JMIR Publications

ABSTRACT

Background:

Universal tobacco-prevention program targeting youths usually involve significant adults assumed to be important vehicles of social influences. Commitment not to use tobacco or to quit use as a formal contract between an adolescent and a significant adult, is a preventive model that has not been widely practiced or explored, and even less formally evaluated.

Objective:

In this article we present the rationale and protocol for the evaluation of the Swedish program “Tobacco-free Duo”, a multi-component school-based program the core of which rests on a formal agreement (contract) between an adolescent and an adult. The adolescent’s commitment mainly concerns avoiding the onset of any tobacco use while the adult commits to support the adolescent in staying tobacco free, being a role model not using tobacco themselves.

Methods:

A mixed-design approach was developed. First, a cluster randomized controlled trial was designed with schools randomly assigned either to the comprehensive multi-component program or to its educational component only. Primary outcome at the adolescent level was identified as “not having tried tobacco” during the three-year junior high school compulsory grades (12-15 years of age). An intention-to-treat cohort-wise approach, an “as treated” approach complemented with a whole school repeated cross-sectional approach, was devised as analytical methods of the trial data. Second, an observational study was added in order to compare the development of smoking prevalence in the schools participating in the experiment with that of a convenience sample of schools not being part of the experimental study. Diverse secondary outcomes at both adolescent and adult level were also included.

Results:

The study was approved by the Regional Ethics Review Board, Umeå (registration nr. 2017/255-31) in 2017. Recruitment of schools started in the fall of 2017 and went on until June 2018. In total 43 schools were recruited to the experimental study and 16 schools were recruited to the observational study. Data collection started in the fall 2018 and is ongoing. The last round of data collection is planned for the spring 2021. Data analysis of baseline characteristics is due to commence, and first results are expected at the end of 2020.

Conclusions:

Methodological, ethical and practical implications of the evaluation protocol are discussed. The protocol illustrates the advantage of combining several sources of data in order to triangulate the main underlying question, i.e. whether a component of public contract and commitment affects youth’s propensity to start using tobacco. The results of these studies will help revise the agenda of this as well as of similar programs. Clinical Trial: Current Controlled Trials ISRCTN52858080 Date: January 4, 2019, retrospectively registered