The effect of newspaper reporting on Covid19 vaccine hesitancy: a randomized controlled trial

Last registered on October 17, 2022
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Pre-Trial

Trial Information

General Information

Title
The effect of newspaper reporting on Covid19 vaccine hesitancy: a randomized controlled trial
RCT ID
AEARCTR-0010196
Initial registration date
October 10, 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
October 17, 2022, 4:10 PM EDT

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

Locations

Country
France
Region
Country
Italy
Region

Primary Investigator

Name
Anna Rinaldi
Affiliation
University of Bari Aldo Moro
Contact Primary Investigator

Other Primary Investigator(s)

Additional Trial Information

Status
Completed
Start date
2021-05-05
End date
2021-06-21
Keywords
Behavior
Additional Keywords
JEL code(s)
D91, D81
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
1,068 people were surveyed in France and Italy to inquire about individual potential acceptance, focusing on time preferences, in a risk-return framework: having the vaccination today, in a month, and in 3 months; perceived risks of vaccination and COVID-19; and expected benefit of the vaccine.
A randomized controlled trial was conducted to understand how everyday stimuli, such as fact-based news about vaccines, impact on audience acceptance of vaccination. The main experiment involved two groups of participants and two different articles about vaccine-related thrombosis taken from two Italian newspapers. One article used a more abstract description and language, and the other used a more anecdotical description and concrete language; each group read only one of these articles. Two other groups were assigned categorization tasks; one was asked to complete a concrete categorization task and the other an abstract categorization task.
All the participants were administered the DOSPERT 2006 risk elicitation questionnaire in health domain to acquire information about personal risk attitude.
External Link(s)

Registration Citation

Citation
Rinaldi, Anna. 2022. "The effect of newspaper reporting on Covid19 vaccine hesitancy: a randomized controlled trial." AEA RCT Registry. October 17. https://doi.org/10.1257/rct.10196-1.0
Sponsors & Partners
Experimental Details

Interventions

Intervention(s)
The main treatment involved two groups of participants and two different articles about vaccine-related thrombosis taken from two Italian newspapers. One article used a more abstract descriptive style and language, while the other used a more anecdotical style and concrete language: each group read only one of these articles. The articles were taken from two Italian newspapers that differ greatly in their journalistic styles and audiences. Both articles are the same length and describe an episode of vaccine-related thrombosis. The abstract text uses a more formal and impersonal language, reporting more scientific considerations; the concrete text uses a more familiar and emotional style and provides a more anecdotical description of the case.
Texts were also weighted according to a concreteness semantic vocabulary, controlling for the mean of the total words contained in the articles (concreteness index = 3.54 for concrete text vs. 2.66 for abstract text; the difference is significant: t-test alpha = 0.05).
Given that the two newspaper texts differ manifestly in their level of abstraction, it was decided to cross-control for the participants’ mindsets in order to understand whether this could be a key element influencing vaccination decisions.
For this reason, two other groups (n=238 in total) were assigned categorization tasks; one was asked to complete a concrete categorization task and the other an abstract categorization.
The control group only answered questionnaires. Questionnaire inquires about individual potential acceptance, focusing on time preferences, in a risk-return framework: getting the jab today, in a month, and in 3 months; perceived risks of vaccination and COVID-19; and expected benefit of the vaccine.
All questionnaires included also DOSPERT questionnaire in health domain.
Intervention Start Date
2021-06-02
Intervention End Date
2021-06-21

Primary Outcomes

Primary Outcomes (end points)
revealed vaccine preferences in a dynamic perspective
number of individuals who want to receive vaccine
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The RCT is designed in this way: in 2 similar nations, in Italy and France, 1,068 individuals divided as follow:
- intervention (a) reading of the abstract text about vaccine related thrombosis
- intervention (b) reading of the abstract text about vaccine related thrombosis
- intervention (c) performing categories task
- intervention (d) performing example task

Simple randomization

Experiment was conducted via Qualtrics.
Experimental Design Details
Randomization Method
randomization done in office by a computer
Randomization Unit
Unvaccinated individuals
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
individuals in 2 nations Italy and France
Sample size: planned number of observations
1,068 unvaccinated individuals
Sample size (or number of clusters) by treatment arms
France (538) - abstract text (153) - concrete text (164) - abstract task (55), concrete task (56) - control (110)
Italy (530) - abstract text (155) - concrete text (163) - abstract task (54), concrete task (55) - control (103)
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
1,000 unvaccinated individuals
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number
Analysis Plan

Post-Trial

Post Trial Information

Study Withdrawal

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Intervention

Is the intervention completed?
No
Data Collection Complete
Yes
Data Collection Completion Date
Final Sample Size: Number of Clusters (Unit of Randomization)
Was attrition correlated with treatment status?
Final Sample Size: Total Number of Observations
Final Sample Size (or Number of Clusters) by Treatment Arms
Data Publication

Data Publication

Is public data available?
No

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials