Persuasion in Medicine: Experimental Evidence on Sender and Signal Effects

NCT ID: NCT04160975

Last Updated: 2021-06-29

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 3245 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2019-12-20
• Study Completion Date: 2021-02-19

Brief Summary

The aim of the study is to identify what sender/signal combinations are most persuasive in encouraging low socioeconomic males living in the U.S. to take-up seasonal flu vaccination. The investigators plan to recruit male subjects and randomly assign them to four persuasion treatments: three of which vary dimensions of the sender of a medical recommendation (racial concordance and authority treatments) and one which varies the signal (standard vs. empathetic). Specifically, the investigators will show subjects videos of either Black or white actors/actresses providing scripted information on the flu vaccination. The investigators will randomize the race of the sender and if the subject is Black, also randomize the authority of the sender, with the actor portraying either a doctor or a layperson. In addition, the investigators will vary the script used in the experiment between one that acknowledges past injustices (indicated as an empathetic script hereafter) and one that does not (indicated as a standard script hereafter). The investigators will provide subjects a free flu shot coupon and elicit the price at which subjects would be willing to give up this coupon for a cash reward. Lastly, in light of the relevance of vaccination take-up in combating COVID-19 pandemic, the investigators will assess demand for information about a COVID-19 vaccine, with subjects invited to receive results of a safety and efficacy review from a trusted or standard source. The design requires the collection of baseline and endline surveys combined with administrative data from pharmacies about coupon redemption. The primary outcomes of interest are posterior beliefs about seasonal flu vaccination, demand and willingness-to-pay (WTP) for a free flu shot coupon, redemption of the coupon, and demand for information about a COVID-19 vaccine.

Detailed Description

The investigators will recruit approximately 3350 African-American or Caucasian adult males with a high-school diploma or less. A pilot study, which ran during the 2019-20 flu season, recruited approximately 850 subjects, and a planned scale-up will recruit an additional 2500 subjects during the 2020-21 flu season. The investigators will oversample African American individuals, emphasizing low-income and minority men because these characteristics are correlated with lower relative take-up of flu vaccination. After informed consent is obtained, subjects will be asked about sociodemographic information (age, education, income and marital status), healthcare experience and past medical history, knowledge and beliefs about flu vaccination, and location of the nearest pharmacy. The investigators will then randomly assign the adult male subjects to videos which contain one of Black or white actors playing the role of either a doctor or a layperson as well as different scripts. The content of the infomercial will be the safety and effectiveness of adult seasonal flu vaccination. After the video, the investigators will obtain information on beliefs regarding vaccination, feedback on the video, attention to the video and willingness-to-pay for a flu shot coupon. The final baseline module will consist of a randomly assigned invitation to receive the results of an upcoming review of a COVID-19 vaccine, with subjects assigned to receive information from a trusted or standard source. The investigators will track flu coupon redemption, which is redeemable at most pharmacies nationwide.

Conditions

Flu, Human; Influenza, Human; Covid19

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: HEALTH_SERVICES_RESEARCH
• Blinding Strategy: DOUBLE

Study Groups

Black R/Race C/Doctor/Standard Script

Video which contains a racially concordant actor playing a doctor and reading a standard script. The receiver of the message will be Black.

Group Type: EXPERIMENTAL

Video about safety and effectiveness of adult seasonal flu vaccination

Intervention Type: BEHAVIORAL

The investigators will show subjects videos of either Black or white male actors providing scripted information on the flu vaccination. The content of the video will be the safety and effectiveness of adult seasonal flu vaccination. The videos contain one of Black or white actors playing the role of either a doctor or a layperson as well as different scripts.

Black R/Race C/Layperson/Standard Script

Video which contains a racially concordant actor playing a layperson and reading a standard script. The receiver of the message will be Black.

Group Type: EXPERIMENTAL

Video about safety and effectiveness of adult seasonal flu vaccination

Intervention Type: BEHAVIORAL

The investigators will show subjects videos of either Black or white male actors providing scripted information on the flu vaccination. The content of the video will be the safety and effectiveness of adult seasonal flu vaccination. The videos contain one of Black or white actors playing the role of either a doctor or a layperson as well as different scripts.

Black R/Race D/Doctor/Standard Script

Video which contains a racially discordant actor playing a doctor and reading a standard script. The receiver of the message will be Black.

Group Type: EXPERIMENTAL

Video about safety and effectiveness of adult seasonal flu vaccination

Intervention Type: BEHAVIORAL

The investigators will show subjects videos of either Black or white male actors providing scripted information on the flu vaccination. The content of the video will be the safety and effectiveness of adult seasonal flu vaccination. The videos contain one of Black or white actors playing the role of either a doctor or a layperson as well as different scripts.

Black R/Race D/Doctor/Acknowledgement Script

Video which contains a racially discordant actor playing a doctor and reading an acknowledgement script. The receiver of the message will be Black.

Group Type: EXPERIMENTAL

Video about safety and effectiveness of adult seasonal flu vaccination

Intervention Type: BEHAVIORAL

The investigators will show subjects videos of either Black or white male actors providing scripted information on the flu vaccination. The content of the video will be the safety and effectiveness of adult seasonal flu vaccination. The videos contain one of Black or white actors playing the role of either a doctor or a layperson as well as different scripts.

White R/Race C/Doctor/Standard Script

Video which contains a racially concordant actor playing a doctor and reading a standard script. The receiver of the message will be White.

Group Type: EXPERIMENTAL

Video about safety and effectiveness of adult seasonal flu vaccination

Intervention Type: BEHAVIORAL

The investigators will show subjects videos of either Black or white male actors providing scripted information on the flu vaccination. The content of the video will be the safety and effectiveness of adult seasonal flu vaccination. The videos contain one of Black or white actors playing the role of either a doctor or a layperson as well as different scripts.

White R/Race D/Doctor/Standard Script

Video which contains a racially discordant actor playing a doctor and reading a standard script. The receiver of the message will be White.

Group Type: EXPERIMENTAL

Video about safety and effectiveness of adult seasonal flu vaccination

Intervention Type: BEHAVIORAL

The investigators will show subjects videos of either Black or white male actors providing scripted information on the flu vaccination. The content of the video will be the safety and effectiveness of adult seasonal flu vaccination. The videos contain one of Black or white actors playing the role of either a doctor or a layperson as well as different scripts.

Interventions

Video about safety and effectiveness of adult seasonal flu vaccination

The investigators will show subjects videos of either Black or white male actors providing scripted information on the flu vaccination. The content of the video will be the safety and effectiveness of adult seasonal flu vaccination. The videos contain one of Black or white actors playing the role of either a doctor or a layperson as well as different scripts.

Intervention Type: BEHAVIORAL

Eligibility Criteria

Inclusion Criteria

• Age: See above.
• Education: Less than a college degree.
• Gender: Male.
• Race: Caucasian or African American.
• Miscellaneous: Has not received the flu shot in the current flu season yet.
• Miscellaneous: Has sound on his device turned on.

Exclusion Criteria

• Fast survey-taking: subjects who are among the 5% fastest in terms of total time spent on survey within race and treatment group.
• Nonsense answers (those that do not have decipherable English) in the open text sections that suggest low effort.
• Inconsistent responses to questions (such as being willing to give up $10 to receive a flu coupon but not $1).
• Repeat survey takers as indicated by duplicate emails or IP addresses in survey data.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 51 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

Ludwig-Maximilians - University of Munich

OTHER

Sponsor Role: collaborator

Massachusetts Institute of Technology

OTHER

Sponsor Role: collaborator

National Institute on Aging (NIA)

NIH

Sponsor Role: collaborator

Harvard University

OTHER

Sponsor Role: lead

Responsible Party

Marcella Alsan

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Harvard University

Cambridge, Massachusetts, United States

Countries

United States

Provided Documents

Document Type: Study Protocol and Statistical Analysis Plan

View Document

Other Identifiers

IRB19-1424

Identifier Type: -

Identifier Source: org_study_id