Plain English Summary
Background and study aims
Each year, thousands of children and adolescents in Sweden start smoking. Tobacco use increases with age and the earlier one starts smoking, the higher the risk to become addicted to nicotine and develop illnesses due to smoking. Although recent figures show that around two thirds of high school smokers want to quit, only about one in ten seek or gain access to evidence-based interventions. The evidence for the effectiveness of text messaging interventions to reduce smoking behaviour is well-established, yet there is still a great need for studies targeting high school pupils. The smoking cessation program NEXit Junior is a 12-week innovative text-based mHealth smoking cessation intervention based upon fully automated short mobile phone text messages. The messages are built from key elements of existing effective interventions, officially recommended practice manuals and guidance from smoking cessation experts. The effectiveness of the original NEXit intervention (targeting university students) was evaluated in a previous study including 1590 university students. Students who received the intervention were almost twice as likely to quit smoking. The aim of this study is to determine the effectiveness of the text-based smoking cessation intervention among high school pupils.
Who can participate?
High school students who smoke at least one cigarette a week and want to quit smoking
What does the study involve?
Participants are randomly allocated to either the intervention group or treatment as usual group. The intervention starts with a motivational phase of one week. In this first phase the participants receive text messages containing motivating information relevant for quitting, e.g. symptoms to expect after quitting, tips to avoid weight gain, tips to cope with cravings, avoiding smoking triggers, motivational support, and how to distract one’s mind from smoking. Participants also receive messages in order to prompt them to get rid of cigarettes, ashtrays and lighters, to avoid environments where they could normally smoke, and encourage them to overcome challenges of quitting. After 1 week the core intervention begins and runs for 12 weeks. Participants receive up to four text messages per day during the first few weeks, and then the number of messages per day decreases. During the last weeks of the program a single message per day is sent, with a few exceptions when participants do not receive any messages. Messages encourage participants to not begin smoking again and focus on their success so far. They are offered coping messages for handling cravings, motivational messages, and support with withdrawal symptoms. Follow-ups are conducted after 3, 6 months and 12 months to find out whether the participants have stopped smoking.
What are the possible benefits and risks of participating?
Participants may benefit from stopping smoking. There are no anticipated risks.
Where is the study run from?
High schools in Sweden
When is the study starting and how long is it expected to run for?
November 2017 to July 2019
Who is funding the study?
Linköping University (Sweden)
Who is the main contact?
Dr Ulrika Müssener
Dr Ulrika Müssener
Department of Medical and Health Sciences
Faculty of Medicine and Health
The effectiveness of a text-based mHealth smoking cessation intervention among high school students: a randomized controlled trial
NEXit Junior study
The study aims to evaluate the effectiveness of an innovative text-based mHealth smoking cessation intervention employing a single-blind two-arm randomized controlled trial (RCT) design with an intervention group and a treatment as usual group. Outcome measures will be assessed at 3 months in order to estimate immediate effects, as well as intermediate and long term effects at 6 and 12 months. The primary hypotheses are that participants in the intervention group will report significantly higher cessation rates, measured as prolonged abstinence and 4-week point prevalence of smoking abstinence, at follow-up compared with participants in the control group. Secondary hypotheses are that the intervention group will report significantly higher rates of 7-day point prevalence of smoking abstinence, higher mean number of quit attempts since taking part in the study, fewer number of uses of other smoking cessation services since first invitation to the study and lower numbers of cigarettes smoked weekly if still smoking at follow-up, compared with the control group.
Ethics Committee in Linköping, 19/09/2017, Ref: Dnr 2017/388-31
Randomized controlled trial
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Not available in web format, please use the contact details to request a participant information sheet
After signing on and completing a baseline questionnaire, participants will be randomized to the intervention or treatment as usual group. Randomization will be fully computerized and automated. No strata or blocks will be used during randomisation, each participant has equal probability of being randomised to either the intervention or control group.
The intervention starts with a motivational phase of one week. In this first phase the participants receive text messages containing motivating information relevant for quitting, e.g. symptoms to expect after quitting (biofeedback messages about what happens in the body after a quit attempt), tips to avoid weight gain, tips to cope with cravings, avoiding smoking triggers, motivational support, and how to distract one’s mind from smoking. Participants will also receive messages in order to prompt them to get rid of cigarettes, ashtrays and lighters, to avoid environments where they could normally smoke, and encourage them to overcome challenges of quitting.
After one week the core intervention begins and runs for 12 weeks. Participants will receive up to four text messages per day during the first few weeks, and then the number of messages per day decrease. During the last weeks of the program a single message per day is sent, with a few exceptions when participants will not receive any messages. Messages will encourage participants to not begin smoking again and focus on their success so far. They will be offered coping messages for handling cravings, motivational messages, and support with withdrawal symptoms.
Follow-ups will be conducted at 3, 6 months and 12 months after enrolment.
Primary outcome measure
Measured at 3, 6 and 12 months after enrolment:
1. Self-reported prolonged abstinence, defined as having not smoked more than five cigarettes in the last eight weeks
2. Self-reported 4-week point prevalence of smoking abstinence (no cigarettes smoked in the past 4 weeks)
Secondary outcome measures
Measured at 3, 6 and 12 months after enrolment:
1. Self-reported 7-day point prevalence of smoking abstinence
2. Mean number of quit attempts since taking part in the study
3. Number of uses of other smoking cessation services since first invitation to the study e.g. prescribed medication, nicotine replacement medication, counselling, calling helpline or any other help
4. Numbers of cigarettes smoked weekly (for participants still smoking at the time of follow-up only)
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. High school students
2. Smoking consumption of at least one cigarette a week
3. Willingness to make an attempt to quit smoking
4. Ownership of a mobile phone
Target number of participants
The study will be performed at all high schools in Sweden (n=1300 schools)
Participant exclusion criteria
Non-smokers and pupils who are not willing to attempt to quit smoking
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
All high schools in Sweden will be asked to partake in the RCT. The trial will be conducted at those high schools which accept to advertise the trial to their pupils.
Linköping University, LiU
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Study protocol article will be published before end of December 2017. The results will be published in scientific articles.
IPD sharing statement:
The datasets generated during and/or analysed during the current study are/will be available upon request from Dr Ulrika Müssener.
Intention to publish date
Participant level data
Available on request
Basic results (scientific)
1. 2018 protocol in: https://www.ncbi.nlm.nih.gov/pubmed/30466484