The study design is a longitudinal cohort study, with repeated measurements of physiological indicators measured in saliva from a subsample of participants, and social survey data from an entire population cohort. The two prospective data collection (saliva and social survey) will be supplemented with retrospective registry data from an entire population cohort. Registry data on all Icelandic children in the 2004 birth cohort will be included in our study.
The study has been approved by all relevant institutes; National Bioethics Committee (Protocol # VSNb2011090008/03.1) and The Personal Protection Authority (Protocol # 2012060762ÞS/-) as well as the organizations providing registry data: The Primary Health Care Clinics, The Directorate of Health, The National University Hospital, The Health Care Institution of South Iceland, West Iceland Health Care Centre, Westfjords Health Care Centre, The Health Care Institution of North Iceland, The Health Care Institution of East Iceland, Akureyri Hospital, Sudurnes Hospital and Health Center, Reykjavik Child Protection Services, the Statistical Bureau of Iceland, and the Educational Testing Institute under the auspices of the Ministry of Education, Science and Culture.
We will survey the entire cohort of children born in Iceland in year 2004; around 4000 children using a protocol from ICSRA that has been used for 20 years in school-based surveys (Kristjansson et al, 2013; Sigfusdottir et al., 2009). The saliva data collection will be restricted to a sample of about 1,000 children.
First wave of survey data will be collected early spring 2017, data will be merged with the already existing registry data on the pregnancy (of mothers), and on the children as newborns, toddlers, school children from a repository for all children born in Iceland from year 2004 and onwards.