An Innovative Conversational Agent (Quitbot) for Smoking Cessation

May 20, 2026 updated by: Jonathan Bricker, Fred Hutchinson Cancer Center

Full Scale Randomized Trial of an Innovative Conversational Agent for Smoking Cessation (QuitBot)

This phase III trial compares two remote digital smoking cessation programs to see how well they work for quitting smoking.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

OUTLINE:

Participants are randomized to 1 of 2 groups. Both groups receive access to a 42-day quit smoking program.

GROUP I: Experimental QuitBot chatbot program, for 42 days to support quitting smoking. After the completion of study, patients are followed up at 3, 6, and 12 months.

GROUP II: Control SmokefreeTXT text messaging program, for 42 days to support quitting smoking. After the completion of study, patients are followed up at 3, 6, and 12 months.

Study Type

Interventional

Enrollment (Actual)

1647

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Washington
      • Seattle, Washington, United States, 98109
        • Fred Hutch/University of Washington Cancer Consortium

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Age 18 or older
  • Smokes at least one cigarette a day for the past 12 months
  • Wants to quit cigarette smoking within the next 30 days (consistent with text messaging intervention trials)
  • If concurrently using any other nicotine or tobacco products, wants to quit using them within the next 30 days
  • Interested in learning skills to quit smoking
  • Willing to be randomly assigned to either intervention
  • Resides in United States (US) and will continue to reside in the US for the next 12 months
  • Has at least daily access to their own smartphone
  • Has text messaging on their smartphone and knows how to download a smartphone application
  • Willing and able to read in English, and
  • Not using other smoking cessation interventions (This eligibility requirement helps ensure results are due to the treatments we recommend rather than those that participants are doing on their own.)

Exclusion Criteria:

  • The reverse of the inclusion criteria

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Group I (QuitBot Experimental)
Participants participate in the QuitBot program for 42 days to support quitting smoking. QuitBot is a novel chatbot smartphone application for smoking cessation.
Other: Experimental Smoking Cessation Program
Participate in Quitbot experimental cessation program
Other Names:
  • Experimental
Active Comparator: Group II (SmokefreeTXT Control)
Participants participate in the SmokefreeTXT program for 42 days to support quitting smoking. SmokefreeTXT is a standard of care smoking cessation text messaging program from the NCI.
Other: Control Smoking Cessation Program
Participate in Quitbot control cessation program
Other Names:
  • Control

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Participants With 30-day Cigarette Smoking Cessation
Time Frame: At 12 months after randomization
The primary endpoint is 30-day point prevalence abstinence for cigarette smoking at 12 months post-randomization. At 12 months, smoking abstinence is assessed by asking participants: "When was the last time you smoked, or even tried, a cigarette?" Response choices are "Earlier today", "24 hours ago", "2-7 days ago", "8-30 days ago", and "Over 30 days ago". Participants reporting no cigarette consumption in the past 30 days are considered abstinent for the 30-day outcome. Missing outcome data are handled using standard intent-to-treat analysis, with all missing data coded as smoking.
At 12 months after randomization

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Participants With 30-day Cigarette Smoking Cessation
Time Frame: At 6 months after randomization
The primary endpoint is 30-day point prevalence abstinence for cigarette smoking at 6 months post-randomization. At 6 months, smoking abstinence is assessed by asking participants: "When was the last time you smoked, or even tried, a cigarette?" Response choices are "Earlier today", "24 hours ago", "2-7 days ago", "8-30 days ago", and "Over 30 days ago". Participants reporting no cigarette consumption in the past 30 days are considered abstinent for the 30-day outcome. Missing outcome data are handled using standard intent-to-treat analysis, with all missing data coded as smoking.
At 6 months after randomization

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Fred Hutchinson Cancer Center

Collaborators

National Cancer Institute (NCI)

Investigators

  • Principal Investigator: Jonathan B. Bricker, Fred Hutch/University of Washington Cancer Consortium

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 24, 2022

Primary Completion (Actual)

May 1, 2025

Study Completion (Actual)

April 8, 2026

Study Registration Dates

First Submitted

March 6, 2020

First Submitted That Met QC Criteria

March 12, 2020

First Posted (Actual)

March 16, 2020

Study Record Updates

Last Update Posted (Actual)

May 22, 2026

Last Update Submitted That Met QC Criteria

May 20, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • RG1006844 (Other Identifier: Fred Hutch/University of Washington Cancer Consortium)
  • 10359 (Other Identifier: Fred Hutch/University of Washington Cancer Consortium)
  • NCI-2020-00136 (Registry Identifier: CTRP (Clinical Trial Reporting Program))
  • R01CA247156 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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