title: SMS-based smoking cessation intervention among university students: study protocol for a randomised controlled trial (NEXit trial).
abstract: 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
  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.
  
  
  CONCLUSIONS
  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.
  
  
  BACKGROUND
  
  ISRCTN75766527, dated assigned 4 November 2014. Protocol version: Version 1, and date 7 November 2014.
authors: Department of Medicine and Health Sciences, Linköping University, 581 83, Linköping, Sweden. ulrika.mussener@liu.se.
authors: Ulrika
authors: U
authors: Müssener
authors: Department of Computer and Information Science, Linköping University, 581 83, Linköping, Sweden. marcus.bendtsen@liu.se.
authors: Marcus
authors: M
authors: Bendtsen
authors: Department of Medicine and Health Sciences, Linköping University, 581 83, Linköping, Sweden. nadine.karlsson@liu.se.
authors: Nadine
authors: N
authors: Karlsson
authors: MRC Biostatistics Unit, Cambridge Institute of Public Health, Robinson Way, Cambridge, CB2 0SR, UK. ian.white@mrc-bsu.cam.ac.uk.
authors: Ian R
authors: IR
authors: White
authors: Department of Medicine and Health Sciences, Linköping University, 581 83, Linköping, Sweden. Jim.mccambridge@york.ac.uk.|Department of Health Sciences, University of York, Heslington, YO10 5DD, UK. Jim.mccambridge@york.ac.uk.
authors: Jim
authors: J
authors: McCambridge
authors: Department of Medical Specialist and Department of Medicine and Health Sciences, Linköping University, Motala, 581 83, Linköping, Sweden. Preben.bendtsen@liu.se.
authors: Preben
authors: P
authors: Bendtsen
mesh_terms: D000328:Adult; D002985:Clinical Protocols; D006801:Humans; D017063:Outcome Assessment, Health Care; D016540:Smoking Cessation / Q000379:methods*; D013334:Students; D060145:Text Messaging; D014495:Universities