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Trial registered on ANZCTR


Registration number
ACTRN12623000753651
Ethics application status
Approved
Date submitted
15/05/2023
Date registered
11/07/2023
Date last updated
11/07/2023
Date data sharing statement initially provided
11/07/2023
Type of registration
Prospectively registered

Titles & IDs
Public title
Improving influenza vaccine uptake in pregnant women
Scientific title
Improving influenza vaccine uptake in Hong Kong pregnant women: a randomised controlled trial
Secondary ID [1] 307749 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
influenza 327326 0
Condition category
Condition code
Public Health 324457 324457 0 0
Health promotion/education
Infection 324467 324467 0 0
Other infectious diseases

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Subjects in the control group will receive the standard information about the VSS that is available from the CHP through text message in smart phones (https://www.chp.gov.hk/en/features/46107.html)
Subjects in intervention group 1 will receive an intervention package through text messages containing the following:
1. the same standard information about the VSS by CHP (https://www.chp.gov.hk/en/features/46107.html) as the control-subjects and
2. additional interventions which include: a concise information sheet designed by our research team specifically for this study including (i) highlight of the risks of influenza in pregnant women and infants and the benefits of influenza vaccination to them, (ii) a hyperlink to the forms required for the VSS, if necessary, with guidelines to complete, and (iii) a hyperlink of Department of Health (DH)’s website to search for VSS registered clinics that do not charge additional fees for influenza vaccination above the subsidy.
When vaccination is possible, they will receive text message reminders for vaccination (also contain the concise information sheet), with a further reminder one to two months later.
Subjects in intervention group 2 will receive the same standard information about the VSS by CHP (https://www.chp.gov.hk/en/features/46107.html) as the control-subjects and the same multiple interventions as the intervention group 1 through text message. In addition the subjects will be informed that should they prefer they can receive free influenza vaccine during future antenatal follow-up visit once the vaccine is available.
Participants will be asked whether they have read the information provided by the research team in questionnaire distributed at three to four weeks after the expected date of delivery.
Intervention code [1] 324221 0
Behaviour
Comparator / control treatment
Subjects in the control group will receive the standard information about the VSS that is available from the Centre for Health Protection (CHP) through text messages on smartphones.
Control group
Active

Outcomes
Primary outcome [1] 332266 0
Influenza vaccine uptake rate in pregnant women in the three study groups. This will be collected in Questionnaire 2 (a questionnaire designed specifically for this study) which will be delivered to the subjects at three to four weeks after the expected date of delivery.
Timepoint [1] 332266 0
Oct 2023 - May 2024
Secondary outcome [1] 412762 0
Knowledge of mothers in relation to influenza disease before and after receiving intervention information. This will be measured by study-specific questionnaire based on Health Belief Model (HBM).
Timepoint [1] 412762 0
before first time receiving intervention material and 4-6 months after second time receiving intervention material
Secondary outcome [2] 423058 0
Attitudes of mothers in relation to influenza disease before and after receiving intervention information. This will be measured by study-specific questionnaire based on Health Belief Model (HBM).
Timepoint [2] 423058 0
before first time receiving intervention material and 4-6 months after second time receiving intervention material
Secondary outcome [3] 423059 0
Knowledge of mothers in relation to influenza vaccine before and after receiving intervention information. This will be measured by study-specific questionnaire based on Health Belief Model (HBM).
Timepoint [3] 423059 0
before first time receiving intervention material and 4-6 months after second time receiving intervention material
Secondary outcome [4] 423060 0
Attitudes of mothers in relation to influenza vaccine before and after receiving intervention information. This will be measured by study-specific questionnaire based on Health Belief Model (HBM).
Timepoint [4] 423060 0
before first time receiving intervention material and 4-6 months after second time receiving intervention material

Eligibility
Key inclusion criteria
The inclusion criteria to subject selection includes: pregnant women in any trimester; at least 18 years old; Cantonese speaking and able to read Chinese; no serious obstetrical complications; no mental or psychosocial problem that might affect their interpretation of study questionnaires; not yet received influenza vaccine during this pregnancy; have plans to continue most antenatal follow-up at the study hospital; have plans to remain in Hong Kong after delivery for at least one month; have smart phones; and can provide signed informed consent.
Minimum age
18 Years
Maximum age
No limit
Sex
Females
Can healthy volunteers participate?
No
Key exclusion criteria
under 18 years old; received influenza vaccine already during this pregnancy;

Study design
Purpose of the study
Educational / counselling / training
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation concealment: Allocation is concealed. Centralised randomisation will only be performed after checking eligibility of subjects, obtaining informed consent and completing the baseline questionnaire.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
We will use statistical software R to randomly generate the treatment allocation in random block sizes with block size kept unknown to the research assistants carrying out recruitment and interviews.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

The people assessing the outcomes
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
DMP Tool will be used to prepare a formal data management plan. To ensure data quality, data will be double-entered and validated using EpiData. Intention-to-treat analysis will be used and any missing influenza vaccination status will be taken as no vaccination. Demographic and maternal health factors will be compared between intervention- and control-subjects. Wilcoxon rank-sum tests will be used for continuous variables and chi-square tests for categorical variables. Chi-square tests will be performed to examine the effectiveness of the intervention package in improving influenza vaccination uptake in pregnant women. Each HBM attitude statement will be scored from 1 to 4 (from strongly disagree to strongly agree). Cronbach’s alpha will be used to measure internal consistency of HBM constructs. Permutation tests will be used to examine any paired difference in attitude scores before and after intervention delivery. All statistical analyses will be performed using statistical software R and a two-tailed p-value < 0.05 will be taken as statistically significant.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
17/07/2023
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
522
Accrual to date
Final
Recruitment outside Australia
Country [1] 24946 0
Hong Kong
State/province [1] 24946 0

Funding & Sponsors
Funding source category [1] 312017 0
Government body
Name [1] 312017 0
Food and Health Bureau - Health and Medical Research Fund
Country [1] 312017 0
Hong Kong
Primary sponsor type
Individual
Name
Li Man Chim, Albert Martin
Address
Department of Paediatrics,
6/F, Lui Che Woo Clinical Sciences Building,
Prince of Wales Hospital,
30-32 Ngan Shing Street,
Shatin, N.T., Hong Kong,
China
Country
Hong Kong
Secondary sponsor category [1] 313518 0
None
Name [1] 313518 0
Address [1] 313518 0
Country [1] 313518 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 311437 0
Joint Chinese University of Hong Kong-New Territories East Cluster Clinical Research Ethics Committee
Ethics committee address [1] 311437 0
Joint CUHK-NTEC Clinical Research Ethics Committee
8/F, Lui Che Woo Clinical Sciences Building,
Prince of Wales Hospital
Shatin, Hong Kong
Ethics committee country [1] 311437 0
Hong Kong
Date submitted for ethics approval [1] 311437 0
15/12/2021
Approval date [1] 311437 0
04/03/2022
Ethics approval number [1] 311437 0
2021.715-T
Ethics committee name [2] 311448 0
Hong Kong East Cluster Research Ethics Committee (HKEC REC)
Ethics committee address [2] 311448 0
3 Lok Man Road, Chai Wan, Hong Kong
Ethics committee country [2] 311448 0
Hong Kong
Date submitted for ethics approval [2] 311448 0
12/04/2022
Approval date [2] 311448 0
07/06/2022
Ethics approval number [2] 311448 0
HKECREC-2022-026

Summary
Brief summary
This randomised controlled trial primarily aims to determine whether influenza vaccine uptake in pregnant women can be increased with a multiple component intervention package (a concise information on influenza and its vaccination, and contact details of nearby clinics offering subsidised influenza vaccines, and vaccination reminders) and with influenza vaccine offered as part of routine antenatal care at no charge. It is hypothesised that the uptake of seasonal influenza vaccine in pregnant women can be improved by providing mothers with either a multicomponent intervention package to encourage influenza vaccine through the Vaccine Subsidy Scheme or to offer free influenza vaccine as part of routine antenatal care.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 121094 0
Prof Li Man Chim, Albert Martin
Address 121094 0
Department of Paediatrics, 6/F, Lui Che Woo Clinicial Sciences Building, Prince of Wales Hospital, Shatin, Hong Kong
Country 121094 0
Hong Kong
Phone 121094 0
+85235052850
Fax 121094 0
Email 121094 0
[email protected]
Contact person for public queries
Name 121095 0
Yeung Hoi Ting Karene
Address 121095 0
Department of Paediatrics, 6/F, Lui Che Woo Clinicial Sciences Building, Prince of Wales Hospital, Shatin, Hong Kong
Country 121095 0
Hong Kong
Phone 121095 0
+85235052861
Fax 121095 0
+85226360020
Email 121095 0
[email protected]
Contact person for scientific queries
Name 121096 0
Yeung Hoi Ting Karene
Address 121096 0
Department of Paediatrics, 6/F, Lui Che Woo Clinicial Sciences Building, Prince of Wales Hospital, Shatin, Hong Kong
Country 121096 0
Hong Kong
Phone 121096 0
+85235052861
Fax 121096 0
+85226360020
Email 121096 0
[email protected]

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?

Current supporting documents:
Doc. No.TypeCitationLinkEmailOther DetailsAttachment
16885Study protocol    384509-(Uploaded-10-07-2023-13-17-27)-Study-related document.pdf
16887Informed consent form    384509-(Uploaded-30-06-2023-14-36-12)-Study-related document.pdf


Updated to:
Doc. No.TypeCitationLinkEmailOther DetailsAttachment
16885Study protocol    384509-(Uploaded-13-03-2024-19-43-53)-Study-related document.pdf
16887Informed consent form    384509-(Uploaded-13-03-2024-19-44-43)-Study-related document.pdf

Results publications and other study-related documents

Documents added manually
Current Study Results
No documents have been uploaded by study researchers.

Update to Study Results
Doc. No.TypeIs Peer Reviewed?DOICitations or Other DetailsAttachment
4174Plain language summaryNo data collection in progress, no result yet

Documents added automatically
No additional documents have been identified.