Effect of Static vs. Conversational AI-Generated Messages on Colorectal Cancer Screening Intent: a Randomized Controlled Trial

NCT07107152 | Completed

• 1 other identifier: crc_857299
• Study Type: interventional
• Target: 915
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to assess whether messages generated by a large language model (LLM), including both static and conversational formats, can increase colorectal cancer (CRC) screening intentions among U.S. adults aged 45-75 who have never completed CRC screening. The main questions it aims to answer are: Do personalized, AI-generated messages increase the self-reported likelihood of completing a stool-based CRC screening test within 12 months? Do they also increase intent to undergo colonoscopy screening within 12 months? Researchers will compare four groups: (1) no message control, (2) expert-written patient education materials, (3) a single AI-generated persuasive message, and (4) a motivational interviewing-style AI chatbot. These comparisons will help assess whether a conversational format offers added benefit over static AI or expert-generated content. Participants will: Be randomly assigned to one of the four study arms Spend at least 3 minutes reading or interacting with their assigned material Complete pre- and post-intervention surveys assessing intent to receive CRC screening Receive messages tailored to their self-reported demographics, including age, political ideology, gender, education, community setting (urban, rural, suburb), self-reported health, and the last time they saw their PCP

Conditions

Colorectal Cancer Control and Prevention

Keywords

chatbot; Artificial Intelligence; large language models; colorectal cancer screening

Outcome Measures

Primary Outcomes (2)

• Change in Self-Reported Likelihood of Completing Stool Test Screening for Colorectal Cancer

  Measured on a 0-100 scale, where 0 = "Extremely unlikely" and 100 = "Extremely likely." Assessed before and after the intervention. Change in score indicates difference in participant intention to complete a stool-based CRC screening test.

  Immediately before and after the intervention (single session; same day)

• Change in Self-Reported Likelihood of Completing Colonoscopy Screening for Colorectal Cancer

  Measured on a 0-100 scale, where 0 = "Extremely unlikely" and 100 = "Extremely likely." Assessed before and after the intervention. Change in score reflects shift in participant intention to complete a colonoscopy within the next 12 months.

  Immediately before and after the intervention (single session; same day)

Secondary Outcomes (4)

• Perceived Empathy of the Intervention

  Immediately after the intervention (single session)

• Comfort Discussing CRC Screening with a Provider

  Immediately before and after the intervention (single session; same day)

• Perceived Message Effectiveness

  Immediately after the intervention (single session)

• Change in Reasons for CRC Screening Hesitancy

  Immediately before and after the intervention (single session)

Study Arms (4)

AI Motivational Interviewing Chatbot

EXPERIMENTAL

The motivational interviewing chatbot refers to a GPT-4.1 based chatbot that has been instructed to follow motivational interviewing principals to persuade participants to get screened for CRC.

Behavioral: AI Chatbot

single GPT generated message

EXPERIMENTAL

The single GPT generated message is a single \~640 word persuasive message generated by GPT-4.1 where GPT-4.1 is provided with the same self-reported demographics.

Behavioral: single GPT generated message

CRC JAMA patient page

ACTIVE COMPARATOR

The 642 word JAMA Patient Page contains up to date information on screening guidelines for CRC directed at patients.

Behavioral: Expert-Written Patient Materials

No Message

NO INTERVENTION

Participants read a \~640 word fictional short story about a cat and dog.

Interventions

single GPT generated message BEHAVIORAL

Participants receive a single \~640-word message generated by GPT-4.1. The message is tailored to participants' self-reported demographics (age, gender, political ideology, education, urbanicity, health status, and last PCP visit). The message provides persuasive content encouraging colorectal cancer screening, emphasizing stool and colonoscopy screening options. Participants are required to read the message for a minimum of 3 minutes.

single GPT generated message

AI Chatbot BEHAVIORAL

Participants engage in a multi-turn conversation with a GPT-4.1 chatbot trained to emulate motivational interviewing techniques. The chatbot personalizes its conversation based on each participant's demographics (age, gender, political ideology, education, urbanicity, health status, and last PCP visit). Conversations last at least 3 minutes and aim to increase participant motivation to complete colorectal cancer screening.

AI Motivational Interviewing Chatbot

Expert-Written Patient Materials BEHAVIORAL

Participants read a 642-word expert-written educational summary from the Journal of the American Medical Association's Patient Page on colorectal cancer screening. The material is designed to provide objective information about screening options and guidelines recommended by the US Preventive Services Task Force. Participants are required to read the material for at least 3 minutes.

CRC JAMA patient page

Eligibility Criteria

• Age: 45 Years - 75 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults aged 45 to 75 years
• Currently residing in the United States
• Self-reported no prior colorectal cancer screening (or unsure if screened)
• Able to read and understand English
• Consent to participate in a behavioral research study

You may not qualify if:

• Previous colonoscopy, stool test, sigmoidoscopy, or CT colonography
• Failure to pass pre- or post-intervention attention checks
• Identified as non-human respondents by reCAPTCHA or other automated bot detection
• Completion time significantly shorter than the median, indicating inattentiveness

Sponsors & Collaborators

• University of Pennsylvania: lead

Study Sites (1)

Participants are recruited online via Prolific

Philadelphia, Pennsylvania, 19104, United States

Location

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: SCREENING
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 30, 2025
• First Posted: August 6, 2025
• Study Start: June 11, 2025
• Primary Completion: June 21, 2025
• Study Completion: June 21, 2025
• Last Updated: August 7, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will share

Locations

US (1)