Implementación de un chatbot basado en estrategias comportamentales para fomentar la continuidad de la vacunación contra el COVID-19: un ensayo controlado aleatorio

Last registered on July 21, 2022
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Pre-Trial

Trial Information

General Information

Title
Implementación de un chatbot basado en estrategias comportamentales para fomentar la continuidad de la vacunación contra el COVID-19: un ensayo controlado aleatorio
RCT ID
AEARCTR-0009758
Initial registration date
July 15, 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
July 21, 2022, 11:33 AM EDT

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

Locations

Country
Argentina
Region

Primary Investigator

Name
Sebastian Salomon-Ballada
Affiliation
The Behavioral Insights Team
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Other Primary Investigator(s)

PI Name
Ivan Budassi
PI Affiliation
Government of Argentina, Behavioural Science and Public Policy Unit.
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PI Name
Fernando Torrente
PI Affiliation
Universidad Favaloro
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PI Name
Lucas Ibañez
PI Affiliation
ECOM Chaco
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PI Name
Adelaida Barrera
PI Affiliation
The Behavioral Insights Team
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PI Name
Dan Brown
PI Affiliation
The Behavioral Insights Team
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PI Name
Pujen Shrestha
PI Affiliation
The Behavioral Insights Team
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PI Name
Bridie Murphy
PI Affiliation
The Behavioral Insights Team
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Additional Trial Information

Status
In development
Start date
2022-07-18
End date
2022-12-31
Keywords
Health
Additional Keywords
Public health
JEL code(s)
I12, I18, O38
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Despite overwhelming medical evidence on the protection offered by second, third and fourth Covid-19 vaccine doses, uptake of these doses remains low in Chaco province, Argentina, even though the vaccine is in ready supply. Several factors may account for this low uptake, including friction costs, intention-behaviour gaps, and lower perception of risk from Covid-19 compared to previous moments of the pandemic. Interactive communication via chatbot may help address these barriers and promote vaccination. In this randomized controlled trial, participants in the intervention group will receive personalized Whatsapp chatbot messages informing them that they are eligible for the next dose, sharing practical information on when and where to get vaccinated, providing planning prompts and enabling them to set reminders to get their next dose of the vaccine on a convenient date. Vaccination outcomes for participants in the intervention group will be compared with those of participants receiving a simple non-chatbot reminder message and of participants receiving no message.
External Link(s)

Registration Citation

Citation
Barrera, Adelaida et al. 2022. "Implementación de un chatbot basado en estrategias comportamentales para fomentar la continuidad de la vacunación contra el COVID-19: un ensayo controlado aleatorio." AEA RCT Registry. July 21. https://doi.org/10.1257/rct.9758-1.0
Sponsors & Partners

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Experimental Details

Interventions

Intervention(s)
Participants will receive personalized Whatsapp chatbot messages informing them they are eligible for the next dose, sharing practical information on when and where to get vaccinated, providing planning prompts, and enabling them to set reminders to get their next dose of the Covid-19 vaccine on a convenient date.
Intervention Start Date
2022-07-19
Intervention End Date
2022-12-31

Primary Outcomes

Primary Outcomes (end points)
‘Next dose’ Covid-19 vaccination rate within four weeks.
Primary Outcomes (explanation)
The primary outcome variable (next dose vaccination rate) is a binary variable indicating whether the individual received the next dose for which they are eligible within four weeks of entering the trial. This variable will be created using administrative data provided by the Ministry of Health which includes information on the date of vaccination.

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
We will conduct a Randomized Controlled Trial (RCT) with three trial arms (an interactive chatbot, a simple message reminder, and a pure control group who receives no message).
Experimental Design Details
The three trial arms consist of the following:

(1) Pure control group
Participants do not receive a message.
Note: Following the trial period, if any messages are found to be effective at encouraging vaccination, these individuals will be sent the most effective message.

(2) Simple message control group
Participants will receive a single ‘static’ whatsapp message (i.e., a message they cannot interact with). Key features of this arm are:
a. Motivational message leveraging loss aversion (“don’t lose your immunity”)
b. No personalized information, information on how to access vaccines, or prompts for planning their next vaccination.

(3) Whatsapp chatbot treatment group
Participants will receive an initial whatsapp message motivating them to get a next dose, which they can interact with. If they consent to receive future messages, they will be able to access additional chatbot functionalities. Key features of this trial arm are:
a. Motivational message leveraging loss aversion (“don’t lose your immunity”)
b. Chatbot functionalities:
–– Personalized information (participants’ name and previous dose information).
–– Information on closest vaccination centers based on users’ input of their postal code or geolocation sharing via Whatsapp (“dropping a pin”).
–– Prompts to plan when and where to receive the next dose (selecting which health center they plan to attend, plus the date and time of day of their intended vaccination).
–– Automated reminder one day ahead of selected date for receiving the next dose of Covid-19 vaccine, including a link to Google Maps directions for how to get to their chosen center.
Randomization Method
Participants will be allocated to a trial arm using simple randomisation at the individual-level, using the participants’ mobile number as their unique identifier.
Randomization Unit
The randomization unit is the individual.
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
241,435 individuals
Sample size: planned number of observations
241,435 individuals
Sample size (or number of clusters) by treatment arms
The sample will be split evenly between groups: 80,478 individuals in each of the three trial arms (chatbot, simple message reminder, no message).
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Baseline rate: 3.8% S.D.: N/A MDES unit: 0.32 percentage points MDES percentage: 8.4%
Supporting Documents and Materials

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IRB

Institutional Review Boards (IRBs)

IRB Name
Comité de Bioética, Fundación Favaloro Hospital Universitario
IRB Approval Date
2022-06-29
IRB Approval Number
DNE 297/2020, Acta Nº 121; CCE: Nº 015; RENIS: Nº 000042; DHHS/OHRP: 00004573
Analysis Plan

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials