NCT07649018

Brief Summary

The goal of this pilot trial is to learn if 1-week NRT sampling, 3-week chewing gum, and 12-week chatbot-delivered instant messaging support works to help smoking cessation in construction workers who smoke. It will also learn about the feasibility, acceptability, and preliminary effectiveness of delivering the comprehensive intervention in construction settings. The main questions it aims to answer are:

  1. 1.Will the integrated intervention, comprising NRT sampling, chewing gum, and chatbot-delivered instant messaging support, show feasibility, acceptability, and appropriateness for delivery in construction worksite settings?
  2. 2.Will participants who receive the comprehensive intervention have a higher validated abstinence rate than those who receive NRT sampling alone?
  3. 3.AWARD advice and brief video
  4. 4.1-week NRT sampling
  5. 5.3-week chewing gum
  6. 6.12-week chatbot-based instant messaging support (via WhatsApp)

Trial Health

63
Monitor

Trial Health Score

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

Enrollment
200

participants targeted

Target at P75+ for not_applicable

Timeline
13mo left

Started Jun 2026

Geographic Reach
1 country

1 active site

Status
not yet 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

First Submitted

Initial submission to the registry

June 9, 2026

Completed
6 days until next milestone

First Posted

Study publicly available on registry

June 15, 2026

Completed
5 days until next milestone

Study Start

First participant enrolled

June 20, 2026

Expected
12 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

May 31, 2027

1 month until next milestone

Study Completion

Last participant's last visit for all outcomes

June 30, 2027

Last Updated

June 15, 2026

Status Verified

June 1, 2026

Enrollment Period

12 months

First QC Date

June 9, 2026

Last Update Submit

June 9, 2026

Conditions

Keywords

Nicotine replacement therapyChewing gumChatbotLarge Language modelDigital healthConstruction worker

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 (6)

  • 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

  • Family well-being

    3- and 6-month follow-ups

  • +1 more secondary outcomes

Other Outcomes (6)

  • Recruitment rate

    Baseline

  • Retention rate

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

  • Chatbot usability

    3-month follow-up

  • +3 more other outcomes

Study Arms (2)

Intervention group

EXPERIMENTAL
Behavioral: AWARD adviceBehavioral: Brief leaflet on health warning and smoking cessationBehavioral: Referral cardBehavioral: Self-help smoking cessation bookletDrug: 1-week nicotine gumBehavioral: 3-week chewing gumBehavioral: 12-week chatbot-based instant messaging supportBehavioral: Brief video

Control group

ACTIVE COMPARATOR
Behavioral: AWARD adviceBehavioral: Brief leaflet on health warning and smoking cessationBehavioral: Referral cardBehavioral: Self-help smoking cessation bookletDrug: 1-week nicotine gumBehavioral: Brief video

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

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 secondhand 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

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

Participants in both group will receive a 1-week supply of free nicotine gum (2 mg or 4 mg). The dosage of nicotine gum will be guided by participants' daily cigarette consumption, in accordance with recommendations from the Department of Health. Research assistants will explain the benefits of NRT for smoking cessation, provide instructions on the correct use of nicotine gum, encourage participants to continue using nicotine gum after completing the free sample where appropriate, and advise participants to reduce smoking or make a quit attempt when using NRT.

Control groupIntervention group

Participants in the intervention group will receive 6 packs of chewing gum at baseline (2 packs per week). Chewing gum will be presented as a practical strategy to replace the hand-to-mouth and oral routines associated with smoking, particularly during work breaks, after meals, in other smoking-related situations at construction sites, or when participants are unwilling to use nicotine gum.

Intervention group

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 Claude model (or more advanced model available) using prompt-engineering and agent-based techniques, will deliver theory-based and structured 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
Brief videoBEHAVIORAL

Participants in both groups will receive a brief motivational video (15-second) via WhatsApp. The video will feature a construction worker who successfully quit smoking in our previous trial, providing a relatable peer role model for participants. The video will welcome participants to the programme, encourage them to make a quit attempt, and promote early use of nicotine gum as a practical strategy for managing cravings and supporting smoking cessation.

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 one cigarette per day in the preceding 3-month
  • Able to communicate in Cantonese (including reading and writing Chinese)
  • Saliva cotinine 30 ng/ml or above
  • Intent to quit / reduce smoking
  • Have instant messaging tool (WhatsApp) installed
  • Able to use instant messaging tool (e.g., WhatsApp) for communication.

You may not qualify if:

  • Smokers who are participating in other smoking cessation programmes
  • Smokers who are using any smoking cessation medication
  • Smokers who are presenting with the following oral diseases, including recent oral surgery or tooth extraction, unstable dentures, significant tooth mobility or advanced periodontal disease, temporomandibular pain or dysfunction, or painful oral mucosal lesions

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

Interventions

Nicotine Chewing GumChewing Gum

Condition Hierarchy (Ancestors)

Health BehaviorBehavior

Intervention Hierarchy (Ancestors)

Plant GumsBiopolymersPolymersMacromolecular SubstancesPolysaccharidesCarbohydratesTobacco Use Cessation DevicesTherapeuticsCandyFoodDiet, Food, and NutritionPhysiological PhenomenaFood and BeveragesPlant ExudatesBiological ProductsComplex Mixtures

Study Officials

  • Man Ping Wang, PhD

    The University of Hong Kong

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Man Ping Wang, PhD

CONTACT

Mengyao Li, Mphil

CONTACT

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

June 9, 2026

First Posted

June 15, 2026

Study Start (Estimated)

June 20, 2026

Primary Completion (Estimated)

May 31, 2027

Study Completion (Estimated)

June 30, 2027

Last Updated

June 15, 2026

Record last verified: 2026-06

Data Sharing

IPD Sharing
Will not share

Locations