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

Build to Quit 「築建無煙」: Gen AI Powered Behavioral Support Plus Chewing Gum Intervention for Construction Workers Who Smoke: A Pragmatic, Pilot, Cluster Randomized Controlled Trial

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)

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.

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:

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