External Publications Using GUI Data

The COVID-19 lockdown and closure of schools, clinics, and community-based services put children with autism spectrum disorders (ASDs) and other developmental disabilities (DDs) at increased risk of negative outcomes. This study aimed to investigate parents’ perceptions of their children’s behavioural outcomes during the COVID-19 lockdown, parents’ satisfaction with services during this time, and willingness to engage in telehealth. A cross-sectional study was conducted in Ireland. Parents (n = 89) completed an online questionnaire that included the strengths and difficulties questionnaire (SDQ-P). Results demonstrated that children with ASD/DDs were vulnerable to negative outcomes including hyperactivity, emotional symptoms, problems with peers and fewer prosocial behaviors. Children’s behavioral outcomes (‘current sample’, n = 89) were also compared with pre-COVID-19 data taken from the Growing Up in Ireland Study (‘GUI sample’, n = 327). The current sample exhibited significantly more behavioral difficulties than the pre-COVID GUI sample (p < 0.001). For the current sample, scores on each of the five SDQ subscales were significantly associated with a total impact score, and parents reported dissatisfaction with support services provided and willingness to engage in behavioral telehealth. Commitment is required to identify barriers to services faced by families in Ireland and to address the need for adapted behavior support services during periods of emergency.

Keywords: COVID-19; intellectual disabilities; developmental disabilities; autism; behavior; behavioral support

The increasing importance of identifying lesbian, gay, bisexual and transgender (LGBT+) populations is a key driver in changes to demographic data collection in representative surveys of youth. While such population-based data are rare, Growing Up in Ireland (GUI), an Irish, government-funded, longitudinal survey, includes sexual orientation and gender identity (SOGI) measurements. This qualitative study responds to a query from the GUI study team and aims to identify how best to collect SOGI data in future waves of GUI. A university Human Research Ethics Committee granted approval for online consultations with LGBT+ youth (n = 6) with experiential expertise in policy making. The research is underpinned by rights-based public patient involvement (PPI) with recorded discussions, which were transcribed and imported into NVivo 12, generating the theme “recognition in research, policy and society”. This co-created article, with the LGBT+ young PPI Panel members, commends the inclusion of SOGI data in GUI and recommends changes in question placement and phrasing. Aligning with best practice, the PPI members provide a template for wording on consecutive sex and gender questions, expanded sexual orientation identity categories and maintaining the existing well-phrased transgender question from GUI. This offers potential to improve the quality of the SOGI data collected and the experience of those completing the questionnaire. These findings extend beyond GUI, with relevance for surveys with youth populations. This paper underscores the potential and benefits of participatory approaches to research with youth and views their role beyond simply as sources of data.

Keywords: LGBT+, sexual minority youth (SMY), gender minority youth (GMY), Growing Up in Ireland (GUI), SOGI measurement, quantitative, qualitative, survey design, PPI

Background
Poverty is associated with poor outcomes, yet exposure to distinct poverty trajectories in early childhood is not well understood.

Objective
To understand the prevalence of different trajectories of household poverty and their association with mid-childhood and primary-parent(mother) indicators of physical health and psychopathology in Ireland.

Methods
We used a nationally representative, prospective cohort (Growing-up-in-Ireland– Infant-Cohort). Household poverty included lowest third income decile, subjective poverty and material deprivation when children were aged 9-months(m),3,5,9-years(y). We used group based multi-trajectory-cluster-modelling to classify trajectories of poverty. Using multivariate logistic regression, adjusted with separate child and mother confounders, we assessed the association of poverty trajectories from 9m to 9y with child outcomes (overweight, any longstanding illness and psychopathology) at age 9y and the same poverty trajectories over the same 9y period with mother outcomes (overweight, any longstanding illness and depression).

Results
Of 11,134 participants, four trajectories were identified: never-in-poverty (43.1%), material/subjective>monetary-poverty (16.1%), monetary>material-poverty (25.6%), and persistent-poverty (15.2%). Children in persistent-poverty compared with never in poverty experienced higher odds of being overweight at 9y (adjusted odds ratio aOR 1.70,95% CI 1.34, 2.16), having a longstanding illness (aOR 1.51,95% CI 1.20, 1.91) and psychopathology (aOR 2.06,95% CI 1.42, 2.99). The outcomes for primary parent (99.7% were mothers) had higher odds of being overweight (aOR 1.49,95% CI 1.16, 1.92), having a longstanding illness (aOR 2.13,95% CI 1.63, 2.79), and depression (aOR 3.54,95% CI 2.54, 4.94).

Conclusions
Any poverty trajectory was associated with poorer psychopathology and physical wellbeing in late childhood for children and their mothers in Ireland.

What is already known on this subject?
Poverty is understood as having both objective (e.g. low household income) and subjective dimensions (e.g., perception of being poor relative to others, poverty related anxiety). Evidence highlights the association between child poverty exposure and child and mother wellbeing outcomes.

What this study adds?
Our study examined predicted trajectories of multi-dimensional poverty and child and mother outcomes using a large national cohort. We identified that any poverty trajectory in childhood had a higher odds of being associated with poor well-being outcomes.

How this study might affect research, practice or policy?
This study highlights the need for strategies to ameliorate any poverty exposure as all poverty trajectories resulted in poorer wellbeing outcomes. Strategies should be considered to ameliorate any poverty exposure in early childhood (e.g., school based resourcing).

Objective
To examine the extent to which early child nutrition, maternal antenatal lifestyle behaviours and child diet and lifestyle explain social class inequalities in the risk of rapid weight gain between birth and 3 years and obesity at age 3 years.

Design
A longitudinal and prospective birth cohort study.

Subjects
Nationally representative sample of 11 134 children and their parents followed from 9 months of age until 3 years. Child weight and maternal height and weight were measured at 9 months and 3 years and child birth weight was extracted from hospital records. Other predictors of child growth and obesity were collected by maternal report at 9 months and 3 years.

Results
Although born lighter on average, children of unskilled manual parents were 274 g heavier than children of professional parents by 3 years of age. The fully adjusted model of rapid growth from birth to 3 years of age and obesity at 3 years of age accounted for all social class differentials. Breastfeeding and age at the introduction of solids were associated with the largest average reduction (41%) in the odds ratio (OR) of rapid growth in the first 9 months of life for each class relative to the professional class. In the period from 9 months to 3 years of age, the class differential in rapid growth was reduced most by measures of the child’s diet and lifestyle. However, the impact of the groups of predictors varied by social class. For early life growth, among the non-manual classes the proportionate reductions are largest when adjusted for early infant nutrition, whereas maternal prenatal smoking is more important for the manual social classes.

Conclusion
Preventative interventions to reduce levels of childhood obesity should be multi-dimensional but different dimensions should be given more or less significance depending on socio-economic group.

Background
The gold standard for categorisation of weight status is clinically measured body mass index (BMI), but this is often not practical in large epidemiological studies.

Objectives
To determine if a child’s weight perception or a mother’s perception of a child’s weight status is a viable alternative to measured height and weight in determining BMI classification. Secondary outcomes are to determine the influence of a mother’s BMI on her ability to categorise the child’s BMI and a child’s ability to recognise his/her own BMI.

Methods
Cross-sectional analysis of the growing up in Ireland cohort study, a nationally representative cohort of 8568 9-year-old children. The variables considered for this analysis are the child’s gender, BMI (International Obesity Taskforce grade derived from measured height and weight) and self-perceived weight status, and the mother’s weight perception of the child, BMI (derived from measured height and weight) and self-perceived weight status. Cohen’s weighted-kappa was used to evaluate the strength of the agreement between pairwise combinations of the BMI variables. Cumulative and adjacent categories logistic regression were used to predict how likely a person rates themselves as under, normal or overweight, based on explanatory variables.

Results
Mothers are more accurate at correctly classifying their child’s BMI (κ=0.5; confidence intervals (CI) 0.38–0.51) than the children themselves (κ=0.25; CI 0.23–0.26). Overweight mothers are better raters of their child’s BMI (κ=0.51; CI 0.49–0.54), compared with normal (κ=0.44; CI 0.41–0.47) or underweight mothers (κ=0.4; CI 0.22–0.58), regardless of whether the mother’s BMI is derived from measured height and weight or self-perceived. The mother’s perception of the child’s weight status is not an influencing factor on the child’s ability to correctly classify him/herself, but the child’s self-perceived weight status influences the mother’s ability to correctly classify the child.

Conclusions
A mother’s BMI classification of her child is a viable alternative to BMI measurement in large epidemiological studies.

Background
Public health policies attempt to increase parental identification of child overweight and obesity. The objective of the present research was to determine the cross-sectional, prospective and longitudinal associations between parental identification of child overweight and child mental health problems.

Methods
We made use of two cohort studies of Australian (Longitudinal Study of Australian Children, LSAC) and Irish children (Growing up in Ireland Study, GUI) that measured parental identification of child overweight and child mental health problems. Participant included 6502 (LSAC) and 7503 (GUI) children (49% female) and their parents. Child mental health problems were measured using child, parent and teacher-reported Strengths and Difficulties Questionnaires (SDQ) at ages 9/10 years old to 12/13 years old. In all analyses we controlled for child Z-BMI.

Results
In LSAC children whose parents identified them as being overweight at age 10 experienced worse mental health at age 10 (β = 0.21, SE = 0.04) and age 12 (β = 0.13, SE = 0.04) than children whose parents failed to identify them as overweight. In GUI children whose parents identified them as being overweight at age 9 experienced worse mental health at age 9 (β = 0.20, SE = 0.04) and age 13 (β = 0.22, SE = 0.04). In LSAC parental identification of child overweight at age 10 did not significantly predict changes in mental health problems from age 10 to 12 (β = −0.02, SE = 0.03). In GUI parental identification of child overweight was predictive of increases in mental health problems from age 9 to 13 (β = 0.08, SE = 0.03).

Conclusions
Parental identification of child overweight and obesity is associated with worse child mental health, independent of child body weight. Parents should be aware of the potential stigma and mental health difficulties associated with labelling a child as overweight.

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
There are few prospective studies of factors that mediate the association between exposure to adverse childhood experiences (ACEs) and obesity in adolescence. Our aim was to address this limitation.

Methods
We used prospective data from the Growing up in Ireland cohort study, with measurements at 9, 13, and 18 years old. The exposures were 14 adverse experiences before age 9. The main outcome was body mass index (BMI) at 18 years. Mediators were daily activity, diet quality, self-image and behavioural difficulties at 13 years.

Results
Among the 4561 adolescents in the final cohort, 77.2% experienced any adversity, 50.5% were female and 26.7% were overweight/obese at 18 years. BMI Z was higher at ages 9 (0.54 vs 0.43, p < 0.05, 95% CI of difference: −0.22, −0.01) and 13 years (0.50 vs 0.35, p < 0.05, 95% CI of difference: −0.25, −0.06), in those exposed to an ACE, compared to those unexposed. Structural equation models revealed that behavioural difficulties (β = 0.01; 95% CI: 0.007–0.018, p < 0.001) and self-concept (β = 0.0027; 95% CI: 0.0004–0.0050, p = 0.026) indirectly mediate the association between exposure to ACEs and BMI at 18 years.

Conclusions
The association between ACEs and BMI in adolescence is mediated by behavioural difficulties and self-concept.

Impact

• In a previous study, we found modest associations between exposure to a range of adverse childhood experiences and weight gain at 13 years of age.
• The strength of the association between adverse childhood experiences and weight gain was lower at 18 years of age compared to the association observed at 13 years and was no longer significant after controlling for confounding and including possible mediators.
• The association between adverse childhood experiences and BMI in adolescence is indirectly mediated by behavioural difficulties and self-concept.

The microbiome-gut-brain axis plays a role in anxiety, the stress response and social development, and is of growing interest in neuropsychiatric conditions. The gut microbiota shows compositional alterations in a variety of psychiatric disorders including depression, generalised anxiety disorder (GAD), autism spectrum disorder (ASD) and schizophrenia but studies investigating the gut microbiome in social anxiety disorder (SAD) are very limited. Using whole-genome shotgun analysis of 49 faecal samples (31 cases and 18 sex- and age-matched controls), we analysed compositional and functional differences in the gut microbiome of patients with SAD in comparison to healthy controls. Overall microbiota composition, as measured by beta-diversity, was found to be different between the SAD and control groups and several taxonomic differences were seen at a genus- and species-level. The relative abundance of the genera Anaeromassillibacillus and Gordonibacter were elevated in SAD, while Parasuterella was enriched in healthy controls. At a species-level, Anaeromassilibacillus sp An250 was found to be more abundant in SAD patients while Parasutterella excrementihominis was higher in controls. No differences were seen in alpha diversity. In relation to functional differences, the gut metabolic module ‘aspartate degradation I’ was elevated in SAD patients. In conclusion, the gut microbiome of patients with SAD differs in composition and function to that of healthy controls. Larger, longitudinal studies are warranted to validate these preliminary results and explore the clinical implications of these microbiome changes.

Caesarean section (CS) rates are increasing globally and exceed 50% in some countries. Childhood obesity has been linked to CS via lack of exposure to vaginal microflora although the literature is inconsistent. We investigated the association between CS birth and the risk of childhood obesity using the nationally representative Growing-Up-in-Ireland (GUI) cohort. The GUI study recruited randomly 11134 infants. The exposure was categorised into normal vaginal birth (VD) [reference], assisted VD, elective (planned) CS and emergency (unplanned) CS. The primary outcome measure was obesity defined according to the International Obesity Taskforce criteria. Statistical analysis included multinomial logistic regression with adjustment for potential confounders. Infants delivered by elective CS had an adjusted relative risk ratio (aRRR) = 1.32; [95% confidence interval (CI) 1.01–1.74] of being obese at age three years. This association was attenuated when macrosomic children were excluded (aRRR = 0.99; [95% CI 0.67–1.45]). Infants delivered by emergency CS had an increased risk of obesity aRRR = 1.56; [95% CI 1.20–2.03]; this association remained after excluding macrosomic children. We found insufficient evidence to support a causal relationship between elective CS and childhood obesity. An increased risk of obesity in children born by emergency CS, but not elective, suggests that there is no causal effect due to vaginal microflora.

We analyse parental smoking and cessation (quitting) associations with teenager e-cigarette, alcohol, tobacco smoking and other drug use, and explore parental smoking as a mechanism for social reproduction. We use data from Waves 1–3 of Growing Up in Ireland (Cohort ’98). Our analytic sample consisted of n = 6,039 participants reporting in all 3 Waves. Data were collected in Waves 1 and 2 when the children were 9 and 13 years old and in Wave 3 at age 17/18 years. Generalized Estimating Equations (GEE) models were used to analyse teenage substance use at Wave 3. Parental smoking was associated with significantly increased risk of all teenage substance use, adjusted odds ratios were aOR2.13 (ever e-cigarette use); aOR1.92 (ever alcohol use); aOR1.88 (current alcohol use); aOR1.90 (ever use of other drugs); aOR2.10 (ever-smoking); and aOR1.91 (current smoking). Primary caregiver smoking cessation (quitting) was associated with a lower risk for teenager current smoking aOR0.62, ever e-cigarette use aOR 0.65 and other drug use aOR 0.57. Primary caregiver smoking behaviour had greater associations than secondary, and age13 exposure more than age 9. Habitus seems to play a role and wealth was protective for teenage smoking. The findings suggest that prevention interventions should target both caregivers and their children.

Objectives
To examine the associations between preeclampsia and longitudinal child developmental and behavioural outcomes using data from a nationally representative study of children living in Ireland.

Methods
We used maternal-reported data from the Growing Up in Ireland longitudinal study of children. Data on preeclampsia and preeclampsia + small for gestational age (SGA) were collected when children were 9-months old. Data on child development and behavioural outcomes were collected at 9-months using the Ages and Stages Questionnaire (ASQ), and at 3 years, 5 years and 7–8 years using the Strengths and Difficulties Questionnaire (SDQ). Multivariate logistic regression analysis was used to examine the association between preeclampsia exposure and failure of ASQ domains, and abnormal SDQ domains. Linear spline multilevel models were used to examine the association between preeclampsia and preeclampsia + SGA and repeated measures of SDQ. All models controlled for several perinatal and sociodemographic factors.

Results
A total of 10,692 children were included in the study at baseline, representing a weighted total of 70,791. Multivariate logistic regression suggested that preeclampsia was not associated with failing any ASQ domain. Preeclampsia was associated with abnormal SDQ cut-off of emotional (≥ 5) and hyperactivity (≥ 7) domains at age 5 years only. In the linear spline model, mean SDQ score was higher at each time point in exposed groups.

Conclusions for Practice
While we did not find strong evidence of associations between preeclampsia and child developmental and behavioural outcomes overall, some associations between preeclampsia-exposure and subtle behavioural issues did persist. Further research is needed to replicate these findings, and determine the clinical significance of changes in SDQ scores.

A Tobacco-Free Future – An all-island report on tobacco, inequalities and childhood 2013 reveals declines in smoking rates among both children and pregnant women over the past decade, both North and South of the border. This report published by the Institute of Public Health in Ireland (IPH) and the TobaccoFree Research Institute Ireland (TFRI), shows that while tobacco control measures are being successful, disadvantaged children are at particular risk of tobacco-related harms.

Children growing up in disadvantaged circumstances face a number of threats to their health and development. Protecting children from the burden of tobacco related harm from both active and passive smoking is a priority action in enhancing population health and reducing health inequalities. Population health strategies on the island of Ireland are increasingly focussing on addressing the root causes of health inequality through social determinants of health approaches and through focussing on early childhood as a key period for intervention. At the same time, governments in both jurisdictions are working to enhance their approaches to effective tobacco control.

The World Health Organization considers that there are three key ‘windows of exposure’ in terms of tobacco-related harm in childhood – in the womb (associated with active or passive smoking by the mother), directly through children taking up smoking and through exposure to second hand smoke (SHS) in indoor and outdoor environments.

This report presents findings on these three windows of exposure based on a range of data sources in the Republic of Ireland and Northern Ireland. The central aim of the report is to contribute to knowledge on the exposure of children to the harmful effects of tobacco smoke at various stages of their development. The findings of the report can support policy makers and service providers in their efforts to make tobacco-free childhoods a reality on the island of Ireland.

This paper outlines the development of an index of child well-being using data from the first wave of the Child Cohort in the Growing up in Ireland study. This national longitudinal study explores children’s lives by collecting data from 8,568 nine-year-old children, their caregivers and their teachers. Well-being indices are useful to describe children’s circumstances, to monitor child outcomes, and to create and assess the efficacy of social polices involving children. Traditionally, macro-level data has been used in the construction of child well-being indices. However, micro-level data is used in this paper to provide a child-centered perspective on their well-being. This index is comprised of three domains; physical health, social & emotional functioning and educational attainment. Fourteen measures were used in the creation of these domains utilising data from children, caregivers and teachers on the child’s current development. The domain content, protocol followed and confirmatory pro-cess used in creating this index are discussed. Evidence is provided supporting the inclusion of the domains and the factorial structure of the index. A child well-being index of this sort is valuable as it manages to efficiently summarize the richness of information provided by multiple informants on the multidimensional nature of child well-being into a single index. Consequently, it can be easily used and understood by the various stakeholders involved in services related to child welfare.

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.

The purpose of this report is to investigate the known correlation between non-traditional family structures and poor outcomes for children.

Discussions of this topic often focus on the distinction between two-parent families and one-parent families but this distinction can be misleading. In the Irish case, the crucial distinction is between children raised by parents who are married and children raised by a lone-parent who has never been married. The focal point here is non-marriage.

This is important since non-marriage appears to be highly selective because the least privileged groups in Irish society are more likely to have children outside of marriage and at a relatively early age.

This argument suggests that selection bias accounts for much of the association between family structure and child outcome i.e. growing up in a non-traditional family has little ‘direct’ or ‘causal’ effect on a child’s outcome. A large body of literature exists which documents a correlation between non-traditional family structure and poorer child development but researchers disagree as to whether this association represents a true causal effect.

The primary objective of the current study, therefore, is to test this selection argument and to examine the extent to which selection effects can account for differences in child wellbeing in various family types.

With screen use becoming more prevalent at a younger age, it is important to research the possible impact screen use has on early cognitive development. The current study examines the screen use of 9001 5-year-olds and their reasoning abilities, using data from the Growing Up in Ireland study. Results show that both the amount of daily screen time, along with the type of screen activity children mostly engage in (video games, educational games, TV/video watching, or a mix of all of these activities), have an impact on 5-year-olds’ reasoning ability. Children who mostly engaged in a mix of activities for under three hours a day scored higher on a reasoning ability task than those who engaged in more than three hours of screen time, or those who engaged in an individual screen activity (e.g., television watching) rather than a mix of activities. However, the results also show screen use plays a very minor role in the development of reasoning ability. Consequently, other factors (e.g., home learning environment, parental education levels) should also be investigated when examining the role of screen use in cognitive development. The implications of these findings may therefore be of interest to parent, educators and policy-makers.

Background
The association between multidimensional household poverty (MHP) and child and mother psychopathology trajectories is not well understood. The aim of this paper is to explore this association.

Methods
We analysed 9241 infants and mothers recruited at 9-months (m) and 32-years (y) respectively from the Growing-up-in-Ireland study and followed up when the child was aged 3, 5, 7, 9 and 13y. MHP was derived from monetary, subjective and material poverty questionnaires completed by mothers before infant age 3y using latent-class-analysis. Confounder-adjusted linear spline multilevel models were used to examine the association between MHP before 3y and trajectories of child (3-to-13y) and mother (34-to-46y) psychopathology wellbeing measures (Strengths-and-difficulties-questionnaire and Centre-for-epidemiological-studies-depression-scale, respectively).

Results
In adjusted models, MHP before 3y was associated with a higher mean difference(MD) (MD:0.67, 95%CI 0.41,0.92) in child psychopathology at 3y and this was broadly similar at age 13y (MD:0.87, 95% CI 0.57,1.17). MHP prior to 3y was associated with a higher mother psychopathology when her child was age 3y (MD:1.07, 95% CI 0.90,1.23) and this persisted albeit with a slight reduction in magnitude at age 13y of the child (MD:0.72, 95% CI 0.53,0.90).

Conclusions
Though replication in other cohorts is required, findings suggest that MHP exposure in child infancy may have early negative life course impacts on mother and child wellbeing that persist for up to a decade. If causal, these findings underscore the importance of early life course policy interventions to prevent and ameliorate poverty to reduce long term psychopathology of mothers and their children.

Objective
To explore whether the associations between developmental delays in the first year of life and psychosocial outcomes in preschool children are affected by participation in organized sport.

Study design
Data were obtained from the infant cohort of the Growing Up in Ireland project. Parents reported on child development (Ages and Stages Questionnaire) at age 1 year, psychosocial characteristics (Strengths and Difficulties Questionnaire) at ages 3 and 5 years, and engagement in organized sport at age 5 years. Data were analyzed using mixed models.

Results
At age 1 year, 15% of the cohort was classified as having developmental delays. These children exhibited more behavioral difficulties (0.55, ±0.27; mean difference, ±95% confidence limits [CL]) (P < .0001) and fewer prosocial behaviors (−0.54, ±0.11) (P < .0001) at age 3 years. For boys in this group, engagement in sport was associated with a significant decrease in behavioral difficulties between ages 3 and 5 years (−0.44, ±0.39) (P = .03). Compared with those classified as lacking regular engagement (ie, never engaging, or engaging <1 hour/week), the relative effect of sport on changes in behavioral difficulties for boys with developmental delays was statistically significant (0.70, ±0.59) (P = .02). Participation in sport was not associated with significant changes in behavioral difficulties for girls, or a significant change in prosocial behaviors for boys or girls.

Conclusions
Regular participation in sport by boys could attenuate some of the behavioral difficulties associated with early development. Lack of opportunities for engaging in sport could negatively affect boys’ behavioral regulation in the preschool period.

The paper examines the effects of socioeconomic background (SES) – measured by social class, family income and parental education – cognitive ability, and gender on a variety of key outcomes from a large longitudinal study based on a representative sample of thirteen-year-olds. The data analysed comprised 6216 children who participated in waves 1 to 3 of the Growing Up in Ireland (GUI) longitudinal survey. The outcome measures drawn from wave 3, when respondents were aged about seventeen, were: examination results and several cognitive measures, life difficulties, and quality of relationships. Three regression models were compared with and without, SES measures (occupational class, household income and parental education) and cognitive ability. On academic and cognitive attainments, cognitive ability at age 13 had substantially more explanatory power than the SES measures together. On measures of adolescent difficulties and on family relationships, cognitive ability was important, but gender and to a lesser extent, household income and parental education had some effects. Claims that class background and family income are of central importance for adolescent outcomes are not supported.