External Publications Using GUI Data

Objective
To longitudinally investigate body mass index (BMI) in young children in Ireland and identify factors and critical time points associated with changes in BMI.

Study design
Data on 11 134 children were collected in the nationally representative Growing Up in Ireland infant cohort study. Height and weight were measured at 9 months, 3 years, and 5 years of age. Multilevel regression was used to identify risk factors associated with changes in BMI over time (n = 10 377), combining a unique set of covariates collected from the child and the 2 main caregivers (usually the mother and father).

Results
The proportion of children ≥85th percentile of World Health Organization growth criteria was 39% at 9 months, 44% at 3 years, and 30% at 5 years. Children born large for gestational age (13%) and those with rapid infant weight gain (25%) consistently had higher BMI. Low average BMIs were consistently seen in children born small for gestational age (10%) or before 37 weeks (7%). Smaller variations in BMI existed for other factors including ethnicity, household structure, caregiver weight status, breastfeeding, sex, socioeconomic status, sleeping hours, childcare, and region.

Conclusions
In this study, differences at birth and in infancy appear to be most strongly associated with variation in BMI at all ages. Nevertheless, belonging to a number of other high-risk groups cumulatively could lead children to develop critical weight states. Policy-makers should target families with interventions before and during pregnancy when dominant risk factors are still modifiable. Longer-term follow-up of children may be needed to study associations later in childhood.

Keywords
Growing Up in Ireland, body mass index, childhood obesity, growth trajectories, multilevel modelling

Objectives
Maternal health behaviours (MHBs) can influence pregnancy outcomes. Despite efforts internationally to encourage positive MHBs, women often fail to comply with pregnancy guidelines. International studies show differences in MHBs between nationalities and an effect of time spent in the host country. There is limited Irish data in this area, with no previous research relating to the effect of time in Ireland.

Study design
This study is a cross-sectional analysis of the Growing Up in Ireland infant cohort, a nationally representative longitudinal study.

Methods
Examination of the MHBs of non-Irish nationals during pregnancy and the effect of time in Ireland on the said behaviours.

Results
An association was found between time spent in Ireland and increased alcohol consumption prevalence. Those living in Ireland for ≤5 years were 60.8% less likely to consume alcohol during pregnancy (0.000) and 29.3% less likely to take folic acid before conception (0.021). Those who smoked during pregnancy were 98.6% more likely to consume alcohol (0.000) and those who consumed alcohol were 95.2% more likely to smoke during pregnancy (0.000).

Conclusions
The results demonstrate differences in MHBs and the influence of time living in Ireland. These findings are of relevance for policy and intervention planning to optimise pregnancy outcomes among non-nationals.

Background
Children with a parent who smokes are more likely to become substance users than those who do not have a parent who smokes. In this study, we examined whether childhood or early adolescent exposure to primary parent smoking increased the risk of subsequent teenage alcohol and drug use at ages 17–18 years.

Methods
For this longitudinal observational study, we analysed data from 6039 teenagers and their parents from the waves 1–3 of the Growing up in Ireland Cohort 98’ Study. Parental smoking was assessed at baseline (9 years) and wave 2 (13 years) with responses coded as yes or no. The primary parent was defined as the person who provided most care and who knew most about the Study Child, usually the mother or mother figure for 98% of study participants. Teenage alcohol and drug use assessed at ages 17–18 years (wave 3) was determined by responses to the question “Have you ever consumed alcohol?” (answers yes or no), drug use was assessed by questions on ever trying aerosols/gas, cannabis, and non-prescribed drugs, with those answering yes being classified as other-drug ever users. We did a logistic regression analysis to examine the associations between parents’ smoking on teenage alcohol and drug use, controlling for covariates: gender, education, income, education, region, and household type. Ethics approval for the GUI project was obtained from the Health Research Board.

Findings
Of the 6039 teenagers included in our study, 2968 (49%) were female, 3070 (51%) were male, 5351 (89%) ever used alcohol, 5065 (85%) were current users, and 2098 (35%) used other drugs. Rates of primary parent smoking were 31% (n=1883) in wave 1 and 30% (n=1829) in wave 2. After adjusting for other exposures known to be associated with teenage substance use, primary parent smoking at waves 1 and 2 was associated with higher odds of teenage alcohol ever use (adjusted odds ratios [aORs] 1·89 [95% CI 1·44–-2·46] at wave 1 and 1·53 [1·20–1·98] at wave 2), current alcohol use (1·88 [1·50–2·36] and 1·59 [1·28–1·97]) and other-drug ever use (1·699 [1·45–1·95] and 1·71 [1·47–1·98]).

Interpretation
Teenagers aged 17–18 years exposed at ages 9 and 13 years to parental smoking were more likely to report significantly higher odds of alcohol and drug use at age 17–18 years. The finding that exposure to parent smoking in childhood increases the risk of teenage alcohol and other drug use suggests a need for interventions aimed at parents who smoke Limitations include potential unmeasured or residual confounders and reliance on self-reported teenage substance use behaviours.

Funding
Royal City of Dublin Hospital Trust, Irish Research Council Government of Ireland Postgraduate Scholarship Programme.

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.

This study is based on the first wave of data on the child cohort (nine year-olds) in the Growing Up in Ireland (GUI) survey. It examines family relationships and their associations with parent and child well-being in the families of the nine year-olds and explores social inequalities in these aspects of family circumstances. The analysis is presented under five headings: the structure of families (a term which encompasses family structure both currently and over time and also includes family size), relationship quality between parents, the individual well-being of parents, relationship quality between parents and children, and the well-being of children.

This paper examines developments in childhood and adolescent obesity in Ireland using two waves of the Growing Up in Ireland survey. Obesity appears to level off between the two waves though there is tentative evidence that the socioeconomic gradient, measured with respect to maternal education and family income, becomes steeper. Exploiting the longitudinal nature of the data, transitions into and out of obesity are examined, with higher rates of transition into obesity observed for those whose mothers have the lowest level of education. Decomposition of the concentration index with respect to income reveals a greater role for income related obesity mobility rather than obesity related income mobility.

This paper examines the relationship between maternal employment, childcare during infancy and the overweight status of pre-school children. Using data from the Infant Cohort of the Growing-Up in Ireland Survey, propensity score matching addresses the issue of potential selection bias, quantile regression allows the impact of both maternal employment and childcare to be examined throughout the weight distribution and multiple imputation is used to address the problem of missing data due to item non-response. The results suggest that both full-time and part-time maternal employment when a child is 9 months old increase the likelihood of being overweight at 3 years old, but only for children of mothers with higher levels of education. Informal childcare at 9 months also has harmful effects on child weight, but again only for children of more educated mothers. Quantile regression finds that the children most impacted by maternal employment are those at the upper percentiles of the weight distribution. When selection on observables is used to assess bias arising from selection on unobservables, maternal employment estimates are determined to be a lower bound, while informal childcare results could be attributed to selection bias. Overall findings are consistent with research from North America and the United Kingdom, and are in contrast to recent findings from the rest of Europe, suggesting the possible role of institutional factors.

Background
There is limited knowledge of the extent of or factors underlying inequalities in uptake of childhood vaccination in Ireland. This paper aims to measure and decompose socioeconomic inequalities in childhood vaccination in the Republic of Ireland.

Methods
The analysis was performed using data from the first wave of the Growing Up in Ireland survey, a nationally representative survey of the carers of over 11,000 nine-month old babies collected in 2008 and 2009. Multivariate analysis was conducted to explore the child and parental factors, including socioeconomic factors that were associated with non-vaccination of children. A concentration index was calculated to measure inequality in childhood vaccination. Subsequent decomposition analysis identified key factors underpinning observed inequalities.

Results
Overall the results confirm a strong socioeconomic gradient in childhood vaccination in the Republic of Ireland. Concentration indices of vaccination (CI = −0.19) show a substantial pro-rich gradient. Results from the decomposition analysis suggest that a substantial proportion of the inequality is explained by household level variables such as socioeconomic status, household structure, income and entitlement to publicly funded care (29.9%, 24% 30.6% and 12.9% respectively). Substantial differences are also observed between children of Irish mothers and immigrant mothers from developing countries.

Conclusions
Vaccination was less likely in lower than in higher income households. Access to publicly funded services was an important factor in explaining inequalities.

Background
Taking oral antibiotics during childhood has been linked with an increased risk of childhood obesity. This study assessed any potential association in number of courses of antibiotics taken between 2–3 and 4–5 years of age and body mass trajectory up to age 5.

Methods
The study was a secondary analysis of 8186 children and their parents from the infant cohort of the Irish National Longitudinal Study of Children. Antibiotic use was measured by parental recall between ages 2–3 and 4–5. Longitudinal models described the relationship between antibiotic exposure and body mass index (BMI) standard deviation scores and binary outcomes, and examined interactions between covariates, which included socioeconomic status, diet assessed by food frequency questionnaires and maternal BMI.

Results
Any antibiotic usage between 2 and 3 years did not predict risk of overweight or obesity at age 5. Four or more courses of antibiotics between 2 and 3 years were independently associated with obesity at age 5 (odds ratio 1.6, 95% confidence interval 1.11–2.31). Effect size was modest (coefficient + 0.09 body mass SD units, standard error 0.04, P = 0.037). Maternal BMI modified the relationship: ≥ 4 courses of antibiotics between 2 and 3 years were associated with a + 0.12 body mass SD units increase in weight at age 5 among children of normal-weight mothers (P = 0.035), but not in children of overweight mothers.

Conclusions
Number of antibiotic courses, rather than antibiotic use, may be an important factor in any link between early antibiotic exposure and subsequent childhood obesity. Research is needed to confirm differential effects on babies of normal versus overweight/obese mothers independent of socioeconomic factors.

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