Semi-personalized IM Smoking Cessation Interventions

Tailored automatic, fix- scheduled regular messages will be sent and counselors will interact with smokers in the intervention group through WhatsApp since initial contact and until 2-month after baseline. The interaction will follow the principle of Motivational Interviewing, which will focus on enabling change through the enhancement of intrinsic motivation and the exploration and resolution of ambivalence. Counsellors will identify discrepancies between participants' thought and their action, support their autonomy, be empathetic towards the participant, avoid confrontation, and adjust to resistance. Any smokers who do not use IM or refuse to receive IM messages will be contacted via SMS messages or telephone calls. For smokers who do not respond to regular messages, 3 additional prompt messages will be sent in the 1st month to initiate a conversation.

AWARD will be delivered to smokers onsite and this includes: Ask about smoking history, Warn about the high risk, Advise to quit or reduce smoking as soon as possible, Refer smokers to smoking cessation services (with a SC service information card), and Do it again: to repeat the intervention; participants who fail to quit or relapse will be encouraged to quit again (and those who have quit smoking will be encouraged to prevent relapse) during telephone follow-ups. The whole process of AWARD can be delivered within 1 to 2 minutes.

One-week free nicotine replacement therapy (NRT) sampling (gum or patch) will be disseminated to participants who are interested to try after completing the baseline questionnaire. An NRT use card containing reminders of NRT use and potential side effects will be given. Counselors and research staff will also check the side effects of NRT use during WhatsApp interaction and telephone follow-ups.

SC ambassadors will introduce various SC services in Hong Kong (using the SC service information card) and motivate smokers to use the SC services. Written consents will be obtained from smokers who are ready to book the service onsite for transfer of their contact telephone numbers to their chosen service providers. Our research staff will transfer the information to the service providers within a week since the enrollment. For smokers in Group A, our research staff will also assist them to re-book the appointments upon their request at follow-up. SC ambassadors will encourage smokers in Group A who are not ready to book SC service to make an early appointment and assist them at follow-up.

All smokers will receive fix-schedule general messages on SC through short message service (SMS) since their initial participation until 2-month after baseline. These messages include: (a) brief health warning, (b) benefit of quitting, (c) methods to quit and to cope with craving, and (d) SC services and their effectiveness. General SC messages will be sent twice per week in the 1st month and once per week in the 2nd month after joining this study.