Publications

2019

This study sought to determine the minimum set of indicators available in cross-agency administrative data that could be used to accurately distinguish children placed in out-of-home-care from the wider group of children known to child protection services, and from the general population unknown to child protection services. Participants comprised a population sample of 72,079 children and their parents, including 1,239 children who had been placed in out-of-home-care, 15,367 children who had been reported to child protection services but had no record of out-of-home-care placement, and 55,473 children who had no previous contact with child protection services (up to age 13–14 years). A combination of six risk indicators was able to classify children placed in out-of-home-care with approximately 95% accuracy. These findings show that several key risk factors available in administrative records held by multiple government agencies may be used to identify vulnerable children, for whom targeted family support services may prevent future out-of-home-care placements.
 
  • Green M.J., Hindmarsh, G., Kariuki, M., Islam, F., Laurens, K.R., Neil, A., Katz, I., Chilvers, M., Harris, F., Carr, V.J. (in press). Mental disorders among children in contact with child protection services. Medical Journal of Australia (accepted for publication 1 July 2019)
Summary to be provided following publication. 

This study examined the associations between chronic physical health conditions which are monitored and managed in NSW public schools under Individual Health Care Plans (namely asthma, allergies and anaphylaxis, type 1 diabetes, and epilepsy) and emotional, social, and behavioural difficulties assessed at age 5 years on the teacher-reported Australian Early Development Census, and at age 11 years using the self-report Middle Childhood Survey. Participants were 21,304 children from the NSW-CDS, of whom 7.5% had a hospital record of at least one of these conditions by early childhood (age 5 years), and 10.7% by middle childhood (age 11 years). Relative to peers who had no hospital records of these chronic health conditions, children with any of these health conditions experienced a small increase in selected emotional, behavioural, and social problems, as well as overall (total) problems at both assessment points (age 5 and age 11 years). Despite these difficulties, children identified with chronic health conditions were just as likely as their peers without such conditions to identify feeling supported or connected at home, school, in their community, and with their natural environment.

This paper examined the incidence of Emergency Department presentations among child offspring of parents with criminal offending records, in a population sample of 72,772 children and their parents drawn from the New South Wales Child Development Study. Rates of Emergency Department presentation, particularly for physical injury, were higher among children with parental history of criminal offending (and greatest for paternal criminal offending), after adjusting for the contribution of other risk factors such as parental mental illness, Aboriginal and/or Torres Strait Islander background, low socioeconomic status, maternal age at birth, and the child's sex. These findings suggest children of parents with a history of criminal offending have an increased risk of childhood presentations to the Emergency Department, including for potentially avoidable physical injury. 
 
Childhood experiences of hallucinations and delusions (psychotic-like experiences) increase risk for concurrent and future psychiatric disorders but are relatively common in the population. For most children, these experiences are benign and transitory, but strategies are needed to identify vulnerable children who may benefit from monitoring or targeted intervention. This study sought to identify patterns of childhood psychotic-like experiences in the general population, and the relationship of particular profiles of responses with other psychopathologies. Participants in the study were 27,000 Australian children from the NSW-CDS population cohort who completed the online self-report Middle Childhood Survey, including items assessing psychotic-like experiences and emotional, peer relationship, conduct, and hyperactivity-inattention psychopathology. Five classes of response patterns to psychotic-like experiences were identified, reflecting None (27.4% of children), Minor (29.7%), Moderate (11.8%), Hallucinatory (21.0%), and Strong (10.2%). The odds of multiple psychopathology were greater in the Hallucinatory and Strong groups.  
 
This paper examined associations between early developmental vulnerabilities (at age 5 years) and (1) the highest level of child protection response (where out-of-home-care was deemed the highest response among other types of reports/responses), and (2) the timing of the first child protection report during early development. The sample included 67,027 children drawn from the New South Wales Child Development Study, of whom 10,944 were reported to child protection services up to age 5 years. The results indicated that children with substantiated maltreatment reports showed the strongest odds of vulnerability on three or more developmental domains relative to children with no child protection report (followed by children placed in out-of-home-care, then children with unsubstantiated child protection reports). Children placed in out-of-home-care showed slightly better physical, cognitive and communication competencies than those with substantiated reports that did not result in out-of-home-care placements (when each group was compared to children with no child protection reports). Children with first maltreatment reports occurring in the first 18 months of life showed the strongest likelihood of developmental vulnerabilities on three or more developmental domains relative to children with reports in later years of childhood, when each group was compared to children with no child protection reports. The findings show early reports of maltreatment may signal the need for targeted remediation of early developmental competencies to mitigate early developmental difficulties.

This paper examined associations between developmental vulnerability profiles determined at the age of 5 years, and subsequent childhood mental illness diagnosed between ages 6 and 13 years, in a population sample of 86,668 children from the New South Wales Child Development Study (NSW-CDS) cohort. Membership of putative risk classes in early childhood were delineated via latent class analysis of Australian Early Development Census subdomains, and children designated as those with established ‘special needs’ at school entry were examined as a separate group of interest. The results indicated that the crude odds of being diagnosed with any mental disorder between the ages of 6–13 years was increased approximately threefold in children showing ‘pervasive' risk or ‘misconduct' risk profiles according to their AEDC vulnerability patterns at age 5 years, relative to children showing no AEDC vulnerabilities. The odds of mental illness among children with special needs was increased approximately sevenfold, relative to children showing no AEDC vulnerabilities, before adjusting for other contributing factors (e.g., parental mental illness history, child protection records, socioeconomic status, child’s sex). These findings show that distinct patterns of early childhood developmental vulnerability are associated with subsequent onset of mental disorders, and that AEDC risk profiles have the potential to inform interventions to mitigate the risk for mental disorders in later childhood and adolescence.

This study examined the relationship between parental offending and the continuity and discontinuity of children’s conduct, attentional, and emotional difficulties from early to middle childhood while also considering the role of timing of the parental offending exposure. We specifically tested associations between mother’s and father’s history and timing of any and violent offending, and patterns of continuity or discontinuity in offspring emotional, conduct, and attentional difficulties between ages 5 and 11 years, in a population sample of 19,208 children and their parents drawn from the New South Wales Child Development Study (NSW-CDS) cohort. Maternal and paternal offending each conferred  increased risk of all patterns of developmental difficulties, including those limited to age 5 only (remitting problems), to age 11 only (incident problems), and difficulties present at both ages 5 and 11 years (persisting problems), with the greatest associations observed between parental offending history and persisting conduct problems. Paternal offending that continued through early and middle childhood had the greatest association with child developmental difficulties, while the timing of maternal offending had a less prominent effect on child developmental difficulties.

This study examined the the link between parental criminal offending history and offspring behaviour in middle childhood, in a population sample of 21,956 children drawn from the NSW Child Development Study (NSW-CDS). Specifically, the prevalence of offending among mothers and fathers was examined in relation to the children’s conduct problems at age 11 years. The findings showed that parental offending history increased the likelihood of conduct problems among offspring, and that maternal violent offending was most strongly associated with conduct problems in middle childhood. The findings suggest that the intergenerational transmission of antisocial behaviour begins early, highlighting the importance of intervention for at-risk children and programs targeted at mothers as well as fathers.

This paper describes the development of a brief school-based instrument designed for use in research and in educational practice. The Survey of School Promotion of Emotional and Social Health (SSPESH)measures the extent to which a school has implemented policies and practices in four health-promoting domains: (a) creating a positive school community, (b) teaching social and emotional skills, (c) engaging the parent community, and (d) supporting students experiencing mental health difficulties. The questionnaire can be used to differentiate high, moderate, and low implementation of whole-school policies and practices that promote the emotional and social health of students. To develop the instrument, responses were gathered via an online survey of Principals in almost 600 Australian primary schools in New South Wales during 2015. The paper describes the preliminary psychometric properties of the instrument (reliability, validity), and the development of the implementation index using Latent Class Analysis methods. This brief 13-item survey can be used by researchers and evaluators for comparative and multivariate analyses. School leadership may find it useful as a brief tool to guide the identification of target areas for whole-school improvement across the four important health-promoting domains.

2018

This report provides a description of the NSW Child Development Study cohort, and what has been measured in the cohort, following the second record linkage (Wave 2) in 2016. The child cohort is comprised of 91,635 children, defined by inclusion in the NSW Australian Early Development Census (AEDC) of 2009 at school entry (n=87,037) and/or the investigator-led Middle Childhood Survey (MCS)conducted in 2015 (n=27,792). The MCS captured 26.6% of the original 2009 AEDC cohort, and also brought 4598 new children into the cohort; 23,194 children contributed records to both the AEDC and MCS assessments. Wave 2 brings together each child’s birth, mortality, health, academic achievement, school enrolment, school suspensions and expulsions, child protection and criminal records, linked with their mothers’ perinatal records, and with both parents’ mortality, health and criminal records, where available. This report describes the linkage rates for each of these record sets, as well detailed information about each record set, and characteristics for the child and their parents. Published findings from the study to date, its strengths and limitations and future directions, are also discussed. 

This study examined the associations between quantity of prenatal smoking and frequency of maternal offending and offspring behavioural and cognitive outcomes at age 5 years, while accounting for other prenatal and family risk factors. Prenatal smoking and frequent maternal offending (comprising two or more offences) were associated with all developmental vulnerabilities examined, even after adjusting for other familial and prenatal risk factors. Population attributable fractions (PAFs) for prenatal smoking ranged from 5.3% to 15.8% and PAFs for maternal offending ranged from 3.4% to 11.8% across the offspring outcomes. These findings suggest prevention and intervention efforts during prenatal periods for vulnerable families may have benefits for both behavioural and cognitive problems in early childhood. 

This study examined connection to the natural environment in relation to well-being in childhood, in the context of other factors known to influence wellbeing such as social supports, attention, and empathic skills. We used a representative sample of 26,848 children from the NSW Child Development Study (NSW-CDS) who completed the Middle Childhood Survey (a self-report survey of mental health and well-being) that was undertaken when the children were aged approximately 11 years. The results indicated that connection to nature was positively, albeit weakly, associated with two indicators of well-being: self-satisfaction and prosocial behaviour, while other factors had stronger effects on wellbeing. For example, social supports had the strongest relationship with self-satisfaction, while empathy had the strongest relationship with prosocial behaviour. These findings suggest that developing a connection to nature can slightly improve well-being, and may augment education-based programs to improve wellbeing in childhood.

Brief self-report questionnaire measures of the Big Five personality dimensions in children are needed for use in large population studies, for which longer instruments are not suited. The Big Five traits describe individual differences in personality within the population, with the expression of each trait in an individual varying along a dimension. These Big Five traits include: Agreeableness (generous, honest, modest vs. selfish, aggressive, arrogant), Conscientiousness (dependable, achievement-driven, constrained vs. disorderly, laid-back, unambitious), Neuroticism (worried, anxious, sad, vs. emotionally stable, calm), Extraversion (warm, outgoing, cheerful vs. introverted, reserved, solitary, sombre), and Openness to experience (curious, exploratory vs. rigid, practical, traditional). This study established the psychometric properties (reliability, validity) of a brief self-report measure of the Big Five personality dimensions in children, using data from 27,415 children in the NSW Child Development Study cohort. The psychometric properties were examined using Item Response Theory methods, exploratory and confirmatory factor analyses. The findings demonstrate the suitability of the brief, 20-item short-form measure of the Big Five personality dimensions in children for administration online in large population-based studies. The questionnaire could be useful in research examining how personality traits in childhood might act as risk or protective factors for later adolescent and adult health and well-being outcomes, and thereby inform public health policy and practices that promote mental health and prevent mental illness.

 This study investigated the effects of in utero exposure to maternal infection and noninfectious diseases during pregnancy on offspring developmental vulnerabilities at age 5 years, in a population sample of 66,045 children drawn from the NSW Child Development Study (NSW-CDS) cohort. Maternal infectious diseases during pregnancy and early childhood infection conferred the largest associations with developmental vulnerabilities at age 5 years; maternal noninfectious illness during pregnancy also retained small but significant associations with developmental vulnerabilities even when adjusted for other physical and mental illness exposures and covariates known to be associated with early childhood development. Among all exposures examined, maternal mental illness first diagnosed prior to childbirth conferred the greatest odds of developmental vulnerability at age 5 years.  Prenatal exposure to infectious or noninfectious diseases appear to influence early childhood physical, social, emotional and cognitive developmental vulnerabilities that may represent intermediate phenotypes for subsequent mental disorders.

 This study examined patterns of association between externalising and internalising vulnerabilities in early childhood and parental mental disorder, in a population sample of 69,116 children drawn from the NSW Child Development Study (NSW-CDS) cohort. Measures of externalising and internalising vulnerability, obtained via the Australian Early Development Census, were linked to administrative health datasets to determine parental psychiatric diagnostic status. Parental mental illness, across diagnostic categories, was associated with all child externalising and internalising domains of vulnerability. These findings have important implications for informing early identification and intervention strategies in high-risk offspring and for research into the causes of mental illness.

This study determined classes of children among the general population who may be at risk for later mental disorder on the basis of early patterns of developmental functioning, and the associations of each risk-class with exposure to childhood maltreatment, parental mental illness, parental offending, and perinatal adversities, and other demographic factors. Data from 16 subdomains of the Australian Early Development Census (AEDC) were used to determine classes of children with shared patterns of developmental vulnerabilities in a population sample of 67,353 children drawn from the New South Wales Child Development Study (NSW-CDS) cohort. Four classes were identified, reflecting putative risk states for mental disorders: (1) disrespectful and aggressive/hyperactive behaviour, labelled ‘misconduct risk’ (6.5%); (2) ‘pervasive risk’ (4.0%); (3) ‘mild generalised risk’ (11.6%); and (4) ‘no risk’ (77.9%). The odds of membership in putative risk groups (relative to the no risk group) were greater among children from backgrounds of child maltreatment, parental history of mental illness, parental history of criminal offending, socioeconomic disadvantage, and perinatal adversities.  

This study examined the structure of the Best Start Kindergarten Assessment (Best Start) of literacy and numeracy, in a general population sample of 37,734 children drawn from the NSW Child Development Study (NSW-CDS) cohort. Analyses conducted on the 11 Best Start scales supported a two-factor structure underpinning literacy and numeracy attainment. This two-factor measure of attainment at school entry is comparable in structure to standardised measures of literacy and numeracy administered in later school years, and may thus facilitate research examining pathways of academic performance over time.

2017

 The study focused on the effects of early life maltreatment on early childhood developmental outcomes, including examination of the effects of multiple maltreatment types and the timing of maltreatment in a large population sample. We specifically examined associations between the type, and timing of childhood maltreatment and early developmental vulnerabilities in a population sample of 68,459 children (34,562 males) drawn from the New South Wales Child Development Study (NSW-CDS) cohort, using linked administrative data for children and their parents (collected from 2001-2009). The mean age of the child sample was 5.62 years (SD=0.37), and 2,135 children had already been exposed to (substantiated) maltreatment according to child protection records. Exposure to any type of childhood maltreatment was associated with pervasive developmental vulnerability at age 5 years. Children exposed to two or more maltreatment types, and with first maltreatment reported after 3 years of age, showed greater likelihood of vulnerability on multiple developmental domains relative to non-maltreated children. These patterns of association were found in the context of other important risk factors for early childhood developmental vulnerabilities that have been implicated in previous studies (e.g., male sex, maternal smoking during pregnancy). 

This study examined the impact of parental criminal offending, both paternal and maternal, on offspring aggression at age 5 years. Parental mental illness, child’s sex, and socioeconomic disadvantage were also accounted for in the analyses. Offspring aggression was assessed using the Aggressive Behaviour subdomain of the Australian Early Development Census (AEDC), a teacher-reported cross-sectional survey on child development. Parental criminal offending was obtained from NSW Bureau of Crime Statistics data and parental mental health was obtained from NSW Admitted Patients and Mental Health Ambulatory data. Parental history of violent and frequent offending increased the risk of high levels of aggression in offspring during early childhood, highlighting the need for intervention with affected families during this key developmental period.

This report examined the impact of parental criminal offending on developmental outcomes at age 5 years. Data from the Australian Early Development Census, a teacher-reported assessment of childhood development across five key domains, was linked with maternal and paternal offending histories obtained from official records. Children whose parents had a history of criminal offending were at significantly greater risk of developmental vulnerability on each of the five domains. The risk of vulnerability increased further when both parents offended, when mothers rather than fathers offended, and when the offending was of a violent nature. For all types of offending, children were more likely to be vulnerable on multiple domains than on a single domain. These findings indicate a widespread impact of parental offending on early childhood development and highlight the need to support affected families in order to improve outcomes.

2016

This report provides a description of the characteristics of children who make up the NSW Child Development Study cohort. This group comprises 87,000 children who commenced their formal school education in 2009, and for whom class teachers completed the Australian Early Development Census (AEDC). Rates for the successful linkage of the AEDC records with other administrative data for the children and their parents are provided within this publication, and information about the demographic characteristics (e.g., sex, geographic and socioeconomic distributions), as well as the representativeness of this group to a comparable national population. The strengths and limitations of the study are also discussed.

This report provides a description of responses to the Middle Childhood Survey (MCS), a computerised self-report assessment of children’s mental health and well-being completed by 27 808 children aged 11-12 years in New South Wales (NSW) schools in 2015. The MCS sample includes 85.9% of students enrolled at the 829 schools who participated in the MCS (35% of eligible schools in NSW), and these participating schools and children are representative of the NSW population. The MCS measured Social Integration, Prosocial Behaviour, Peer Relationship Problems, Supportive Relationships (at Home, School and in the Community), Empathy, Emotional Symptoms, Conduct Problems, Aggression, Attention, Inhibitory Control, Hyperactivity-Inattention, Total Difficulties (internalising and externalising psychopathology), Perceptual Sensitivity, Psychotic-Like Experiences, Personality, Self-esteem, Daytime Sleepiness and Connection to Nature. This report presents response distributions on each of these indices, indicating the range of competencies and vulnerabilities in the population. 

This study examined the relationship between early childhood infections requiring hospitalisation and developmental vulnerability at age 5 years, as assessed using the Australian Early Development Census (AEDC). The AEDC provides an index of each child’s level of function on five domains, including Physical Health and Wellbeing, Social Competence, Emotional Maturity, Language and Cognitive Skills, Communication Skills and General Knowledge. Hospital admissions for infections were associated with vulnerability on all five developmental domains. This suggests that severe infections during early childhood may pose a risk to development by school-age.

This study examined the associations between early childhood maltreatment (age 0-5 years) and childhood social and emotional functioning at approximately age 5 years. This was achieved by linking Family and Community Services Data, parental Mental Health Ambulatory and Admitted Patients Data and Australian Early Development Census Data.  Medium-sized associations were found between maltreatment and poor social competency, aggressive behaviour, and hyperactive/inattentive behaviour, and small associations were found between maltreatment and poor prosocial/helping and anxious/fearful behaviour. These associations overshadowed the impact of having a parent with schizophrenia spectrum disorders. The results suggest childhood maltreatment may adversely impact on early childhood social and emotional functioning to a greater extent than parental schizophrenia and related disorders. 

2015

This scientific review provides a summary of the available evidence relating to risk factors for the development of schizophrenia spectrum disorders (e.g., schizophrenia, schizoaffective disorder), and affective psychoses (e.g., bipolar disorder). A total of 127 papers were reviewed for the purpose of evaluating the evidence for various risk factors as potentially conferring risk for psychoses, and to highlight gaps in the evidence base.  Factors which conferred the greatest risk, or were observed most consistently to confer risk to both affective and non-affective (schizophrenia spectrum) psychoses, included: obstetric complications, maternal illness during pregnancy (especially infections), other maternal physical factors, negative family emotional environment, psychopathology and psychotic symptoms, and cognitive and motor dysfunctions. 

2014

This study describes a method that we have tested to determine the performance of four different methods for assigning a single diagnosis (for a psychotic disorder) from health records in which multiple diagnoses can be recorded for a single individual over time. Administrative health records are valuable research tools but the methods to extract accurate mental health diagnoses can be challenging because of the number of admissions for any given individual. The methods tested in this report include testing the validity of using: ‘any’ diagnosis, ‘most recent’ diagnosis, ‘most frequent’ (modal) diagnosis or ‘hierarchy’ (where a diagnostic hierarchy was applied). Overall agreement between administrative and reference diagnoses was modest with different methods producing results of varying accuracy. This illustrates that the choice of methods used to summarise health records can impact the accuracy of diagnosis and hence is an important consideration for study methods. 

This scientific report examined the association between early life risk factors and academic achievement at Kindergarten (approx. age 5) and in Grade 3 (approx. age 8). This was achieved by linking the NSW Midwives data collection with the Best Start Kindergarten Assessment. Increasing maternal age and lack of maternal prenatal smoking were associated with improved academic performance. The results suggest that programs that target children with less developed academic skills during the first year of school may improve subsequent results.