, 65-68]) aged 20-84 years; fatal incidence was 4.2-fold greater (38/100 000 [95% CI, 31-46] versus 9/100 000 [95% CI, 9-10]). Disparities were particularly apparent at younger ages (20-54 years), where age-standardized stroke incidence was 4.3-fold greater in Aboriginal people (90/100 000 [95% CI, 81-100]) than non-Aboriginal people (21/100 000 [95% CI, 20-22]).

CONCLUSIONS

Stroke occurred more commonly, and at younger ages, in Aboriginal than non-Aboriginal populations. Greater prevalence of baseline comorbidities was present in the younger Aboriginal population. Improved primary prevention is required. To optimize stroke prevention, interventions should include culturally appropriate community-based health promotion and integrated support for nonmetropolitan health services.

Risk of kidney disease following a pregnancy complicated by diabetes: a longitudinal, population-based data-linkage study among Aboriginal women in the Northern Territory, Australia

AIMS/HYPOTHESIS

The aim of this work was to investigate the risk of developing chronic kidney disease (CKD) or end-stage kidney disease (ESKD) following a pregnancy complicated by gestational diabetes mellitus (GDM) or pre-existing diabetes among Aboriginal women in the Northern Territory (NT), Australia.

METHODS

We undertook a longitudinal study of linked healthcare datasets. All Aboriginal women who gave birth between 2000 and 2016 were eligible for inclusion. Diabetes status in the index pregnancy was as recorded in the NT Perinatal Data Collection. Outcomes included any stage of CKD and ESKD as defined by ICD-10 coding in the NT Hospital Inpatient Activity dataset between 2000 and 2018. Risk was compared using Cox proportional hazards regression.

RESULTS

Among 10,508 Aboriginal women, the mean age was 23.1 (SD 6.1) years; 731 (7.0%) had GDM and 239 (2.3%) had pre-existing diabetes in pregnancy. Median follow-up was 12.1 years. Compared with women with no diabetes during pregnancy, women with GDM had increased risk of CKD (9.2% vs 2.2%, adjusted HR 5.2 [95% CI 3.9, 7.1]) and ESKD (2.4% vs 0.4%, adjusted HR 10.8 [95% CI 5.6, 20.8]). Among women with pre-existing diabetes in pregnancy, 29.1% developed CKD (adjusted HR 10.9 [95% CI 7.7, 15.4]) and 9.9% developed ESKD (adjusted HR 28.0 [95% CI 13.4, 58.6]).

CONCLUSIONS/INTERPRETATION

Aboriginal women in the NT with GDM or pre-existing diabetes during pregnancy are at high risk of developing CKD and ESKD. Pregnancy presents an important opportunity to identify kidney disease risk. Strategies to prevent kidney disease and address the social determinants of health are needed.

Suicides in Aboriginal and non-Aboriginal people following hospital admission for suicidal ideation and self-harm: A retrospective cohort data linkage study from the Northern Territory

PURPOSE

This study aimed to explore risk factors for suicide in Aboriginal and non-Aboriginal people following hospital admission for suicidal ideation and self-harm in the Northern Territory, Australia to help clarify opportunities for improved care and intervention for these population groups.

METHODS

Individuals with at least one hospital admission involving suicidal ideation and/or self-harm between 1 July 2001 and 31 December 2013 were retrospectively recruited and followed up using linked mortality records to 31 December 2014. Survival analyses stratified by Indigenous status identified socio-demographic and clinical characteristics from index hospital admissions associated with suicide.

RESULTS

Just over half of the 4391 cohort members identified as Aboriginal (n = 2304; 52.4%). By 2014, 281 deaths were observed comprising 68 suicides, representing a 2.6% and 2.0% probability of suicide for Aboriginal and non-Aboriginal people, respectively. After adjusting for other characteristics, a higher risk of suicide was associated with male sex (Aboriginal adjusted hazard ratio: 4.14; 95% confidence interval: [1.76, 9.75]; non-Aboriginal adjusted hazard ratio: 5.96; 95% confidence interval: [1.98, 17.88]) and repeat hospital admissions involving self-harm (Aboriginal adjusted hazard ratio: 1.37; 95% confidence interval: [1.21, 1.55]; non-Aboriginal adjusted hazard ratio: 1.29; 95% confidence interval: [1.10, 1.51]). Severe mental disorders were associated with a four times higher risk of suicide (adjusted hazard ratio: 4.23; 95% confidence interval: [1.93, 9.27]) in Aboriginal people only.

CONCLUSION

The findings highlight non-clinical risk factors for suicide that suggest the need for comprehensive psychosocial assessment tailored to Aboriginal and non-Aboriginal people hospitalised with suicidal ideation or self-harm. Implementing appropriate management and aftercare within a broader public health framework is needed to support recovery and reduce long-term suicide risk in the community, especially for Aboriginal people and males.

The extent of violence inflicted on adolescent Aboriginal girls in the Northern Territory

Background

Australian Aboriginal and Torres Strait Islander women are at very high risk of violence but there is little evidence about the age at which their higher exposure to violence commences. The aim of this study was to investigate violence inflicted on Aboriginal girls during childhood and adolescence, relative to Aboriginal boys and non-Aboriginal girls.

Methods

This was a retrospective cohort study using de-identified administrative data for NT residents aged 0-17 years. This study used linked hospital and child protection data to investigate hospitalization for injury caused by assault and substantiated child maltreatment involving violence (physical and sexual abuse).

Results

The incidence of assault hospitalization and substantiated physical/sexual abuse was much higher for Aboriginal than non-Aboriginal adolescents but similar for girls and boys to about age ten, then increased much more for Aboriginal girls than boys. In the 14-17 age-group, assault hospitalization incidence was 125% higher for Aboriginal girls than boys but 56% lower for non-Aboriginal girls than boys. 4.6% of Aboriginal girls were hospitalized (30.9% more than once) for assault between twelfth and eighteenth birthdays, compared to 3.4% of Aboriginal boys and 0.3% of non-Aboriginal girls. The incidence of assault hospitalization during adolescence was over three times higher for Aboriginal children who had substantiated child maltreatment during childhood.

Conclusion

The very high levels of violence suffered by Aboriginal women commence in the pre-teen years. Non-Aboriginal girls are ‘protected’ from the rising levels of violence that boys experience as they progress through adolescence, but Aboriginal girls are not afforded such protection.

Prevalence and incidence of diabetes among Aboriginal people in remote communities of the Northern Territory, Australia: a retrospective, longitudinal data-linkage study

OBJECTIVES

To assess the prevalence and incidence of diabetes among Aboriginal peoples in remote communities of the Northern Territory (NT), Australia.

DESIGN

Retrospective cohort analysis of linked clinical and administrative data sets from 1 July 2012 to 30 June 2019.

SETTING

Remote health centres using the NT Government Primary Care Information System (51 out of a total of 84 remote health centres in the NT).

PARTICIPANTS

All Aboriginal clients residing in remote communities serviced by these health centres (N=21 267).

PRIMARY OUTCOME MEASURES

Diabetes diagnoses were established using hospital and primary care coding, biochemistry and prescription data.

RESULTS

Diabetes prevalence across all ages increased from 14.4% (95% CI: 13.9% to 14.9%) to 17.0% (95% CI: 16.5% to 17.5%) over 7 years. Among adults (≥20 years), the 2018/2019 diabetes prevalence was 28.6% (95% CI: 27.8% to 29.4%), being higher in Central Australia (39.5%, 95% CI: 37.8% to 41.1%) compared with the Top End region (24.2%, 95% CI: 23.3% to 25.1%, p<0.001). Between 2016/2017 and 2018/2019, diabetes incidence across all ages was 7.9 per 1000 person-years (95% CI: 7.3 to 8.7 per 1000 person-years). The adult incidence of diabetes was 12.6 per 1000 person-years (95% CI: 11.5 to 13.8 per 1000 person-years).

CONCLUSIONS

The burden of diabetes in the remote Aboriginal population of the NT is among the highest in the world. Strengthened systems of care and public health prevention strategies, developed in partnership with Aboriginal communities, are needed.

Learning from alcohol (policy) reforms in the Northern Territory (LEARNT): protocol for a mixed-methods study examining the impacts of the banned drinker register

INTRODUCTION

The Banned Drinker Register (BDR) was reintroduced in the Northern Territory (NT) in September 2017. The BDR is a supply reduction measure and involves placing people who consume alcohol at harmful levels on a register prohibiting the purchase, possession and consumption of alcohol. The current study aims to evaluate the impacts of the reintroduction of the BDR, in the context of other major alcohol policy initiatives introduced across the NT such as Police Auxiliary Liquor Inspectors and a minimum unit price for alcohol of US$1.30 per standard drink.

METHODS AND ANALYSES

The Learning from Alcohol (policy) Reforms in the Northern Territory project will use a mixed-methods approach and contain four major components: epidemiological analysis of trends over time (outcomes include health, justice and social welfare data); individual-level data linkage including those on the BDR (outcomes include health and justice data); qualitative interviews with key stakeholders in the NT (n≥50); and qualitative interviews among people who are, or were previously, on the BDR, as well as the families and communities connected to those on the BDR (n=150). The impacts of the BDR on epidemiological data will be examined using time series analysis. Linked data will use generalised mixed models to analyse the relationship between outcomes and exposures, utilising appropriate distributions. Qualitative data will be analysed using thematic analysis.

ETHICS AND DISSEMINATION

Ethics approvals have been obtained from NT Department of Health and Menzies School of Health Research Human Research Ethics Committee (HREC), Central Australia HREC and Deakin University HREC. In addition to peer-reviewed publications, we will report our findings to key organisational, policy, government and community stakeholders via conferences, briefings and lay summaries.

Effects of turnover and stability of health staff on quality of care in remote communities of the Northern Territory, Australia: a retrospective cohort study

OBJECTIVES

To evaluate the relationship between markers of staff employment stability and use of short-term healthcare workers with markers of quality of care. A secondary objective was to identify clinic-specific factors which may counter hypothesised reduced quality of care associated with lower stability, higher turnover or higher use of short-term staff.

DESIGN

Retrospective cohort study (Northern Territory (NT) Department of Health Primary Care Information Systems).

SETTING

All 48 government primary healthcare clinics in remote communities in NT, Australia (2011-2015).

PARTICIPANTS

25 413 patients drawn from participating clinics during the study period.

OUTCOME MEASURES

Associations between independent variables (resident remote area nurse and Aboriginal Health Practitioner turnover rates, stability rates and the proportional use of agency nurses) and indicators of health service quality in child and maternal health, chronic disease management and preventive health activity were tested using linear regression, adjusting for community and clinic size. Latent class modelling was used to investigate between-clinic heterogeneity.

RESULTS

The proportion of resident Aboriginal clients receiving high-quality care as measured by various quality indicators varied considerably across indicators and clinics. Higher quality care was more likely to be received for management of chronic diseases such as diabetes and least likely to be received for general/preventive adult health checks. Many indicators had target goals of 0.80 which were mostly not achieved. The evidence for associations between decreased stability measures or increased use of agency nurses and reduced achievement of quality indicators was not supported as hypothesised. For the majority of associations, the overall effect sizes were small (close to zero) and failed to reach statistical significance. Where statistically significant associations were found, they were generally in the hypothesised direction.

CONCLUSIONS

Overall, minimal evidence of the hypothesised negative effects of increased turnover, decreased stability and increased reliance on temporary staff on quality of care was found. Substantial variations in clinic-specific estimates of association were evident, suggesting that clinic-specific factors may counter any potential negative effects of decreased staff employment stability. Investigation of clinic-specific factors using latent class analysis failed to yield clinic characteristics that adequately explain between-clinic variation in associations. Understanding the reasons for this variation would significantly aid the provision of clinical care in remote Australia.

Opportunities for prevention: a data-linkage study to inform a public health response to youth offending in the Northern Territory, Australia

BACKGROUND

Numerous studies have demonstrated a strong link between child maltreatment and subsequent youth offending, leading to calls for early intervention initiatives. However, there have been few whole-population studies into the dimensions of statutory child maltreatment responses that can inform these programs. The aim of this study was to investigate the sex-specific association between level and timing of child protection system (CPS) contact and youth offending.

METHODS

This retrospective cohort study used linked individual-level records from multiple agencies, for 10,438Aboriginal children born in the Northern Territory between 1999 and 2006. The outcome measure was the first alleged offence. Key explanatory variables were level (no contact through to out-of-home care) and timing (0-4 years, 5-9 years, or both) of CPS contact. The Kaplan-Meier method was used to estimate cumulative incidence and a flexible parametric survival model to estimate hazard ratios (HR).

RESULTS

Children with no record of CPS contact before age 10 had the lowest cumulative incidence of first alleged offence by age 18 (boys: 23.4% [95%CI:21.0-26.1]; girls: 6.6% [95%CI:5.3-8.2]) and those with a record of out-of-home care the highest CI (boys: 45.5% [95%CI:37.0-54.9]; girls: 18.6% [95%CI:13.0-26.2]). The association of CPS contact with the relative risk of a first alleged offence was greatest for children aged 10-13 years and decreased with age. Timing of CPS contact was also associated with increasing cumulative incidence. The relative risk for first alleged offence was generally higher for children with CPS contact, of any type, during both developmental phases including notifications during both phases (boys, HR at age 11: 8.9 [95%CI:4.2-17.2]; girls, HR at age 11: 13.7 [95%CI:3.8-48.9]) and substantiations during both phases (boys, HR at age 11: 17.0 [95%CI:9.6-30.0]; girls, HR at age 11: 54.1 [95%CI:18.1-162]).

CONCLUSION

The increased risk of offending associated with level and timing of early CPS contact highlights opportunities for a differentiated public health response to improve life trajectories for children and to reduce youth crime. Although children with unsubstantiated notifications of maltreatment do not meet the criteria for a statutory CPS response, the higher risk of offending among these children supports their inclusion in targeted preventive interventions.

Understanding and responding to the cost and health impact of short-term health staffing in remote and rural Aboriginal and Torres Strait Islander community-controlled health services: a mixed methods study protocol

INTRODUCTION

Access to high-quality primary healthcare is limited for remote residents in Australia. Increasingly, remote health services are reliant on short-term or 'fly-in, fly-out/drive-in, drive-out' health workforce to deliver primary healthcare. A key strategy to achieving health service access equity, particularly evident in remote Australia, has been the development of Aboriginal Community Controlled Health Services (ACCHSs). This study aims to generate new knowledge about (1) the impact of short-term staffing in remote and rural ACCHSs on Aboriginal and Torres Strait Islander communities; (2) the potential mitigating effect of community control; and (3) effective, context-specific evidence-based retention strategies.

METHODS AND ANALYSIS

This paper describes a 3-year, mixed methods study involving 12 ACCHSs across three states. The methods are situated within an evidence-based programme logic framework for rural and remote primary healthcare services. Quantitative data will be used to describe staffing stability and turnover, with multiple regression analyses to determine associations between independent variables (population size, geographical remoteness, resident staff turnover and socioeconomic status) and dependent variables related to patient care, service cost, quality and effectiveness. Qualitative assessment will include interviews and focus groups with clinical staff, clinic users, regionally-based retrieval staff and representatives of jurisdictional peak bodies for the ACCHS sector, to understand the impact of short-term staff on quality and continuity of patient care, as well as satisfaction and acceptability of services.

ETHICS AND DISSEMINATION

The study has ethics approval from the Human Research Ethics Committee of the Northern Territory Department of Health and Menzies School of Health Research (project number DR03171), Central Australian Human Research Ethics Committee (CA-19-3493), Western Australian Aboriginal Health Ethics Committee (WAAHEC-938) and Far North Queensland Human Research Ethics Committee (HREC/2019/QCH/56393). Results will be disseminated through peer-reviewed journals, the project steering committee and community/stakeholder engagement activities to be determined by each ACCHS.

Patterns of child protection service involvement by Aboriginal children associated with a higher risk of self-harm in adolescence: A retrospective population cohort study using linked administrative data

BACKGROUND

A history of child maltreatment is known to elevate the risk of self-harm in adolescence. However, this link has not been investigated for Aboriginal children who experience a greater burden of both.

OBJECTIVE

Identify patterns of involvement with child protection services by Aboriginal children associated with a higher risk of self-harm in adolescence.

PARTICIPANTS AND SETTING

A cohort study was established using linked administrative records of Aboriginal children born in the Northern Territory (NT) of Australia.

METHODS

Survival analysis techniques were used to determine the risk of self-harm in adolescence associated with different levels and timing of child protection involvement throughout childhood.

RESULT

The relative risk of self-harm was greatest for children with substantiated maltreatment in both early and middle childhood had nine times higher risk for self-harm (aHR: 9.11, 95% CI: 3.39-24.46,p < 0.001) and six times higher for children who experienced notifications in early childhood and substantiated maltreatment in middle childhood (aHR: 6.72, 95% CI:2.16-20.90, p < 0.001). Other patterns of child protection involvement observed in middle childhood alone also conferred a higher relative risk of self-harm in adolescence.

CONCLUSION

This study confirms a higher risk of self-harm in adolescence is associated with child maltreatment, especially in middle childhood. Addressing the intergenerational trauma in Aboriginal families is crucial to preventing child maltreatment and informing reforms to child protection responses that can better identify and address the culturally-specific unmet needs of Aboriginal families. This would go some way to fostering the healthy growth and development of Aboriginal children and reduce self-harm risk.

Acute myocardial infarction incidence and survival in Aboriginal and non-Aboriginal populations: an observational study in the Northern Territory of Australia, 1992-2014

OBJECTIVES

To examine long-term trends in acute myocardial infarction (AMI) incidence and survival among Aboriginal and non-Aboriginal people.

DESIGN

Retrospective cohort study.

SETTING, PARTICIPANTS

All first AMI hospital cases and deaths due to ischaemic heart disease in the Northern Territory of Australia (NT), 1992-2014.

MAIN OUTCOME MEASURES

Age standardised incidence, survival and mortality.

RESULTS

The upward trend in Aboriginal AMI incidence plateaued around 2007 for males and 2001 for females. AMI incidence decreased for non-Aboriginal population, consistent with the national trends. AMI incidence was higher and survival lower for males, for Aboriginal people and in older age groups. In 2014, the age standardised incidence was 881 and 579 per 100 000 for Aboriginal males and females, respectively, compared with 290 and 187 per 100 000 for non-Aboriginal counterparts. The incidence disparity between Aboriginal and non-Aboriginal population was much greater in younger than older age groups. Survival after an AMI improved over time, and more so for Aboriginal than non-Aboriginal patients, because of a decrease in prehospital deaths and improved survival of hospitalised cases.

CONCLUSIONS

There was an important breakpoint in increasing trends of Aboriginal AMI incidence between 2001 and 2007. The disparity in AMI survival between the NT Aboriginal and non-Aboriginal populations reduced over time as survival improved for both populations.

Impact of hearing impairment on early childhood development in Australian Aboriginal children: A data linkage study

AIM

To investigate the association between hearing impairment (HI) and measures of early childhood development in Aboriginal children at age 5 years.

METHODS

An observational cohort study (n = 1037) of children aged 4.0-7.3 years (median 5.4 years), living in remote Northern Territory (NT) communities, was conducted using multiple linked administrative datasets, including the NT Perinatal Data Register, Remote Hearing Assessment records (2007-2015) and Australian Early Development Censuses (AEDC, 2009, 2012 and 2015). Outcome measures were summary and domain-specific AEDC results using both dichotomous and continuous variables (domain scores).

RESULTS

Compared with normal hearing children, after adjustment for selected confounding factors, those with moderate or worse HI had an adjusted odds ratio of 1.69 (95% confidence interval (CI), 1.03-2.77) for being developmentally vulnerable in two or more of the five AEDC domains. Children with mild HI and those with moderate to worse HI had lower domain score sum by -1.60 (95% CI, -3.02 to -0.18) and - 2.40 (95% CI, -4.50 to -0.30), respectively. There was also evidence for an association between HI and poorer outcomes in the 'language and cognitive skills', 'communication skills and general knowledge' and 'physical health and wellbeing' domains.

CONCLUSIONS

Otitis media-related HI is associated with increased risk for poorer outcomes in early childhood development and this risk appears to increase with higher levels of HI. Prevention and early treatment of otitis media will reduce both the disease and the associated negative impact on early child development, especially the development of language, cognitive and communication skills and physical health and wellbeing.

Cost impact of high staff turnover on primary care in remote Australia

Objectives The aim of this study was to estimate the costs of providing primary care and quantify the cost impact of high staff turnover in Northern Territory (NT) remote communities. Methods This cost impact assessment used administrative data from NT Department of Health datasets, including the government accounting system and personnel information and payroll systems between 2004 and 2015, and the primary care information system from 2007 to 2015. Data related to 54 government-managed clinics providing primary care for approximately 27200 Aboriginal and non-Aboriginal people. Main outcome measures were average costs per consultation and per capita, cost differentials by clinic, year and levels of staff turnover. Linear regression and dominance analysis were used to assess the effect of staff turnover on primary care costs, after adjusting for remoteness and weighting analysis by service population. Both current and constant prices were used. Results On average, in constant prices, there was a nearly 10% annual increase in remote clinic expenditure between 2004 and 2015 and an almost 15% annual increase in consultation numbers since 2007. In real terms, the average costs per consultation decreased markedly from A$273 in 2007 to A$197 in 2015, a figure still well above the Medicare bulk-billing rate. The cost differentials between clinics were proportional to staff turnover and remoteness (both P<0.001). A 10% higher annual turnover rate pertains to an A$6.12 increase in costs per consultation. Conclusions High staff turnover exacerbates the already high costs of providing primary care in remote areas, costing approximately A$50 extra per consultation. This equates to an extra A$400000 per clinic per year on average, or A$21million annually for the NT government. Over time, sustained investments in developing a more stable primary care workforce should not only improve primary care in remote areas, but also reduce the costs of excessive turnover and overall service delivery costs. What is known about the topic? Population size and geographical remoteness are important cost drivers in remote clinics, whereas elsewhere in Australia the high use of short-term staff to fill positions has been identified as a major contributor to higher nurse turnover costs and to overall health service costs. Nursing staff expenditure accounts for a large proportion (46%) of total expenditure in NT remote health services, whereas expenditure on Aboriginal Health Practitioners (AHPs) comprises only 6%. Annual nurse turnover rates in remote NT clinics average approximately 150%, whereas levels of 40% in other contexts are considered high. What does this paper add? Annual expenditure for NT remote clinics has increased, on average, by 10% per annum between 2004 and 2015, but small declines in real expenditure have been observed from a maximum in 2012. Expenditure on nursing staff comprises 40% of overall expenditure in remote clinics, whereas expenditure on AHPs comprises less than 5%. The cost impact of every 10% increase in remote nurse and AHP annual turnover has been quantified as an extra A$6.12 per primary care consultation, which equates, on average, to an extra A$400000 per remote clinic, and an extra A$21million overall for the NT Department of Health each year. The average real expenditure per primary care consultation has decreased from A$273 in 2007 to A$197 in 2015, representing a statistically significant linear trend reduction of A$7.71 per consultation annually. What are the implications for practitioners (and other decision-makers)? Adjusting policy settings away from the high use of short-term staff to investment in appropriate training 'pipelines' for the remote primary care workforce may, in the medium and longer term, result in reduced turnover of resident staff and associated cost savings. Targeted recruitment and retention strategies that ensure individual primary care workers are an optimal fit with the remote communities in which they work, together with improved professional and personal support for staff residing in remote communities, may also help reduce turnover, improve workforce stability and lead to stronger therapeutic relationships and better health outcomes.

SAFety, Effectiveness of care and Resource use among Australian Hospitals (SAFER Hospitals): a protocol for a population-wide cohort study of outcomes of hospital care

INTRODUCTION

Despite global concerns about the safety and quality of health care, population-wide studies of hospital outcomes are uncommon. The SAFety, Effectiveness of care and Resource use among Australian Hospitals (SAFER Hospitals) study seeks to estimate the incidence of serious adverse events, mortality, unplanned rehospitalisations and direct costs following hospital encounters using nationwide data, and to assess the variation and trends in these outcomes.

METHODS AND ANALYSIS

SAFER Hospitals is a cohort study with retrospective and prospective components. The retrospective component uses data from 2012 to 2018 on all hospitalised patients age ≥18 years included in each State and Territories' Admitted Patient Collections. These routinely collected datasets record every hospital encounter from all public and most private hospitals using a standardised set of variables including patient demographics, primary and secondary diagnoses, procedures and patient status at discharge. The study outcomes are deaths, adverse events, readmissions and emergency care visits. Hospitalisation data will be linked to subsequent hospitalisations and each region's Emergency Department Data Collections and Death Registries to assess readmissions, emergency care encounters and deaths after discharge. Direct hospital costs associated with adverse outcomes will be estimated using data from the National Cost Data Collection. Variation in these outcomes among hospitals will be assessed adjusting for differences in hospitals' case-mix. The prospective component of the study will evaluate the temporal change in outcomes every 4 years from 2019 until 2030.

ETHICS AND DISSEMINATION

Human Research Ethics Committees of the respective Australian states and territories provided ethical approval to conduct this study. A waiver of informed consent was granted for the use of de-identified patient data. Study findings will be disseminated via presentations at conferences and publications in peer-reviewed journals.

Diabetes during pregnancy and birthweight trends among Aboriginal and non-Aboriginal people in the Northern Territory of Australia over 30 years

Background

Early-life risk factors, including maternal hyperglycaemia and birthweight, are thought to contribute to the high burden of cardiometabolic disease experienced by Indigenous populations. We examined rates of pre-existing diabetes in pregnancy, gestational diabetes mellitus (GDM) and extremes of birthweight over three decades in the Northern Territory (NT) of Australia.

Methods

We performed a retrospective cohort analysis of the NT Perinatal Data Collection from 1987 to 2016, including all births >20 weeks gestation, stratified by maternal Aboriginal identification. Key outcomes were annual rates of pre-existing diabetes, GDM, small-for-gestational-age, large-for-gestational-age, low birthweight (<2500 g), and high birthweight (>4000 g). Logistic regression was used to assess trends and interactions.

Findings

109 349 babies were born to 64 877 mothers, 36% of whom identified as Aboriginal ethnicity. Among Aboriginal women, rates of GDM and pre-existing diabetes, respectively, were 3 · 4% and 0 · 6% in 1987 and rose to 13% and 5 · 7% in 2016 (both trends p<0 · 001). Among non-Aboriginal women, rates of GDM increased from 1 · 9% in 1987 to 11% in 2016 (p<0 · 001), while pre-existing diabetes was uncommon (≤0 · 7% throughout). Rates of small-for-gestational-age decreased, while rates of large-for-gestational-age and high birthweight increased in both groups (all trends p<0 · 001). Multivariable modelling suggests that hyperglycaemia was largely responsible for the growing rate of large-for-gestational-age births among Aboriginal women.

Interpretation

The burden of hyperglycaemia in pregnancy has grown substantially in the NT over three decades and is impacting birthweight trends. The prevalence of pre-gestational diabetes in Aboriginal women is among the highest in the world.

Funding

Diabetes Australia Research Program.

Aboriginal and Non-Aboriginal Emergency Department Presentations Involving Suicide-Related Thoughts and Behaviors

Background: Rates of hospital admission for suicide-related thoughts and behaviors (SRTBs) are elevated in the Northern Territory (NT) of Australia, especially by Aboriginal people, but very little is known about emergency department (ED) presentations. Aim: We aimed to profile ED presentations in the NT involving SRTBs by Indigenous status and compare discharge arrangements. Method: Logistic regression analyses were performed on data from electronic patient records of consecutive ED presentations involving SRTBs. Results: During the study period, 167 presentations were observed. Aboriginal patients were more likely to present from remote areas and to report substance misuse and family conflict or violence compared with non-Aboriginal patients. In both groups, males were more likely than females to be admitted as were persons presenting with self-harm compared with those who had suicidal thoughts only. No differences in discharge arrangements were identified by Indigenous status. Limitations: The small scale of the study and use of administrative records points to the need for further research to improve the quality of the evidence. Conclusion: While presentations by high-risk groups are more likely to be admitted for further care, the assessment of psychosocial risks and needs in EDs is vital to informing decisions for aftercare that support recovery in the community for Aboriginal patients and patients discharged from EDs.

The link between hearing impairment and child maltreatment among Aboriginal children in the Northern Territory of Australia: is there an opportunity for a public health approach in child protection?

Background

International studies provide evidence of an association between child disabilities, including hearing impairment (HI), and child maltreatment. There are high prevalences of ear disease with associated HI, and child maltreatment among Australian Aboriginal children, but the link between HI and child maltreatment is unknown. This study investigates the association between HI and child maltreatment for Aboriginal children living in the Northern Territory (NT) of Australia.

Methods

This was a retrospective cohort study of 3895 Aboriginal school-aged children (born between 1999 and 2008) living in remote NT communities. The study used linked individual-level information from health, education and child protection services. The outcome variables were child maltreatment notifications and substantiations. The key explanatory variable, HI, was based on audiometric assessment. The Kaplan–Meier estimator method was used in univariate analysis; Cox proportional hazards regression was used in multivariable analysis.

Results

A majority of the study cohort lived in very remote (94.5%) and most disadvantaged (93.1%) regions. Among all children in the study cohort, 56.1% had a record of either HI or unilateral hearing loss (UHL), and for those with a history of contact with child protection services (n = 2757), 56.7% had a record of HI/UHL (n = 1564). In the 1999–2003 birth cohort, by age 12 years, 53.5% of children with a record of moderate or worse HI had at least one maltreatment notification, compared to 47.3% of children with normal hearing. In the 2004–2008 cohort, the corresponding results were 83.4 and 71.7% respectively. In multivariable analysis, using the full cohort, children with moderate or worse HI had higher risk of any child maltreatment notification (adjusted Hazard Ratios (adjHR): 1.16, 95% CI:1.04–1.30), notification for neglect (adjHR:1.17, 95% CI:1.04–1.31) and substantiation (adjHR:1.20, 95% CI:1.04–1.40), than children with normal hearing. In the 2004–2008 birth cohort, children with moderate or worse HI had higher risk of a substantiated episode of physical abuse (adjHR:1.47, 95% CI:1.07–2.03) than children with normal hearing.

Conclusion

Our findings demonstrate the urgent need for HI and child maltreatment prevention strategies through raised community awareness and inter-agency collaboration. Effective information-sharing between service providers is a critical first step to a public health approach in child protection.

Performance of cardiovascular risk prediction equations in Indigenous Australians

OBJECTIVE

To assess the performance of cardiovascular disease (CVD) risk equations in Indigenous Australians.

METHODS

We conducted an individual participant meta-analysis using longitudinal data of 3618 Indigenous Australians (55% women) aged 30-74 years without CVD from population-based cohorts of the Cardiovascular Risk in IndigenouS People(CRISP) consortium. Predicted risk was calculated using: 1991 and 2008 Framingham Heart Study (FHS), the Pooled Cohorts (PC), GloboRisk and the Central Australian Rural Practitioners Association (CARPA) modification of the FHS equation. Calibration, discrimination and diagnostic accuracy were evaluated. Risks were calculated with and without the use of clinical criteria to identify high-risk individuals.

RESULTS

When applied without clinical criteria, all equations, except the CARPA-adjusted FHS, underestimated CVD risk (range of percentage difference between observed and predicted CVD risks: -55% to -14%), with underestimation greater in women (-63% to -13%) than men (-47% to -18%) and in younger age groups. Discrimination ranged from 0.66 to 0.72. The CARPA-adjusted FHS equation showed good calibration but overestimated risk in younger people, those without diabetes and those not at high clinical risk. When clinical criteria were used with risk equations, the CARPA-adjusted FHS algorithm scored 64% of those who had CVD events as high risk; corresponding figures for the 1991-FHS were 58% and were 87% for the PC equation for non-Hispanic whites. However, specificity fell.

CONCLUSION

The CARPA-adjusted FHS CVD risk equation and clinical criteria performed the best, achieving higher combined sensitivity and specificity than other equations. However, future research should investigate whether modifications to this algorithm combination might lead to improved risk prediction.

The Impact of Hearing Impairment on the Life Trajectories of Aboriginal Children in Remote Australia: Protocol for the Hearing Loss in Kids Project

BACKGROUND

Previous studies have reported a high prevalence of chronic otitis media (OM) and hearing impairment (HI) in Aboriginal children in the Northern Territory (NT) of Australia. Children affected by these disorders are believed to be at increased risk for adverse outcomes in early childhood development, school attendance, academic performance, and child maltreatment and youth offending. However, to date, there have been no studies quantifying the association between HI and these outcomes in this population.

OBJECTIVE

This study will investigate the association between HI and the 5 outcomes in Aboriginal children living in remote NT communities.

METHODS

Individual-level information linked across multiple administrative datasets will be used to conduct a series of retrospective observational studies on selected developmental and school outcomes. The predictor variables for all studies are the results from audiometric hearing assessments. The outcome measures are as follows: Australian Early Development Census results, representing developmental readiness for school, assessed around 5 years of age; Year 1 school attendance rates; Year 3 school-based academic performance, assessed in the National Assessment Program-Literacy and Numeracy; incidence of child maltreatment events (including both notifications and substantiated cases); and incidence of a first guilty verdict for youth offenders. Confounding and moderating factors available for the analysis include both community-level factors (including school fixed effects, socioeconomic status, level of remoteness, and housing crowdedness) and individual-level factors (including maternal and perinatal health and hospital admissions in early childhood).

RESULTS

The study commenced in 2018, with ethics and data custodian approvals for data access and linkage. This has enabled the completion of data linkage and the commencement of data analysis for individual component studies, with findings expected to be published in 2019 and 2020.

CONCLUSIONS

This study will provide first evidence of the impact of OM-related HI on the developmental, educational, and social outcomes of Australian Aboriginal children. The findings are expected to have significant implications for policy development, service design, and resource allocation.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR1-10.2196/15464.

All-cause mortality following low-dose aspirin treatment for patients with high cardiovascular risk in remote Australian Aboriginal communities: an observational study

OBJECTIVES

To evaluate the benefit and risk of low-dose acetylsalicylic acid (aspirin) in patients from remote Aboriginal communities in the Northern Territory, Australia.

DESIGN

Retrospective cohort study using primary care and hospital data routinely used for healthcare. Aspirin users and non-users were compared before and after controlling confounders by matching. Marginal structural models (MSM) were applied to ascertain the benefit and risk.

SETTING

The benefit and harm of aspirin were investigated in patients aged ≥18 years from 54 remote Aboriginal communities.

PARTICIPANTS

None had a previous cardiovascular event or major bleeds. Patients on anticoagulants or other antiplatelets were excluded.

INTERVENTION

Aspirin at a dose of 75-162 mg/day.

OUTCOME MEASURES

Endpoints were all-cause, cardiovascular mortality and incidences of cardiovascular events and major bleeds.

RESULTS

8167 predominantly Aboriginal adults were included and followed between July 2009 and June 2017 (aspirin users n=1865, non-users n=6302, mean follow-up 4 years with hospitalisations 6.4 per person). Univariate analysis found material differences in demographics, prevalence of chronic diseases and outcome measures between aspirin users and non-users before matching. After matching, aspirin was significantly associated with reduced all-cause mortality (HR=0.45: 95% CI 0.34 to 0.60; p<0.001), but not bleeding (HR=1.13: 95% CI 0.39 to 3.26; p=0.820). After using MSMs to eliminate the effects of confounders, loss of follow-up and time dependency of treatment, aspirin was associated with reduced all-cause mortality (HR=0.60: 95% CI 0.47 to 0.76; p<0.001), independent of age (HR=1.06; p<0.001), presence of diabetes (HR=1.42; p<0.001), hypertension (HR=1.61; p<0.001) and alcohol abuse (HR=1.81; p<0.001). No association between aspirin and major bleeding was found (HR=1.14: 95% CI 0.48 to 2.73; p=0.765). Sensitivity analysis suggested these findings were unlikely to have been the result of unmeasured confounding.

CONCLUSION

Aspirin was associated with reduced all-cause mortality. Bleeding risk was less compared with survival benefits. Aspirin should be considered for primary prevention in Aboriginal people with high cardiovascular risk.

Remote health workforce turnover and retention: what are the policy and practice priorities?

BACKGROUND

Residents of remote communities in Australia and other geographically large countries have comparatively poorer access to high-quality primary health care. To inform ongoing policy development and practice in relation to remote area health service delivery, particularly in remote Indigenous communities, this review synthesizes the key findings of (1) a comprehensive study of workforce turnover and retention in remote Northern Territory (NT) of Australia and (2) a narrative review of relevant international literature on remote and rural health workforce retention strategies. This synthesis provides a valuable summary of the current state of international knowledge about improving remote health workforce retention.

MAIN TEXT

Annual turnover rates of NT remote area nurses (148%) and Aboriginal health practitioners (80%) are very high and 12-month stability rates low (48% and 76%, respectively). In remote NT, use of agency nurses has increased substantially. Primary care costs are high and proportional to staff turnover and remoteness. Effectiveness of care decreases with higher turnover and use of short-term staff, such that higher staff turnover is always less cost-effective. If staff turnover in remote clinics were halved, the potential savings would be approximately A$32 million per annum. Staff turnover and retention were affected by management style and effectiveness, and employment of Indigenous staff. Review of the international literature reveals three broad themes: Targeted enrolment into training and appropriate education designed to produce a competent, accessible, acceptable and 'fit-for-purpose' workforce; addressing broader health system issues that ensure a safe and supportive work environment; and providing ongoing individual and family support. Key educational initiatives include prioritising remote origin and Indigenous students for university entry; maximising training in remote areas; contextualising curricula; providing financial, pedagogical and pastoral support; and ensuring clear, supported career pathways and continuing professional development. Health system initiatives include ensuring adequate funding; providing adequate infrastructure including fit-for-purpose clinics, housing, transport and information technology; offering flexible employment arrangements whilst ensuring a good 'fit' between individual staff and the community (especially with regard to cultural skills); optimising co-ordination and management of services that empower staff and create positive practice environments; and prioritising community participation and employment of locals. Individual and family supports include offering tailored financial incentives, psychological support and 'time out'.

CONCLUSION

Optimal remote health workforce stability and preventing excessive 'avoidable' turnover mandates alignment of government and health authority policies with both health service requirements and individual health professional and community needs. Supportive underpinning policies include: Strong intersectoral collaboration between the health and education sectors to ensure a fit-for-purpose workforce;A funding policy which mandates the development and implementation of an equitable, needs-based formula for funding remote health services;Policies that facilitate transition to community control, prioritise Indigenous training and employment, and mandate a culturally safe work context; andAn employment policy which provides flexibility of employment conditions in order to be able to offer individually customised retention packages There is considerable extant evidence from around the world about effective retention strategies that contribute to slowing excessive remote health workforce turnover, resulting in significant cost savings and improved continuity of care. The immediate problem comprises an 'implementation gap' in translating empirical research evidence into actions designed to resolve existing problems. If we wish to ameliorate the very high turnover of staff in remote areas, in order to provide an equitable service to populations with arguably the highest health needs, we need political and executive commitment to get the policy settings right and ensure the coordinated implementation of multiple strategies, including better linking existing strategies and 'filling the gaps' where necessary.

Hearing and justice: The link between hearing impairment in early childhood and youth offending in Aboriginal children living in remote communities of the Northern Territory, Australia

BACKGROUND

High prevalence of chronic middle ear disease has persisted in Australian Aboriginal children, and the related hearing impairment (HI) has been implicated in a range of social outcomes. This study investigated the association between HI in early childhood and youth offending.

METHOD

This was a retrospective cohort study of 1533 Aboriginal children (born between 1996 and 2001) living in remote Northern Territory communities. The study used linked individual-level information from health, education, child protection and youth justice services. The outcome variable was a youth being "found guilty of an offence". The key explanatory variable, hearing impairment, was based on audiometric assessment. Other variables were: child maltreatment notifications, Year 7 school enrolment by mother, Year 7 school attendance and community 'fixed- effects'. The Cox proportional hazards model was used to estimate the association between HI and youth offending; and the Royston R2 measure to estimate the separate contributions of risk factors to youth offending.

RESULTS

The proportion of hearing loss was high in children with records of offence (boys: 55.6%, girls: 36.7%) and those without (boys: 46.1%; girls: 49.0%). In univariate analysis, a higher risk of offending was found among boys with moderate or worse HI (HR: 1.77 [95% CI: 1.05-2.98]) and mild HI (HR: 1.54 [95% CI:1.06-2.23]). This association was attenuated in multivariable analysis (moderate HI, HR: 1.43 [95% CI:0.78-2.62]; mild HI, HR: 1.37 [95% CI: 0.83-2.26]). No evidence for an association was found in girls. HI contributed 3.2% and 6.5% of variation in offending among boys and girls respectively. Factors contributing greater variance included: community 'fixed-effects' (boys: 14.6%, girls: 36.5%), child maltreatment notification (boys: 14.2%, girls: 23.9%) and year 7 school attendance (boys: 7.9%; girls 12.1%). Enrolment by mother explained substantial variation for girls (25.4%) but not boys (0.2%).

CONCLUSION

There was evidence, in univariate analysis, for an association between HI and youth offending for boys however this association was not evident after controlling for other factors. Our findings highlight a range of risk factors that underpin the pathway to youth-offending, demonstrating the urgent need for interagency collaboration to meet the complex needs of vulnerable children in the Northern Territory.

The impact of hearing impairment on Aboriginal children's school attendance in remote Northern Territory: a data linkage study

OBJECTIVE

To investigate the association between hearing impairment (HI) and Year 1 school attendance in Aboriginal children in the Northern Territory (NT) of Australia.

METHODS

Observational cohort study (n=3,744) by analysing linked individual-level information for Aboriginal children from the NT Government school attendance records, NT Perinatal Register and Remote Hearing Assessment dataset, and community level data for relative remoteness, socioeconomic disadvantage and housing crowdedness.

RESULTS

Children with unilateral hearing loss, mild HI and moderate or worse HI had significantly lower Year 1 attendance than those with normal hearing, attending 5.6 (95%CI, -9.10 ∼-2.10), 4.0 (95%CI, -7.17 ∼-0.90) and 6.1 (95%CI, -10.71 ∼-1.49) days fewer, respectively. Other variables that yielded significant association were: male gender, having attended preschool less than 20% of available days, speaking English as second language, twin birth and average household size >5.

CONCLUSIONS

Aboriginal children with any level of HI are likely to have lower school attendance rates in Year 1 than their peers with normal hearing. Implications for public health: In this population, where the prevalence of otitis media and accompanying HI remains extremely high, the early detection and management of hearing loss on entry into primary school should be included in the measures to improve school attendance.

Projecting demands for renal replacement therapy in the Northern Territory: a stochastic Markov model

Objective The aim of the present study was to evaluate the potential effects of different health intervention strategies on demand for renal replacement therapy (RRT) services in the Northern Territory (NT). Methods A Markov chain simulation model was developed to estimate demand for haemodialysis (HD) and kidney transplantation (Tx) over the next 10 years, based on RRT registry data between 2002 and 2013. Four policy-relevant scenarios were evaluated: (1) increased Tx; (2) increased self-care dialysis; (3) reduced incidence of end-stage kidney disease (ESKD); and (4) reduced mortality. Results There were 957 new cases of ESKD during the study period, with most patients being Indigenous people (85%). The median age was 50 years at onset and 57 years at death, 12 and 13 years younger respectively than Australian medians. The prevalence of RRT increased 5.6% annually, 20% higher than the national rate (4.7%). If current trends continue (baseline scenario), the demand for facility-based HD (FHD) would approach 100000 treatments (95% confidence interval 75000-121000) in 2023, a 5% annual increase. Increasing Tx (0.3%), increasing self-care (5%) and reducing incidence (5%) each attenuate demand for FHD to ~70000 annually by 2023. Conclusions The present study demonstrates the effects of changing service patterns to increase Tx, self-care and prevention, all of which will substantially attenuate the growth in FHD requirements in the NT. What is known about the topic? The burden of ESKD is projected to increase in the NT, with demand for FHD doubling every 15 years. Little is known about the potential effect of changes in health policy and clinical practice on demand. What does this paper add? This study assessed the usefulness of a stochastic Markov model to evaluate the effects of potential policy changes on FHD demand. What are the implications for practitioners? The scenarios simulated by the stochastic Markov models suggest that changes in current ESKD management practices would have a large effect on future demand for FHD.

Does delay in planned diabetes care influence outcomes for aboriginal Australians? A study of quality in health care

BACKGROUND

To examine the association between delay in planned diabetes care and quality of outcomes.

METHODS

A retrospective analysis of primary care and inpatient records for 2567 Aboriginal patients, with diabetes, living in 49 remote communities in the Northern Territory of Australia. Poisson regression was used to estimate the association between delay from diagnosis to documented diabetes care plan and three outcome measures: mean HbA1c level, most recent blood pressure and number of diabetes-related hospital admissions.

RESULTS

Compared with no delay (< 60 days), patients with delay had increased risk of elevated mean HbA1c: 60 days to < 2 years, incidence rate ratio (IRR), 1.2 (95% CI:1.07-1.39); 2 years to < 4 years, incidence rate ratio (IRR), 1.2 (95% CI:1.04-1.45); 4 years and over, incidence rate ratio (IRR), 1.3 (95% CI:1.12-1.52). There was no evidence of association between delay and optimal blood pressure control. Risk of diabetes-related admission increased with increased delay. Compared with no delay the IRRs for delay were: 60 days to < 2 years, 1.2 (95% CI:1.07-1.42); 2 to < 4 years, 1.3 (95% CI: 1.15-1.58): and 4 years and over, 2.6 (95% CI,2.28-3.08).

CONCLUSION

The study found that a timely diabetes care plan was associated with better short-term blood glucose control and fewer diabetes-related admissions but not with improved blood pressure control. Delays may be a result of both patient and service-related factors.

Costs and effects of higher turnover of nurses and Aboriginal health practitioners and higher use of short-term nurses in remote Australian primary care services: an observational cohort study

OBJECTIVES

To compare the costs and effects of higher turnover of resident nurses and Aboriginal health practitioners and higher use of agency-employed nurses in remote primary care (PC) services and quantify associations between staffing patterns and health outcomes in remote PC clinics in the Northern Territory (NT) of Australia.

DESIGN

Observational cohort study, using hospital admission, financial and payroll data for the period 2013-2015.

SETTING

53 NT Government run PC clinics in remote communities.

OUTCOME MEASURES

Incremental cost-effectiveness ratios were calculated for higher compared with lower turnover and higher compared with lower use of agency-employed nurses. Costs comprised PC, travel and hospitalisation costs. Effect measures were total hospitalisations and years of life lost per 1000 person-months. Multiple regression was performed to investigate associations between overall health costs and turnover rates and use of agency-employed nurses, after adjusting for key confounders.

RESULTS

Higher turnover was associated with significantly higher hospitalisation rates (p<0.001) and higher average health costs (p=0.002) than lower turnover. Lower turnover was always more cost-effective. Average costs were significantly (p<0.001) higher when higher proportions of agency-employed nurses were employed. The probability that lower use of agency-employed nurses was more cost-effective was 0.84. Halving turnover and reducing use of a short-term workforce have the potential to save $32 million annually in the NT.

CONCLUSION

High turnover of health staff is costly and associated with poorer health outcomes for Aboriginal peoples living in remote communities. High reliance on agency nurses is also very likely to be cost-ineffective. Investment in a coordinated range of workforce strategies that support recruitment and retention of resident nurses and Aboriginal health practitioners in remote clinics is needed to stabilise the workforce, minimise the risks of high staff turnover and over-reliance on agency nurses and thereby significantly reduce expenditure and improve health outcomes.

Estimating the total prevalence and incidence of end-stage kidney disease among Aboriginal and non-Aboriginal populations in the Northern Territory of Australia, using multiple data sources

Background

Most estimates for End Stage Kidney Disease (ESKD) prevalence and incidence are based on renal replacement therapy (RRT) registers. However, not all people with ESKD will commence RRT and estimates based only on RRT registry data will underestimate the true burden of ESKD in the community. This study estimates the total number of Northern Territory (NT) residents with ESKD including: those receiving RRT, those diagnosed but not receiving RRT and an estimate of “undiagnosed” cases.

Methods

Four data sources were used to identify NT residents with a diagnosis of ESKD: public hospital admissions, Australia and New Zealand Dialysis and Transplant Registry registrations, death registrations and, for the Aboriginal population only, electronic primary care records. Three data sources contained information recorded between 1 July 2008 and 31 December 2013, death registration data extended to 31 December 2014 to capture 2013 prevalent cases. A capture–recapture method was used to estimate both diagnosed and undiagnosed cases by making use of probability patterns of overlapping multiple data sources.

Results

In 2013, the estimated ESKD prevalence in the NT Aboriginal population was 11.01 (95% confidence interval (CI) 10.24–11.78) per 1000, and 0.90 (95% CI 0.76–1.05) per 1000 in the NT non-Aboriginal population. The age-adjusted rates were 17.97 (95% CI 17.82–18.11) and 1.07 (95% CI 1.05–1.09) per 1000 in the NT Aboriginal and non-Aboriginal populations respectively. The proportion of individuals receiving RRT was 71.4% of Aboriginal and 75.5% of non-Aboriginal prevalent ESKD cases. The age-adjusted ESKD incidence was also greater for the Aboriginal (5.26 (95% CI 4.44–6.08) per 1000 population) than non-Aboriginal population (0.36 (95% CI 0.25–0.47) per 1000).

Conclusion

This study provides comprehensive estimates of the burden of ESKD including those cases that are not identified in relevant health data sources. The results are important for informing strategies to reduce the total burden of ESKD and to manage the potential unmet demand, particularly from comparatively young Aboriginal patients who may be suitable for RRT but do not currently access the services for social, geographic or cultural reasons.

Electronic supplementary material

The online version of this article (doi: 10.1186/s12882-017-0791-3) contains supplementary material, which is available to authorized users.

Long-term trends in supply and sustainability of the health workforce in remote Aboriginal communities in the Northern Territory of Australia

Background

International evidence suggests that a key to improving health and attaining more equitable health outcomes for disadvantaged populations is a health system with a strong primary care sector. Longstanding problems with health workforce supply and turnover in remote Aboriginal communities in the Northern Territory (NT), Australia, jeopardise primary care delivery and the effort to overcome the substantial gaps in health outcomes for this population. This research describes temporal changes in workforce supply in government-operated clinics in remote NT communities through a period in which there has been a substantial increase in health funding.

Methods

Descriptive and Markov-switching dynamic regression analysis of NT Government Department of Health payroll and financial data for the resident health workforce in 54 remote clinics, 2004–2015. The workforce included registered Remote Area Nurses and Midwives (nurses), Aboriginal Health Practitioners (AHPs) and staff in administrative and logistic roles. Main outcome measures: total number of unique employees per year; average annual headcounts; average full-time equivalent (FTE) positions; agency employed nurse FTE estimates; high and low supply state estimates.

Results

Overall increases in workforce supply occurred between 2004 and 2015, especially for administrative and logistic positions. Supply of nurses and AHPs increased from an average 2.6 to 3.2 FTE per clinic, although supply of AHPs has declined since 2010. Each year almost twice as many individual NT government-employed nurses or AHPs are required for each FTE position.

Following funding increases, some clinics doubled their nursing and AHP workforce and achieved relative stability in supply. However, most clinics increased staffing to a much smaller extent or not at all, typically experiencing a “fading” of supply following an initial increase associated with greater funding, and frequently cycling periods of higher and lower staffing levels.

Conclusions

Overall increases in workforce supply in remote NT communities between 2004 and 2015 have been affected by continuing very high turnover of nurses and AHPs, and compounded by recent declines in AHP supply. Despite substantial increases in resourcing, an imperative remains to implement more robust health service models which better support the supply and retention of resident health staff.

Cost-effectiveness of stroke care in Aboriginal and non-Aboriginal patients: an observational cohort study in the Northern Territory of Australia

OBJECTIVE

To assess cost-effectiveness of stroke care for Aboriginal compared with non-Aboriginal patients in the Northern Territory (NT), Australia.

DESIGN

Cost-effectiveness analysis using data from a cohort-based follow-up study of stroke incidents.

SETTING

Public hospitals in the NT from 1992 to 2013.

PARTICIPANTS

Individual patient data were extracted and linked from the hospital inpatient and primary care information systems.

OUTCOME MEASURES

Incremental cost-effectiveness ratios were calculated and assessed graphically. Survival time was used to measure effectiveness of stroke care, in comparison with the net costs per life-year gained, from a healthcare perspective, by applying multivariable models to account for time-dependent confounding.

RESULTS

2158 patients with incident stroke were included (1171 males, 1178 aged <65 years and 966 from remote areas). 992 patients were of Aboriginal origin (46.0%, disproportionately higher than the population proportion of 27%). Of all cases, 42.6% were ischaemic and 29.8% haemorrhagic stroke. Average age of stroke onset was 51 years in Aboriginal, compared with 65 years in non-Aboriginal patients (p<0.001). Aboriginal patients had 71.4% more hospital bed-days, and 7.4% fewer procedures than non-Aboriginal patients. Observed health costs averaged $A50 400 per Aboriginal compared with $A33 700 per non-Aboriginal patient (p<0.001). The differential costs and effects for each population were distributed evenly across the incremental cost-effectiveness plane threshold line, indicating no difference in cost-effectiveness between populations. After further adjustment for confounding and censoring, cost-effectiveness appeared greater for Aboriginal than non-Aboriginal patients, but this was not statistically significant (p=0.25).

CONCLUSIONS

Stroke care for the NT Aboriginal population is at least as cost-effective as the non-Aboriginal population. Stroke care presents worthwhile and equitable survival benefits for Aboriginal patients in remote communities, notwithstanding their higher level burden of disease. These findings are relevant for healthcare planning and policy development regarding equal access to stroke care for Aboriginal patients.

Patterns of resident health workforce turnover and retention in remote communities of the Northern Territory of Australia, 2013-2015

BACKGROUND

The geographical maldistribution of the health workforce is a persisting global issue linked to inequitable access to health services and poorer health outcomes for rural and remote populations. In the Northern Territory (NT), anecdotal reports suggest that the primary care workforce in remote Aboriginal communities is characterised by high turnover, low stability and high use of temporary staffing; however, there is a lack of reliable information to guide workforce policy improvements. This study quantifies current turnover and retention in remote NT communities and investigates correlations between turnover and retention metrics and health service/community characteristics.

METHODS

This study used the NT Department of Health 2013-2015 payroll and financial datasets for resident health workforce in 53 remote primary care clinics. Main outcome measures include annual turnover rates, annual stability rates, 12-month survival probabilities and median survival.

RESULTS

At any time point, the clinics had a median of 2.0 nurses, 0.6 Aboriginal health practitioners (AHPs), 2.2 other employees and 0.4 additional agency-employed nurses. Mean annual turnover rates for nurses and AHPs combined were extremely high, irrespective of whether turnover was defined as no longer working in any remote clinic (66%) or no longer working at a specific remote clinic (128%). Stability rates were low, and only 20% of nurses and AHPs remain working at a specific remote clinic 12 months after commencing. Half left within 4 months. Nurse and AHP turnover correlated with other workforce measures. However, there was little correlation between most workforce metrics and health service characteristics.

CONCLUSIONS

NT Government-funded remote clinics are small, experience very high staff turnover and make considerable use of agency nurses. These staffing patterns, also found in remote settings elsewhere in Australia and globally, not only incur higher direct costs for service provision-and therefore may compromise long-term sustainability-but also are almost certainly contributing to sub-optimal continuity of care, compromised health outcomes and poorer levels of staff safety. To address these deficiencies, it is imperative that investments in implementing, adequately resourcing and evaluating staffing models which stabilise the remote primary care workforce occur as a matter of priority.

Associations of mortality and cardiovascular disease risks with diabetes and albuminuria in urban Indigenous Australians: the DRUID follow-up study

AIM

To assess the relationships of diabetes and albuminuria with all-cause mortality and cardiovascular disease outcomes in a population without prior cardiovascular disease using data from the Darwin Region Urban Indigenous Diabetes (DRUID) study.

METHODS

We conducted a prospective cohort study of 706 participants (aged 15-81 years, 68% women) without prior cardiovascular disease who underwent a 75-g oral glucose tolerance test. Deaths and fatal or non-fatal cardiovascular disease were determined over 7 years, and hazard ratios with 95% CIs and population attributable risks were estimated for baseline glycaemia and albuminuria.

RESULTS

Compared with normoglycaemia and after adjustment for age, sex, hypertension, dyslipidaemia and smoking, known diabetes was associated with an adjusted hazard ratio of 4.8 (95% CI 1.5-14.7) for all-cause mortality and 5.6 (95% CI 2.1-15.2) for cardiovascular disease. Compared with normoalbuminuria, the respective adjusted risks for macroalbuminuria were 10.9 (95% CI 3.7-32.1) and 3.9 (95% CI 1.4-10.8). The Adjusted all-cause mortality and cardiovascular disease estimated population attributable risks for diabetes were 27% and 32%, and for albuminuria they were 32% and 21%, respectively.

CONCLUSIONS

In our study population, the burden of mortality and cardiovascular disease was largely driven by diabetes and albuminuria. This finding on the influence of diabetes and albuminuria is consistent with reports in other high-risk Indigenous populations and should be better reflected in risk scores and intervention programmes.

Trends in cancer incidence and survival for Indigenous and non-Indigenous people in the Northern Territory

OBJECTIVE

To assess trends in cancer incidence and survival for Indigenous and non-Indigenous Australians in the Northern Territory.

DESIGN

Retrospective analysis of population-based cancer registration data.

SETTING

New cancer diagnoses in the NT, 1991-2012.

MAIN OUTCOME MEASURES

Age-adjusted incidence rates; rate ratios comparing incidence in NT Indigenous and non-Indigenous populations with that for other Australians; 5-year survival; multivariable Poisson regression of excess mortality.

RESULTS

The incidence of most cancers in the NT non-Indigenous population was similar to that for other Australians. For the NT Indigenous population, the incidence of cancer at several sites was much higher (v other Australians: lung, 84% higher; head and neck, 325% higher; liver, 366% higher; cervix, 120% higher). With the exception of cervical cancer (65% decrease), incidence rates in the Indigenous population did not fall between 1991-1996 and 2007-2012. The incidence of several other cancers (breast, bowel, prostate, melanoma) was much lower in 1991-1996 than for other Australians, but had increased markedly by 2007-2012 (breast, 274% increase; bowel, 120% increase; prostate, 116% increase). Five-year survival was lower for NT Indigenous than for NT non-Indigenous patients, but had increased for both populations between 1991-2000 and 2001-2010.

CONCLUSION

The incidence of several cancers that were formerly less common in NT Indigenous people has increased, without a concomitant reduction in the incidence of higher incidence cancers (several of which are smoking-related). The excess burden of cancer in this population will persist until lifestyle risks are mitigated, particularly by reducing the extraordinarily high prevalence of smoking.

Assessing the Impact and Cost of Short-Term Health Workforce in Remote Indigenous Communities in Australia: A Mixed Methods Study Protocol

Background

Remote Australia is a complex environment characterized by workforce shortages, isolated practice, a large resident Indigenous population, high levels of health need, and limited access to services. In recent years, there has been an increasing trend of utilizing a short-term visiting (fly-in/fly-out) health workforce in many remote areas. However, there is a dearth of evidence relating to the impact of this transitory workforce on the existing resident workforce, consumer satisfaction, and the effectiveness of current services.

Objective

This study aims to provide rigorous empirical data by addressing the following objectives: (1) to identify the impact of short-term health staff on the workload, professional satisfaction, and retention of resident health teams in remote areas; (2) to identify the impact of short-term health staff on the quality, safety, and continuity of patient care; and (3) to identify the impact of short-term health staff on service cost and effectiveness.

Methods

Mixed methods will be used. Administrative data will be extracted that relates to all 54 remote clinics managed by the Northern Territory Department of Health, covering a population of 35,800. The study period will be 2010 to 2014. All 18 Aboriginal Community-Controlled Health Services in the Northern Territory will also be invited to participate. We will use these quantitative data to describe staffing stability and turnover in these communities, and then utilize multiple regression analyses to determine associations between the key independent variables of interest (resident staff turnover, stability or median survival, and socioeconomic status, community size, and per capita funding) and dependent variables related to patient care, service cost, quality, and effectiveness. The qualitative component of the study will involve in-depth interviews and focus groups with staff and patients, respectively, in six remote communities. Three communities will be high staff turnover communities and three characterized by low turnover. This will provide information on service quality, impact on resident and visiting staff, and patient satisfaction with the services. The research team will work with staff, patients, and a key stakeholder group of senior policymakers to develop workforce strategies to maintain or attain remote health workforce stability.

Results

The study commenced in 2015. As of October 2016, fieldwork has been almost completed and quantitative analysis has commenced. Results are expected to be published in 2017.

Conclusions

The study has commenced, but it is too early to provide results or conclusions.

Trends in hospital admissions involving suicidal behaviour in the Northern Territory, 2001-2013

OBJECTIVE

To investigate trends in hospital admissions involving suicidal behaviour in the Northern Territory (NT) resident population over the period 2001-2013.

METHODS

Estimates of age-standardised rates and average changes in the annual rate of hospital admissions involving suicidal behaviour were calculated by socio-demographic characteristics and types of suicidal behaviour.

RESULTS

Overall rates for Indigenous admissions were 2.7 times higher than non-Indigenous admissions and had increased by almost twice as much. While male and female rates of admission were similar for both Indigenous and non-Indigenous residents, the average annual change in rates was greater for Indigenous females (13.4%) compared to males (8.8%) and for non-Indigenous males (7.7%) compared to females (5.2%). Younger and middle-aged Indigenous admissions experienced increasing rates of admissions, whilst trends were similar across age groups for non-Indigenous admissions. Admissions with a diagnosis of suicidal ideation increased the most across all groups. Trends in intentional self-harm admissions differed according to Indigenous status and sex.

CONCLUSIONS

There have been substantial increases in hospital admissions involving suicidal behaviour in the NT, most markedly for Indigenous residents. Indigenous females and youth appear to be at increasing risk. The steep increase in suicidal ideation across all groups warrants further investigation.

A retrospective population-based study of induction of labour trends and associated factors among aboriginal and non-aboriginal mothers in the northern territory between 2001 and 2012

Background

Induction of labour (IOL) has become more common among many populations, but the trends and drivers of IOL in the Northern Territory (NT) of Australia are not known. This study investigated trends in IOL and associated factors among NT Aboriginal and non-Aboriginal mothers between 2001 and 2012.

Methods

A retrospective analysis of all NT resident women who birthed in the NT between 2001 and 2012 at ≥32 weeks gestation. Demographic, medical and obstetric data were obtained from the NT Midwives’ Collection. The prevalence of IOL was calculated by Aboriginal status and parity of the mother and year of birth. The prevalence of each main indication for induction among women was compared for 2001–2003 and 2010–2012. Linear and logistic regression was used to test for association between predictive factors and IOL in bivariate and multivariate analysis, separately for Aboriginal and non-Aboriginal mothers.

Results

A total of 42,765 eligible births between 2001 and 2012 were included. IOL was less common for Aboriginal than non-Aboriginal mothers in 2001 (18.0 % and 25.1 %, respectively), but increased to be similar to non-Aboriginal mothers in 2012 (22.6 % and 24.8 %, respectively). Aboriginal primiparous mothers demonstrated the greatest increase in IOL. The most common indication for IOL for both groups was post-dates, which changed little over time. Medical and obstetric complications were more common for Aboriginal mothers except late-term pregnancy. Prevalence of diabetes in pregnancy increased considerably among both Aboriginal and non-Aboriginal mothers, but was responsible for only a small proportion of IOLs. Increasing prevalence of risk factors did not explain the increased IOL prevalence for Aboriginal mothers.

Conclusions

IOL is now as common for Aboriginal as non-Aboriginal mothers, though their demographic, medical and obstetric profiles are markedly different. Medical indications did not explain the recent increase in IOL among Aboriginal mothers; changes in maternal or clinical decision-making may have been involved.

Assessing improvements in survival for stroke patients in the Northern Territory 1992-2013: a marginal structural analysis

OBJECTIVE

The aim of the present study was to investigate changes in stroke survival among Indigenous and non-Indigenous patients in the Northern Territory (NT).

METHODS

A longitudinal study was undertaken of stroke patients admitted to NT public hospitals between 1992 and 2013. The Kaplan-Meier method and proportional hazards regression were used for survival analysis. A marginal structural model was applied to adjust for time-dependent confounders and informative censoring. RESULTS; There were 4754 stroke in-patients over the period, with 3540 new cases and 837 stroke deaths. Mean age of onset for Indigenous patients (51.7 years) was 12.3 years younger than that for non-Indigenous patients. After adjustments for confounders and loss to follow-up, in-hospital deaths were more likely among Indigenous patients (hazard ratio (HR) = 1.56; P < 0.01) and less likely among males (HR = 0.86; P < 0.05) and patients from remote areas (HR = 0.72; P < 0.01). There was a 3% decrease annually in mortality hazard from 1992 to 2013. Renal disease, cancer and chronic obstructive pulmonary disease had deleterious effects on stroke survival.

CONCLUSIONS

Stroke survival has improved in the NT over the past two decades. The marginal structural models provide a powerful methodological tool that can be applied to hospital administrative data to assess changes in quality of care and the impact of interventions.

Impact of perinatal health and socio-demographic factors on school education outcomes: A population study of Indigenous and non-Indigenous children in the Northern Territory

AIM

This study investigated the association between early-life risk factors and school education outcomes.

METHODS

This is an historical cohort study of 7601 children (61% were Indigenous) born in the Northern Territory between 1999 and 2004. Information was linked, for each child on: perinatal health, student enrolment and National Assessment Program - Literacy and Numeracy (NAPLAN) Year 3 results. Logistic regression was used to estimate the association between selected risk factors and a NAPLAN result 'below' the national minimum standard (NMS) in reading and numeracy.

RESULTS

Indigenous children had much higher odds, than non-Indigenous children, of a result below the NMS for both reading (odds ratio (OR): 8.58, 95% confidence interval (CI): 7.55-9.74) ) and numeracy (OR: 11.52, 95% CI: 9.94-13.35). When adjusted for all other variables, the increased odds were attenuated for both reading (OR: 2.89, 95% CI: 2.46-3.40) and numeracy (OR: 3.19, 95% CI: 2.65-3.84). Common risk factors for Indigenous and non-Indigenous children included higher birth order, maternal smoking in pregnancy and being a boy. There were gradients of decreasing risk with increasing education level of primary care giver and increasing maternal age. Among Indigenous children only, risks increased when living in remote areas, with younger age (<8 years) and low birthweight.

CONCLUSIONS

The study highlights that many of the risk factors associated with poor education outcomes among Indigenous children are shared with the general population. The results inform a targeted, cross-agency response to address modifiable early-life risk factors for educational disadvantage. Data linkage, using existing administrative datasets, provides a useful addition to methods that identify priority areas for prevention and early intervention.

Disparity in Mortality From Rheumatic Heart Disease in Indigenous Australians

Background

Recent estimates of the global burden of rheumatic heart disease (RHD) have highlighted the paucity of reliable RHD mortality data from populations most affected by RHD.

Methods and Results

We investigated RHD mortality rates and trends for Indigenous and non-Indigenous Australians in the Northern Territory (NT) for the period 1977–2005 and seminationally (NT plus 4 other states, covering 89% of Indigenous Australians) from 1997 to 2005 using vital statistics data. All analysis was undertaken by Indigenous status, sex, and age at death. In the NT, 90% of all deaths from RHD were among Indigenous persons; however, the Indigenous population makes up only 30.4% of the NT population. The death rate ratio (Indigenous compared with non-Indigenous) was 54.80 in the NT and 12.74 in the other 4 states (estimated at the median age of 50 years). Non-Indigenous death rates were low for all age groups except ≥65 years, indicating RHD deaths in the elderly non-Indigenous population. Death rates decreased at a more rapid rate for non-Indigenous than Indigenous persons in the NT between 1997 and 2005. Indigenous persons in other parts of Australia showed lower death rates than their NT counterparts, but the death rates for Indigenous persons in all states were still much higher than rates for non-Indigenous Australians.

Conclusions

Indigenous Australians are much more likely to die from RHD than other Australians. Among the Indigenous population, RHD mortality is much higher in the NT than elsewhere in Australia, exceeding levels reported in many industrialized countries more than a century ago. With the paucity of data from high-prevalence areas, these data contribute substantially to understanding the global burden of RHD mortality.

The relationship between number of primary health care visits and hospitalisations: evidence from linked clinic and hospital data for remote Indigenous Australians

BACKGROUND

Primary health care (PHC) is widely regarded as essential for preventing and treating ill health. However, the evidence on whether improved PHC reduces hospitalisations has been mixed. This study examines the relationship between PHC and hospital inpatient care in a population with high health need, high rates of hospitalisation and relatively poor PHC access.

METHODS

The cross-sectional study used linked individual level PHC visit and hospitalisation data for 52 739 Indigenous residents from 54 remote communities in the Northern Territory of Australia between 1 July 2007 and 30 June 2011. The association between PHC visits and hospitalisations was modelled using simple and spline quadratic regression for key demographics and disease groups including potentially avoidable hospitalisations.

RESULTS

At the aggregate level, the average annual number of PHC visits per person had a U-shaped association with hospitalisations. For all conditions combined, there was an inverse association between PHC visits and hospitalisations for people with less than four clinic visits per year, but a positive association for those visiting the clinic four times or more. For patients with diabetes, ischaemic heart disease or renal disease, the minimum level of hospitalisation was found when there was 20-30 PHC visits a year, and for children with otitis media and dental conditions, 5-8 visits a year.

CONCLUSIONS

The results of this study demonstrate a U-shape relationship between PHC visits and hospitalisations. Under the conditions of remote Indigenous Australians, there may be an optimal level of PHC at which hospitalisations are at a minimum. The authors propose that the effectiveness of a health system may hinge on a refined balance, rather than a straight-line relationship between primary health care and tertiary care.

Decomposing Indigenous life expectancy gap by risk factors: a life table analysis

Background

The estimated gap in life expectancy (LE) between Indigenous and non-Indigenous Australians was 12 years for men and 10 years for women, whereas the Northern Territory Indigenous LE gap was at least 50% greater than the national figures. This study aims to explain the Indigenous LE gap by common modifiable risk factors.

Methods

This study covered the period from 1986 to 2005. Unit record death data from the Northern Territory were used to assess the differences in LE at birth between the Indigenous and non-Indigenous populations by socioeconomic disadvantage, smoking, alcohol abuse, obesity, pollution, and intimate partner violence. The population attributable fractions were applied to estimate the numbers of deaths associated with the selected risks. The standard life table and cause decomposition technique was used to examine the individual and joint effects on health inequality.

Results

The findings from this study indicate that among the selected risk factors, socioeconomic disadvantage was the leading health risk and accounted for one-third to one-half of the Indigenous LE gap. A combination of all six selected risks explained over 60% of the Indigenous LE gap.

Conclusions

Improving socioeconomic status, smoking cessation, and overweight reduction are critical to closing the Indigenous LE gap. This paper presents a useful way to explain the impact of risk factors of health inequalities, and suggests that reducing poverty should be placed squarely at the centre of the strategies to close the Indigenous LE gap.

The end of the Australia antigen? An ecological study of the impact of universal newborn hepatitis B vaccination two decades on

BACKGROUND

A universal newborn hepatitis B (HBV) vaccination program was introduced in the Northern Territory of Australia in 1990, followed by a school-based catch-up program. We evaluated the prevalence of hepatitis B infection in birthing women up to 20 years after vaccination and compared this to women born before the programs commenced.

METHODS

A cohort of birthing mothers was defined from Northern Territory public hospital birth records between 2005 and 2010 and linked to laboratory confirmed notifications of chronic HBV, based principally on a record of hepatitis B surface antigen detection. Prevalence of HBV was compared between women born before or after implementation of the newborn and catch-up vaccination programs.

FINDINGS

Among 10797 birthing mothers, 138 (1.3%) linked to a chronic HBV record. HBV prevalence was substantially higher in Aboriginal women compared to non-Indigenous women (2.4% versus 0.04%; p<0.001). Among 5678 Aboriginal women, those eligible for catch-up and newborn HBV vaccination programs had a significantly lower HBV prevalence than older women born prior to the programs: HBV prevalence respectively 2.2% versus 3.5%, (OR 0.61, 95%CI 0.43-0.88) and 0.8% versus 3.5% (OR 0.21, 95%CI 0.11-0.43). This represents a risk reduction of respectively 40% and 80% compared to unvaccinated women.

INTERPRETATION

The progressively greater reduction in the prevalence of chronic HBV in adult Aboriginal women co-inciding with eligibility for catch-up and newborn vaccination programs is consistent with a significant impact from both programs. The use of data derived from antenatal screening to track ongoing vaccine impact is applicable to a range of settings globally.

Living longer with a greater health burden--changes in the burden of disease and injury in the Northern Territory Indigenous population between 1994-1998 and 1999-2003

OBJECTIVE

To measure changes over time in the burden of disease for Northern Territory (NT) Indigenous and non-Indigenous population.

METHODS

The numbers, and crude and age-adjusted rates of disability adjusted life years (DALY) were calculated for periods 1994-1998 and 1999-2003. A measure of information bias was developed to adjust for the tendency of years lost to disability (a component of DALY) to increase over time because of increasing data availability. The jackknife method was used for DALY uncertainty assessment.

RESULTS

The all-cause DALY rate was stable for the non-Indigenous population, but increased for the Indigenous population. For both populations, the burden of premature death decreased while the burden of disability increased. For the Indigenous population, there were substantial increases in DALY rates for type 2 diabetes, depression, nephritis/nephrosis, suicide and sense organ disorders.

CONCLUSIONS

The burden of disease for Indigenous people increased over the study periods, with improvement in the burden of fatal outcomes more than offset by substantial increase in the prevalence and severity of non-fatal conditions.

IMPLICATIONS

The paradoxical shift of living longer with a greater health burden has not been previously reported for Indigenous Australians, and highlights the critical importance of prevention for sustaining life expectancy improvement and managing escalation of health costs. This study also demonstrated the usefulness of the DALY to monitor population health.

Evaluation of an Australian indigenous housing programme: community level impact on crowding, infrastructure function and hygiene

BACKGROUND AND AIM

Housing programmes in indigenous Australian communities have focused largely on achieving good standards of infrastructure function. The impact of this approach was assessed on three potentially important housing-related influences on child health at the community level: (1) crowding, (2) the functional state of the house infrastructure and (3) the hygienic condition of the houses.

METHODS

A before-and-after study, including house infrastructure surveys and structured interviews with the main householder, was conducted in all homes of young children in 10 remote Australian indigenous communities.

RESULTS

Compared with baseline, follow-up surveys showed (1) a small non-significant decrease in the mean number of people per bedroom in the house on the night before the survey (3.4, 95% CI 3.1 to 3.6 at baseline vs 3.2, 95% CI 2.9 to 3.4 at follow-up; natural logarithm transformed t test, t=1.3, p=0.102); (2) a marginally significant overall improvement in infrastructure function scores (Kruskal-Wallis test, χ(2)=3.9, p=0.047); and (3) no clear overall improvement in hygiene (Kruskal-Wallis test, χ(2)=0.3, p=0.605).

CONCLUSION

Housing programmes of this scale that focus on the provision of infrastructure alone appear unlikely to lead to more hygienic general living environments, at least in this study context. A broader ecological approach to housing programmes delivered in these communities is needed if potential health benefits are to be maximised. This ecological approach would require a balanced programme of improving access to health hardware, hygiene promotion and creating a broader enabling environment in communities.