Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12625000880448p
Ethics application status
Submitted, not yet approved
Date submitted
28/07/2025
Date registered
13/08/2025
Date last updated
13/08/2025
Date data sharing statement initially provided
13/08/2025
Type of registration
Prospectively registered

Titles & IDs
Public title
Bridge to Better: Testing a universally delivered self-harm prevention program in Australian primary schools
Scientific title
A Two-Arm Parallel Cluster Randomised Trial of a Universal Self-Harm Prevention Program in Australian Primary Schools: A Hybrid Type I Effectiveness-Implementation Study
Secondary ID [1] 315013 0
Nil known
Universal Trial Number (UTN)
U1111-1323-1715
Trial acronym
B2B
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Self-harm 338353 0
Psychological wellbeing 338354 0
Condition category
Condition code
Mental Health 334648 334648 0 0
Suicide
Mental Health 334649 334649 0 0
Other mental health disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Overview: The Bridge-to-Better (B2B) intervention is a comprehensive, ecological approach to universal prevention, designed to influence all aspects of the classroom — curriculum, pedagogy/practice, organisation, and climate. It involves a 3-part ‘staged’ approach to component delivery:

Part 1: Setting Up Supportive Classrooms – modifying/enhancing routines and built environments of classrooms (Module 1)

Part 2: Connected classrooms – building relational care, autonomy support teaching practice/pedagogy (Modules 2–4)

Part 3: Emotion regulation skills training – strengthening students’ internal resources to adaptively manage emotions (Modules 5–7)

These components will be delivered through a combination of online teacher training, classroom modifications, and classroom activities (including an animated video series).

The intervention will be delivered to all children (regardless of risk for self-harm) in stages 2 and 3 (Years 3-6) of NSW primary schools. As a universal, whole–of–classroom, delivery model, the intervention will not be tailored or personalised to individuals or groups.

Program structure: The intervention is comprised of 7 Modules, covering Parts 1–3 of B2B. Within these, there are 15 teacher–training sessions (10–15 minutes each) and 70 classrooms activities that are delivered over a 26-week period, by teachers (face-to-face) – during class time.

As per our ‘staged’ delivery approach (Parts 1–3), the classroom connectedness/classroom climate components will be initiated first (Parts 1, 2; Modules 1–4), approximately 8 weeks before introducing the emotion regulation component (Part 3). Once the first emotion regulation Modules are introduced (Modules 5–7), all 'Parts' of the program will run in parallel.

Exposure:

Part 1 (2 weeks): Setting Up Supportive Classrooms. Teachers complete 1 x 15-minute online training module and learn simple practices for modifying their class routines and classroom environments that are then integrated daily over the 26-week period.

Part 2: Teachers complete 5x 15–minute online training modules over 8 weeks (total = 75mins) focused on strengths–based, autonomy supported teach practices. They learn to continuously implement these practices into their pedagogy. They also learn simple relational practices and establish a peer–recognition system.

Part 3: Teachers complete 9x 15-minute online training modules over 18 weeks (total = 135mins) to learn emotion regulation skills, and to model these for students. The emotion regulation skills these will learn are: emotional awareness, functions of emotions, self-compassion, control and acceptance, downregulation, upregulation, cognitive reappraisal.
The students will be taught these skills via an animation series developed specifically for this program, shown in class, followed by 8x classroom activity bundles delivered over a two–week period (i.e., 9x lessons, two weeks each).
Classroom exposure = 747mins total (10 mins p/day, 4 days p/week + 3min video p/fortnight).

Teachers will receive training in the program prior to initiating the Module–based training, as well as all the materials they need to deliver the program, including a program guide and accompanying student and teacher workbooks. All trainings, program guides, and workbooks have been specifically developed for this program. The research team will be available to provide schools and teachers with additional support and guidance

Teachers will be required to complete regular fidelity check surveys across the duration of intervention delivery to measure adherence to the intervention protocol.
Intervention code [1] 331610 0
Prevention
Intervention code [2] 331611 0
Behaviour
Comparator / control treatment
Active control – classroom enhancement strategy

The control group in this trial will only receive Part 1 - Setting Up Supportive Classrooms of the B2B intervention. This component will be delivered exactly as it is for the intervention group (see above).
Control group
Active

Outcomes
Primary outcome [1] 342325 0
Deliberate self-harm
Timepoint [1] 342325 0
Baseline (T0) - prior to beginning of the intervention Post-intervention (T1) - immediately following the end of the intervention 12-month follow-up (T2) - 12-months after the end of the intervention (primary timepoint)
Primary outcome [2] 342326 0
Psychological wellbeing
Timepoint [2] 342326 0
Baseline (T0) - prior to beginning of the intervention Post-intervention (T1) - immediately following the end of the intervention 12-month follow-up (T2) - 12-months after the end of the intervention (primary timepoint)
Secondary outcome [1] 450330 0
Depression
Timepoint [1] 450330 0
Baseline (T0) - prior to beginning of the intervention Post-intervention (T1) - immediately following the end of the intervention 12-month follow-up (T2) - 12-months after the end of the intervention
Secondary outcome [2] 450331 0
Stress
Timepoint [2] 450331 0
Baseline (T0) - prior to beginning of the intervention Post-intervention (T1) - immediately following the end of the intervention 12-month follow-up (T2) - 12-months after the end of the intervention
Secondary outcome [3] 450332 0
Behavioural problems
Timepoint [3] 450332 0
Baseline (T0) - prior to beginning of the intervention Post-intervention (T1) - immediately following the end of the intervention 12-month follow-up (T2) - 12-months after the end of the intervention
Secondary outcome [4] 450333 0
Self-injurious thoughts
Timepoint [4] 450333 0
Baseline (T0) - prior to beginning of the intervention Post-intervention (T1) - immediately following the end of the intervention 12-month follow-up (T2) - 12-months after the end of the intervention
Secondary outcome [5] 450334 0
Program adoption
Timepoint [5] 450334 0
Baseline (T0) - prior to beginning of the intervention Post-intervention (T1) - immediately following the end of the intervention
Secondary outcome [6] 450335 0
Teacher burnout
Timepoint [6] 450335 0
Baseline (T0) - prior to beginning of the intervention Post-intervention (T1) - immediately following the end of the intervention 12-month follow-up (T2) - 12-months after the end of the intervention

Eligibility
Key inclusion criteria
Schools:
•Mainstream, government, Independent, and/or Catholic primary schools from New South Wales, Australia, where there is evidence of higher than average rates of self-harm hospital representations among 12-17 years old. We will include schools from urban, regional, and rural locations.
•Schools willing to commit to the delivery of the Bridge to Better (B2B) study if they are allocated to the Intervention group, including teacher training and teacher and student assessments.

Educators:
•Within consenting schools, participating teachers will be classroom teachers who teach Years 3 to 6
•Teachers in permanent positions or contracted for a minimum of 1 year, to increase the likelihood that they will remain teaching within the school during the research period.
•Teachers must provide written opt-in consent
•Teachers must commit to completing the training in the delivery of the B2B intervention, and subsequently, to deliver the B2B intervention (should their school be randomised to the exposure of the trial)

Students:
•Participating students will attend a school that has consented to participate in the trial and be in Years 3 to 6 in the year they are to complete the baseline assessment.
•Written opt-in parental consent must be provided
•Students with parental consent must provide written assent
Minimum age
7 Years
Maximum age
13 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Schools:
•Special needs schools, known as Schools for Specific Purposes, or Alternative schools that do not deliver mainstream curricula
•Schools already participating in a research trial where the intervention is universally delivered and targets mental health or wellbeing type outcomes

There are no specific exclusion criteria for educators or students in addition to the school-level exclusion criteria

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation concealment will be achieved as all schools will be recruited before randomisation of schools to trial arms, with the allocation list being generated by an independent unblinded statistician and applied ‘en bloc’ to the entire cohort.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Schools will be assigned to trial arms in a 1:1 ratio using covariate-based constrained randomisation. A list of acceptable possible allocations will be produced such that equal numbers of schools are allocated to each arm, and such that the imbalance between the arms in the following factors is acceptably low
•Size of K – Year 6 population (large [300 children or more] vs small [fewer than 300 children])
•Level of educational advantage (below vs above median ICSEA value – 1000)
•Sex composition of schools (boys only, girls only, mixed)
•Geography (rural, remote, and metropolitan areas)
•Level of academic achievement (below vs above average NAPLAN results for literacy and numeracy)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Safety/efficacy
Statistical methods / analysis
For the self-harm primary endpoint, the prevalence of non-suicidal self-harm in children aged 12 or younger was estimated to be 6.2%. Based on other prevention programs, a clinically meaningful effect would be a 50% relative reduction in this rate, to 3.1% in the intervention arm. For the psychological well-being primary endpoint, a clinically meaningful effect would be a 2.5-point increase on the 0-25 scale of the WHO-5, which has an estimated standard deviation of 5.9. Average intracluster correlation coefficients are observed to be 0.025 for binary outcomes and 0.04 for continuous outcomes.

With a two-sided significance level adjusted for multiple testing of 0.025 (0.05/2 for each of the primary endpoints), 72 schools and 4536 students (36 schools and 2268 students per arm) with complete data will provide at least 80% power to detect the clinically meaningful difference in self-harm prevalence with a 5% familywise type I error probability, as well as providing greater than 99% power to detect the clinically meaningful difference in psychological well-being. To reach this target, assuming an estimated attrition rate of up to 30% we will aim to recruit 3240 students per arm (6480 total sample size).

The primary analyses will be performed under an intention-to-treat principle, in which outcomes will be analysed according to the randomised allocations, regardless of fidelity to the protocol.

The unit of inference for the primary outcomes will be at the student level. The analysis of each outcome will use a generalised linear mixed model (logistic model for self-harm, and an appropriate continuous model for wellbeing), including a random effect for school, a fixed effect of trial arm and adjusted for the student’s baseline outcome value and the school-level factors used to balance the randomisation. To account for multiple comparisons, the two-sided p-value from a likelihood ratio test will be compared to a significance level of 0.025 and each estimated adjusted intervention effect will be reported along with a two-sided 97.5% confidence interval.

Secondary outcomes, including safety (suicidal ideation, stress, self–harm) collected at the student level will be analysed in a similar fashion, with the model form depending on the nature of the outcome (e.g., a linear mixed model will be used for continuous outcomes). Outcomes collected at the classroom– and school– levels will be analysed accordingly, with appropriate adjustment for clustering.

Pre-specified interaction analyses will be undertaken to assess if there is evidence that the intervention effect differed between subgroups based on the following baseline characteristics: child age, child gender, school size, regionality, incidence of self-harm at baseline and socio-economic status.
Missing data will be summarised and assessed to examine the appropriateness of analysis assumptions. Sensitivity analyses will be performed to assess the impact of variations in these assumptions on the study’s conclusions. At post-intervention (T1) schools will also be asked whether any mental health or wellbeing programs were implemented at their school.
This information will be treated as a potential confounding factor and included in sensitivity analyses to account for its possible influence on outcomes.

Additional analyses will be planned to estimate the efficacy of the planned intervention, adjusting the observed intention-to-treat effect for between-school differences in fidelity, measured by our bespoke fidelity measure.

To assess the impact of the program on self–harm, we aim to undertake a supplementary analysis of self-harm rates reported among children aged 10–14 in New South Wales emergency department and admitted patient hospitalisation data in addition to the student self–harm data and the school–level administrative data. We will examine the change in the rate of children hospitalised due to self-harm in the 24–months before and after the study period, comparing this between regions that did and did not include schools participating in the study, and accounting for the proportion of students that were exposed to the intervention in participating regions. The school administrative data will include aggregate counts of students in K–6 known to have engaged in self-harm, and the frequency of self-harm incidents over the past 12 months – per school - collected for the two years preceding the trial and for the trial year (total of three years), subject to availability. This longitudinal administrative data will allow us to contextualise and triangulate student self-report findings and observe trends over time.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
3/11/2025
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
7/12/2029
Actual
Sample size
Target
6480
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
NSW

Funding & Sponsors
Funding source category [1] 319578 0
Government body
Name [1] 319578 0
Medical Research Future Fund, Department of Health, Disability, and Ageing
Country [1] 319578 0
Australia
Primary sponsor type
University
Name
University of New South Wales (UNSW)
Address
Country
Australia
Secondary sponsor category [1] 322075 0
None
Name [1] 322075 0
Address [1] 322075 0
Country [1] 322075 0

Ethics approval
Ethics application status
Submitted, not yet approved
Ethics committee name [1] 318141 0
The University of New South Wales Committee B
Ethics committee address [1] 318141 0
Ethics committee country [1] 318141 0
Australia
Date submitted for ethics approval [1] 318141 0
23/06/2025
Approval date [1] 318141 0
Ethics approval number [1] 318141 0

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 143246 0
A/Prof Michelle Tye
Address 143246 0
Black Dog Institute, Hospital Road, Randwick, NSW 2031
Country 143246 0
Australia
Phone 143246 0
+61 2 9065 9152
Fax 143246 0
Email 143246 0
[email protected]
Contact person for public queries
Name 143247 0
Michelle Tye
Address 143247 0
Black Dog Institute, Hospital Road, Randwick, NSW 2031
Country 143247 0
Australia
Phone 143247 0
+61 0293824530
Fax 143247 0
Email 143247 0
[email protected]
Contact person for scientific queries
Name 143248 0
Michelle Tye
Address 143248 0
Black Dog Institute, Hospital Road, Randwick, NSW 2031
Country 143248 0
Australia
Phone 143248 0
+61 0293824530
Fax 143248 0
Email 143248 0
[email protected]

Data sharing statement
Will the study consider sharing individual participant data?
Yes
Will there be any conditions when requesting access to individual participant data?
Persons/groups eligible to request access:
• Researchers
Conditions for requesting access:
• Yes, conditions apply:
• Requires review on a case-by-case basis by the trial custodian, sponsor or data sharing committee
• Requires a scientifically sound proposal or protocol
• Requires approval by an ethics committee
• Requires a data sharing agreement between data requester and trial custodian or sponsor
What individual participant data might be shared?
• All de-identified individual participant data
What types of analyses could be done with individual participant data?
• Any type of analysis (i.e. no restrictions on data re-use)
When can requests for individual participant data be made (start and end dates)?
From:
At the end of the study
To:
No end date
Where can requests to access individual participant data be made, or data be obtained directly?
• Email of trial custodian, sponsor or committee: [email protected]

Are there extra considerations when requesting access to individual participant data?
No


What supporting documents are/will be available?

No Supporting Document Provided


Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.