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Not yet recruitingNCT07649018Updated Jun 17, 2026

Gen AI Powered Behavioral Support Plus Chewing Gum Intervention for Construction Workers Who Smoke

An interventional study of AWARD advice and Brief leaflet on health warning and smoking cessation in Smoking Cessation, sponsored by The University of Hong Kong. Not yet recruiting at 1 site in Hong Kong. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-06-17.

Sponsored by The University of Hong Kong · Not applicable, Interventional, and Health services research

Phase
Not applicable
Study type
Interventional
Enrollment
200
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study 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. 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. Will participants who receive the comprehensive intervention have a higher validated abstinence rate than those who receive NRT sampling alone?

Researchers will compare the integrated intervention, comprising NRT sampling, chewing gum, and chatbot-delivered instant messaging support, to the standard care group (NRT sampling alone) to see if the integrated intervention works to promote smoking cessation.

Participants in the intervention group will receive:

  1. AWARD advice and brief video
  2. 1-week NRT sampling
  3. 3-week chewing gum
  4. 12-week chatbot-based instant messaging support (via WhatsApp)
Read the detailed description

Hong Kong has achieved a sustained reduction in daily cigarette smoking, from 23.3% in the early 1980s to 8.5% in 2025. However, the current prevalence remains above the Government's Towards 2025 target of 7.8%, indicating the need for continued and targeted cessation efforts. The construction industry represents a particularly important setting for intervention, as recent legislative amendments to designate construction sites as no-smoking areas have further strengthened the policy basis for promoting smoke-free worksites.

Construction workers (CWs) are a high-priority population for smoking cessation because they have consistently higher smoking prevalence than many other occupational groups and the general population. In Hong Kong, a workplace health study found that 45% of construction workers were daily smokers, nearly twice the prevalence among office clerks/professionals. For CWs, smoking may compound existing occupational health risks by increasing susceptibility to respiratory and cardiovascular diseases in a physically demanding and dust-exposed work environment.

This study proposes a comprehensive worksite-targeted smoking cessation intervention model for CWs who smoke in Hong Kong, integrating NRT sampling, chewing gum support, and chatbot-delivered instant messaging. NRT is an evidence-based pharmacotherapy for reducing nicotine withdrawal symptoms and supporting smoking abstinence, and has been widely used in community-based cessation interventions. For CWs, short-term NRT sampling may provide immediate access to evidence-based pharmacological support, reduce early withdrawal symptoms, and lower the initial barrier to treatment uptake in a worksite setting. Chewing gum may complement NRT sampling by serving as a low-cost behavioral substitute for smoking, particularly by replacing the hand-to-mouth and oral routines associated with cigarette use. Chatbot-delivered instant messaging support can further extend the intervention beyond the worksite by providing 24/7 support, reminders for NRT and chewing gum use, and real-time assistance during cravings or high-risk smoking situations.

02

Conditions studied

  • Smoking Cessation

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Keywords

  • Nicotine replacement therapy
  • Chewing gum
  • Chatbot
  • Large Language model
  • Digital health
  • Construction worker
03

In context

Smoking Cessation

304 studies on the registry are indexed under Smoking Cessation; 139 are open to participants now.

This study's planned enrollment of 200 is above the median of 154 across 285 interventional studies indexed under Smoking Cessation.

Browse Smoking Cessation studies →

Lead sponsor

The University of Hong Kong is the lead sponsor of 1,262 studies on the registry; 340 are open to participants now.

Of its 8 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  1. Hong Kong residents aged 18 or above
  2. Smoke at least one cigarette per day in the preceding 3-month
  3. Able to communicate in Cantonese (including reading and writing Chinese)
  4. Saliva cotinine 30 ng/ml or above
  5. Intent to quit / reduce smoking
  6. Have instant messaging tool (WhatsApp) installed
  7. Able to use instant messaging tool (e.g., WhatsApp) for communication.

Exclusion criteria

Exclusion Criteria:

  1. Smokers who are participating in other smoking cessation programmes
  2. Smokers who are using any smoking cessation medication
  3. 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
05

Study design

Phase
Not applicable
Primary purpose
Health services research
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Single (Outcomes assessor)
Enrollment
200 participants (estimated)

Study arms

  • Experimental
    Intervention group

    Behavioral: AWARD advice · Behavioral: Brief leaflet on health warning and smoking cessation · Behavioral: Referral card · Behavioral: Self-help smoking cessation booklet · Drug: 1-week nicotine gum · Behavioral: 3-week chewing gum · Behavioral: 12-week chatbot-based instant messaging support · Behavioral: Brief video

  • Active comparator
    Control group

    Behavioral: AWARD advice · Behavioral: Brief leaflet on health warning and smoking cessation · Behavioral: Referral card · Behavioral: Self-help smoking cessation booklet · Drug: 1-week nicotine gum · Behavioral: Brief video

Interventions

  • BehavioralAWARD advice

    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.

  • BehavioralBrief leaflet on health warning and smoking cessation

    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.

  • BehavioralReferral card

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

  • BehavioralSelf-help smoking cessation booklet

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

  • Drug1-week nicotine gum

    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.

  • Behavioral3-week chewing gum

    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.

  • Behavioral12-week chatbot-based instant messaging support

    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.

  • BehavioralBrief video

    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.

06

What researchers measure

Primary outcomes

  1. Biochemically validated abstinence

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

    Time frame: 6-month follow-up

Secondary outcomes

  1. Biochemically validated abstinence

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

    Time frame: 3-month follow-up

  2. Self-reported 7-day point prevalence abstinence

    Smokers who did not smoke even a puff in the 7 days preceding the follow-up

    Time frame: 3- and 6-month follow-ups

  3. Self-reported reduction

    Defined by at least 50% reduction in baseline daily number of cigarettes

    Time frame: 1-, 2-, 3- and 6-month follow-ups

  4. Self-reported use of smoking cessation service

    Use of smoking cessation service at 1-, 2-, 3- and 6-month follow-ups.

    Time frame: 1-, 2-, 3- and 6-month follow-ups

  5. Family well-being

    Family well-being will be assessed using the 3H scale, which measures perceived family health, happiness, and harmony on a 0-10 scale.

    Time frame: 3- and 6-month follow-ups

  6. Perceived family happiness

    Perceived family happiness will be measured using a single-item self-reported family happiness scale ranging from 0 to 10.

    Time frame: 3- and 6-month follow-ups

Other outcomes

  1. Recruitment rate

    Defined as the number of participants divided by the number of eligible smokers

    Time frame: Baseline

  2. Retention rate

    Defined as the number of participants who completed the follow-up divided by the number of participants

    Time frame: 1-, 2-, 3- and 6-month follow-ups

  3. Chatbot usability

    Chatbot usability will be evaluated using the 11-item Bot Usability Scale (BUS), which assesses perceived effectiveness, efficiency, and satisfaction. The score of the Bot Usability Scale ranges from 0 to 100, with the higher score indicating more usability of the chatbot.

    Time frame: 3-month follow-up

  4. Acceptability of NRT sampling

    Acceptability of NRT sampling will be assessed through 4 brief items (score range from 0 to10) on perceived usefulness for craving relief, perceived side effects, willingness to continue using NRT after the free sample, and overall satisfaction with the NRT gum.

    Time frame: 1-, 2-, 3- and 6-month follow-ups

  5. Acceptability of chewing gum

    Acceptability of chewing gum will be assessed through 3 brief items (score range from 0 to 10) on perceived usefulness for behavioral substitution, perceived fit with construction worksite routines, and willingness to continue using chewing gum as a cessation aid.

    Time frame: 1-, 2-, 3- and 6-month follow-ups

  6. Self-reported adverse events

    Self-reported adverse events related to nicotine gum and chewing gum will be assessed using a binary question: "Have you experienced any adverse events when using nicotine gum or chewing gum?"

    Time frame: 1-, 2-, 3- and 6-month follow-ups

07

Study locations

1 site
  • Hong Kong Council on Smoking and Health (COSH)
    Hong Kong, Hong Kong 999077, Hong Kong
    • Fung Wong · Contact · +852 2180 5186
    • Mengyao Li, Mphil · Sub investigator
    • Tai Hing Lam, MD · Sub investigator
    • Tzu Tsun Luk, PhD · Sub investigator
    • Ziqiu Guo, PhD · Sub investigator
    • Xiaoyun Xie, MPH · Sub investigator
    • Yilan Wu, Mphil · Sub investigator
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jun 17, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT07649018
Lead sponsor
The University of Hong Kong
Responsible party
Prof. Wang Man-Ping (Professor, The University of Hong Kong) — Principal investigator
First posted
Jun 15, 2026
Start date
Jun 20, 2026 (estimated)
Primary completion
May 31, 2027 (estimated)
Completion
Jun 30, 2027 (estimated)
Last update
Jun 17, 2026

Study contacts

Man Ping Wang, PhD
Contact
mpwang@hku.hk
+852 3917 6636
Mengyao Li, Mphil
Contact
lmy0814@connect.hku.hk
+852 6851 8462
Man Ping Wang, PhD
principal investigator · The University of Hong Kong

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is not yet recruiting, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.

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