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Trial registered on ANZCTR

Registration number
Ethics application status
Submitted, not yet approved
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
A comparison between computer based Positive Search Training and Cognitive Behavioural Training in children with anxiety disorders an Australian Childhood Anxiety Treatment Study (A-CATS)
Scientific title
Improving access to treatment for children with anxiety disorders: A randomised controlled non-inferiority trial between positive search training and cognitive behavioural training for anxiety
Secondary ID [1] 297101 0
Nil Known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Anxiety disorders 311112 0
Condition category
Condition code
Mental Health 309742 309742 0 0

Study type
Description of intervention(s) / exposure
The project involves a two arm, nationwide randomised controlled non-inferiority trial over five years comparing Positive Search training (PST) and computer-delivered Cognitive Behavioural Therapy (CBT). BRAVE-ONLINE will be used as the referent treatment in the CBT arm; a well-established online CBT program for childhood anxiety disorders.

Positive Search Training
Families randomised to PST will be telephoned within a week of allocation to schedule initial set-up procedures. They will be posted an information booklet containing information about PST, a rationale for the training given that PST is an explicit form of attention training, information on setting-up PST on the family computer, and the USB drive. A 45-min telephone call will be conducted between the research assistant and parents to cover material in the booklet and set-up PST on their computer. Parents will open PST on the computer in a quiet room in the house and children will complete 4 x PST sessions (25 min per session) each week for 3 weeks. A 5-min weekly scripted call from the research assistant will be conducted to check there are no technical or scheduling difficulties and no other treatments or service usage (e.g., CBT, medication). How it works: PST is programmed in Java, completed on a PC/laptop with headphones and a microphone (provided if necessary) and uses a wide variety of picture stimuli. PST contains 224 trials per session (divided into 9 blocks of different trial sizes) yielding 2688 trials over 12 sessions completed within 3 weeks. Children receive verbal and written instructions that they will learn to ‘look for good’, to ‘look for calm’, to ‘use both options’, and to ‘never give up’ using the positive search strategies. In each of the 9 blocks, children search arrays for ‘good’ (e.g., happy children; cute animals) or ‘calm’ (e.g., a vase; a book) targets or both types of targets among threat distractors in 3x3 and 4x4 arrays of varying size and spacing. They receive verbal and written instructions before each block about which search strategy to use (e.g., ‘look for good’) expressed as melodious jingles that children repeat out loud and are recorded. Children click on the pictures until they select the positive/calm target and then the next trial begins. They are prompted after each block to say out-loud the search strategies they are learning. Children play short intermission games between blocks that emphasise the positive search strategies to increase engagement. They provide treatment satisfaction ratings and hear the catch-phrase jingles before the program closes. Output files containing trial identifiers, reaction-times, number of mouse-clicks on each trial and verbalisations of the search strategies are automatically emailed after each session, this provides monitoring of adherence to the intervention. The treatment is programmed so that it requires the child to complete the session before submitting.
Intervention code [1] 313370 0
Treatment: Other
Comparator / control treatment
Comparative study.
Computer-delivered CBT
Families randomised to CBT will be telephoned within a week of allocation to schedule initial set-up procedures. They will be notified that they will be completing the BRAVE-ONLINE programs, developed by Spence and Donovan, which are efficacious online CBT programs for children with anxiety disorders. They will be posted a resource folder containing website and browser information, handouts and session outlines and directions to the BRAVE-ONLINE website for registration. They will be requested to complete all the sessions and homework activities as instructed. Children complete 10 child sessions (one per week) and parents will complete 6 sessions over 10 weeks. Sessions are of 20-60 min in duration, the CBT content is contained within the programs, and the sessions include interactive games, quizzes and animations. Children and parents type responses into the program, which are monitored by a BRAVE therapist who provides weekly emails tailored to family responses. There are two 30-min phone calls with the BRAVE therapist to introduce the program prior to session 1 and assist with exposure hierarchy development prior to session 5. Child sessions focus on psychoeducation, relaxation training, identification of physiological cues of anxiety, cognitive strategies, graded exposure, problem solving, and self-reinforcement. Parent sessions cover the topics and also include parenting strategies to manage an anxious child. Children will complete refresher sessions 1- and 3-months after treatment, in line with the treatment protocol used in prior studies. These sessions take 30 60 mins children are alerted via email to complete the sessions, when completed, therapists are notified via the system and will check in with children.
Monitoring adherence to the intervention is enabled through the online system of the program. When a child or parent completes a session the therapist is emailed an alert and can download the progress. The treatment is programmed so that it requires a child to complete the session before submitting.

The primary aim of this project is to determine the clinical efficacy, cost-effectiveness and patient acceptability of PST for childhood anxiety disorders using a nationwide randomized controlled non-inferiority design with 380 anxious children between 7 and 12 years of age. Computer-delivered PST (N = 190) will be compared with computer-delivered CBT (N = 190) with an economic analysis alongside.
Control group

Primary outcome [1] 318704 0
Clinically rated diagnostic anxiety severity

Outcome is assessed using the Anxiety Disorders Interview Schedule Parent and Child versions - Clinician Severity Rating
Timepoint [1] 318704 0
Post Intervention commencement (3 weeks)
6 Months Post Intervention (Primary Timepoint)
12 Months Post-Intervention
Secondary outcome [1] 365775 0
Change in Global functioning assessed with the clinician rated Children's Global Assessment Scale
Timepoint [1] 365775 0
Post Intervention commencement (3 weeks)
6 Months Post Intervention
12 Months Post-Intervention
Secondary outcome [2] 365776 0
Illness severity will be assessed with the Clinician Global Impression Scale
Timepoint [2] 365776 0
Post Intervention commencement (3 weeks)
6 Months Post Intervention
12 Months Post-Intervention
Secondary outcome [3] 365777 0
Anxiety Symptoms will be assessed with the child and parent versions of the Spence Children's Anxiety Scale child and parent versions and the Children Anxiety Life Interference Scale child and parent version
Timepoint [3] 365777 0
Post Intervention commencement (3 weeks)
6 Months Post Intervention
12 Months Post-Intervention
Secondary outcome [4] 365838 0
Change in attention control will be assessed using the Attention Control Scale: Child and parent Version
Timepoint [4] 365838 0
Post Intervention commencement (3 weeks)
6 Months Post Intervention
12 Months Post-Intervention
Secondary outcome [5] 365839 0
Change in attention bias will be assessed with a visual search task developed by Prof Waters to assess the change in attention search for positive stimuli and inhibition of threat distractors using 3x3 and 4x4 arrays with emotional face stimuli
Timepoint [5] 365839 0
Post Intervention commencement (3 weeks)
6 Months Post Intervention
12 Months Post-Intervention
Secondary outcome [6] 365841 0
An indicator of depressive symptoms will be assessed using the Short Mood and Feelings Questionnaire for children
Timepoint [6] 365841 0
Post Intervention commencement (3 weeks)
6 Months Post Intervention
12 Months Post-Intervention
Secondary outcome [7] 365843 0
Health outcomes will be assessed with the Child Health Utilities Index 9 Dimension and the EQ-5D-5L for parents.
Timepoint [7] 365843 0
Post Intervention commencement (3 weeks)
6 Months Post Intervention
12 Months Post-Intervention
Secondary outcome [8] 365851 0
Treatment satisfaction was assessed using the Treatment satisfaction scale
Timepoint [8] 365851 0
6 Months post treatment
Secondary outcome [9] 365853 0
Treatment credibility will be assessed using the Credibility Scale for parents
Timepoint [9] 365853 0
Post PST Treatment (3 weeks)

Key inclusion criteria
Inclusion: (a) child is 7 to 12 years of age; (b) meets criteria for a DSM-5 anxiety disorder, (c) willingness to cease concurrent psychotherapy, (d) willingness to stabilise medication (if applicable) at the same dose for 12 weeks prior to diagnostic assessment.
There is no specific inclusion criteria for parents
Minimum age
7 Years
Maximum age
12 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Exclusion: child with a (a) non-anxiety primary diagnosis, (b) pervasive developmental disorder or intellectual disability, (c) impairments that prevent computer use, (d) prior CBT or PST treatment as reported by parents. A depressive or externalizing disorder secondary to an anxiety disorder will NOT be an exclusion.
There is no specific exclusion criteria for parents

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Eligible families will be randomised to PST or CBT using a randomisation schedule
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Randomisation schedule is generated and managed by the Griffith Clinical Trials Randomisation Service using block sizes of 8 and 10 and randomisation at a 1:1 ratio. Randomisation will be stratified by gender
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features

The design is a repeated measures evaluation of outcomes across treatments with multi-informant assessments at (a) baseline, (b) the post-PST end-point, (c) the primary 6-month end-point, and (d) the 12-month long-term follow-up.
Not Applicable
Type of endpoint(s)
Statistical methods / analysis

Statistical methods. Non-inferiority margin: By the primary 6-month end-point, it is expected that PST will be non-inferior to CBT on the primary outcome measure, the 0-8 clinician severity rating from the ADIS (CSR). As recommended, we have defined the non-inferiority margin based on our extensive clinical experience treating children’s anxiety disorders using computer CBT and PST. To ensure that the mean CSR difference observed between PST and CBT at 6-months is clinically unimportant, we defined the non-inferiority margin at 0.33 standard deviations (SDs). Assuming the standard deviation (SD) = 1.78 (from a prior trial of BRAVE-ONLINE compared to waitlist control) this equates to 0.59 units on the CSR. Power and sample size: To power the study for the specified non-inferiority margin (0.33 SDs), and assuming (one-sided) alpha = 0.025, and power = 90%, a total sample size of 380 participants (190 per treatment) will be required to complete the study. In practice, this means that if the upper bound of the 95% confidence interval for the mean CSR difference between PST and CBT does not extend beyond 0.59 units at the 6-month end-point, we will conclude there is evidence to reject the null hypothesis that PST is inferior to CBT. In terms of the hypothesis that PST will be superior to CBT on the primary CSR outcome at the 3-week PST end-point, we have observed large effects (n2 = .13) for CSR change from pre- to post-PST relative to waitlist control. As CSR change after 3-weeks of computer CBT has not been examined in prior trials, with a sample size of 380, (two-tailed) alpha = 0.05, and a medium estimated effect (f = .5) of 3 weeks of CBT, we will have >90% power to test the hypothesis that PST will produce greater CSR reduction than CBT at the 3-week end-point. To account for exclusions (20% based on our prior research), we will recruit 475 anxious children.
Primary and secondary continuous outcome variables (CSR, CGAS, CGI, SCAS, CALIS, ACS, SMFQ-C, CHU-9D, EQ-5D-5L ) will be analysed using a linear mixed effects model because of its superior qualities regarding the estimation of missing data as well as in reducing the risk of committing type I errors.

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 301667 0
Government body
Name [1] 301667 0
National Health and Medical Research Council
Address [1] 301667 0
PO Box 1421
Canberra, ACT, 2601
Country [1] 301667 0
Primary sponsor type
Griffith University
176 Messines Ridge Rd,
Mt Gravatt, QLD, 4122
Secondary sponsor category [1] 301382 0
Name [1] 301382 0
Address [1] 301382 0
Country [1] 301382 0

Ethics approval
Ethics application status
Submitted, not yet approved
Ethics committee name [1] 302387 0
Griffith University Human Research Ethics Committee
Ethics committee address [1] 302387 0
Office for Research
Griffith University
Level 0, Bray Centre
Qld 4111
Ethics committee country [1] 302387 0
Date submitted for ethics approval [1] 302387 0
Approval date [1] 302387 0
Ethics approval number [1] 302387 0

Brief summary
This is a nationwide study funded by the National Health and Medical Research Council that will determine the clinical efficacy, cost -effectiveness and patient acceptability of a new treatment for children who have anxiety disorders. For many children and their parents, anxiety can be highly disruptive and prevent children from doing things that other children their age can do.
Participants will be 380 anxious children aged 7 - 12 years.
This project will examine two computer-delivered treatment conditions and determine if they are as effective as each other in alleviating children’s anxiety disorders.
Children will be randomly assigned into one of two treatment conditions that are delivered via computer at home. One treatment condition is called positive search training (PST), this will take 30 minutes to complete, 4 times a week over 3 weeks on a computer, laptop or tablet. Children view a wide variety of pictures and learn to focus their attention on the positive and calm pictures among them. PST also includes verbalisations, catch phrases and interactive games. The second treatment program is called cognitive behavioural training (CBT). Children complete 10 sessions (one per week) over 10 weeks and parents complete 6 sessions over 10 weeks, on a computer, laptop or tablet. The sessions are 20 - 60 minutes in duration, and include a variety of interactive games, quizzes and animations. Both treatment conditions are accompanied with instructions and phone calls to assist with setting up the treatment at home and children's progress will be monitored by therapists and project staff throughout the duration of treatment.
The following hypotheses will be examined:
(a) Primary clinical outcome: PST will produce significantly greater reductions on the primary outcome measure of clinician rated diagnostic anxiety severity by the post-PST end-point compared to computer-delivered CBT. By the primary 6-month end-point, PST will be non-inferior to CBT. Between the post-PST and 6-month end-points, diagnostic severity will remain low in children who received PST and decline in children who received CBT, such that any differences between PST and CBT will be clinically unimportant at the 6-month end-point and the 12-month follow-up.
Also examined will be cost effectiveness and patient acceptability. PST will be associated with lower treatment costs and greater child and parent acceptability
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 90058 0
Prof Allison Waters
Address 90058 0
Griffith University
176 Messines Ridge Rd
Mt Gravatt, Qld, 4122
Country 90058 0
Phone 90058 0
+61 07 37353434
Fax 90058 0
Email 90058 0
Contact person for public queries
Name 90059 0
Prof Allison Waters
Address 90059 0
Griffith University
176 Messines Ridge Rd
Mt Gravatt, Qld, 4122
Country 90059 0
Phone 90059 0
+61 07 37353434
Fax 90059 0
Email 90059 0
Contact person for scientific queries
Name 90060 0
Prof Allison Waters
Address 90060 0
Griffith University
176 Messines Ridge Rd
Mt Gravatt, Qld, 4122
Country 90060 0
Phone 90060 0
+61 07 37353434
Fax 90060 0
Email 90060 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
What supporting documents are/will be available?
No other documents available
Summary results
No Results