IYDS: International Youth Development Study
The International Youth Development Study (IYDS) is a long-term study that looks at the development of healthy and problem behaviours among young people in the state of Victoria, Australia and the state of Washington, United States. IYDS is one of the first studies designed to examine whether or not differences in Australian and American cultures and schools affect youth development. The study began in 2002. The original sample included approximately 1000 students at each of three year levels in both Victoria and Washington, giving a total of nearly 6000 participants. The study continues to follow-up participants into adulthood.
| Year | 2002 | 2003 | 2004 | 2006 | 2007 | 2008 | 2010 | 2012 | 2014 |
|---|---|---|---|---|---|---|---|---|---|
| Wave | W1 | W2 | W3 | W4 | W5 | W6 | F1 | F2 | F3 |
| Year level (cohort) | Yr5 (Y) Yr7 (M) Yr9 (O) |
Yr6 (Y) Yr8 (M) Yr10 (O) |
Yr7 (Y) Yr9 (M) – |
Yr9 (Y) – – |
Yr10 (Y) – – |
Yr11 (Y) – – |
(Y) (M) (O) |
(Y) (M) (O) |
(Y) (M) (O) |
| Age range | 9.8 – 16.5 yrs | 11 – 17.4 yrs | 11.9 – 16.5 yrs | 14.1 – 16.5 yrs | 15 – 17.4 yrs | 16.1 – 18.6 yrs | 17.9 – 24.6 yrs | 20 – 26.9 yrs | 22 – 28.9 yrs |
| # | 2884 | 2884 | 1909 | 927 | 927 | 926 | 2872 | 2871 | 2870 |
| Identifiers and miscellaneous | |||||||||
| Anthropometrics | |||||||||
| Behavioural problems | |||||||||
| Demographics | |||||||||
| Driving history | |||||||||
| Education | |||||||||
| General health | |||||||||
| Mental health | |||||||||
| Parenting | |||||||||
| Physical activity and lifestyle | |||||||||
| Puberty | |||||||||
| Relationships | |||||||||
| Reproductive health | |||||||||
| Resilience and wellbeing | |||||||||
| Respiratory health | |||||||||
| Substance use | |||||||||
| Temperament and personality | |||||||||
| Uni/College policies | |||||||||
| Workplace policies | |||||||||
| Young adult transitions | |||||||||
| Year | 2002 | 2003 | 2004 | 2006 | 2007 | 2008 | 2010 | 2012 | 2014 |
|---|---|---|---|---|---|---|---|---|---|
| Wave | W1 | W2 | W3 | W4 | W5 | W6 | F1 | F2 | F3 |
| Year level (cohort) | Yr5 (Y) Yr7 (M) Yr9 (O) |
Yr6 (Y) Yr8 (M) Yr10 (O) |
– Yr9 (M) – |
N/A | N/A | N/A | N/A | N/A | – (M) – |
| Age range | 9.7 – 17.2 yrs | 10.8 – 18.4 yrs | 14 – 18.6 yrs | N/A | N/A | N/A | N/A | N/A | 24 – 26 yrs |
| # | 2885 | 2885 | 961 | N/A | N/A | N/A | N/A | N/A | 955 |
| Identifiers and miscellaneous | Identifiers and miscellaneous | ||||||||
| Anthropometrics | |||||||||
| Behavioural problems | Behavioural problems | ||||||||
| Demographics | Demographics | ||||||||
| Driving history | |||||||||
| Education | Education | ||||||||
| General health | |||||||||
| Mental health | Mental health | ||||||||
| Parenting | Parenting | ||||||||
| Puberty | |||||||||
| Relationships | Relationships | ||||||||
| Reproductive health | Reproductive health | ||||||||
| Resilience and wellbeing | Resilience and wellbeing | ||||||||
| Respiratory health | Respiratory health | ||||||||
| Substance use | Substance use | ||||||||
| Temperament and personality | Temperament and personality | ||||||||
| Uni/College policies | |||||||||
| Workplace policies | |||||||||
| Young adult transitions | |||||||||
| Study Summary | |
|---|---|
| Study name | International Youth Development Study |
| Study abbreviation | IYDS |
| Current principal investigator/s | John Toumbourou (Deakin University) Richard Catalano (USA) Sheryl Hemphill (Australian Catholic University) |
| Current project manager | Rachel Smith |
| Primary institution | Centre for Adolescent Health, Murdoch Childrens Research Institute |
| Collaborating institution/s | Social Development Research Group, University of Washington Australian Catholic University Deakin University |
| Major funding sources | NHMRC ARC NIAAA |
| Study website | http://www.rch.org.au/iyds/ |
| Key reference for study (published study protocol) | McMorris, B.J., Hemphill, S.A., Toumbourou, J.W., Catalano, R.F. and Patton, G.C. (2007). Prevalence of substance use and delinquent behavior in adolescents from Victoria, Australia and Washington State, United States. Health Education and Behavior, 34: 634-650 |
| Are data available to others outside study team? | Data are available according to study protocols, namely: approval of proposal by Principal Investigators; Data Sharing Collaboration Agreement read and agreed to by all parties, Fair Use Agreement signed by applicant and Principal Investigators. |
| Study focus (e.g. social development) | Risk and protective factors, as well as healthy and problem behaviours in young people including substance use, delinquency, violence, risky sex, depression and self-harm. |
| Sampling frame | In 2002, a two-stage cluster sample design was used to recruit students in both states (Victoria, Australia and Washington State, USA). In the first stage, schools were selected at random, based on a probability proportional to grade-level size from a stratified sampling frame of all schools in Victoria (government, Catholic and independent) and Washington (public, private and alternative). At Stage 2, single intact classes from each school for the selected grade level (Grade 5 (Y), 7 (M) or 9 (O)) were chosen at random; in a few cases, 2 classes from different year levels were randomly chosen at a school. |
| Study type (e.g. randomised control trial, cohort, case-control) | Longitudinal cohort study |
| Year commenced | 2002 |
| Ongoing recruitment? | No |
| Commencement sample (N) | AUS: 2884 USA: 2885 (Total 5,769) |
| Annual attrition rate (%) | Of the total eligible sample, 98.65% were re-surveyed in Wave 2 (2003), 97.59% in Wave 3 (2004), 86.93% in Wave 4 (2006), 89.2% in Wave 5 (2007), and 85.3% in Wave 6 (2008). For the young adult follow up surveys, 84% of the total eligible sample were surveyed in follow up 1 (2010), 83% in follow up 2 (2012), and 87% in follow up 3 (2014). |
| Intergenerational (e.g. offspring)? | No |
| Imaging (e.g. fMRI, ultrasound, retinal photograph)? | No |
| Linkage (e.g. BioGrid, VPDC, NAPLAN, Medicare)? | No |
| Biosamples (e.g. buccal, blood, hair)? | No |
| Ethics approvals or requirements (e.g. specific, extended, unspecified, other)? | The IYDS has ethics approval through the University of Melbourne Human Research Ethics Committee (060045X). This project only (Specific consent) |
| Wave | Year | Age (mean, range) | Eligible sample (not deceased, not withdrawn) |
|---|---|---|---|
| W1 | 2002 | AUS: 13, 9.8 – 16.5 (Y) (M) (O) USA: 13.1, 9.7 – 17.2 (Y) (M) (O) |
2884 (Y) (M) (O) 2885 (Y) (M) (O) |
| W2 | 2003 | AUS: 14, 11 – 17.4 (Y) (M) (O) USA: 14.1, 10.8 – 18.4 (Y) (M) (O) |
2884 (Y) (M) (O) 2885 (Y) (M) (O) |
| W3 | 2004 | AUS: 14, 11.9 – 16.5 (Y) (M) USA: 15.1, 14 – 18.6 (M) |
1909 (Y) (M) 961 (M) |
| W4 | 2006 | AUS: 15.2, 14.1 – 16.5 (Y) | 927 (Y) |
| W5 | 2007 | AUS: 16, 15 – 17.4 (Y) | 927 (Y) |
| W6 | 2008 | AUS: 17, 16.1 – 18.6 (Y) | 926 (Y) |
| N/A | 2009 | AUS: 19 – 22 (M) (O) | Tracking and locating survey only |
| F1 (Follow-up 1) | 2010 | AUS: 21, 17.9 – 24.6 (Y) (M) (O) | 2872 (Y) (M) (O) |
| F2 (Follow-up 2) | 2012 | AUS: 23, 20 – 26.9 (Y) (M) (O) | 2871 (Y) (M) (O) |
| F3 (Follow-up 3) | 2014 | AUS: 25, 22 – 28.9 (Y) (M) (O) USA: 25, 24 – 26 (M) |
2870 (Y) (M) (O) 955 (M) |
IYDS Project Manager
Rachel Smith
Ph: 1 800 200 141
Email: rachel.smith@mcri.edu.au
Postal Address
Centre for Adolescent Health
Level 2 East
Royal Children’s Hospital
Parkville Victoria 3052
Email: iyds@rch.org.au