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Trial registered on ANZCTR


Registration number
ACTRN12617001315303
Ethics application status
Approved
Date submitted
31/08/2017
Date registered
13/09/2017
Date last updated
13/09/2017
Type of registration
Retrospectively registered

Titles & IDs
Public title
Using communication strategies to increase influenza vaccination coverage in Australian indigenous infants.
Scientific title
Using behavioural communication to optimise flu vaccination in infant indigenous populations in Victoria
Secondary ID [1] 292761 0
Nil
Universal Trial Number (UTN)
U1111-1201-3903
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Influenza 304551 0
Condition category
Condition code
Infection 303875 303875 0 0
Other infectious diseases
Public Health 304010 304010 0 0
Health promotion/education

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
A. Mailed letter addressed to parents / guardians of indigenous children under 5 years of age residing in Victoria, Australia. The letter states that indigenous children under 5 are eligible to receive a free influenza vaccine, outlines why vaccination is important and encourages the parent / guardian to arrange this with a local healthcare provider. The letter is a standard letter with text only.

B. Mailed pamphlet addressed to parents / guardians of indigenous children under 5 years of age residing in Victoria, Australia. The pamphlet states that indigenous children under 5 are eligible to receive a free influenza vaccine, outlines why vaccination is important and encourages the parent / guardian to arrange this with a local healthcare provider. The pamphlet contains similar information to the letter in group A, but is presented using text + illustrations rather than text only.

For intervention groups, one letter (group A) or pamphlet (group B) was delivered by surface mail early in the influenza season in Victoria (May 17 2017) . Eligible parents / guardians were identified through the Australian Immunisation Registry (AIR) by the Victorian Department of Health and Human Services (DHHS).
Intervention code [1] 298999 0
Prevention
Intervention code [2] 299000 0
Behaviour
Comparator / control treatment
C. Control group receive no mailed communication
Control group
Active

Outcomes
Primary outcome [1] 303234 0
% of eligible infants receiving the influenza vaccine, assessed by pre and post trial reference to the Australian Immunisation Register (AIR), which records details of vaccinations given to children under 7 years of age who live in Australia. The AIR database will be queried against trial eligibility criteria by staff at DHHS on behalf of the research team, who are blinded to all identifying information.
Timepoint [1] 303234 0
August 31 2017
Secondary outcome [1] 338309 0
Inward correspondence (mail, phone calls) pertaining to the trial received by DHHS as the contact identified on the materials during the intervention period (May 17 - August 31 2017) will be grouped into the following categories:
1. Mail recipient is not eligible as they do not identify as Aboriginal / Torres Strait Islander;
2. Mail recipient does not reside at address;
3. Other e.g. complaints or queries regarding the trial
Timepoint [1] 338309 0
August 31 2017

Eligibility
Key inclusion criteria
Parents / guardians of indigenous (Aboriginal or Torres Strait Islander) infants / children aged between 6 months and 5 years of age and residing in Victoria, Australia.

This trial recruited participants (parents of indigenous children aged 6 months – 5 years) through the Australian Immunisation Register (AIR). This registry records all immunisations given at general practices, community clinics and other providers since Sep 30 2016 on a national database which can be accessed by state and territory health departments. AIR is an ‘opt-out’ registry – the uses of the data are made public, and those who do not want their information shared with third parties can opt out. (see: https://www.humanservices.gov.au/individuals/services/medicare/australian-immunisation-register#group-128 ).

The participants were recruited behalf of the researchers through the Victorian Department of Health and Human Services (DHHS), and sent one of two forms of communication encouraging them to make an appointment for a free influenza vaccine for their child.

It was not possible for DHHS to identify the birthdates of the parents on the AIR database. Therefore, parents of eligible infants for this trial aged under 18 years of age were not excluded from this study.
Minimum age
16 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Parents / guardians of NON-indigenous infants / children

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)
Eligible participants were centrally randomised at DHHS by computer into one of the three study conditions.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using Microsoft Excel's =RANDBETWEEN feature to allocate individuals a group number (1, 2 or 3). Once allocated, the distribution of postcode and gender across groups was checked to ensure samples were not biased.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

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
The population for the study was 6,619 with an existing compliance rate of approximately 2%. The population was split into three groups with around 2200 in each. Assuming a 95% level of confidence and an 80% power level, we should be able to detect a minimum difference of 1.36 percentage points.

Basic descriptive statistics will be used to describe participant groups (gender, postcode). Differences in proportions between the three groups will be analysed using Chi-Square.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC

Funding & Sponsors
Funding source category [1] 297395 0
Government body
Name [1] 297395 0
Public Sector Innovation Fund
Address [1] 297395 0
Victorian Department of Premier and Cabinet
Level 29, 35 Collins St, Melbourne Victoria 3000
Country [1] 297395 0
Australia
Primary sponsor type
University
Name
Monash University
Address
Wellington Road
Clayton
Victoria 3800
Australia
Country
Australia
Secondary sponsor category [1] 296418 0
None
Name [1] 296418 0
Address [1] 296418 0
Country [1] 296418 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 298494 0
Monash University Human Research Ethics Committee
Ethics committee address [1] 298494 0
Human Research Ethics, Research Office,
Chancellery Building E
MONASH UNIVERSITY VIC 3800
Ethics committee country [1] 298494 0
Australia
Date submitted for ethics approval [1] 298494 0
17/03/2017
Approval date [1] 298494 0
03/05/2017
Ethics approval number [1] 298494 0
8632

Summary
Brief summary
Infants are susceptible to a large number of illnesses and diseases. As a result, Australia has a strict protocol for immunising infants and young children at various ages. One of the few immunisations which is not mandatory for infants is the influenza vaccine. Influenza is often perceived as an 'adult' illness, however, as with many illnesses infants are even more susceptible than adults and it is recommended that both children and adults are immunised
annually. The Aboriginal and Torres Strait Islander community in Victoria are considered a high-risk group for illnesses such as influenza and as a a result, the vaccine is offered for free for Indigenous infants and children and has been so since 2010. Unfortunately, the rate of immunisation is only around 2% which means many children are at risk of contracting this preventable disease. The aim of this project is to develop and test different messages for parents of Indigenous children to educate and encourage them to seek out the free flu vaccine for their infant/young child.
Trial website
not applicable
Trial related presentations / publications
Borg K, Bragge P, Beasley M, Sutton K, Halliday J, Knott, C. Optimising flu vaccination among Aboriginal children in Victoria. Annual NHMRC Symposium on Research Translation. Oral presentation, November 14 – 15 2017, Queensland, Australia.
Public notes

Contacts
Principal investigator
Name 77270 0
A/Prof Peter Bragge
Address 77270 0
BehaviourWorks Australia, Monash Sustainable Development Institute, Monash University
8 Scenic Boulevard, Clayton Campus
Clayton VIC 3800
Country 77270 0
Australia
Phone 77270 0
+61 403 197 275
Fax 77270 0
Email 77270 0
peter.bragge@monash.edu
Contact person for public queries
Name 77271 0
A/Prof Peter Bragge
Address 77271 0
BehaviourWorks Australia, Monash Sustainable Development Institute, Monash University
8 Scenic Boulevard, Clayton Campus
Clayton VIC 3800
Country 77271 0
Australia
Phone 77271 0
+61 403 197 275
Fax 77271 0
Email 77271 0
peter.bragge@monash.edu
Contact person for scientific queries
Name 77272 0
A/Prof Peter Bragge
Address 77272 0
BehaviourWorks Australia, Monash Sustainable Development Institute, Monash University
8 Scenic Boulevard, Clayton Campus
Clayton VIC 3800
Country 77272 0
Australia
Phone 77272 0
+61 403 197 275
Fax 77272 0
Email 77272 0
peter.bragge@monash.edu

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary