Growing Up in Ireland - the National Longitudinal Study of Children is a landmark study of children and youth which has been running since 2006. In summary the project seeks to further our understanding of what it means to be a child or young person growing up in modern Ireland, with a view to informing policy on what both helps and hinders development. A two cohort, cross-sequential longitudinal design was adopted and began with one cohort (the Infant Cohort) of 11,134 infants (aged 9 months) and a second cohort (the Child Cohort) of 8,568 9-year-olds. Being longitudinal in nature, the same children are followed over time. The families of the Infant Cohort have been interviewed when the children were 9 months, 3 years, 5 years, 7/8 years, 9 years and subsequently at 13 years of age, while the Child Cohort and their parents/guardians were interviewed at 9, 13, 17/18 and 20 years of age. This wave of data concerns the Wave 6 interviews of the Infant Cohort at 13 years of age. These data have been collected by the Growing Up in Ireland study. The Growing Up in Ireland study was funded from 2006 to 2022 by the Government of Ireland through the Department of Children, Equality, Disability, Integration and Youth. Until the end of 2022 the study was managed by DCEDIY in association with the Central Statistics Office (CSO) and was overseen and supported by an interdepartmental governance structure. This included an inter-departmental Steering Group with responsibility for strategic oversight and an interdepartmental Project Team with responsibility for operational oversight. Ethical oversight of the study was provided by an independent and dedicated Research Ethics Committee (REC). The study was carried out on behalf of DCEDIY by a team of researchers at by the Economic and Social Research Institute (ESRI) and Trinity College Dublin. The data have been collected under the Statistics Act 1993.

Probability: Stratified: Proportional Simple systematic selection procedure based on a random start and constant sampling fraction This section presents a brief outline of the sampling at Wave 1, to a background to the sampling procedures used. The Child Benefit register was used as the sampling frame for the first Wave of Cohort ’08. Child Benefit is a universal monthly social welfare payment to families with children. Children should be registered with the appropriate authorities within 6 months of birth or becoming part of the family (e.g. through adoption), or of the family coming to reside in Ireland. This administrative database had some extremely attractive characteristics as a sampling frame. It contained a comprehensive up-to-date listing of eligible members of the relevant population; had a wide range of relevant characteristic variables of claimants (mostly mothers); and was already in an electronic form that could be accessed for sampling purposes. There were just over 70,000 births in Ireland in 2007. The Wave 1 sample for Cohort ‘08 study was selected from the 41,185 infants registered on the Child Benefit Register as having been born between 1st December 2007 and 30th June 2008. The target sample was selected over this seven-month period, with a view to carrying out fieldwork for Wave 1 when the children were 9 months of age, between September 2008 and March/April 2009. The sample was selected on a systematic basis, with a random start. Prior to selection, the sample was sorted by marital status of the claimant (usually the mother), county of residence and nationality of the claimant, as well as number of children in the payment or ‘claim’. A simple systematic selection procedure based on a random start and constant sampling fraction was used. In total, 11,134 children were recruited onto the first wave of the study; representing a response rate of 65 per cent of all families approached and 69 per cent of valid contacts made in the course of the fieldwork. A total of 9,723 children and their families were contacted for interview in Wave 6, when the children were 13 years old. This included families who were interviewed in Wave 5, when the children were aged 9 years and some families who were interviewed in previous waves but were not interviewed at wave 5. We did not contact families who had left Ireland or those who had asked not to be contacted again. Due to the on-going restrictions caused by Covid-19, interviewers carried out the interviews with families by telephone, with a short follow up web-based self-complete survey. A total of 6,655 questionnaire were returned, amounting to 59.8% of the families interviewed at 9 months of age.

Telephone Interview: CAT

Self-administered questionnaire: Computer-assisted (CASI)