The Child to Adult Transition Study (CATS)

CATS is a unique longitudinal study of children in metropolitan Melbourne as they transition through adolescence and into adulthood.

The study began in 2012 and follows over 1200 children from grade 3 (8-9 years of age) through adolescence and into adulthood. The young people are assessed once every year. The study also collected information from teachers through primary school, and parents through to year 8 (13-14 years) then again in year 11 (16-17 years). The main focus of the study is on the health and emotional development of young people during the middle years (8-14 years) and through the primary to secondary transition. The study aims to improve our understanding of the many influences that the effect the health and emotional adjustment of children as they traverse late childhood and adolescence. The study looks at the experiences of children and their families, their changing social context as they move through secondary school and beyond, and their reactions to the biological changes of puberty. The information collected as part of this large study will help us identify when and how to promote the best health and emotional adjustment in young people.

The CATS cohort are currently transitioning out of high school after completing their final two years of schooling during the COVID 19 pandemic. CATS plans to follow this important group of young people as they enter the workforce or begin further education in a COVID-19 world. With eight waves of data collection pre-pandemic, the study is ideally placed to investigate the impact of the pandemic on this new generation of young Australians.

Study Summary
Study name Child to Adult Transition Study
Study abbreviation CATS
Current principal investigator/s George Patton
Current project manager

Paul Hockey

Primary Institution/s Murdoch Children’s Research Institute - MCRI
Collaborating Institution/s The University of Melbourne - UoM
University of South Australia
University of New South Wales
University College London Institute of Child Health, UK - UCL
La Trobe University
Major funding source/s National Health and Medical Research Council - NHMRC
Study website
Key reference for study Mundy, L.K., Simmons, J.G., Allen, N.B., Viner, R.M., Bayer, J.K., Olds, T., Williams, J., Olsson, C., Romaniuk, H., Mensah, F., Sawyer, S.M., Degenhardt, L., Alati, R., Wake, M., Jacka, F. and Patton, G.C.. Study protocol: the Childhood to Adolescence Transition Study (CATS). BMC Pediatr. 2013 Oct 8;13:160. doi: 10.1186/1471-2431-13-160
Study focus

The health and emotional development of children as they pass through puberty and the middle years of school, to improve the understanding of the many influences that effect the health and emotional adjustment during these transition years

Sampling frame

All Grade 3 students (8-9 years of age) from a stratified cluster sample of schools in Melbourne, Australia were invited to take part.

Primary study type Longitudinal cohort
Primary participant (at recruitment) Index child
Year commenced


Is this study ongoing? Yes - the study is ongoing
Ongoing recruitment? No
Sample size (N)


Survey data available? Yes
Imaging data available? Yes
Linkage to administrative dataset/s? Yes, linkage to (at least one) administrative dataset completed
Biosamples available? Yes
Are data available to others outside study team, with appropriate safeguards and structures in line with the cohort’s ethics and governance processes? Yes
Are there any costs associated with data/sample access for approved requests? There are usually no costs associated with access
Broadest type of participant consent available Extended consent (can be used for future ethically approved research related to this project)
Wave Year Age Sample size (N)
1 2012 8-9 years N(Total)=1239
2 2013 9-10 years N(Total)=1158
3 2014 10-11 years N(Total)=1119
4 2015 11-12 years N(Total)=1066
5 2016 12-13 years N(Total)=1175
6 2017 13-14 years N(Total)=1177
7 2018 14-15 years N(Total)=1137
8 2019 15-16 years N(Total)=1102
9 2020 16-17 years N(Total)=1084
10 2021 17-18 years
Study Contacts
Principal investigator/s George Patton
Project manager

Paul Hockey

Study Contact

Phone: +61 3 9345 6732
Address: Murdoch Children's Research Institute,
Royal Children’s Hospital
Flemington Road, Parkville
Victoria 3052 Australia