Data collection waves


Growing Up in New Zealand is a longitudinal study, which means we plan to stay in touch with families until their child is 21 years old. Early life development from before birth is recognised as critical for the ongoing health, wellbeing and resilience of children and their families. That's why the study collected detailed information about the children and their mothers from before birth up to the age of four and a half on ten occasions.

Each Data Collection Wave (DCW) gathers information across six inter-connected domains:

  • Health and wellbeing
  • Psychosocial and cognitive development
  • Education
  • Family/whānau
  • Culture and identity
  • Societal context and neighbourhood environment


Each wave is planned according to a balance of age-appropriate information from all the inter-connected domains, in the context of the overarching longitudinal research objectives, while being as policy-relevant as possible. The study ensures that the methods used to collect domain-specific evidence acknowledge the unique New Zealand population and environmental context.

Data collection wave timeline


Data collection wave timeline

Longitudinal information collected to date


  • Data from the antenatal DCW (completed in June 2010) which consisted of a face-to-face Computer Assisted Personal Interview (CAPI) with the pregnant mother (most often in the last trimester of her pregnancy) and with her partner (almost always the father). Baseline results were presented in Report 1: Before we are born in November 2010.

  • Data from the second face-to-face CAPI with the child's mother and her partner which took place when the cohort children were nine months old. This DCW was completed in January 2011. 9-month results were presented in Report 2: Now we are born in March 2012.

  • Information collated from linkage to routinely collected perinatal health records, completed in late 2011. This data provides information about the latter stages of pregnancy, the child's birth and immediate neonatal outcomes. Linkage to the perinatal data was achieved through accessing records held by the three District Health Boards where the majority of the Growing Up in New Zealand children were born, as well as information from midwifery organisations. The child's National Health Index (NHI) number facilitated these linkages.

  • Information from the third face-to-face CAPI which occurred when the children were two years old. This CAPI also involved direct observations and developmental and anthropometric assessments of the children. Results from the 2-year data collection wave were presented in Report 3: Now we are Two.

  • Data from the fourth face-to-face CAPI with the child's mother and her partner which took place when the cohort children were at pre-school age (54 months old). This CAPI involved direct observations and developmental and anthropometric assessments of the children, as well as the collection of swab and spit samples. Results from this DCW were presented in Report 7: Now we are Four.
  • 'Starting school' information collected from the mothers in the study when the child was six years old. This data collection wave was the first to use an online questionnaire to capture the mother's responses. It will be in the field until mid 2016.

 

In addition, brief Computer Assisted Telephone Interviews (CATI) were conducted six weeks after the expected date of delivery (EDD) of the cohort children (the first point of contact after birth), and when the children were approximately 35 weeks, 16 months, 23 months, 31 months and 45 months old. These CATI calls allowed for the collection of age-appropriate developmental information and assisted with cohort retention.

Download our questionnaires and technical reports