Evaluating the Efficacy of a Text Messaging-based Shisha Smoking Cessation Intervention for Young Adults in Hong Kong: A Randomised Controlled Pilot Trial

Shisha smoking becomes the most prevalent form of tobacco use among university students in Hong Kong. The World Health Organisation (WHO) has urged healthcare professionals, policy makers and researchers to establish cultural-specific preventing and controlling strategies for shisha smoking to address this uprising public health threat. To date, only limited researches have been conducted focusing on reducing shisha use. Medications, like varenicline and bupropion, do not outweigh behavioural intervention alone for shisha smoking cessation. Early interventions adopting from traditional tobacco smoking cessation interventions were unsuccessful in lowering the smoking rates since these interventions were unable to cover the unique features of shisha smoking, such as the social dimension, the intermittent smoking patterns and the positive attitudes towards shisha. Though a Cochrane review and meta- analysis conducted in 2022 supported the use of behavioural intervention to promote shisha abstinence (risk ratio = 3.19, 95% CI: 2.17-4.69), the level of evidence remained unsatisfactory as there were only 9 interventional studies included. The authors further suggested that more interventional studies with the use of e-health behavioural interventions for shisha smoking cessation might enhance the robustness on its efficacies.

There are strong cultural differences for the practice of shisha smoking. For example, shisha smoking is a religiously acceptable culture that deeply ingrained in Middle Eastern countries whereas it is more of a social activity in Hong Kong. In fact, culture-based shisha cessation strategies showed preliminary promising results in reducing shisha smoking. For instance, an Iranian study which recruited 212 shisha-exclusive women to evaluate the effectiveness of a 4-month in-person educational program revealed that the programme had significantly increased shisha abstinence rates, health knowledge, self-efficacy, and intention to quit when compared to the control group. A recent randomised controlled trial adopting a 6-week smoker-tailored mobile messaging intervention among 319 young adults in the US demonstrated promising results in shisha abstinence and reduced the frequency of use last up to 6 months. Up-to-date, there is no Chinese- or Hong Kong-culture based shisha smoking intervention programme available. Thus, the development of a culture specific shisha cessation interventional program for shisha smokers in Hong Kong is deemed necessary.

In short, shisha smoking is common in Hong Kong especially among youth and young adults despite its hazardous effects being similar to cigarette smoking. A growing amount of evidence has supported the use of shisha-specific behavioural interventions to address this public health threat. With the recommendation from WHO on the culture specific interventions for shisha smoking cessation but a lack of such cessation intervention in the East Asian region, there is an utmost urgent need to develop and research on a shisha smoking cessation intervention for young adults in Hong Kong.

In light of such contexts, we developed a culture specific smartphone text messaging-based shisha smoking cessation intervention for young adults in Hong Kong using the well-structured intervention mapping method. Intervention mapping is an iterative process that is commonly used to develop, implement and evaluate theory-based health or behavioural interventions. It has been widely adopted to design and implement behavioural interventions in shisha smoking and cigarette smoking cessation studies. Based on the shisha smoker's individual characteristics, the developed text messaging-based intervention contains personalised messages with both text and visual elements emphasising the negative impacts of shisha smoking. Supported by previous overseas and local studies using mHealth intervention, together with the high penetration rates of smartphone use in Hong Kong and the openness to mobile health interventions, smartphone instant messaging applications, such as WhatsApp, Telegram and Signal, will be the powerful and effective delivery modes for this text messaging-based shisha smoking cessation intervention among Hong Kong young adults.

The current randomised controlled pilot trial aims to evaluate the efficacy of the culture specific text-messaging based shisha smoking cessation intervention for young adults in Hong Kong. It is hypothesised that participants randomly allocated to the intervention can achieve higher shisha abstinence, which maintain through the three months follow-up study period than the participants in the control group. For secondary outcomes, it is hypothesised that participants in the intervention group will have lowered level of dependency, increased knowledge on risk, improved readiness to quit, and more negative attitudes on shisha smoking during the study period.