Back to resultsVolatility and Heterogeneity of Vaccine Sentiments Means Continuous Monitoring is Needed When Measuring Message Effectiveness
Primary Purpose
Vaccine-Preventable Diseases, Vaccine Refusal
Status
Completed
Phase
Not Applicable
Locations
Hong Kong
Study Type
Interventional
Intervention
Google ads
Sponsored by
About this trial
This is an interventional health services research trial for Vaccine-Preventable Diseases focused on measuring Vaccine hesitancy, Google ads, Vaccine messages, Vaccine confidence
Eligibility Criteria
Inclusion Criteria:
- General users of Google search in Hong Kong
Exclusion Criteria:
- None
Sites / Locations
- The University of Hong Kong
Arms of the Study
Arm 1
Arm 2
Arm 3
Arm 4
Arm 5
Arm 6
Arm 7
Arm Type
Active Comparator
Experimental
Experimental
Experimental
Experimental
Experimental
Experimental
Arm Label
Government
Comparison
Exemption
Family
Lottery
Mortality
Reopen
Arm Description
Participants were shown with the government slogan for the COVID-19 vaccine campaign in 2021. This was the control arm.
The ad emphasized that vaccine uptake in Hong Kong substantially lagged behind that in comparable populations such as Singapore and the UK.
The ad emphasized that vaccinated people could be exempted from some disruptive control measures such as mandatory testing
The ad prompted people to get vaccinated in order to protect their family.
The ad prompted people to get vaccinated in order to be eligible for the numerous COVID-19 lotteries in Hong Kong
The ad emphasized that COVID-19 has caused millions of deaths worldwide.
The ad prompted people to get vaccinated to help Hong Kong reopen sooner.
Outcomes
Primary Outcome Measures
Number of bookings following each message delivery within 6 hours
The number of bookings made within X = 6 hours following each message delivery
Secondary Outcome Measures
Number of bookings following each message delivery within 3 hours
The number of bookings made within X = 3 hours following each message delivery
Number of bookings following each message delivery within 12 hours
The number of bookings made within X = 12 hours following each message delivery
Full Information
NCT ID
NCT05499299
First Posted
August 10, 2022
Last Updated
August 12, 2022
Sponsor
The University of Hong Kong
1. Study Identification
Unique Protocol Identification Number
NCT05499299
Brief Title
Volatility and Heterogeneity of Vaccine Sentiments Means Continuous Monitoring is Needed When Measuring Message Effectiveness
Official Title
The Effect of Optimised Online Advertising on the Uptake of COVID-19 Vaccines in Hong Kong
Study Type
Interventional
2. Study Status
Record Verification Date
August 2022
Overall Recruitment Status
Completed
Study Start Date
July 1, 2021 (Actual)
Primary Completion Date
October 31, 2021 (Actual)
Study Completion Date
April 1, 2022 (Actual)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Sponsor
Name of the Sponsor
The University of Hong Kong
4. Oversight
Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
No
5. Study Description
Brief Summary
The success of vaccination programs often depends on the effectiveness of the vaccine messages, particularly during emergencies such as the COVID-19 pandemic. The current suboptimal uptake of COVID-19 vaccines across many parts of the world highlights the tremendous challenges in overcoming vaccine hesitancy and refusal even in the context of a world-devastating pandemic. The investigators conducted a randomized controlled trial in Hong Kong to evaluate the impact of seven vaccine messages on COVID-19 vaccine uptake (with the government slogan as the control). The participants included 127,000 individuals who googled COVID-19-related information during July-October 2021.
Detailed Description
This study aims to evaluate the effectiveness of using the Google advertising platforms on influencing the uptake of COVID-19 vaccines in Hong Kong. When completed, the rich database compiled through this proposed study will provide increased insight into vaccine hesitancy in Hong Kong. Insights from the optimised online advertising trial can aid in providing crucial technical and theoretical support to the relevant health authorities for any potential evidence-based policy intervention in addressing vaccine hesitancy issues or the public's concerns towards vaccines in Hong Kong.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Vaccine-Preventable Diseases, Vaccine Refusal
Keywords
Vaccine hesitancy, Google ads, Vaccine messages, Vaccine confidence
7. Study Design
Primary Purpose
Health Services Research
Study Phase
Not Applicable
Interventional Study Model
Parallel Assignment
Masking
Participant
Allocation
Randomized
Enrollment
127000 (Actual)
8. Arms, Groups, and Interventions
Arm Title
Government
Arm Type
Active Comparator
Arm Description
Participants were shown with the government slogan for the COVID-19 vaccine campaign in 2021. This was the control arm.
Arm Title
Comparison
Arm Type
Experimental
Arm Description
The ad emphasized that vaccine uptake in Hong Kong substantially lagged behind that in comparable populations such as Singapore and the UK.
Arm Title
Exemption
Arm Type
Experimental
Arm Description
The ad emphasized that vaccinated people could be exempted from some disruptive control measures such as mandatory testing
Arm Title
Family
Arm Type
Experimental
Arm Description
The ad prompted people to get vaccinated in order to protect their family.
Arm Title
Lottery
Arm Type
Experimental
Arm Description
The ad prompted people to get vaccinated in order to be eligible for the numerous COVID-19 lotteries in Hong Kong
Arm Title
Mortality
Arm Type
Experimental
Arm Description
The ad emphasized that COVID-19 has caused millions of deaths worldwide.
Arm Title
Reopen
Arm Type
Experimental
Arm Description
The ad prompted people to get vaccinated to help Hong Kong reopen sooner.
Intervention Type
Behavioral
Intervention Name(s)
Google ads
Intervention Description
Individuals who googled COVID-19 information in Hong Kong were randomized to see one of the seven ads and, if they clicked on the ads, the corresponding vaccine message on our website
Primary Outcome Measure Information:
Title
Number of bookings following each message delivery within 6 hours
Description
The number of bookings made within X = 6 hours following each message delivery
Time Frame
6 hours
Secondary Outcome Measure Information:
Title
Number of bookings following each message delivery within 3 hours
Description
The number of bookings made within X = 3 hours following each message delivery
Time Frame
3 hours
Title
Number of bookings following each message delivery within 12 hours
Description
The number of bookings made within X = 12 hours following each message delivery
Time Frame
12 hours
10. Eligibility
Sex
All
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria:
General users of Google search in Hong Kong
Exclusion Criteria:
None
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Joseph T Wu, PhD
Organizational Affiliation
The University of Hong Kong
Official's Role
Principal Investigator
Facility Information:
Facility Name
The University of Hong Kong
City
Hong Kong
Country
Hong Kong
12. IPD Sharing Statement
Plan to Share IPD
Yes
IPD Sharing Plan Description
Proposals should be directed to kathysleung@connect.hku.hk; to gain access, data requestors will need to sign a data access agreement
IPD Sharing Time Frame
Beginning 9 months and ending 36 months following article publication
IPD Sharing Access Criteria
Researchers who provide a methodologically sound proposal for meta-analysis. Proposals should be directed to Kathyleung@connect.hku.hk; to gain access, data requestors will need to sign a data access agreement.
Learn more about this trial
Volatility and Heterogeneity of Vaccine Sentiments Means Continuous Monitoring is Needed When Measuring Message Effectiveness
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