Record Linkage in the NSW-CDS

An established state population cohort of 93,118 children is being followed from birth into early adulthood via successive waves of record linkage (see Figure below) to determine risk and protective factors for health, educational, social, child protection and criminology outcomes in adolescence and adulthood.

Wave 1

The first record linkage (wave 1) for the NSW-CDS was intended to provide information about the early childhood years (from birth to 5 years) for children who were assessed using the Australian Early Development Census as they started school in 2009 (aged 5-6 years). The record linkage brought together information about physical and mental health, education, child protection and criminal justice system contacts, for the children and their parents, in a way that protects the anonymity of all people involved. This linkage was conducted during 2013-2014, and statistical analysis and dissemination activities are currently being finalised.

Wave 2

The second record linkage (wave 2) provides information about the same cohort of children from birth to 12-13 years of age, as well as children who completed the Middle Childhood Survey in 2015 (aged 11-12 years). This second linkage is supplemented by the inclusion of additional data collections, including the Middle Childhood Survey, alongside other information about physical health, mental health and education, child protection and criminal justice system contacts, for the children and their parents. Conducted in 2016, statistical analyses and dissemination activities using wave 2 data are currently underway.

Wave 3

The next record linkage (wave 3) is proposed for completion in late 2019, to provide information about the same cohort of children from birth to 15-16 years of age. In addition to expanding the longitudinal data by three years, this linkage will comprise the same record sets as have been brought together in previous record linkages, together with the addition of Commonwealth data sets (e.g., Medicare records for GP visits). This will increase the level information obtained about physical and mental health contacts since many common ailments seen by GPs would not have been included in previous record linkages that were based on hospital contact data, which generally ascertain more severe health conditions.