Compartmentalised enzyme-induced phase transformations in self-assembling lipid systems.

HYPOTHESIS: Understanding the digestion of lipid-based pharmaceutical formulations and food systems is necessary for optimising drug and nutrient delivery and has been extensively studied in bulk emulsion systems using the pH-stat method [1]. However, this approach is not suitable for investigation of individual lipid droplets, in particular the interface where the lipase acts. Microfluidic approaches to study digestion at lipid-water interfaces using droplet trapping have been proposed, however the aqueous phase in that case washes over the interface presenting uncertainty over the stoichiometry of interactions [2]. The internal interface of a Janus-like droplet, containing distinct aqueous and lipid compartments, mimics the interface of a lipid droplet in aqueous solution with controlled stoichiometry [3]. Hence, it was hypothesised that the internal interface of Janus droplets can offer a precise way to study the enzymatic digestion of lipids formulations. EXPERIMENTS: Using microfluidic methods, Janus-like droplets were formed by coalescing emulsion droplets containing lipid formulation and pancreatic lipase. Polarised light microscopy (PLM) and in-situ small-angle X-ray scattering (SAXS) were used to investigate the droplets. FINDINGS: PLM revealed the growth of an aligned inverse hexagonal phase (H2), and with SAXS showed that this phase transformation and alignment resulted from enzymatic digestion. A subsequent partial transformation from H2 to inverse bicontinuous cubic phase occurred when simulated intestinal fluid was used instead of Tris buffer. Suggesting that phospholipids and bile salts could diffuse across the internal interface to locally affect their surroundings.

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.

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, ß = 0.22 and indirect, ß = 0.16). Pregnancy factors (gestational diabetes and maternal smoking (indirect, ß = -0.09) and child-related factors (English as a second language and not attending preschool (direct, ß = -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 (ß = 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.

A novel droplet-based approach to study phase transformations in lyotropic liquid crystalline systems.

HYPOTHESIS: Lyotropic liquid crystals (LLC) and their phase transformations in response to stimuli have gathered much interest for controlled and 'on-demand' drug applications. Bulk methods of preparation impose limitations on studying the transformations, especially induced by compositional changes, such as enzymatic changes to lipid structure. Here we hypothesise that controlled microfluidic production and coalescence of dissimilar aqueous and lipid droplets emulsified in a third mutually immiscible liquid will provide a new approach to the spatio-temporal study of structure formation in lyotropic liquid crystalline materials. EXPERIMENTS: Separate lipid and aqueous droplets, dispersed in a fluorocarbon oil were generated using a microfluidic format. The chip, prepared as a hybrid polydimethylsiloxane (PDMS) and glass microfluidic device, was constructed to enable in-situ acquisition of time-resolved synchrotron small angle X-ray scattering (SAXS) and crossed polarised light microscopy of the coalesced droplets to determine the structures present during aging. FINDINGS: Janus-like droplets formed upon coalesce, with distinct lipid and aqueous portions with a gradient between the two sides of the merged droplet. SAXS and polarised light microscopy revealed a progression of mesophases as the lipid portion was hydrated by the aqueous portion via the diffusion limited interface which separated the portions. Thus demonstrating, on a droplet scale, a new approach for studying the phase transformation kinetics and identification of non-equilibrium phase in droplet-based lyotropic liquid systems.

Glass-embedded PDMS microfluidic device for enhanced concentration of nanoparticles using an ultrasonic nanosieve.

Surface acoustic wave (SAW) driven devices typically employ polymeric microfluidic channels of low acoustic impedance mismatch to the fluid in contact, to allow precise control of the wave field. Several of these applications, however, can benefit from the implementation of an acoustically reflective surface at the microfluidic channel's ceiling to increase energy retention within the fluid and hence, performance of the device. In this work, we embed a glass insert at the ceiling of the PDMS microfluidic channel used in a SAW activated nanosieve, which utilises a microparticle resonance for enrichment of nanoparticles. Due to the system's independence of performance on channel geometry and wave field pattern, the glass-inserted device allowed for a 30-fold increase in flow rate, from 0.05 µl min-1 to 1.5 µL min-1, whilst maintaining high capture efficiencies of >90%, when compared to its previously reported design. This effectively enables the system to process larger volume samples, which typically is a main limitation of these type of devices. This work demonstrates a simple way to increase the performance and throughput of SAW-based devices, especially within systems that can benefit from the energy retention.

Complex early childhood experiences: Characteristics of Northern Territory children across health, education and child protection data.

Early identification of vulnerable children to protect them from harm and support them in achieving their long-term potential is a community priority. This is particularly important in the Northern Territory (NT) of Australia, where Aboriginal children are about 40% of all children, and for whom the trauma and disadvantage experienced by Aboriginal Australians has ongoing intergenerational impacts. Given that shared social determinants influence child outcomes across the domains of health, education and welfare, there is growing interest in collaborative interventions that simultaneously respond to outcomes in all domains. There is increasing recognition that many children receive services from multiple NT government agencies, however there is limited understanding of the pattern and scale of overlap of these services. In this paper, NT health, education, child protection and perinatal datasets have been linked for the first time. The records of 8,267 children born in the NT in 2006-2009 were analysed using a person-centred analytic approach. Unsupervised machine learning techniques were used to discover clusters of NT children who experience different patterns of risk. Modelling revealed four or five distinct clusters including a cluster of children who are predominantly ill and experience some neglect, a cluster who predominantly experience abuse and a cluster who predominantly experience neglect. These three, high risk clusters all have low school attendance and together comprise 10-15% of the population. There is a large group of thriving children, with low health needs, high school attendance and low CPS contact. Finally, an unexpected cluster is a modestly sized group of non-attendees, mostly Aboriginal children, who have low school attendance but are otherwise thriving. The high risk groups experience vulnerability in all three domains of health, education and child protection, supporting the need for a flexible, rather than strictly differentiated response. Interagency cooperation would be valuable to provide a suitably collective and coordinated response for the most vulnerable children.

Nonequilibrium interfacial diffusion across microdroplet interface.

Increases in complexity attainable in molecular self-assembly necessitates both advanced molecular design as well as microenvironmental control. Such control is offered by microfluidics, where precise chemical compositions and gradients can be readily established. A droplet microfluidic platform combining upstream step emulsification with downstream hydrodynamic microtraps has been designed to facilitate molecular self-assembly. The step emulsification rapidly generates uniform droplets which act as reaction chambers. The hydrodynamic microtraps hold droplets against the flow ensuring they are exposed to a continuous supply of fresh fluid for constant reagent extraction and/or delivery. Additionally, the droplet immobilization permits real-time droplet characterization and reaction monitoring. Subsequently, droplets can be released from the traps through flow reversal, allowing post-process characterization. The microfluidic system was demonstrated by the phase separation of lyotropic droplets. Ethanol/water droplets were created in a continuous ambient squalene/monoolein microflow, causing the continuous extraction of ethanol from the droplets and delivery of monoolein from the ambient microflow. Unlike conventional bulk techniques and continuous microfluidics, where finite microchannel lengths necessarily impose limits to the extent to which slow processes can proceed, this approach allows extended duration reactions whilst enabling real time process monitoring.

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.

Incidence of treated first-episode psychosis amongst Aboriginal and non-Aboriginal youth in the Top End of the Northern Territory, Australia.

OBJECTIVES: This study aims to estimate the incidence rate of first episode of psychosis (FEP) in the Top End of the Northern Territory (NT), exploring how rates vary by age, sex, Aboriginal status and remoteness. METHOD: Youths (ages 15-24) presenting with FEP to the two specialist mental health services in the Top End were identified through audit of the electronic health records between 2014-2018. Population demographic data were collected from the 2016 Australian National Census. Statistical analysis estimated variation in incidence rates by age, sex, Aboriginal status and remoteness. RESULTS: A total of 236 youths with FEP were included in the study. The overall incidence rate was 174 per 100,000 person-years. Rates were very high in the Aboriginal (331 per 100,000 person-years) and remote populations (308 per 100,000 person-years), and lower in the non-Aboriginal population (85 per 100,000 person-years). CONCLUSION: This study shows high rates of FEP in young people in the Top End, attributable to very high rates in the Aboriginal population, many of whom live in remote areas. Resources should be allocated to support this high-risk group.

Pathways to school success: Self-regulation and executive function, preschool attendance and early academic achievement of Aboriginal and non-Aboriginal children in Australia's Northern Territory.

BACKGROUND: With the pending implementation of the Closing the Gap 2020 recommendations, there is an urgent need to better understand the contributing factors of, and pathways to positive educational outcomes for both Aboriginal and non-Aboriginal children. This deeper understanding is particularly important in the Northern Territory (NT) of Australia, in which the majority of Aboriginal children lived in remote communities and have language backgrounds other than English (i.e. 75%). METHODS: This study linked the Australian Early Development Census (AEDC) to the attendance data (i.e. government preschool and primary schools) and Year 3 National Assessment Program for Literacy and Numeracy (NAPLAN). Structural equation modelling was used to investigate the pathway from self-regulation and executive function (SR-EF) at age 5 to early academic achievement (i.e. Year 3 reading/numeracy at age 8) for 3,199 NT children. RESULT: The study confirms the expected importance of SR-EF for all children but suggests the different pathways for Aboriginal and non-Aboriginal children. For non-Aboriginal children, there was a significant indirect effect of SR-EF (ß = 0.38, p<0.001) on early academic achievement, mediated by early literacy/numeracy skills (at age 5). For Aboriginal children, there were significant indirect effects of SR-EF (ß = 0.19, p<0.001) and preschool attendance (ß = 0.20, p<0.001), mediated by early literacy/numeracy skills and early primary school attendance (i.e. Transition Years to Year 2 (age 5-7)). CONCLUSION: This study highlights the need for further investigation and development of culturally, linguistically and contextually responsive programs and policies to support SR-EF skills in the current Australian education context. There is a pressing need to better understand how current policies and programs enhance children and their families' sense of safety and support to nurture these skills. This study also confirms the critical importance of school attendance for improved educational outcomes of Aboriginal children. However, the factors contributing to non-attendance are complex, hence the solutions require multi-sectoral collaboration in place-based design for effective implementation.

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.

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.

The impact of hearing impairment on early academic achievement in Aboriginal children living in remote Australia: a data linkage study.

BACKGROUND: The prevalence of otitis media (OM) and related hearing loss has remained persistently high among some groups of Australian Aboriginal children who are also reported to have poor academic outcomes. The general literature remains inconclusive about the association between OM-related hearing loss and academic performance in primary school. This study aimed to investigate this association in Aboriginal children living in the Northern Territory (NT) of Australia. METHODS: A retrospective, observational cohort study was conducted for 2208 NT Aboriginal children, aged about 8 years, living in remote and very remote communities. The explanatory variable was audiometrically determined hearing level as recorded in the Remote Hearing Assessment dataset. The outcome variable consisted of scale scores in the five domains of the National Assessment Program - Literacy and Numeracy (NAPLAN) for Year 3. Other linked datasets used in the study included school attendance records, perinatal records and community level information on relative remoteness, socioeconomic disadvantage and housing crowdedness. Fixed effects linear regression models were used for statistical analyses. RESULTS: Compared with children with normal hearing and after controlling for a range of covariates, children with mild hearing impairment (HI) scored lower in Writing and Spelling by 15.0 points (95% CI: - 22.4 to - 7.6, p < 0.0005) and 5.0 points (95% CI: - 9.6 to - 0.3, p = 0.037), equivalent to 7.3 and 2.1% of the mean score, respectively. Children with moderate or worse HI scored lower in Writing and Numeracy by 13.4 points (95% CI, - 24.8 to - 1.9, p = 0.022) and 15.2 points (95% CI, - 27.6 to - 2.7, p = 0.017), both equivalent to 6.3% of the mean score the respective domain. Other factors associated with poorer NAPLAN results included being male, lower Year 2 school attendance, low birthweight, average household size> 5 persons, living in a very remote community and speaking English as a second language. CONCLUSIONS: OM-related HI was independently associated with poorer early year academic achievement in Aboriginal children living in remote NT communities. Interventions to improve academic outcomes for Aboriginal children must incorporate actions to address the negative impact associated with HI through early detection, effective treatment and ongoing support for affected children.

Exosome trapping and enrichment using a sound wave activated nano-sieve (SWANS).

Exosomes, a form of extracellular vesicle, are an important precursor in regenerative medicine. Microfluidic methods exist to capture these sub-micrometer sized objects from small quantities of sample, ideal for multiple diagnostic applications. To address the challenge of extraction from large volumes, we use the visual access offered by microfluidic techniques to probe the physical mechanisms behind a method which is compatible with future upscaling. The sound wave actuated nano-sieve uses resonant modes in a packed bed of microparticles to exert trapping forces on nanoparticles. Here, we examine the role of the microparticle size, demonstrating better performance from 15 µm particles than 7 µm particles. When applied to biological samples, we demonstrate for the first time that a packed bed of these larger particles is capable of capturing exosomes and liposomes, the captured particles being on average 20 to 40 times smaller than the pores within the trapped bed.

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.

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.

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.

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.

What birthweight percentile is associated with optimal perinatal mortality and childhood education outcomes?

BACKGROUND: Small for gestational age, defined as birthweight <10th percentile for gestational age, is known to be associated with clinically meaningful impairments in health and development. The effects of variation within the normal range of birthweight percentile on perinatal mortality and childhood education remain less well defined. OBJECTIVE: We sought to quantify the association among birthweight percentile, perinatal mortality, and educational outcomes and to determine the optimal birthweight percentile for those outcomes in Aboriginal and non-Aboriginal Australian children. STUDY DESIGN: This was a retrospective cohort study. Perinatal data for all children born in the Northern Territory, Australia, from 1999 through 2008 were linked to measures of educational attainment at age 8-9 years. Multivariable analysis was used to determine the optimal birthweight percentile for low perinatal mortality and high reading and numeracy scores. RESULTS: The birth cohort contained 35,239 births (42% Aboriginal), of which 11,214 had linked and valid education records. Median birthweight percentile was 29.2 in Aboriginal infants and 44.0 in non-Aboriginal infants. The odds of perinatal mortality decreased by 4% with each 1-percentile increase birthweight percentile overall (adjusted odds ratio, 0.96; P = .000) and lowest mortality rates were at the 61st and 78th percentile in Aboriginal and non-Aboriginal infants, respectively. Although birthweights <10th percentile were associated with greatly increased odds of perinatal mortality, the increased risk extended well beyond this cut-off. Birthweight percentile was also positively correlated with scores in reading (P = .000) and numeracy (P = .000). In non-Aboriginal children, reading and numeracy scores peaked at the 66th percentile, but for Aboriginal children there was continuous benefit with increasing birthweight percentile. Birthweight percentile explained 1% of the variation in education outcomes, with much greater variation explained by other perinatal and sociodemographic factors. CONCLUSION: Birthweights between the 50th-93rd percentiles were most consistently associated with both low perinatal mortality and high reading and numeracy scores, suggesting that small for gestational age does not sufficiently capture the risks associated with variation in fetal growth. Our data indicate that the effect of birthweight percentile accounts for 1% of variation in perinatal and education outcomes.