SMS-based smoking cessation intervention among university students: study protocol for a randomised controlled trial (NEXit trial)

BACKGROUND: Most smoking efforts targeting young people have so far been focused on prevention of initiation, whereas smoking cessation interventions have largely been targeted towards adult populations. Thus, there is limited evidence for effective smoking cessation interventions in young people, even though many young people want to quit smoking. Mobile communication technology has the potential to reach large numbers of young people and recent text-based smoking cessation interventions using phones have shown promising results. METHODS/DESIGN: The study aims to evaluate a newly developed text-based smoking cessation intervention for students in colleges and universities in Sweden. The design is a randomised controlled trial (RCT) with a delayed/waiting list intervention control condition. The trial will be performed simultaneously in all colleges and universities served by 25 student health care centres in Sweden. Outcomes will be evaluated after 4 months, with 2 cessation primary outcomes and 4 secondary outcomes. After outcome evaluation the control group will be given access to the intervention. DISCUSSION: The study will examine the effectiveness of a stand-alone SMS text-based intervention. The intervention starts with a motivational phase in which the participants are given an opportunity to set a quit date within 4 weeks of randomisation. This first phase and the subsequent core intervention phase of 12 weeks are totally automated in order to easily integrate the intervention into the daily routines of student and other health care settings. As well as providing data for the effectiveness of the intervention, the study will also provide data for methodological analyses addressing a number issues commonly challenging in Internet-based RCTs. For example, an extensive follow-up strategy will be used in order to evaluate the use of repeated attempts in the analysis, and in particular to explore the validity of a possible missing not at random assumption that the odds ratio between the primary outcome and response is the same at every attempt. TRIAL REGISTRATION: ISRCTN: ISRCTN75766527, dated assigned 4 November 2014. Protocol version: Version 1, and date 7 November 2014. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13063-015-0640-2) contains supplementary material, which is available to authorized users.