Carrying weapons and intent to harm among Victorian secondary school students in 1999 and 2009

Sheryl A Hemphill, Michelle A Tollit, Helena Romaniuk, Joanne Williams, John W Toumbourou, Lyndal Bond and George C Patton
Med J Aust 2013; 199 (11): 769-771. || doi: 10.5694/mja12.11645
Published online: 16 December 2013

Youth violence (for example, carrying a weapon or attacking someone with intent to harm) is one of the most important social and public health problems worldwide.1-3 The costs of youth violence stem from harm caused to victims, as well as policing and criminal justice responses and community perceptions of reduced safety.3,4 Violence was listed in the top three issues concerning young Australians in 2010.5 Eight per cent of Victorian students in Years 7 and 9 engaged in violent behaviour in 2002, with higher rates among boys than girls.6 In addition, rates of youth violence are higher in disadvantaged communities7 and in regional communities with unstable populations and economic structures as well as high unemployment,8 and lower among youths from immigrant families.9

There have been reports of increases in violent offences perpetrated by youth in Australia10 and media reports suggest more youth are violent.11,12 National population-based surveys could measure whether rates of self-reported violence among youth have changed over time, but Australia does not have such surveys. In this article, we analyse data from Victorian surveys of secondary school students in 1999 and 2009 to examine whether rates of carrying a weapon and attacking someone with intent to harm have increased, after adjusting for sample demographic characteristics.


Data for this study were drawn from two Victorian cross-sectional surveys; the 1999 Adolescent Health and Wellbeing Survey13 and the 2009 Victorian Adolescent Health and Wellbeing Survey (HOWRU).14 Both surveys used a modified version of the Communities That Care Youth Survey15,16 to measure behavioural and mental health outcomes, as well as risk and protective factors.

Both surveys used a two-stage cluster sampling approach. The first stage consisted of a stratified random sample of government (public) and non-government (Catholic and independent) schools from each of 36 areas across Victoria — the 31 metropolitan government areas and the five state government regions outside the metropolitan area. Schools were selected randomly with a probability proportional to the number of Year 7, 9 and 11 students in the school. In the second stage, a random sample was taken of one class at each year level.

Data collection covered the first three school terms (February to September) in 1999 and the second and third terms (April to November) in 2009. Responses to questionnaires were anonymous. Students completed the questionnaire in class, taking about 40 minutes in 1999 for a pen-and-paper survey and about 60 minutes in 2009 to complete a longer online survey (although computers were not available for 19% of surveys, so paper versions were used). Students were supervised by trained research staff while they completed the survey. In 1999, copies of the questionnaire with a prepaid return envelope were left at the school to be returned to researchers by students who were absent on the day of the survey. For 2009, there was no follow-up to collect surveys from absent students.


Carrying a weapon was measured by asking students whether in the past 12 months they had carried a weapon. Attacking someone with intent to harm was measured by asking students whether in the past 12 months they had attacked someone with the idea of seriously hurting them. In the 1999 survey, participants responded to both questions on an 8-point scale ranging from “No” to “Yes, more than 40 times”. In the 2009 survey, items were rated on a 5-point scale ranging from “Never” to “10 or more times”. For both surveys, responses to these items were recoded and dichotomised to 0 (“No/Never”) or 1 (“At least once”).

Demographic measures controlled in the analyses included age, sex, language spoken at home, and geographic location of school. Student residential socioeconomic disadvantage was measured using four quartiles: (0–25th quartile [most disadvantaged], 26th–50th quartile [disadvantaged], 51st–75th quartile [advantaged] and 76th-100th quartile [most disadvantaged]), on the index of relative socioeconomic disadvantage from the Australian Bureau of Statistics’ Socio-Economic Indices for Areas (SEIFA) for 1996 and 2006.17,18

Statistical analysis

Prevalence rates with 95% CIs were estimated for the outcomes of interest in each survey. In unadjusted analyses, the relationship between year of survey and the outcomes was analysed by logistic generalised estimating equations (GEE) to take account of the clustering of students in schools. These analyses were then repeated, controlling for all demographic measures. A complete case analysis was performed with Stata, version 11 (StataCorp), that included only students who responded to all the variables analysed here.

Ethics approval

Ethics approval for both surveys was obtained from the Royal Children’s Hospital Human Research Ethics Committee and relevant education authorities. For the 1999 survey, active informed consent was required from parents for students to participate. In the 2009 survey, passive informed consent from parents was required in most schools, but active informed consent from parents was required at some Catholic schools. For both surveys, informed assent was sought from students on the day of the survey.


The student participation rate was 70% (8984 students) in the 1999 survey and 76% (10 273 students) in the 2009 survey. There were complete case data for 92% of students in the 1999 survey (7998) and 91% of students in the 2009 survey (9364). Box 1 describes the school and student samples for each survey.

The prevalence rate for carrying a weapon was about 15.0% in both the 1999 and 2009 surveys and the prevalence rate for attacking someone with intent to harm was about 7.0% in both surveys. Rates for both outcomes did not differ over time. More boys than girls engaged in these behaviours (Box 2).


We found no change over time in the self-reported rates of student violent behaviour based on two indicators, carrying weapons or attacking someone with intent to harm, even after controlling for demographic changes. Our findings suggest that changes in policing and court policies rather than in youth behaviour may explain increases in violence offences.19 Consistent with previous research,7 more boys than girls carried weapons or attacked another with intent to harm.

A strength of our study is that the methods used in the 1999 and 2009 surveys were virtually identical, enabling comparison of rates of behaviour across a 10-year period. However, response rates in the two surveys differed, with a lower response rate in 1999, most likely most likely because that survey required active parental consent. The survey measures, which originated in the United States, have been used in other high-income countries, and had been extensively tested before their use with Victorian students. Although the survey relies on youth self-report, this is considered a reliable data source for behaviours not always visible to adults, such as violence, and the reliability of reporting is unlikely to have changed over the decade.20,21

Violence in adolescence remains an important social and health issue. Yet our study challenges trends in offence data and recent media reports of increasing youth violence by finding no shifts in two self-report indices between 1999 and 2009. Our findings illustrate the need for sound self-report data for planning balanced policy responses and to challenge some negative media portrayals that can create erroneous and damaging stereotypes of young people.22

1 Description of the Victorian secondary school samples in 1999 and 2009


1999 Survey

2009 Survey

School sample

Number of government areas







Number of schools

In sampling frame*









Type of school


126 (65.0%)

112 (59.3%)


41 (21.1%)

40 (21.2%)


27 (13.9%)

37 (19.6%)

Student sample

Total number in analysed sample



Mean age in years (SE)

14.1 (0.02)

14.4 (0.02)


3622 (45.3%)

4492 (48.0%)

English spoken at home

6500 (81.3%)

6942 (74.1%)

School located in metropolitan area

5811 (72.7%)

7878 (84.1%)

Neighbourhood disadvantage

Most disadvantaged

2007 (25.1%)

2378 (25.4%)


2004 (25.1%)

2466 (26.3%)


1982 (24.8%)

2164 (23.1%)

Most advantaged

2005 (25.1%)

2356 (25.2%)

* In both 1999 and 2009, special schools were not included in the sampling frame.

2 Rates of carrying a weapon and attacking someone with intent to harm in 1999 and 2009

Carrying a weapon

Attacking someone with intent to harm






% (95% CI)


% (95% CI)


% (95% CI)


% (95% CI)






Overall sample*


15.1% (14.3%–15.9%)


14.9% (14.2%–15.6%)


7.5% (6.9%–8.1%)


7.3% (6.8%–7.8%)



7.6% (6.9%–8.4%)


7.1% (6.4%–7.8%)


4.4% (3.8%–5.0%)


4.4% (3.8%–5.0%)



24.1% (22.7%–25.5%)


23.4% (22.1%–24.6%)


11.2% (10.2%–12.2%)


10.5% (9.9%–11.4%)

* For the overall sample, we found no difference in rates between 1999 and 2009 surveys whether findings were or were not adjusted for demographic characteristics. This was the case for both carrying a weapon (unadjusted odds ratio [OR], 1.0; 95% CI, 0.9–1.1 and adjusted OR, 0.9; 95% CI, 0.8–1.1) and attacking someone with intent to harm (unadjusted OR, 1.0, 95% CI, 0.8–1.1 and adjusted OR, 0.9; 95% CI, 0.8–1.0).

Received 8 November 2012, accepted 8 July 2013

  • Sheryl A Hemphill1
  • Michelle A Tollit1
  • Helena Romaniuk2
  • Joanne Williams2
  • John W Toumbourou3
  • Lyndal Bond4
  • George C Patton2

  • 1 School of Psychology, Australian Catholic University, Melbourne, VIC.
  • 2 Murdoch Childrens Research Institute, Melbourne, VIC.
  • 3 Deakin University, Geelong, VIC.
  • 4 Centre of Excellence in Intervention and Prevention Science, Melbourne, VIC.



Completion of the Adolescent Health and Wellbeing Survey in 1999 was made possible by funding from the Victorian Department of Human Services. In 2009, the Victorian Adolescent Health and Wellbeing Survey (HOWRU) was funded by the Victorian Department of Education and Early Childhood Development. The analyses of this data were supported by funding from the Centre for Adolescent Health’s Adolescent Forensic Health Service, Royal Children’s Hospital. We express our appreciation and thanks to project staff and participants for their valuable contribution to the two projects described in this article.

Competing interests:

No relevant disclosures.

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