Promoting seasonal influenza vaccination among community-dwelling older adults
| ISRCTN | ISRCTN21980321 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN21980321 |
| Secondary identifying numbers | 15601623 |
- Submission date
- 20/10/2024
- Registration date
- 21/10/2024
- Last edited
- 09/04/2025
- Recruitment status
- Recruiting
- Overall study status
- Ongoing
- Condition category
- Infections and Infestations
Plain English summary of protocol
Background and study aims
Older adults aged ≥65 years bear a disproportionate burden of influenza. Although free seasonal influenza vaccination (SIV) is provided, the vaccination rate among community-dwelling older adults in Hong Kong remains suboptimal. This study aims to combine narratives and implementation intentions to improve SIV promotion.
Who can participate?
Senior adults aged ≥ 65 years who currently living in the community, and have not received SIV in the current season or made any appointment for SIV
What does the study involve?
A three-arm study is proposed to examine the effects of using a WhatsApp-based intervention combining narratives and implementation intentions in increasing the uptake of SIV in community-dwelling older adults, compared to two control conditions involving only narrative messages or topic-matched didactic messages.
What are the possible benefits and risks of participating?
1. Benefits: Participants will learn more about influenza prevention and may engage in SIV and prevent themselves from influenza infection as a result. They will receive supermarket coupons as compensation for their participation.
2. Risks: There are no known risks associated with participating in this study. Completing the intervention and the evaluation surveys may cause fatigue among some participants.
Where is the study run from?
This study is managed by the Department of Rehabilitation Sciences of the Hong Kong Polytechnic University.
When is the study starting and how long is it expected to run for?
January 2024 to March 2026
Who is funding the study?
The General Research Fund of the Hong Kong Research Grants Council.
Who is the main contact?
Dr. Meiqi Xin, meiqi.xin@polyu.edu.hk
Contact information
Public, Scientific, Principal Investigator
ST518, 5/F, Core T, The Hong Kong Polytechnic University
Hong Kong
0000
Hong Kong
 ORCID ID |
0000-0002-8636-4918 |
|---|---|
| Phone | +852 27664840 |
| meiqi.xin@polyu.edu.hk |
Study information
| Study design | Three-arm randomized controlled trial |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Randomised controlled trial |
| Study setting(s) | Community |
| Study type | Prevention |
| Participant information sheet | Not available in web format, please use contact details to request a participant information sheet |
| Scientific title | Combining biographical narratives and implementation intentions to promote seasonal influenza vaccination among community-dwelling older adults: a randomized controlled trial |
| Study acronym | SILVER |
| Study objectives | Hypothesis 1: The BNII Group (an integrated intervention combining biographical narratives and implementation intentions) will have a higher influenza vaccination rate than the BN (a control condition involving only biographical narratives) Group, who will have a higher influenza vaccination rate than the DD Group (a control condition involving only didactic messages). Hypothesis 2: The BNII and BN Groups will have higher attitudes, injunctive norms, perceived behavioral control, self-efficacy, and behavioral intention than the DD Group. Hypothesis 3: The efficacy of BNII and BN, relative to DD, will be mediated through reduced resistance to persuasion. |
| Ethics approval(s) |
Approved 17/10/2024, The Hong Kong Polytechnic University Institutional Review Board (The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, 0000, Hong Kong; +852 2766 4831; benjamin.yee@polyu.edu.hk), ref: HSEARS20230308010-02 |
| Health condition(s) or problem(s) studied | Prevention of seasonal influenza in community-dwelling older adults |
| Intervention | Community-dwelling older adults will be randomly allocated to three groups: (1) the BNII Group will receive an integrated intervention comprising biographical narrative messages and a complementary implementation intentions intervention (an intervention condition); (2) the BN Group will receive only biographical narrative messages (a control condition); (3) the DD Group will receive only didactic messages (a control condition). For all three groups, relevant intervention content will be delivered through instant messaging (WhatsApp). The intervention will last for 4-6 weeks. |
| Intervention type | Behavioural |
| Primary outcome measure | The uptake of seasonal influenza vaccination will be measured using a survey three months after the intervention |
| Secondary outcome measures | Perceptions of seasonal influenza vaccination, including attitudes, injunctive norms, perceived behavioral control, self-efficacy, and behavioral intention, measured using a structured questionnaire at baseline, immediately after the intervention, and three months after the intervention |
| Overall study start date | 01/01/2024 |
| Completion date | 31/03/2026 |
Eligibility
| Participant type(s) | Resident, Population |
|---|---|
| Age group | Senior |
| Lower age limit | 65 Years |
| Sex | Both |
| Target number of participants | 576 |
| Key inclusion criteria | 1. Aged ≥ 65 years 2. Currently living in the community 3. Not received seasonal influenza vaccination (SIV) in the current season or made any appointment for SIV 4. Regularly use a smartphone (at least once a week) 5. Residing in Hong Kong in the future 6 months 6. Being able to read Chinese |
| Key exclusion criteria | 1. Not eligible for SIV according to official guidelines (e.g., a history of severe hypersensitivity to a previous dose of SIV or relevant components) 2. Having taken up SIV annually in the past 3 years 3. Not having the mental or cognitive capacity to take part in the study |
| Date of first enrolment | 24/10/2024 |
| Date of final enrolment | 15/11/2025 |
Locations
Countries of recruitment
- Hong Kong
Study participating centre
Hong Kong
0000
Hong Kong
Sponsor information
Government
7/F., Shui On Centre, 6-8 Harbour Road, Wanchai
Hong Kong
0000
Hong Kong
| Phone | +852 2524 3987 |
|---|---|
| ugc@ugc.edu.hk | |
| Website | https://www.ugc.edu.hk |
"ROR" |
https://ror.org/00djwmt25 |
Funders
Funder type
Research council
No information available
Results and Publications
| Intention to publish date | 30/09/2026 |
|---|---|
| Individual participant data (IPD) Intention to share | Yes |
| IPD sharing plan summary | Available on request |
| Publication and dissemination plan | Planned publication in a peer-reviewed journal |
| IPD sharing plan | The datasets generated during and/or analysed during the current study will be available upon request from Dr. Meiqi XIN (meiqi.xin@polyu.edu.hk) |
Editorial Notes
09/04/2025: The following changes were made to the trial record:
1. The recruitment end date was changed from 30/04/2025 to 15/11/2025.
2. The acronym was changed from BNII to SILVER.
21/10/2024: Study's existence confirmed by the Hong Kong Polytechnic University Institutional Review Board.
