Promoting Vaccination Take-up at the Last Mile: Evidence from a Randomized Controlled Trial in Rural Indonesia

Last registered on June 18, 2022
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Pre-Trial

Trial Information

General Information

Title
Promoting Vaccine Take-Up and Tackling Vaccine Hesitancy: The Role of Local Health Workers and Leaders in Indonesia
RCT ID
AEARCTR-0008601
Initial registration date
June 16, 2022

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
June 18, 2022, 10:23 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Locations

Country
Indonesia
Region
West Java

Primary Investigator

Name
Armand Sim
Affiliation
Monash University
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Other Primary Investigator(s)

PI Name
Asad Islam
PI Affiliation
Monash University
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PI Name
Jahen Rezki
PI Affiliation
University of Indonesia
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PI Name
Giovanni van Empel
PI Affiliation
Monash University
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PI Name
Michael Vlassopoulos
PI Affiliation
University of Southampton
Contact Investigator

Additional Trial Information

Status
In development
Start date
2022-02-12
End date
2022-10-31
Keywords
Behavior, Health
Additional Keywords
COVID-19, vaccine hesitancy, Indonesia, health behavior
JEL code(s)
I1, I12, I18, I20, I3
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
In settings where some resistance and rampant misinformation against vaccine exist even after it becomes increasingly available, the prospect of accelerating the progress to end the COVID-19 pandemic is rather bleak. To address this issue, we conduct a personalized- information intervention targeted towards unvaccinated individuals aged 18+ years old. For this purpose, we recruit ambassadors—laypersons, health cadres, and influential individuals—from local villages to deliver a comprehensive set of information on COVID-19 vaccine and promote vaccination using an interpersonal behavioral change communication approach which requires the ambassadors to deliver tailored information to each individual through two one-on-one meetings. To investigate which type of ambassadors is the most effective in conducting this task, we conduct a cluster randomized experiment in rural West Java, Indonesia that varies the ambassadors at the village level. We planned to recruit 3,600 unvaccinated individuals spread across 300 villages in three districts in West Java, Indonesia.
External Link(s)

Registration Citation

Citation
Islam, Asad et al. 2022. "Promoting Vaccine Take-Up and Tackling Vaccine Hesitancy: The Role of Local Health Workers and Leaders in Indonesia ." AEA RCT Registry. June 18. https://doi.org/10.1257/rct.8601
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
We conduct a cluster randomized experiment that varies the type of vaccine ambassadors—health care workers, local leaders, and laypersons—at the village level. Each ambassador—recruited from local communities—is tasked to deliver the same information contents on COVID-19 and COVID-19 vaccines (e.g., benefits and risks of taking up vaccines) to participants. To increase the chance of success, ambassadors will also use participants' personal information from baseline survey, such as reasons and barriers to vaccination, to tailor a more targeted approach for each participant. Ambassadors use interpersonal behavioral communication change approach as their communication strategy.
Intervention Start Date
2022-06-09
Intervention End Date
2022-07-06

Primary Outcomes

Primary Outcomes (end points)
1. Vaccination uptake

2. Vaccination intention: willingness to get vaccinated and registered for vaccination but declined

3. Vaccination status of others
Primary Outcomes (explanation)
1. Vaccination uptake
Measures the actual vaccination. Binary variable that equals to one if participants report having received the first and/or second dose of vaccine (verified by physical or digital proof).

2. Vaccination intention

A. Willingness to get vaccinated
Measures the degree of vaccination intention, likert scale variable (1-5). This variable will be normalized to have 0-1 support.

B. Registered for vaccination but declined
Measures vaccination intention but vaccination fails to materialize due to health or other reasons. Binary variable that equals to one if participants report having registered for vaccine but declined by health workers for health or other reasons.

3. Vaccination status of others
Measures potential spillover effects of the intervention on reported vaccination status of household members and friends/relatives.

Household vaccination rate ranges between 0 and 1.

Vaccination status of close friends/relatives is constructed from responses to "How many people in your personal network (close family and/or friends) have been vaccinated against COVID-19?" (conditional on responding “yes” to "Have any of your relatives / neighbors / acquaintances been vaccinated since our last visit?"). This variable is measured using likert scale 1 (few) to 4 (all). This variable will be normalized to have 0-1 support.

Secondary Outcomes

Secondary Outcomes (end points)
1. Compliance to COVID-19 health protocols

2. Post-intervention COVID infection

3. Mental health: general mental health status and mental health status attributed to COVID-19

4. Perceived quality of the ambassadors and intervention

5. Participation during information session

6. Knowledge about COVID-19 and vaccines

7. Beliefs about COVID-19 and vaccines

Secondary Outcomes (explanation)
1. Compliance to COVID-19 health protocols
Index variable constructed from responses to questions on hand-washing, mask-wearing, and maintaining physical distance.

2. Post-intervention COVID infection
Binary variable that equals to one if respondents report getting infected with COVID after the intervention.

3. Mental health: general mental health status and mental health status attributed to COVID-19

A. General mental health status
Index variable constructed from questions on non-specific cause of depression and other questions.

B. Mental health status attributed to COVID-19
Index variable constructed from questions on depression and other questions driven by fear of COVID-19.

4. Perceived quality of the ambassadors and intervention
Index variable constructed from questions on participants' self-assessment on the quality of information delivery by the ambassadors and intervention as a whole.

5. Participation during information session
Index variable constructed from questions on participants' participation, such as number of correct information on knowledge on COVID-19 and vaccines.

6. Knowledge about COVID-19 and vaccines
Index variable constructed from questions on health belief model related to knowledge about COVID-19 and vaccines, such as benefits and risks of COVID-19 vaccines.

7. Beliefs about COVID-19 and vaccines
Index variable constructed from questions on health belief model related to beliefs on vulnerability to catching COVID-19 and barriers to COVID-19 vaccines, among other things.

Experimental Design

Experimental Design
We conduct a cluster randomized experiment that varies the type of ambassadors at the village level. Other than local eminent person ambassadors, which are nominated by participants, health cadres and layperson ambassadors are randomly selected using list provided by village officials.
Experimental Design Details
Not available
Randomization Method
Cluster level randomization (village level) by computer software. Within each cluster, eligible population (list provided by village officials) will be randomly selected by computer software.
Randomization Unit
Village
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
300 Villages
Sample size: planned number of observations
3,600 Observations
Sample size (or number of clusters) by treatment arms
Each treatment arm consists of 100 villages and roughly 1200 individuals.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
Monash University Human Research Ethics Committee
IRB Approval Date
2021-11-04
IRB Approval Number
N/A
IRB Name
Komite Etik Penelitian Lembaga Penyelidikan Ekonomi & Masyarakat Fakultas Ekonomi dan Bisnis Universitas Indonesia
IRB Approval Date
2021-12-06
IRB Approval Number
012/ UN2.F6.D2.LPM/PPM.KEP/2021
Analysis Plan