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Trial registered on ANZCTR


Registration number
ACTRN12617001307392
Ethics application status
Approved
Date submitted
6/09/2017
Date registered
12/09/2017
Date last updated
12/09/2017
Type of registration
Retrospectively registered

Titles & IDs
Public title
Trialing short message service reminders to parents for increasing adolescent Human papillomavirus (HPV) vaccination rates in a council delivered secondary school vaccine program
Scientific title
Trialing short message service reminders to parents for increasing adolescent Human papillomavirus (HPV) vaccination rates in a council delivered secondary school vaccine program
Secondary ID [1] 292823 0
None
Universal Trial Number (UTN)
U1111-1201-7060
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Genital warts 304649 0
Cervical cancer 304650 0
Human papillomavirus (HPV) 304688 0
Condition category
Condition code
Infection 303970 303970 0 0
Sexually transmitted infections
Public Health 303999 303999 0 0
Health promotion/education

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Context: In Victoria, the HPV vaccine is delivered with the Secondary School Vaccine Program. In this program, local government (i.e., councils) visit each participating school three times across the year to offer each dose of the HPV vaccine. Council can also contact parents for the purpose of delivering the program. However, councils do not send reminders to parents about an upcoming school session. We assessed whether sending a Short-Message-Service (SMS) reminder would increase HPV vaccination rates within the program.

Intervention: Participating councils sent a reminder to parents (of students who had consent to receive the HPV vaccine within the Victorian Secondary School Vaccine Program) two working days before the third school visit (unless the school visit fell on a Monday or Tuesday, in which case the reminder was sent one working day before the visit).

There were two intervention conditions: Motivational SMS (arm A) vs. Self-regulatory SMS (arm B), and one control condition: No SMS (arm C). The only difference between the intervention conditions was the message content:
Arm A: Reminder from [council name]: [name of child] has a vaccine appointment at school this [day of week]. Vaccine preventable diseases are still a problem in the community and children most at risk are those that have not been immunised. Please contact [council phone number] if your child cannot attend.
Arm B: Reminder from [council name]: [name of child] has a vaccine appointment at school this [day of week]. Make a plan now for how [name of child] will get to school on-time on immunisation day. Please contact [council phone number] if your child cannot attend. Thank you.
The SMS reminders were personalised by including the childs name in the message (previous research shows this can increase the effect of communication).
Intervention code [1] 299070 0
Prevention
Intervention code [2] 299091 0
Behaviour
Comparator / control treatment
The control group (arm C) did not receive an SMS reminder. Their experience was the same as it would have been if they had not been involved in this research.
Control group
Active

Outcomes
Primary outcome [1] 303305 0
Proportion of participants who received a dose of the HPV vaccine on the day of the third school visit. Councils keep record of this data as part of their routine delivery of the school vaccine program.
Timepoint [1] 303305 0
On the day of the third school visit (schools had their third school visit anytime from September to November (2016)
Secondary outcome [1] 338594 0
Proportion of participants who received a dose of the HPV vaccine from, and including, the day of the third school visit till the end of the year. Council collect this information as part of their routine delivery of the school vaccine program. This extended follow-up period was also assessed because some students may attend a council catch-up session after the third school visit. We wanted to account for this, to see if the interventions had a lasting effect.
Timepoint [1] 338594 0
On the day of the third school visit up until the end of the year (2016). Note: schools had their third school visit anytime from September to November (2016).

Eligibility
Key inclusion criteria
From the 79 councils in Victoria, the research team identified 12 with a sufficient number of schools in their catchment to participate in the study. The Victorian Department of Health and Human Services then invited these councils to participate in the study on behalf of the research team. Seven councils, representing 108 schools, agreed to participate in the research. From these schools, the research team identified eligible schools to participate in the study according to the following criteria: 1 ) equal to or greater than 20 students enrolled in year 7 to ensure the anonymity of the participating students, 2) the school had provided a class list with parental/guardian mobile phone numbers to enable intervention delivery, 3) the school had not already completed the third and final school visit (in 2016 the HPV vaccine was delivered over three school visits in Victoria), 4) the school did not have a grade 6 cohort – to reduce the risk of contamination, based on the assumption that parents are more likely to communicate with each other when they share a longer history at the school.. This resulted in 31 (28.70%) of the 108 schools being included in the study.

Of the 5,479 year 7 students enrolled in these schools 4,386 (80.05%) had consent to receive the HPV vaccine within the secondary school vaccine program and were therefore included in the study.
Minimum age
10 Years
Maximum age
14 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Students who do not have consent to receive the HPV vaccine within the secondary school vaccine program.

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 is not concealed
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Excel's RANDBETWEEN function was used to randomly allocate students into the trial arms.
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)
Statistical methods / analysis
Previous research using reminders to increase vaccination rates in adolescent populations have shown to have a small (i.e., ~ 3% point increase) but statistically significant effect (i.e., p<.05). Using these estimates, along with an expected baseline line level of 90% (i.e., 90% of participants in the control condition will receive a dose of the vaccine at the third school visit) and standard levels of power (0.8) and standard two-sided significance testing, the current trial required at least n = 1,422 participants in each group. With three study conditions this bring the total required sample size to N = 4,266 participants.

Prior to analysing the results of the trial, a series of randomisation checks were conducted. The aim of these was to determine whether the randomisation process was effective at creating three equivalent groups. This was done using chi-square (categorical factors) and ANOVA (continuous factors). None of the randomisation checks showed a significant difference between the study conditions,

Data analysis: Chi-square analysis of independence (Bonferroni method) was conducted to assess whether the intervention conditions increased the likelihood of a student receiving the HPV vaccine, and if so, which message was most effective.

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] 297453 0
Government body
Name [1] 297453 0
Public Sector Innovation, Department of Premier and Cabinet, Victorian State Government
Address [1] 297453 0
Public Sector Innovation
Department of Premier and Cabinet
Level 29, 35 Collins Street,
Melbourne VIC 3000
Australia
Country [1] 297453 0
Australia
Primary sponsor type
University
Name
Monash University
Address
BehaviourWorks Australia
Monash Sustainable Development Institute
Monash University
8 Scenic Boulevard, Clayton Campus
Clayton VIC 3800
Australia
Country
Australia
Secondary sponsor category [1] 296448 0
Government body
Name [1] 296448 0
Department of Health and Human Services
Address [1] 296448 0
Immunisation Section,
Health Protection Branch
Regulation, Health Protection & Emergency Management Division
Department of Health & Human Services
50 Lonsdale Street
Melbourne, VIC, 3000
Country [1] 296448 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 298559 0
Monash University Human Research Ethics Committee
Ethics committee address [1] 298559 0
Monash University
Room 111, Chancellery Building E
24 Sports Walk
Clayton Campus
Wellington Rd
Clayton VIC 3800, Australia
Ethics committee country [1] 298559 0
Australia
Date submitted for ethics approval [1] 298559 0
27/04/2016
Approval date [1] 298559 0
06/05/2016
Ethics approval number [1] 298559 0
CF16/1385 - 2016000753

Summary
Brief summary
Like many countries around the world, Australia is committed to vaccination as evidenced by programs and regulations at all levels of government. However, these initiatives have generally not drawn upon behavioural science to influence vaccination rates. The Gardasil quadrivalent 3-dose human papillomavirus (HPV) vaccine, which protects against genital warts and most cervical cancers, is provided in Victoria through a secondary school program, administered by local government (i.e., councils). This study aimed to test the hypothesis that sending an SMS reminder to parents/guardians who had consented to their child receiving the HPV vaccine would lead to greater HPV vaccine uptake within the council delivered school vaccination program. The secondary aim was to assess the effect of self-regulatory versus motivational message content in the SMS.
Trial website
Trial related presentations / publications
Public notes
Attachments [1] 2020 2020 0 0

Contacts
Principal investigator
Name 77466 0
A/Prof Peter Bragge
Address 77466 0
BehaviourWorks Australia
Monash Sustainable Development Institute
Monash University
8 Scenic Boulevard, Clayton Campus
Clayton VIC 3800
Australia
Country 77466 0
Australia
Phone 77466 0
+61 3 9905 9664
Fax 77466 0
Email 77466 0
peter.bragge@monash.edu
Contact person for public queries
Name 77467 0
Mr Fraser Tull
Address 77467 0
BehaviourWorks Australia
Monash Sustainable Development Institute
Monash University
8 Scenic Boulevard, Clayton Campus
Clayton VIC 3800
Australia
Country 77467 0
Australia
Phone 77467 0
+61 (0)407 965 196
Fax 77467 0
Email 77467 0
fraser.tull@monash.edu
Contact person for scientific queries
Name 77468 0
Mr Fraser Tull
Address 77468 0
BehaviourWorks Australia
Monash Sustainable Development Institute
Monash University
8 Scenic Boulevard, Clayton Campus
Clayton VIC 3800
Australia
Country 77468 0
Australia
Phone 77468 0
+61 (0)407 965 196
Fax 77468 0
Email 77468 0
fraser.tull@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