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Trial registered on ANZCTR


Registration number
ACTRN12622001554752
Ethics application status
Approved
Date submitted
30/11/2022
Date registered
16/12/2022
Date last updated
16/12/2022
Date data sharing statement initially provided
16/12/2022
Type of registration
Retrospectively registered

Titles & IDs
Public title
Impact of persuasive messaging on parents' intention to vaccinate their child for COVID-19
Scientific title
Impact of persuasive messaging on parents' intention to vaccinate their child for COVID-19
Secondary ID [1] 308420 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Vaccination intention 328222 0
COVID-19 328359 0
Condition category
Condition code
Public Health 325271 325271 0 0
Health promotion/education
Mental Health 325539 325539 0 0
Studies of normal psychology, cognitive function and behaviour

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The intervention is a short piece of written material designed to encourage parents to vaccinate their child aged 5-11 years for COVID-19. The messages were designed specifically for this study. The intervention is delivered as part of an online experiment over the internet. After answering some questions about themselves, participants are asked to read the written information on their computer or phone screen. They are given the intervention once. The anticipated time needed to read the text is approximately 30 seconds. Participants must spend a minimum of 30 seconds on this screen. This requirements to stay on the intervention screen is used for the purpose of encouraging adherence to the intervention. There is no further assessment of intervention adherence.

Arm 1 is a message focusing on the personal health impacts of vaccinating. Arm 2 is a message focusing on family and community health impacts of vaccinating. Arm 3 is a message focusing on non-health benefits of vaccinating (freedom messaging). Arm 4 is a message focusing on personal choice and control (personal choice-based messaging).
Intervention code [1] 324971 0
Behaviour
Comparator / control treatment
Arm 5 is a control message, providing information about eligibility requirements for the paediatric COVID-19 vaccine summarised from an official Australian government notice. The control message is also designed to be read in 30 seconds.
Control group
Active

Outcomes
Primary outcome [1] 333252 0
Intention to vaccinate child for COVID-19. This outcome will be assessed using a single survey item (a 5-point Likert scale from ‘Definitely not’ to ‘Definitely yes’)
Timepoint [1] 333252 0
Immediately after receiving the intervention
Secondary outcome [1] 416348 0
Belief about safety of COVID-19 vaccine for children. This outcome will be assessed using a single survey item (5-point Likert scale from strongly disagree to strongly agree)
Timepoint [1] 416348 0
Immediately after receiving the intervention
Secondary outcome [2] 416349 0
Belief about effectiveness of COVID-19 vaccine for children. This outcome will be assessed using a single survey item (5-point Likert scale from strongly disagree to strongly agree)
Timepoint [2] 416349 0
Immediately after receiving the intervention
Secondary outcome [3] 416359 0
Belief about necessity of COVID-19 vaccine to protect child's health. This outcome will be assessed using a single survey item (5-point Likert scale from strongly disagree to strongly agree)
Timepoint [3] 416359 0
Immediately after receiving the intervention
Secondary outcome [4] 416360 0
Belief about necessity of COVID-19 vaccine for children to protect others' health. This outcome will be assessed using a single survey item (5-point Likert scale from strongly disagree to strongly agree)
Timepoint [4] 416360 0
Immediately after receiving the intervention
Secondary outcome [5] 416361 0
Belief about the risk of child contracting COVID-19 without a COVID-19 vaccine.. This outcome will be assessed using a single survey item (5-point Likert scale from strongly disagree to strongly agree)
Timepoint [5] 416361 0
Immediately after receiving the intervention

Eligibility
Key inclusion criteria
• 18 years or older
• living in Australia
• parent of a child aged between 5-11 years at the time of the study
• competent in reading and writing in English
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Parents of children who are medically exempt from COVID-19 vaccination
Parents of children already vaccinated against COVID-19

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)
computerised sequence generation
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s


Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
A sample size of 430 parents, with more than 85 parents per intervention group, was considered adequate to estimate an effect size of Cohen’s d = 0.2 (difference in score between two groups) with a specified power of 80% at a = 0.01 level of significance. To account for a drop-out/poor quality response rate of approximately 10%, the sample size was increased to 480.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
14/01/2022
Date of last participant enrolment
Anticipated
Actual
31/01/2022
Date of last data collection
Anticipated
Actual
31/01/2022
Sample size
Target
480
Accrual to date
Final
550
Recruitment in Australia
Recruitment state(s)
ACT,NSW,NT,QLD,SA,TAS,WA,VIC

Funding & Sponsors
Funding source category [1] 312671 0
Government body
Name [1] 312671 0
NSW Health
Country [1] 312671 0
Australia
Primary sponsor type
Other Collaborative groups
Name
Kids Research
Address
1787 Hawkesbury Rd, Westmead NSW 2145
Country
Australia
Secondary sponsor category [1] 314281 0
Other
Name [1] 314281 0
Murdoch Children's Research Institute
Address [1] 314281 0
The Royal Children's Hospital
50 Flemington RD
Parkville, VIC 3052
Country [1] 314281 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 311974 0
Sydney Children's Hospitals Network Human Research Ethics Committee
Ethics committee address [1] 311974 0
Ethics committee country [1] 311974 0
Australia
Date submitted for ethics approval [1] 311974 0
02/11/2021
Approval date [1] 311974 0
14/12/2021
Ethics approval number [1] 311974 0
2021/ETH00181 (Amendment ID 74493)

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

Contacts
Principal investigator
Name 123026 0
Dr Jessica Kaufman
Address 123026 0
Royal Children's Hospital, 50 Flemington Rd, Parkville VIC 3052
Country 123026 0
Australia
Phone 123026 0
+61 3 9345 4890
Fax 123026 0
Email 123026 0
jess.kaufman@mcri.edu.au
Contact person for public queries
Name 123027 0
Jessica Kaufman
Address 123027 0
Royal Children's Hospital, 50 Flemington Rd, Parkville VIC 3052
Country 123027 0
Australia
Phone 123027 0
+61 3 9345 4890
Fax 123027 0
Email 123027 0
jess.kaufman@mcri.edu.au
Contact person for scientific queries
Name 123028 0
Jessica Kaufman
Address 123028 0
Royal Children's Hospital, 50 Flemington Rd, Parkville VIC 3052
Country 123028 0
Australia
Phone 123028 0
+61 3 9345 4890
Fax 123028 0
Email 123028 0
jess.kaufman@mcri.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
Individual de-identified participant data collected during the trial
When will data be available (start and end dates)?
Immediately following publication, no end date
Available to whom?
To researchers who provide a methodologically sound proposal
Available for what types of analyses?
for meta-analyses
How or where can data be obtained?
Access subject to approval by the Principal Investigator (jess.kaufman@mcri.edu.au)


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.