Disparities between Aboriginal and non-Aboriginal perinatal mortality rates in Western Australia from 1980 to 2015.

BACKGROUND: Perinatal mortality rates are typically higher in Aboriginal than non-Aboriginal populations of Australia. OBJECTIVES: This study aimed to examine the pattern of stillbirth and neonatal mortality rate disparities over time in Western Australia, including an evaluation of these disparities across gestational age groupings. METHODS: All singleton births (≥20 weeks gestation) in Western Australia between 1980 and 2015 were included. Linked data were obtained from core population health datasets of Western Australia. Stillbirth and neonatal mortality rates and percentage changes in the rates over time were calculated by Aboriginal status and gestational age categories. RESULTS: From 1980 to 2015, data were available for 930 926 births (925 715 livebirths, 5211 stillbirths and 2476 neonatal deaths). Over the study period, there was a substantial reduction in both the Aboriginal (19.6%) and non-Aboriginal (32.3%) stillbirth rates. These reductions were evident in most gestational age categories among non-Aboriginal births and in Aboriginal term births. Concomitantly, neonatal mortality rates decreased in all gestational age windows for both populations, ranging from 32.1% to 77.5%. The overall stillbirth and neonatal mortality rate differences between Aboriginal and non-Aboriginal birth decreased by 0.6 per 1000 births and 3.9 per 1000 livebirths, respectively, although the rate ratios (RR 2.51, 95% CI 2.14, 2.94) and (RR 2.94, 95% CI 2.24, 3.85), respectively reflect a persistent excess of Aboriginal perinatal mortality across the study period. CONCLUSIONS: Despite steady improvements in perinatal mortality rates in Western Australia over 3½ decades, the gap between Aboriginal and non-Aboriginal rates remains unchanged in relative terms. There is a continuing, pressing need to address modifiable risk factors for preventable early mortality in Aboriginal populations.

Infant removals: The need to address the over-representation of Aboriginal infants and community concerns of another 'stolen generation'.

OBJECTIVES: The removal of a child from their parents is traumatising, particularly in Aboriginal communities where a history of child removals has led to intergenerational trauma. This study will determine where disparities in child protection involvement exist among Aboriginal and non-Aboriginal children and characteristics associated with infant removals. Challenges faced by child protection and other agencies, and opportunities for overcoming these, are discussed. METHODS: Data from both the Australian Institute of Health and Welfare and linked Western Australian government data was used to examine disparities between Aboriginal and non-Aboriginal children in the child protection and out-of-home care system. RESULTS: Nationally, Aboriginal children are ten times more likely to be placed in out-of-home care than non-Aboriginal children and this disparity starts in infancy. Infants were removed from parents with high levels of risk. Aboriginal infants were at increased risk of being removed from women with substance-use problems and had greater proportions removed from remote, disadvantaged communities than were non-Aboriginal infants. CONCLUSIONS: Aboriginal infants have a high rate of removal. Although there are many complexities to be understood and challenges to overcome, there are also potential strategies. The disparity between Aboriginal and non-Aboriginal infant removals needs to be seen as a priority requiring urgent action to prevent further intergenerational trauma.

Trends in alcohol-related injury admissions in adolescents in Western Australia and England: population-based cohort study.

BACKGROUND: Alcohol-related harm in young people is now a global health priority. We examined trends in hospital admissions for alcohol-related injuries for adolescents in Western Australia (WA) and in England, identified groups most at risk and determined causes of injuries. METHODS: Annual incidence rates for alcohol-related injury rates were calculated using population-level hospital admissions data for WA and England. We compared trends in different types of alcohol-related injury by age and gender. RESULTS: Despite a decrease in the overall rate of injury admissions for people aged 13-17 years in WA, alcohol-related injuries have increased significantly from 1990 to 2009 (from 8 to 12 per 10 000). Conversely, alcohol-related injury rates have declined in England since 2007. In England, self-harm is the most frequently recorded cause of alcohol-related injury. In WA, unintentional injury is most common; however, violence-related harm is increasing for boys and girls. CONCLUSION: Alcohol-related harm of sufficient severity to require hospital admission is increasing among adolescents in WA. Declining trends in England suggest that this trend is not inevitable or irreversible. More needs to be done to address alcohol-related harm, and on-going monitoring is required to assess the effectiveness of strategies.

Maltreatment Risk Among Children With Disabilities.

BACKGROUND: Children with disabilities are at increased risk of child maltreatment; however, there is a gap in the evidence about whether all disabilities are at equal risk and whether risk factors vary according to the type of disability. METHODS: A population-based record-linkage study of all children born in Western Australia between 1990 and 2010. Children with disabilities were identified by using population-based registers and risk of maltreatment determined by allegations reported to the Department for Child Protection and Family Support. RESULTS: Although children with disabilities make up 10.4% of the population, they represent 25.9% of children with a maltreatment allegation and 29.0% of those with a substantiated allegation; however, increased risk of maltreatment was not consistent across all disability types. Children with intellectual disability, mental/behavioral problems, and conduct disorder continued to have increased risk of an allegation and substantiated allegation after adjusting for child, family, and neighborhood risk factors. In contrast, adjusting for these factors resulted in children with autism having a lower risk, and children with Down syndrome and birth defects/cerebral palsy having the same risk as children without disability. CONCLUSIONS: The prevalence of disabilities in the child protection system suggests a need for awareness of the scope of issues faced by these children and the need for interagency collaboration to ensure children's complex needs are met. Supports are needed for families with children with disabilities to assist in meeting the child's health and developmental needs, but also to support the parents in managing the often more complex parenting environment.

Data linkage in an established longitudinal cohort: the Western Australian Pregnancy Cohort (Raine) Study.

The Western Australian Data Linkage System is one of a few comprehensive, population-based data linkage systems worldwide, creating links between information from different sources relating to the same individual, family, place or event, while maintaining privacy. The Raine Study is an established cohort study with more than 2000 currently active participants. Individual consent was obtained from participants for information in publicly held databases to be linked to their study data. A waiver of consent was granted where it was impracticable to obtain consent. Approvals to link the datasets were obtained from relevant ethics committees and data custodians. The Raine Study dataset was subsequently linked to academic testing data collected by the Western Australian Department of Education. Examination of diet and academic performance showed that children who were predominantly breastfed for at least 6 months scored higher academically at age 10 than children who were breastfed for less than 6 months. A further study found that better diet quality at ages 1, 2 and 3 years was associated with higher academic scores at ages 10 and 12 years. Examination of nutritional intake at 14 years of age found that a better dietary pattern was associated with higher academic performance. The detailed longitudinal data collected in the Raine Study allowed for adjustment for multiple covariates and confounders. Data linkage reduces the burden on cohort participants by providing additional information without the need to contact participants. It can give information on participants who have been lost to follow-up; provide or complement missing data; give the opportunity for validation studies comparing recall of participants with administrative records; increase the population sample of studies by adding control participants from the general population; and allow for the adjustment of multiple covariates and confounders. The Raine Study dataset is extensive and detailed, and can be further improved by linking to other external data sources. By linking educational outcomes to the Raine Study database, it was shown across three different age groups that a healthy diet was consistently associated with higher academic performance.

Stillbirth and neonatal death rates across time: the influence of pregnancy terminations and birth defects in a Western Australian population-based cohort study.

BACKGROUND: The stillbirth rate in most high income countries reduced in the early part of the 20(th) century but has apparently been static over the past 2½ decades. However, there has not been any account taken of pregnancy terminations and birth defects on these trends. The current study sought to quantify these relationships using linked Western Australian administrative data for the years 1986-2010. METHODS: We analysed a retrospective, population-based cohort of Western Australia births from 1986 to 2010, with de-identified linked data from core population health datasets. RESULTS: The study revealed a significant decrease in the neonatal death rate from 1986 to 2010 (6.1 to 2.1 neonatal deaths per 1000 births; p < .01), while the overall stillbirth rate remained static. The stillbirth trend was driven by deaths in the extremely preterm period (20-27 weeks; which account for about half of all recorded stillbirths and neonatal deaths), masking significant decreases in the rate of stillbirth at very preterm (28-31 weeks), moderate to late preterm (32-36 weeks), and term (37+ weeks). For singletons, birth defects made up an increasing proportion of stillbirths and decreasing proportion of neonatal deaths over the study period-a shift that appears to have been largely driven by the increase in late pregnancy terminations (20 weeks or more gestation). After accounting for pregnancy terminations, we observed a significant downward trend in stillbirth and neonatal death rates at every gestational age. CONCLUSIONS: Changes in clinical practice related to pregnancy terminations have played a substantial role in shaping stillbirth and neonatal death rates in Western Australia over the 2½ decades to 2010. The study underscores the need to disaggregate perinatal mortality data in order to support a fuller consideration of the influence of pregnancy terminations and birth defects when assessing change over time in the rates of stillbirth and neonatal death.

Hospital Utilisation in Indigenous and Non-Indigenous Infants under 12 Months of Age in Western Australia, Prospective Population Based Data Linkage Study.

BACKGROUND: Indigenous infants (infants aged under 12 months) have the highest hospital admission and emergency department presentation risks in Australia. However, there have been no recent reports comparing hospital utilisation between Indigenous and non-Indigenous infants. METHODS: Our primary objective was to use a large prospective population-based linked dataset to assess the risk of all-cause hospital admission and emergency department presentation in Indigenous compared to non-Indigenous infants in Western Australia (WA). Secondary objectives were to assess the effect of socio-economic status (Index of Relative Socio-Economic Disadvantage [IRSD]) on hospital utilisation and to understand the causes of hospital utilisation. FINDINGS: There were 3,382 (5.4%) Indigenous and 59,583 (94.6%) non-Indigenous live births in WA from 1 January 2010 to 31 December 2011. Indigenous infants had a greater risk of hospital admission (adjusted odds ratio [aOR] 1.90, 95% confidence interval [95% CI] 1.77-2.04, p = <0.001) and emergency department presentation (aOR 2.15, 95% CI 1.98-2.33, p = <0.001) compared to non-Indigenous infants. Fifty nine percent (59.0%) of admissions in Indigenous children were classified as preventable compared to 31.2% of admissions in non-Indigenous infants (aOR 2.12, 95% CI 1.88-2.39). The risk of hospital admission in the most disadvantaged (IRSD 1) infants in the total cohort (35.7%) was similar to the risk in the least disadvantaged (IRSD 5) infants (30.6%) (aOR 1.04, 95% CI 0.96-1.13, p = 0.356). INTERPRETATION: WA Indigenous infants have much higher hospital utilisation than non Indigenous infants. WA health services should prioritise Indigenous infants regardless of their socio economic status or where they live.

Maternal mental health and risk of child protection involvement: mental health diagnoses associated with increased risk.

BACKGROUND: Previous research shows that maternal mental illness is an important risk factor for child maltreatment. This study aims to quantify the relationship between maternal mental health and risk of child maltreatment according to the different types of mental health diagnoses. METHODS: The study used a retrospective cohort of children born in Western Australia between 1990 and 2005, with deidentified linked data from routine health and child protection collections. RESULTS: Nearly 1 in 10 children (9.2%) of mothers with a prior mental health contact had a maltreatment allegation. Alternatively, almost half the children with a maltreatment allegation had a mother with a mental health contact. After adjusting for other risk factors, a history of mental health contacts was associated with a more than doubled risk of allegations (HR=2.64, 95% CI 2.50 to 2.80). Overall, all mental health diagnostic groups were associated with an increased risk of allegations. The greatest risk was found for maternal intellectual disability, followed by disorders of childhood and psychological development, personality disorders, substance-related disorders, and organic disorders. Maltreatment allegations were substantiated at a slightly higher rate than for the general population. CONCLUSIONS: Our study shows that maternal mental health is an important factor in child protection involvement. The level of risk varies across diagnostic groups. It is important that mothers with mental health issues are offered appropriate support and services. Adult mental health services should also be aware and discuss the impact of maternal mental health on the family and children's safety and well-being.

Changes in Caesarean Delivery Rates in Western Australia from 1995 to 2010 by Gestational Age at Birth.

BACKGROUND: The caesarean delivery rate in the developed world has been increasing. It is not well understood how caesarean delivery rates have changed by gestational age at birth in Western Australia, particularly in relation to the introduction of the early-term delivery guidelines in Australia in 2006. METHODS: Data from the Western Australian Midwives Notification System were used to identify 193,136 singletons born to primiparous women at 34-42 weeks' gestation during 1995-2010. Caesarean delivery rates were calculated by gestational age group (34-36 weeks, 37-38 weeks, and 39-42 weeks) and stratified into pre-labour and in-labour caesarean delivery. The average annual percent change (AAPC) for the caesarean delivery rates was calculated using joinpoint regression. Log-binomial regression was used to estimate the risk of having a caesarean delivery while adjusting for maternal and antenatal factors. RESULTS: Caesarean delivery rates rose steadily from 1995 to 2005 (AAPC = 5.9%, [95% confidence interval (CI) 4.9, 6.9]), but stabilised since then (AAPC = 0.9%, [95% CI -1.9, 3.8]). The rate of in-labour caesarean deliveries rose consistently from 1995 to 2010 across all gestational age groups. The pre-labour caesarean delivery rate rise was most dominant at 37-38 weeks' gestation from 1995 to 2005 (AAPC = 6.8%, [95% CI 5.4, 8.2]), but declined during 2006-10 (AAPC = -4.5, [95% CI -6.7, -2.3]), while at the same time the rate at 39-42 weeks rose slightly. CONCLUSIONS: The rise in pre-labour caesarean deliveries during 1995-2005 occurred predominantly at 37-38 weeks' gestation, but declined again from 2006 to 2010. This suggests that the recently developed Australian early-term delivery guidelines may have had some success in reducing early-term deliveries in Western Australia.

Childhood hospitalisation with infection and cardiovascular disease in early-mid adulthood: a longitudinal population-based study.

BACKGROUND: Pathogen-specific and overall infection burden may contribute to atherosclerosis and cardiovascular disease (CVD), but the effect of infection severity and timing is unknown. We investigated whether childhood infection-related hospitalisation (IRH, a marker of severity) was associated with subsequent adult CVD hospitalisation. METHODS: Using longitudinal population-based statutorily-collected administrative health data from Western Australia (1970-2009), we identified adults hospitalised with CVD (ischaemic heart disease, ischaemic stroke, and peripheral vascular disease) and matched them (10:1) to population controls. We used Cox regression to assess relationships between number and type of childhood IRH and adulthood CVD hospitalisation, adjusting for sex, age, Indigenous status, socioeconomic status, and birth weight. RESULTS: 631 subjects with CVD-related hospitalisation in adulthood (≥ 18 years) were matched with 6310 controls. One or more childhood (< 18 years) IRH was predictive of adult CVD-related hospitalisation (adjusted hazard ratio, 1.3; 95% CI 1.1-1.6; P < 0.001). The association showed a dose-response; ≥ 3 childhood IRH was associated with a 2.2 times increased risk of CVD-related hospitalisation in adulthood (adjusted hazard ratio, 2.2; 95% CI 1.7-2.9; P < 0.001). The association was observed across all clinical diagnostic groups of infection (upper respiratory tract infection, lower respiratory tract infection, infectious gastroenteritis, urinary tract infection, skin and soft tissue infection, and other viral infection), and individually with CVD diagnostic categories (ischaemic heart disease, ischaemic stroke and peripheral vascular disease). CONCLUSIONS: Severe childhood infection is associated with CVD hospitalisations in adulthood in a dose-dependent manner, independent of population-level risk factors.

Re-evaluation of link between interpregnancy interval and adverse birth outcomes: retrospective cohort study matching two intervals per mother.

OBJECTIVE: To re-evaluate the causal effect of interpregnancy interval on adverse birth outcomes, on the basis that previous studies relying on between mother comparisons may have inadequately adjusted for confounding by maternal risk factors. DESIGN: Retrospective cohort study using conditional logistic regression (matching two intervals per mother so each mother acts as her own control) to model the incidence of adverse birth outcomes as a function of interpregnancy interval; additional unconditional logistic regression with adjustment for confounders enabled comparison with the unmatched design of previous studies. SETTING: Perth, Western Australia, 1980-2010. PARTICIPANTS: 40 441 mothers who each delivered three liveborn singleton neonates. MAIN OUTCOME MEASURES: Preterm birth (<37 weeks), small for gestational age birth (<10th centile of birth weight by sex and gestational age), and low birth weight (<2500 g). RESULTS: Within mother analysis of interpregnancy intervals indicated a much weaker effect of short intervals on the odds of preterm birth and low birth weight compared with estimates generated using a traditional between mother analysis. The traditional unmatched design estimated an adjusted odds ratio for an interpregnancy interval of 0-5 months (relative to the reference category of 18-23 months) of 1.41 (95% confidence interval 1.31 to 1.51) for preterm birth, 1.26 (1.15 to 1.37) for low birth weight, and 0.98 (0.92 to 1.06) for small for gestational age birth. In comparison, the matched design showed a much weaker effect of short interpregnancy interval on preterm birth (odds ratio 1.07, 0.86 to 1.34) and low birth weight (1.03, 0.79 to 1.34), and the effect for small for gestational age birth remained small (1.08, 0.87 to 1.34). Both the unmatched and matched models estimated a high odds of small for gestational age birth and low birth weight for long interpregnancy intervals (longer than 59 months), but the estimated effect of long interpregnancy intervals on the odds of preterm birth was much weaker in the matched model than in the unmatched model. CONCLUSION: This study questions the causal effect of short interpregnancy intervals on adverse birth outcomes and points to the possibility of unmeasured or inadequately specified maternal factors in previous studies.