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Trial registered on ANZCTR


Registration number
ACTRN12624001176550
Ethics application status
Approved
Date submitted
12/09/2024
Date registered
25/09/2024
Date last updated
13/10/2024
Date data sharing statement initially provided
25/09/2024
Type of registration
Prospectively registered

Titles & IDs
Public title
Evaluation of a Japanese encephalitis vaccine decision aid in adults travelling overseas to at-risk areas
Scientific title
Randomised Controlled Trial of a web-based Japanese encephalitis vaccine decision aid on decisional conflict in adults travelling overseas to at-risk areas
Secondary ID [1] 312657 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Japanese encephalitis 334598 0
Vaccine decision-making 335123 0
Condition category
Condition code
Public Health 331207 331207 0 0
Health promotion/education
Infection 331208 331208 0 0
Other infectious diseases

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Intervention being studied:
The intervention is an online Japanese Encephalitis Vaccine Decision Aid (JEVADA), developed according to the International Patient Decision Aids Standards (IPDAS) and created using a comprehensive co-design and user-testing process (described below). JEVADA takes users through a self-guided, step-by-step process, divided into three key sections, along with additional resources such as a Frequently Asked Questions (FAQ) page. It provides detailed information on Japanese encephalitis, including its geographic distribution, transmission methods, clinical features, severity, and associated risks. Preventive measures, including mosquito bite avoidance strategies and a comparison of the available vaccines in Australia, are also covered. JEVADA encourages participants to reflect on their personal circumstances, values, and beliefs to help guide their vaccination decision, while prompting them to consult with a healthcare provider to discuss their options. The tool includes visual aids and interactive elements to support decision-making, such as a side-by-side risk-benefit analysis and a values clarification exercise. JEVADA is designed as an educational resource, and emphasises the importance of consulting a trusted healthcare provider before making a vaccination decision. A downloadable short-form PDF version of the decision aid, offering a condensed version of the content (without interactive features), is also available.

Mode of delivery:
Online.

Procedures:
Participants assigned to the intervention arm will receive a link to JEVADA and will be asked to review the materials.

Timing:
The intervention will be delivered in a single session, during which participants will also complete pre- and post-intervention surveys. The estimated time to review JEVADA is approximately 15 minutes.

Location:
Participants can access JEVADA from any location of their choice.

Strategies to monitor adherence:
Participants will complete self-reported questions regarding the extent of their review, including time spent and whether they reviewed the entire content or only specific sections. Additionally, we will track the time elapsed between the completion of pre- and post-intervention surveys. Website analytics will also be used to capture the timing, frequency, and duration of visits to the decision aid website during the intervention period.

JEVADA co-design and user testing process:
The co-design process involved Australian consumers and healthcare providers. Three rounds of Zoom workshops, each lasting two hours, were held over five months. The first two rounds focused on decisional needs and design requirements, with separate sessions for consumers and providers. Participants reviewed example components and gave feedback. In the final round, both groups were brought together to evaluate a prototype of the decision aid, commenting on its language, layout, and presentation. Feedback was collected verbally, via chat, and through an online whiteboard. Those who missed the final session provided feedback by email.
User testing involved semi-structured Zoom interviews with a new group of consumers and providers. A "think aloud" method was used to explore their interactions with the prototype. Additional feedback was collected through a follow-up survey. Content experts in vaccination, vector-borne diseases, encephalitis, and travel medicine also reviewed the decision aid and provided feedback via an online survey.
A steering group of experts in immunisation, travel medicine, vaccine communication, social science, and a consumer representative oversaw the process. They worked with a graphic designer to create iterative PDF prototypes informed by co-design and user testing, which were later adapted into a web-based format by a developer.
Intervention code [1] 329156 0
Prevention
Intervention code [2] 329548 0
Behaviour
Comparator / control treatment
Comparator being studied:
Participants randomised to the comparator arm will be provided a link to an online health information page on Japanese encephalitis (JE), hosted by Healthdirect Australia. Healthdirect Australia is a national virtual public health information service, which collaborates with federal, state, and territory governments to offer a wide range of evidence-based health resources. The JE webpage covers key information on the disease, including geographic distribution, modes of transmission, symptoms, severity, and preventive measures such as mosquito bite avoidance and vaccines available in Australia. The content is presented in a single, continuous page, organised into sub-sections for ease of navigation. The page also includes tools for symptom checking and locating local health services, alongside accessibility features such as text enlargement, page-masking, and text-to-speech options. Users can download the information as a PDF, and additional resources and support links are provided.

Mode of delivery:
Online.

Procedures:
Participants in the comparator arm will receive a link to the Healthdirect page and will be asked to review the content.

Timing:
The comparator will be accessed in a single session, during which participants will also complete pre- and post-intervention surveys. Reviewing the Healthdirect page is expected to take approximately 11 minutes.

Location:
Participants can access the Healthdirect JE webpage from any location of their choice.
Control group
Active

Outcomes
Primary outcome [1] 338956 0
Decisional Conflict
Timepoint [1] 338956 0
Decisional conflict will be measured at two timepoints: immediately before and immediately after participants engage with the intervention or control.
Secondary outcome [1] 438022 0
Intention to vaccinate
Timepoint [1] 438022 0
Intention to vaccinate will be measured at two timepoints: immediately before and immediately after participants engage with the intervention or control.
Secondary outcome [2] 438023 0
Knowledge of Japanese encephalitis (JE)
Timepoint [2] 438023 0
Knowledge will be measured at two timepoints: immediately before and immediately after participants engage with the intervention or control.
Secondary outcome [3] 438330 0
JE vaccine uptake
Timepoint [3] 438330 0
3-6 months post-intervention

Eligibility
Key inclusion criteria
Currently living in Australia
Able to read and understand English
Intention to travel to a country (outside of Australia) where JE is a risk within the next 6-months
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Given that the survey will be conducted in English and recruitment will be online, participation will be limited to individuals who are reasonably fluent in written English and have access to the Internet.

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)
We will use REDCap’s automated randomisation module for participant assignment. A statistician, independent of the central research team, will create and upload the randomisation tables. The randomisation tables will be concealed from the primary investigators and used by REDCap for real-time allocation.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by a statistician
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?


The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Data will be analysed using the statistical analysis software package STATA v18. Baseline characteristics of participants will be tabulated by randomisation groups. Continuous variables will be summarised using means (standard deviations), while categorical variables will be summarised by frequencies (percentages). Graphical visualisations will be conducted where appropriate.

Linear regression will be used to estimate the effect of intervention (vs control) on change in DCS scores (post- vs. pre-intervention) with pre-intervention DCS scores adjusted for in the model, i.e. an analysis of covariance (ANCOVA) structure. Statistical significance will be declared if a two-sided p-value is <0.05.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
21/10/2024
Actual
Date of last participant enrolment
Anticipated
25/11/2024
Actual
Date of last data collection
Anticipated
21/04/2025
Actual
Sample size
Target
500
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
ACT,NSW,NT,QLD,SA,TAS,WA,VIC

Funding & Sponsors
Funding source category [1] 317072 0
University
Name [1] 317072 0
Monash University Early Career Research Excellence Program
Country [1] 317072 0
Australia
Funding source category [2] 317130 0
Government body
Name [2] 317130 0
National Health and Medical Research Council Emerging Leadership Fellowship
Country [2] 317130 0
Australia
Primary sponsor type
University
Name
Monash University
Address
Country
Australia
Secondary sponsor category [1] 319394 0
None
Name [1] 319394 0
Address [1] 319394 0
Country [1] 319394 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 315821 0
Monash University Human Research Ethics Committee
Ethics committee address [1] 315821 0
Ethics committee country [1] 315821 0
Australia
Date submitted for ethics approval [1] 315821 0
04/10/2024
Approval date [1] 315821 0
08/10/2024
Ethics approval number [1] 315821 0
44547

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

Contacts
Principal investigator
Name 135910 0
Dr Sarah McGuinness
Address 135910 0
School of Public Health and Preventive Medicine, Monash University, 553 St Kilda Road Melbourne VIC 3004
Country 135910 0
Australia
Phone 135910 0
+61 3 9903 0118
Fax 135910 0
Email 135910 0
sarah.mcguinness@monash.edu
Contact person for public queries
Name 135911 0
Owen Eades
Address 135911 0
School of Public Health and Preventive Medicine, Monash University, 553 St Kilda Road Melbourne VIC 3004
Country 135911 0
Australia
Phone 135911 0
+61 403418173
Fax 135911 0
Email 135911 0
owen.eades@monash.edu
Contact person for scientific queries
Name 135912 0
Sarah McGuinness
Address 135912 0
School of Public Health and Preventive Medicine, Monash University, 553 St Kilda Road Melbourne VIC 3004
Country 135912 0
Australia
Phone 135912 0
+61 3 9903 0118
Fax 135912 0
Email 135912 0
sarah.mcguinness@monash.edu

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


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.