This study aims to evaluate the effectiveness of a general health promotion (GHP) approach to motivate smokers with chronic diseases to quit smoking. Subjects in the intervention group will receive a brief Motivational Interviewing (MI) using a GHP approach. Subjects in the control group will receive a self-help booklet on smoking cessation at the time of recruitment.

Smoking has harmful effects on nearly every organ of the body and causes seven million deaths worldwide every year. Although the prevalence of daily cigarette smoking in Hong Kong has decreased from 23.3% in 1982 to 10.5 % in 2015, there are still 641,300 daily smokers and 400,000 hospitalisations per year that are attributable to smoking. Having a disease and requiring medical attention present an excellent 'teachable moment' and opportunity for initiating smoking cessation in patients, because they will be more likely to be motivated to alter their habits and improve their health. However, cigarette smoking is addictive and quitting is very difficult, with a high rate of relapse, particularly among patients with chronic diseases.

During the past decade, the investigators have conducted several trials on promoting smoking cessation to smokers with chronic diseases, including cardiac, type 2 diabetes mellitus, and cancer. It is found that many smokers with chronic diseases had a long smoking history, high nicotine dependency, no quit attempt, and no intention to quit. Results of these studies indicated that about 68% smokers with cardiac diseases, 70% with diabetes mellitus and 73% with cancer recruited in Special Out-Patient Clinics (SOPC) were still in the pre-contemplation stage. This revealed that most Hong Kong smokers with chronic diseases perceived more barriers in quitting than the benefits of quitting. Nevertheless, our previous smoking cessation interventions mostly focused on using brief interventions including stage-matched smoking cessation advice. Such interventions could be too brief and inadequate to make a great impact on such smokers. Moreover, the investigators found that using strong warnings to communicate the risk of continued smoking might not be accepted by some of them. Hence, the investigators need to develop and evaluate a more innovative intervention to enhance the effectiveness in promoting smoking cessation for smokers with chronic diseases. Most importantly, the new strategy should have a good potential implementation in many clinical settings.

Smoking has been found to be associated with physical inactivity, unhealthy diet, and drinking. The interrelationship of health behaviours suggests that there could be a higher level of attribute that determines such behaviours together. Our previous studies showed that people with a general intention to promote their health are more likely to engage in desirable health-related lifestyle practices. In addition, research results showed that people once engaged in any desirable health-related lifestyle practices would progressively move to later stages of change for other health behaviours. Based on this concept, a general health promotion approach will be used to motivate smokers with intention to promote health to first engage in any desirable health-related lifestyle practices that are chosen by individual smokers, such as regular physical activity and healthy diet. It is anticipated that once they are engaged in any desirable health-related lifestyle practice they will eventually be more motivated to quit smoking.

Inclusion Criteria:

• aged 18 years or above,
• able to speak Cantonese and read Chinese
• no intention to quit smoking (pre-contemplation stage), but are willing to take action to promote health
• have a smart phone and able to use instant messaging tool (e.g. WhatsApp, WeChat) for communication, and
• willing to receive health promotion advices via WhatsApp/WeChat in the smart phone throughout the study

Exclusion Criteria:

• unable to give informed consent or participate in our intervention due to impaired mental status, cognitive impairment, or communication barrier, and
• participation in other smoking cessation programmes or services