NCT06914492

Brief Summary

The goal of this trial is to learn if chatbot-based instant messaging works to help smoking cessation in general adult smokers. It will also learn about the experience, attitude, and perception of using an LLM-based chatbot. The main questions it aims to answer are:

  1. 1.Will LLM-based chatbot smoking cessation intervention have a higher validated abstinence rate than the control group?
  2. 2.Will LLM-based chatbot smoking cessation intervention have a higher self-reported abstinence rate, smoking reduction rate, and smoking cessation services use rate than the control group?
  3. 3.AWARD advice
  4. 4.Personalized active referral
  5. 5.12 weeks of chatbot-based instant messaging support (via WhatsApp)

Trial Health

75
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
1,094

participants targeted

Target at P75+ for not_applicable

Timeline
14mo left

Started Jun 2025

Typical duration for not_applicable

Geographic Reach
1 country

1 active site

Status
active not recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress43%
Jun 2025Jun 2027

First Submitted

Initial submission to the registry

March 31, 2025

Completed
6 days until next milestone

First Posted

Study publicly available on registry

April 6, 2025

Completed
3 months until next milestone

Study Start

First participant enrolled

June 21, 2025

Completed
1 year until next milestone

Primary Completion

Last participant's last visit for primary outcome

June 30, 2026

Expected
1 year until next milestone

Study Completion

Last participant's last visit for all outcomes

June 30, 2027

Last Updated

December 1, 2025

Status Verified

May 1, 2025

Enrollment Period

1 year

First QC Date

March 31, 2025

Last Update Submit

November 22, 2025

Conditions

Smoking Cessation

Keywords

Large-language modelChatbotSmoking cessationBehavioral counsellingDigital health

Outcome Measures

Primary Outcomes (1)

  • Biochemically validated abstinence

    Defined as exhaled CO level \<4ppm and saliva cotinine level ≤30 ng/ml

    6-month follow-up

Secondary Outcomes (4)

  • Biochemically validated abstinence

    3-month follow-up

  • Self-reported 7-day point prevalence abstinence

    3- and 6-month follow-ups

  • Self-reported reduction

    1-, 2-, 3- and 6-month follow-ups

  • Self-reported use of smoking cessation service

    1-, 2-, 3- and 6-month follow-ups

Study Arms (2)

Intervention group

EXPERIMENTAL
Behavioral: AWARD adviceBehavioral: Brief leaflet on health warning and smoking cessationBehavioral: Referral cardBehavioral: Self-help smoking cessation bookletBehavioral: Personalized active referralBehavioral: 12 weeks of chatbot-based instant messaging supportBehavioral: Reminder messages

Control group

ACTIVE COMPARATOR
Behavioral: AWARD adviceBehavioral: Brief leaflet on health warning and smoking cessationBehavioral: Referral cardBehavioral: Self-help smoking cessation bookletBehavioral: Personalized active referralBehavioral: Reminder messages

Interventions

AWARD adviceBEHAVIORAL

AWARD advice include Ask about smoking history, Warn about the high risk, Advise to quit, Refer smokers to smoking cessation services (with a referral card), and Do it again.

Control groupIntervention group
Brief leaflet on health warning and smoking cessationBEHAVIORAL

The contents of the leaflet include (1) highlights of the absolute risk of death due to smoking; (2) the whole list of diseases caused by active and second-hand smoking; (3) ten horrible pictorial warnings of health consequences of smoking and second-hand smoking in one page to maximize the impacts; (4) benefits of SC and (5) simple messages to encourage participants to quit smoking.

Control groupIntervention group
Referral cardBEHAVIORAL

The contents consist of brief information and a highlight of existing smoking cessation services, contact methods, motivation information and strong supporting messages or slogans.

Control groupIntervention group
Self-help smoking cessation bookletBEHAVIORAL

The contents include information about the benefits of quitting, smoking and diseases, methods to quit, how to handle withdrawal symptoms, declaration of quitting, etc.

Control groupIntervention group
Personalized active referralBEHAVIORAL

Smokers will be introduced to various SC services in Hong Kong (using the referral card) and be motivated to use these services. Well-trained SC ambassadors will assist smoker to choose favourite/most convenient or preferred type of services. Research staff will assist participants in booking or re-booking the SC services at the 1- and 2-month follow-ups (after very brief questionnaire surveys). Participants' contact information will be forwarded to SC services providers within seven days, and providers are expected to contact the participants within 1-2 weeks. Research staff will also monitor SC services use of the participants at each follow-up (1-, 2-, 3- and 6- month) and assist participants to book or re-book the appointments if necessary at 1- and 2- month follow-up. We shall liaise with the existing service providers and seek their assistance in helping our smokers in helping our smokers in a timely manner.

Control groupIntervention group
12 weeks of chatbot-based instant messaging supportBEHAVIORAL

Participants in the intervention group will receive 12 weeks of instant messaging support delivered by the LLM-based chatbot accessible via WhatsApp platform. The chatbot, powered by GPT-4o model (or more advanced model available) using prompt-engineering and agent-based techniques, will deliver brief theory-based, structured SC intervention alongside freeform, on-demand support. The structured intervention session deploys the 5As model (Ask, Advise, Assess, Assist, and Arrange follow-up) and 5Rs model (Relevance, Risks, Rewards, Roadblocks, Repetition), as used in our previous telephone-counselling trials and recommended by WHO for brief SC intervention.

Intervention group
Reminder messagesBEHAVIORAL

WhatsApp messages on follow-up survey reminders.

Control groupIntervention group

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Hong Kong residents aged 18 or above
  • Smoke at least 1 tobacco stick (includes HTP) per day or use e-cigarette daily in the past 3-month
  • Able to communicate in Chinese
  • Exhaled carbon monoxide level ≥4 part per million or a positive salivary cotinine test
  • Intention to quit/reducing smoking
  • Have instant messaging tool (WhatsApp) installed
  • Able to use the instant messaging tool (e.g., WhatsApp) for communication

You may not qualify if:

  • Smokers who have communication barriers (either physical or cognitive).
  • Smokers who are currently participating in other smoking cessation programs or services.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Hong Kong Council on Smoking and Health (COSH)

Hong Kong, Hong Kong, 999077, Hong Kong

Location

MeSH Terms

Conditions

Smoking Cessation

Condition Hierarchy (Ancestors)

Health BehaviorBehavior

Study Officials

  • Man Ping Wang, PhD

    The University of Hong Kong

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
OUTCOMES ASSESSOR
Purpose
HEALTH SERVICES RESEARCH
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Professor

Study Record Dates

First Submitted

March 31, 2025

First Posted

April 6, 2025

Study Start

June 21, 2025

Primary Completion (Estimated)

June 30, 2026

Study Completion (Estimated)

June 30, 2027

Last Updated

December 1, 2025

Record last verified: 2025-05

Data Sharing

IPD Sharing
Will not share

Locations

HK(1)