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Conversations With AI Chatbots Increase Short-Term Vaccine Intentions But Do Not Outperform Standard Public Health Messaging

Not Applicable
Completed
Conditions
HPV Vaccination Intent
Registration Number
NCT07132125
Lead Sponsor
University of Pennsylvania
Brief Summary

The goal of this clinical trial is to test whether short conversations with large language model (LLM) chatbots can persuade vaccine-hesitant parents to vaccinate their children against human papillomavirus (HPV). The study compares two chatbot styles to official public health information and to a no-message control. Parents of HPV-eligible children first complete a survey about their attitudes toward the HPV vaccine and their main concerns. They are then randomly assigned to read public health materials, have a three-minute conversation with either a default-style chatbot or a conversational-style chatbot tailored to their concern, or receive no message. The main outcome is change in intent to vaccinate immediately after the intervention, with follow-up surveys at 15 and 45 days.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
930
Inclusion Criteria
  • Adults aged 18 years and up
  • Living in Canada, the UK, or the USA
  • At least one child eligible for HPV vaccine based on country-specific guidelines who has not received any doses of the vaccine or whose vaccination status is unknown
Exclusion Criteria
  • Failure to pass attention checks
  • Identified as non-human respondents by reCAPTCHA or other automated bot detection

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Primary Outcome Measures
NameTimeMethod
Change in intent to vaccinate child against HPV within the next 12 monthsBaseline to immediately post-intervention

Self-reported likelihood, on a 0-100 scale, of vaccinating the participant's youngest HPV vaccine-eligible child (identified in pre-survey) within the next 12 months. Measured before and immediately after the intervention to assess short-term changes in vaccination intent.

Secondary Outcome Measures
NameTimeMethod
Change in intent to vaccinate child against HPV at 15-day follow-upBaseline to 15 days post-intervention

Self-reported likelihood, on a 0-100 scale, of vaccinating the participant's youngest HPV vaccine-eligible child within the next 12 months. Measured at baseline and 15 days after the intervention to assess durability of effects.

Change in intent to vaccinate child against HPV at 45-day follow-upBaseline to 45 days post-intervention

Self-reported likelihood, on a 0-100 scale, of vaccinating the participant's youngest HPV vaccine-eligible child within the next 12 months. Measured at baseline and 45 days after the intervention to assess durability of effects.

Change in importance ratings of HPV vaccine concernsBaseline to immediately post-intervention

Change in participant ratings (0-100 scale) of importance for each HPV vaccine concern (list derived from National Immunization Surveys) between baseline and immediately post-intervention.

Change in general parental vaccine hesitancy (PACV-5)Baseline to immediately post-intervention

Change in scores on the 5-item Parent Attitudes about Childhood Vaccines (PACV-5) scale. Measured at baseline and immediately after the intervention.

Willingness to donate payment to vaccine education charityImmediately post-intervention

Percentage of survey payment participants choose to donate (0%, 10%, 30%, or 50%) to an immunization-related charity during the post-intervention survey.

Willingness to be recontacted for future researchImmediately post-intervention

Participant self-reported willingness (yes/no) to be contacted for future studies

Ratings of empathy, usefulness, and relevance of intervention contentImmediately post-intervention

Participant ratings (1-5 scale) of how empathetic, useful, and relevant they found the assigned chatbot conversation or public health reading material.

Change in intent to vaccinate child for influenza and COVID-19Measured at baseline and immediately post-intervention.

Self-reported likelihood, on a 0-100 scale, of vaccinating the participant's youngest eligible child for influenza or COVID-19 within the next 12 months.

Clicks on HPV vaccine appointment scheduling linkImmediately post-intervention

Whether participants click a provided link to schedule an HPV vaccine appointment through CVS during the post-intervention survey.

Trial Locations

Locations (1)

Participants are recruited online via Prolific

🇺🇸

Philadelphia, Pennsylvania, United States

Participants are recruited online via Prolific
🇺🇸Philadelphia, Pennsylvania, United States

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