mHealth smoking cessation intervention among high-school pupils (NEXit Junior): study protocol for a randomized controlled trial

Smoking is responsible for about 10% of the total disease burden in Sweden, and around 6000 people die every year due to smoking [1]. In Sweden, the prevalence of daily smoking among young people aged between 16 and 29 years has been stable during the last 5 years at approximately 11–13% among women and 7–10% among men. The figures for occasional smoking were approximately 19–22% for women and 22–24% for men during the same period [2, 3]. Around 25% of high-school pupils were smoking in 2016 and a third of those were daily smokers [4].

However, most tobacco control programs in schools focus on prevention of uptake rather than offering support for quitting smoking [5]. Implementation of smoking cessation interventions at the high-school level could, therefore, have a major impact on population health. A recent Cochrane review including 28 trials suggested that interventions that have shown to be effective among adults, e.g., motivational enhancement, could also be effective among adolescents. However, the review also showed that there is currently insufficient evidence to recommend a specific method of intervention for young people and that more data are needed on long-term cessation [6]. Furthermore, although recent figures show that around two thirds of high-school smokers want to quit [7], only about one in ten seeks or gains access to evidence-based interventions [8, 9].

During the last decade, the number of Internet and computerized interventions has expanded substantially, moving interventions from the health care sector to the homes of the general population. However, a meta-review, including 41 studies on online prevention aimed at lifestyle behaviors, showed that the majority of users were female, highly educated, white, and living in high-income countries. Also that the overall use of the interventions was low [10].

In contrast to Internet-based interventions delivered on computers, mobile health (mHealth) interventions have the capacity to interact in a more dynamic way as individual messages are delivered at certain predetermined intervals. Text-based interventions also offer other advantages. Users can access text-messaging services (SMS) whenever they feel an urge to smoke, and these interventions can be provided to individuals within their own environment and delivered in real time [11‐14]. Also, mHealth interventions using a “push” technique, such as text messages, do not require the user to seek out information or maintain engagement by going to a website. As the growth of mobile phone ownership and usage is expected to continue to grow, mobile technology offers an innovative way to reach smokers worldwide [14].

Various challenges and tasks can be sent via text messages that require a user response. This may allow two-way communication in real-time, facilitating adherence to the intervention and providing short, timed bursts of information throughout the day. Because nearly all young people have a mobile phone, mHealth interventions could reach a large proportion of the target group and could have a significant impact as a result of the high levels of exposure, low cost, and strong adherence to text-based interventions [15, 16].

There is increasing evidence that text-messaging programs on mobile phones can help people to modify their health behaviors. The evidence is particularly strong for smoking cessation. A recent Cochrane review indicated that smoking cessation programs by text messaging increased long-term quit rates by 67% [15]. Text messages have been found to help increase access to educational and support services that promote smoking cessation across diverse populations [14]. A recent meta-review on text-message interventions for smoking cessation, including 13 studies, showed that cessation rates for the intervention group were 36% higher than for the control group [17]. An earlier review including five studies showed a similar short-term effect of text-message interventions on smoking cessation; however, limited long-term effects were found [17]. Interventions including text messages have also been found to be effective among young adults [11, 16]. A study aiming to test the efficacy of a text-based intervention in high school showed significant smoking abstinence among occasional smokers [18]. However, the study included a small sample size. A meta-analysis investigating text-messaging interventions targeting smoking among adolescents concluded that although there is supporting evidence, a greater understanding is needed on how the interventions work, i.e., mechanisms of change. Furthermore, to our knowledge, no studies have been performed in Sweden targeting high-school pupils, and there is a need for an effective intervention that can be implemented and offered via high schools.

In our previous research, we developed an mHealth intervention, NEXit, targeting smoking among university students. NEXit was developed by our research group, using formative research methods (for more details [19]). The text messages in the main NEXit study were developed based on existing evidence-based practice, expert guidance, and official smoking cessation manuals recommended in Sweden. Key elements from previous text- and Internet-based interventions were also included, e.g., problem-solving tips and distraction techniques. The effectiveness of the main NEXit intervention was evaluated in a two-arm randomized controlled trial (RCT) including 1590 participants of between 21 and 30 years of age. The trial showed a significant difference between the intervention group (25.9%) and the control group (delayed intervention) (14.6%) on 8-week prolonged abstinence. For 4-week point prevalence of complete cessation, the numbers were 20.6 and 14.2%, respectively. Students who received the intervention were almost twice as likely to quit smoking than students in the control group [20].

This article presents the study protocol of a RCT testing the effectiveness of an mHealth intervention targeting smoking among high-school pupils in Sweden.

All high schools in Sweden are bound by law to offer a smoke-free environment for their pupils. However, little effort has gone into finding effective ways of systematically helping pupils who wish to quit smoking; the emphasis is on the prevention of uptake. Following the success of our NEXit smoking cessation trial among university students, we believe that a similar mHealth intervention targeting high-school pupils may also be effective. The potential direct benefit from the trial is an intervention program that can be made available nationwide at very low cost, requiring little or no resources from participating high schools.

Although smoking cessation programs delivered via text messages have been evaluated previously, there has not been much research on the medium- and long-term effects of the intervention. The current research project, therefore, investigates not only the immediate effect at 3 months but also the intermediate and long-term effects at 6 and 12 months.

A limitation of the study is that follow-up will not be biochemically verified, but will rather rely on participants’ self-reported abstinence. However, any bias in reporting may be assumed to be equal in both the intervention group and the control group. Also, The Society for Research on Nicotine and Tobacco recommends that, in population-based studies with limited face-to-face contact, it is neither required nor desirable to use biochemical verification [22].