External Publications Using GUI Data

Background
Social inequalities in the prevalence of childhood overweight and obesity are well-established, but less is known about when the social gradient first emerges and how it evolves across childhood and adolescence.

Objective
This study examines maternal education differentials in children’s body mass trajectories in infancy, childhood and adolescence using data from four contemporary European child cohorts.

Methods
Prospective data on children’s body mass index (BMI) were obtained from four cohort studies—Generation XXI (G21—Portugal), Growing Up in Ireland (GUI) infant and child cohorts, and the Millennium Cohort Study (MCS—UK)—involving a total sample of 41,399 children and 120,140 observations. Children’s BMI trajectories were modelled by maternal education level using mixed-effect models.

Results
Maternal educational inequalities in children’s BMI were evident as early as three years of age. Children from lower maternal educational backgrounds were characterised by accelerated BMI growth, and the extent of the disparity was such that boys from primary-educated backgrounds measured 0.42 kg/m2 (95% CI 0.24, 0.60) heavier at 7 years of age in G21, 0.90 kg/m2(95% CI 0.60, 1.19) heavier at 13 years of age in GUI and 0.75 kg/m2 (95% CI 0.52, 0.97) heavier in MCS at 14 years of age. The corresponding figures for girls were 0.71 kg/m2 (95% CI 0.50, 0.91), 1.31 kg/m2 (95% CI 1.00, 1.62) and 0.76 kg/m2 (95% CI 0.53, 1.00) in G21, GUI and MCS, respectively.

Conclusions
Maternal education is a strong predictor of BMI across European nations. Socio-economic differentials emerge early and widen across childhood, highlighting the need for early intervention.

Background
There are no early, accurate, scalable methods for identifying infants at high risk of poor cognitive outcomes in childhood. We aim to develop an explainable predictive model, using machine learning and population-based cohort data, for this purpose.

Methods
Data were from 8858 participants in the Growing Up in Ireland cohort, a nationally representative study of infants and their primary caregivers (PCGs). Maternal, infant, and socioeconomic characteristics were collected at 9-months and cognitive ability measured at age 5 years. Data preprocessing, synthetic minority oversampling, and feature selection were performed prior to training a variety of machine learning models using ten-fold cross validated grid search to tune hyperparameters. Final models were tested on an unseen test set.

Results
A random forest (RF) model containing 15 participant-reported features in the first year of infant life, achieved an area under the receiver operating characteristic curve (AUROC) of 0.77 for predicting low cognitive ability at age 5. This model could detect 72% of infants with low cognitive ability, with a specificity of 66%.

Conclusions
Model performance would need to be improved before consideration as a population-level screening tool. However, this is a first step towards early, individual, risk stratification to allow targeted childhood screening.

Impact
• This study is among the first to investigate whether machine learning methods can be used at a population-level to predict which infants are at high risk of low cognitive ability in childhood.
• A random forest model using 15 features which could be easily collected in the perinatal period achieved an AUROC of 0.77 for predicting low cognitive ability.
• Improved predictive performance would be required to implement this model at a population level but this may be a first step towards early, individual, risk stratification.

BACKGROUND AND OBJECTIVES
There is mixed evidence from correlational studies that breastfeeding impacts children’s development. Propensity score matching with large samples can be an effective tool to remove potential bias from observed confounders in correlational studies. The aim of this study was to investigate the impact of breastfeeding on children’s cognitive and noncognitive development at 3 and 5 years of age.

METHODS
Participants included ∼8000 families from the Growing Up in Ireland longitudinal infant cohort, who were identified from the Child Benefit Register and randomly selected to participate. Parent and teacher reports and standardized assessments were used to collect information on children’s problem behaviors, expressive vocabulary, and cognitive abilities at age 3 and 5 years. Breastfeeding information was collected via maternal report. Propensity score matching was used to compare the average treatment effects on those who were breastfed.

RESULTS
Before matching, breastfeeding was associated with better development on almost every outcome. After matching and adjustment for multiple testing, only 1 of the 13 outcomes remained statistically significant: children’s hyperactivity (difference score, –0.84; 95% confidence interval, –1.33 to –0.35) at age 3 years for children who were breastfed for at least 6 months. No statistically significant differences were observed postmatching on any outcome at age 5 years.

CONCLUSIONS
Although 1 positive benefit of breastfeeding was found by using propensity score matching, the effect size was modest in practical terms. No support was found for statistically significant gains at age 5 years, suggesting that the earlier observed benefit from breastfeeding may not be maintained once children enter school.

The Strengths and Difficulties Questionnaire (SDQ) is a brief 25-item instrument that has been widely employed in clinical and epidemiological studies to assess children’s psychological adjustment. Despite its widespread application in child and adolescent research, concerns have been expressed regarding the construct validity of the instrument and whether it might be tainted by a method factor that may undermine its utility as a diagnostic tool. We employed a confirmatory factor analytic approach to compare the goodness of fit of four competing models suggested by the extant literature for the parent-informant version of the questionnaire using data for 8514 nine-year-old children participating in the Growing Up in Ireland Study – a large population based cohort study in the Republic of Ireland. While analysis of the data provided support for the traditional five-factor conceptualisation of the instrument, a six-factor model which incorporated a method factor was found to fit the data marginally better. Nevertheless, we conclude that the existence of method effects does not present any great threat to the structural validity of the instrument taking account of patterns in the data and model parsimony.

This collection brings together various cutting-edge and accessible perspectives and insights into the rich, complex and intriguing stage of life that is childhood. Contributions here relate specifically to the Irish context, with many seamless connections also made to the universal themes of childhood and their relevance within the international context. The chapters are organised into four themes: (1) Children and families in education and special education settings; (2) Childrenâ (TM)s environment and play spaces; (3) Childrenâ (TM)s voice in research, classrooms and non-traditional settings; and (4) Childrenâ (TM)s experiences in STEM education. Across the chapters, the authors identify current best practices and place them within the overall context of current trends in research into childhood. There is a complementary balance of theoretical and practical knowledge presented throughout the volume. Given the variety of perspectives and contributions presented here, it will be of interest to those working in professional practice, such as educators, psychologists, sociologists, and the more general public, including parents and policymakers.

Background
Parental obesity is a predominant risk factor for childhood obesity. Family factors including socio-economic status (SES) play a role in determining parent weight. It is essential to unpick how shared family factors impact on child weight. This study aims to investigate the association between measured parent weight status, familial socio-economic factors and the risk of childhood obesity at age 9.

Methodology/Principal Findings
Cross sectional analysis of the first wave (2008) of the Growing Up in Ireland (GUI) study. GUI is a nationally representative study of 9-year-old children (N = 8,568). Schools were selected from the national total (response rate 82%) and age eligible children (response rate 57%) were invited to participate. Children and their parents had height and weight measurements taken using standard methods. Data were reweighted to account for the sampling design. Childhood overweight and obesity prevalence were calculated using International Obesity Taskforce definitions. Multinomial logistic regression examined the association between parent weight status, indicators of SES and child weight. Overall, 25% of children were either overweight (19.3%) or obese (6.6%). Parental obesity was a significant predictor of child obesity. Of children with normal weight parents, 14.4% were overweight or obese whereas 46.2% of children with obese parents were overweight or obese. Maternal education and household class were more consistently associated with a child being in a higher body mass index category than household income. Adjusted regression indicated that female gender, one parent family type, lower maternal education, lower household class and a heavier parent weight status significantly increased the odds of childhood obesity.

Conclusions/Significance
Parental weight appears to be the most influential factor driving the childhood obesity epidemic in Ireland and is an independent predictor of child obesity across SES groups. Due to the high prevalence of obesity in parents and children, population based interventions are required.

Background
Population-based studies provide important data to inform policy and service planning for vulnerable children in society. The aim of this study was to characterise social and educational circumstances and self-concept among a nationally representative sample of 13 year olds with developmental disabilities in Ireland.

Methods
A cross-sectional, secondary analysis of data collected from the Growing Up in Ireland (GUI) study was conducted. Descriptive statistics were used to calculate the reported prevalence of disabilities as reported by parents. Differences across the groups (those with and without disabilities) were analysed in relation to gender, socio-economic and school factors. Special education support received in school was described. The association between low self-concept scores (as measured by the Piers Harris Self-Concept Scales 2) and disability type was examined by use of multi-level logistic regression.

Results
Seventeen percent (17.36%) of the sample was reported to have a diagnosis of one or more developmental disabilities. Those with a disability were more likely to live in poorer households, have poorer health status, to experience more episodes of bullying at school, and to have more negative views of school (p<0.05) than their typically-developing peers.

Forty nine percent of children with developmental disabilities were not receiving support in school as reported by parents. Discrepancies in the nature of support received were identified across disability types. Adjusting for individual and school level factors, a disability diagnosis was associated with increased odds of low self-concept scores on three of five self-concept domains. Further associations were identified which differed across disability type.

Conclusions
The findings show that 13 year olds with a disability in Ireland have complex social and educational needs. Findings also suggest significant levels of unmet educational need across this age group. Apparent inequities in access to support in school require further investigation. Reliable measures to provide robust prevalence figures about childhood disabilities in Ireland are needed.

Background
The Covid pandemic arrived in Ireland on February 29, 2020. In the following weeks various restrictions were introduced to stem the spread of the disease. Anxiety over the spread of the disease and over the restrictions introduced had an adverse effect upon mental health. This study examines the change in mental health for two groups: young adults aged around 23 at the time of onset of Covid (the 1998 cohort) and a sample of principal carers (PCs) of children who were aged 13 at the onset of Covid (the 2008 cohort).

Methods
Data were obtained from the two cohorts of the longitudinal Growing Up In Ireland (GUI) survey. The sample included 1953 young adults (from the 1998 cohort) and 3547 principal carers (from the 2008 cohort). Mental health as measured by the Centre for Epidemiological Studies Depression—8 scale was obtained for the last pre-Covid wave and for the Covid wave (surveyed in December 2020). Observations for which CES-D8 was not available in either pre or post Covid waves were excluded. Post-Covid sampling weights were applied. The change in depression rates was decomposed into a growth and distribution effect using a Shapley decomposition. The socioeconomic gradient of CES-D8 was examined pre and post Covid using concentration indices and a transition matrix was constructed to examine the dynamics of changes in CES-D8 and depression pre and post-Covid.

Results
Relative to the last pre-Covid survey, mental health, as measured by CES-D8 deteriorated for both the young adults of the 1998 cohort and the PCs of the 2008 cohort. For young adults, the deterioration was more pronounced for females. There was no observable socioeconomic gradient for poor mental health amongst young adults, both pre and post Covid. For mothers from the 2008 cohort, a gradient was observed during the pre-COVID-19 pandemic period with poorer mental health status for lower-income and less educated mothers. This gradient was less pronounced post-Covid, the levelling-off arising from a greater deterioration in mental health for higher-income and better-educated PCs.

Conclusion
Both observed cohorts showed a significant deterioration in mental health post Covid. For young adults the effect was significantly more pronounced among females and this is consistent with generally poorer mental health amongst females in this age group. There was little or no socioeconomic gradient observed for young adults, but the gradient became more shallow for principal carers. Care must be taken in terms of drawing policy implications from this study as the Covid-19 pandemic was arguably a unique event, even allowing for the likelihood of future pandemics. However, the study highlights the vulnerability of young adults, especially females, to the mental health effects arising from major public health shocks.

Little is known about the link between childhood and adolescent mental health (MH) difficulties and political outcomes in adulthood. This represents an important knowledge gap in understanding early individual-level factors for future political outcomes. Using the Growing up in Ireland cohort, which follows 8568 children from 9 to 20 years, we examine how different MH difficulties, and their co-occurrence, are associated with various political outcomes. The results show childhood/adolescent MH difficulties are important predictors of political outcomes at age 20. Adolescents with chronic co-occurring MH difficulties starting in childhood report a lower interest in politics, lower trust in politicians, are less likely to register to vote, but if voting, are more likely to vote for an antiestablishment party. Adolescents with chronic emotional MH difficulties starting in childhood also report lower trust in politicians, are less likely to register to vote, and report a higher likelihood of voting for an antiestablishment party when voting. Additionally, they evidence lower levels of external political efficacy.

Background:
Regulatory problems in infancy are associated with internalizing and externalizing symptom trajectories across childhood. It is unknown whether early screen media exposure exacerbates the association between infant regulatory problems and childhood internalizing and externalizing symptom trajectories.

Methods:
We studied 10,170 individuals from the Growing Up in Ireland ’08 cohort. Parents reported on their children’s regulatory problems at 9 months, screen media exposure at 3 years, and internalizing and externalizing symptoms at 3, 5, 7, and 9 years. Children were categorized based on their patterns of co-developing internalizing and externalizing symptoms using parallel process latent class growth analysis. Subsequently, multinominal logistic regression analyses were conducted to estimate whether screen media exposure (&gt;1 hour or &gt;2 hours) moderated the association between regulatory problems in infancy and co-developing internalizing and externalizing symptom classes across childhood.

Results:
There were four groups of children with distinct patterns of co-developing internalizing and externalizing symptoms: 1) low stable internalizing and low decreasing externalizing symptoms (N= 6236; 61.3%); 2) low stable internalizing and moderate stable externalizing symptoms (N= 2029; 20%); 3) moderate increasing internalizing and moderate decreasing externalizing symptoms (N= 1263; 12.4%); 4) moderate increasing internalizing and high increasing externalizing symptoms (N= 642; 6.3%). Presence of regulatory problems at 9 months and excessive screen media exposure at 3 years (particularly &gt;2 hours) were independently associated with increased likelihood of all classes. Excessive screen media exposure at 3 years did not significantly moderate the association between regulatory problems at 9 months and internalizing and externalizing symptom trajectories.

Conclusions:
Both regulatory problems in infancy and screen media exposure &gt;2 hours in early childhood are early risk factors for the development of internalizing and externalizing symptoms. However, the association between infant regulatory problems and childhood internalizing and externalizing symptoms appears to operate independently of excessive screen media exposure. Clinicians should be aware of, and treat, regulatory problems in infancy to prevent chronic patterns of self-regulatory problems across childhood. Further, they should discuss and advocate for family media plans with parents to help decrease the long-term negative effects on internalizing and externalizing symptoms.

Background
Childhood adversity (CA) is commonly associated with an increased risk of subsequent psychopathology. It is important to identify potential mediators of this relationship which can allow for the development of interventions. In a large population-based cohort study we investigated the relationship between CA and late adolescent psychopathology and early adolescent candidate mediators of this relationship.

Methods
We used data from three waves (n = 6039) of Cohort 98′ of the Growing up in Ireland Study (age 9, 13 and 17). We used doubly robust counterfactual analyses to investigate the relationship between CA (reported at age-9) with psychopathology (internalizing and externalizing problems), measured using the Strengths and Difficulties Questionnaire at age-17. Counterfactual and traditional mediation was used to investigate the mediating effects of the parent-child relationship, peer relations, self-concept, computer usage and physical activity.

Results
CA was associated with an increased risk of internalizing and externalizing problems at age-17. Parent-child conflict mediated 35 and 42% of the relationship between CA and late adolescent externalizing problems and internalizing problems, respectively. Self-concept and physical activity mediated an additional proportion of the relationship between CA and internalizing problems. These results were robust to unmeasured confounding.

Conclusions
Parent-child conflict explains more than a third of the relationship between CA and later psychopathology. Self-concept and physical activity explain the additional proportion of the relationship between CA and internalizing problems. This suggests that these factors may be good targets for intervention in young people who have experienced CA to prevent subsequent psychopathology.

Keywords
Childhood adversity, parent-child conflict, psychopathology, self-concept and physical activity

The notion that digital-screen engagement decreases adolescent well-being has become a recurring feature in public, political, and scientific conversation. The current level of psychological evidence, however, is far removed from the certainty voiced by many commentators. There is little clear-cut evidence that screen time decreases adolescent well-being, and most psychological results are based on single-country, exploratory studies that rely on inaccurate but popular self-report measures of digital-screen engagement. In this study, which encompassed three nationally representative large-scale data sets from Ireland, the United States, and the United Kingdom (N = 17,247 after data exclusions) and included time-use-diary measures of digital-screen engagement, we used both exploratory and confirmatory study designs to introduce methodological and analytical improvements to a growing psychological research area. We found little evidence for substantial negative associations between digital-screen engagement—measured throughout the day or particularly before bedtime—and adolescent well-being.

Objective
Early complementary feeding has been shown to increase the risk of overweight, obesity and chronic diseases later in life. Poor compliance with current guidelines on complementary feeding has been reported by Irish studies. The aim of the present paper is to identify predictors of early complementary feeding in order to help health professionals target population groups in greater need of dietary intervention as well as to provide effective advice.

Design
Cross-sectional analysis of the national, longitudinal Growing Up in Ireland study.

Setting
Data were derived from the first wave (2007–2008) of the Growing Up in Ireland infant cohort.

Subjects
A cohort of mothers (n 11 134) from the Republic of Ireland, interviewed when their infants were 9 months of age.

Results
Of the infants, 1469 (13·5 %) had been regularly taking solids in the period between 12 and 16 weeks; this percentage increased to 47·0 % of the sample in the period between 16 and 20 weeks. Timing of formula feeding commencement, high maternal BMI and choosing a relative as the infant’s minder were strongly associated with early introduction of solids both in bivariate and multivariate analysis. Those infants who started formula feeding at >4 months were 88·4% less likely to be introduced to solids early compared with those who started at <2 months (OR = 0·116; 95% CI 0·072, 0·186; P < 0·001).

Conclusions
The results demonstrate that biological, social and behavioural aspects exert an important role in infant feeding practices. These findings are relevant to the design of policies and intervention programmes aimed at educating parents.

Keywords
Complementary feeding, Infant’s diet, Early weaning

This paper examines patterns of continuity and change in the texture, meanings and rhythms of family relationships between young (school-aged) children and their grandparents in Ireland, from the first half of the twentieth century through 2008, focusing on memories and contemporary experiences of grandparent/grandchild relationships from a ‘child’s eye’ perspective. The paper is based on a qualitative longitudinal analysis of two major datasets:
(1) Life Histories and Social Change, which consists principally of life history interviews with three twentieth century birth cohorts of Irish people and
(2) the Growing Up in Ireland Qualitative Study which consists of semistructured interviews with a sub-sample of children born at the turn of the twenty-first century (and their parents) in one of the two birth cohorts that form part of a prospective national panel study.

This study investigated trajectories of concomitant internalising, externalising, and peer problems, and associated risk factors for group-membership, using a person-centered approach to better understand heterogeneity in subgroups identified. A cohort of 7,507 children in Ireland was followed from infancy to late childhood (50.3%, males; 84.9% Irish). The parent-version of the Strengths and Difficulties Questionnaire was used when children were 3, 5, 7 and 9 years of age. Information on antecedent risk factors was collected when children were 9 months. Group-based multi-trajectory modelling and multinomial logistic regression were used. Six subgroups of children with distinct profiles were identified, evidencing both homotypic and heterotypic comorbidity. No support of a ‘pure’ internalising, externalising or peer problems group was found in any identified trajectory group. Difficulties in one problem domain indicated the presence of difficulty in another problem domain for all children in elevated groups. Risk factors associated with group-membership were complex, with only three common factors across elevated groups: prenatal exposure to smoking, maternal education, and maternal stress. Specific risk factors for group-membership included low birth weight, sex, maternal age, maternal depression, family composition, social class, medical card status and quality of attachment. Despite some overlap in predictors, the combination of predictors specific to each group would suggest tailored programming. For children with the most acute problems, programming targets should include families with boys, born with low birth weight, exposed to smoking prenatally, with mothers who have lower levels of education, postnatal depression, increased stress and fewer financial resources.

This chapters addresses digital inequalities in young people’s daily lives and well-being. The chapter examines how adolescents’ digital engagement differs across family socioeconomic status (SES) and gender, and how it relates to their mental health outcomes. Analyses use longitudinal data from the Growing Up in Ireland study from age 9 to 18, combined with cross-national data from the Health Behaviour in School-Aged survey on adolescents aged 11-15 across 35 industrialised countries. Longitudinal analyses reveal that low-SES adolescents and girls experience higher mental health problems as they increase their time using digital devices, compared to high-SES adolescents and boys. Cross-national analyses indicate that, while boys spend more time in digital activities, girls are at higher risks of experiencing mental health problems from engaging with digital activities. However, the magnitude of these gendered patterns differs markedly across national contexts. Cross-country comparisons on SES yield mixed results: in some countries low-SES adolescents are mentally more harmed by their digital engagement (i.e., Switzerland, Austria, Norway), but in other countries high-SES adolescents are those at higher mental health risks from using digital devices (i.e., Portugal, Czech Republic, Bulgaria). The chapter findings are discussed within the existing literature on digital inequalities and young people’s well-being.

Epidemiological evidence suggests that poor physical health and depression are highly co-morbid. To date, however, no study has considered whether depression in parents caring for children with developmental disabilities is partly driven by poor physical health. Using data from the Growing Up in Ireland national cohort study (2006 to date), 627 parents of children with developmental disabilities were compared with 7941 parents of typically developing children on scores from the Centre for Epidemiological Depression Scale, chronic health conditions, socio-demographic and child behavioural characteristics. Having a child with disabilities was associated with a higher risk of depression (odds ratio (OR) = 1.83, 95% confidence interval (CI): 1.43, 2.35) compared to parents of typically developing children. Adjusting for the presence of chronic health conditions accounted for some of this excess risk (OR = 1.77, 95% CI: 1.38, 2.27). The association between having a child with disabilities and increased risk of depression was explained, however, by adjusting for the child problem behaviours (OR = 1.07, 95% CI: 0.81, 1.43). This study has confirmed, in a population-based sample, the high risk of depression in parents caring for children with developmental disabilities after adjusting for the presence of a chronic health condition. Importantly, given that poor mental health in these parents is associated with a battery of negative health and social family outcomes, it is imperative that health professionals pay attention to the mental health needs of these parents.

Epidemiological evidence suggests that obesity and depression are highly co-morbid. In a national cohort study, we examined whether parents caring for children with disabilities were more likely to be classified as obese compared to parents of children without disabilities and if obesity was associated with depressive symptoms or child behaviour characteristics. Using data from the Growing Up in Ireland National Longitudinal Study of Children (2006 to date), 627 parents of children with developmental disabilities were compared with 7941 parents of typically developing children on objectively measured levels of obesity (body mass index ≥30 kg/m2), depression, health behaviours, chronic health conditions, socio-demographic and child behavioural characteristics. Parents of children with disabilities were more likely to be classified as obese compared to control parents (24.5% vs. 19.6%, p = 0.005, Cramer’s V < 0.1). Depression was not associated with obesity. However, the odds of obesity increased with increasing child problem behaviour (OR 1.05, 95% CI 1.03–1.06). Over half (57%) of obese parents caring for children with disabilities reported trying to lose weight often or very often. This study has confirmed, in a population-based sample, the high risk of obesity in parents caring for children with disabilities after adjusting for the presence of depression and other health behaviours; increasing child problem behaviours were predictive of obesity. Importantly, given the negative health correlates of obesity, it is imperative that health professionals pay attention to weight issues in these parents and support their efforts in managing these issues.

Given growing concerns about disadvantaged boys’ achievement and disengagement from learning, this paper investigates differences in reading ability by gender and social origin. It uses data from the Growing Up in Ireland study to investigate how parents’ approach to learning at home and children’s exposure to early care and education contribute to these differences. We find that both children’s gender and their family’s social class influence their cognitive development between age 3 and age 9, though the effects are additive, with little variation in the gender gap across social class groups. Parents from more advantaged social classes read more to their 3-year-old children than other parents, yet by age 5, when most children have started primary school, these class differences in parental reading are much lower. Parental reading, ECCE participation and length of primary school exposure were found to facilitate language development and partly explain differences in reading scores at age 9, although strong direct effects of social class remained, even accounting for vocabulary score at age 3. The benefits from parental reading, ECCE and exposure to school are broadly similar for boys and girls, though there is some evidence that boys benefit more than girls from longer exposure to school.