Implementation fidelity describes how well an intervention is implemented in the real-world setting. Assessing implementation fidelity is essential in the understanding of intervention results. In most studies, implementation fidelity is measured insufficiently, though, not taking into account the complexity of the concept nor the intervention. The objective of the present study was to develop an overall quantitative measure of implementation fidelity, to examine the degree of implementation fidelity and the association of implementation and effect of a randomized school-based smoking prevention trial—the X:IT study. A cluster-randomized trial testing is a multi-component intervention to prevent smoking among adolescents in 94 Danish elementary schools (51 intervention, 43 control schools). Participants were grade 7 pupils (mean age 12.5 years). Data was collected by electronic questionnaires among pupils at baseline (n = 4161), the first follow-up (n = 3764), and the second follow-up (n = 3269) and among school coordinators at intervention schools at the first and second follow-up (50 and 39 coordinators). Intervention: The intervention included three components: (1) smoke-free school grounds, (2) smoke-free curriculum, and (3) parental involvement, contracts, and dialogues. Implementation fidelity was assessed by four domains: adherence, dose, quality of delivery, and participant responsiveness. These were combined into an overall school-wise implementation index. The association of implementation and smoking was examined by logistic regression analyses. One fourth of the schools was characterized as high implementers of the program (all three components) at both first (12 schools, 24.0 %) and second follow-up (11 schools, 28.2 %). Implementation fidelity was strongly associated with smoking at the first and second follow-up, e.g., the odds for smoking at schools with high implementation both years were OR = 0.44 (95 % CI 0.32 to 0.68). Using an overall measure based on several aspects of implementation fidelity, we showed a negative graded association between implementation and smoking. This study suggests that higher degrees of implementation will improve the effect of the X:IT intervention. Studying the association between implementation and effect is extremely important; only by doing so, we can distinguish the quality of the intervention from the success of the implementation. Current Controlled Trials ISRCTN77415416

While smoking is declining among young people, smokeless tobacco use is increasing. Identifying who is using smokeless tobacco and why is essential in preventing smokeless tobacco use. This study aimed to comprehensively explore the factors of young people's use of smokeless tobacco in western countries and identify research gaps. We conducted a systematic scoping review of studies that examined factors associated with smokeless tobacco use among young people (ages 13-29) from western countries published between January 2011 and September 2021. Searches were conducted in CINAHL, Medline, and Scopus. Studies on adults, total tobacco use (i.e., did not differentiate between tobacco product types), dual and multiple uses of tobacco, and studies on smokeless tobacco cessation programs were excluded. A total of 160 studies were included in this scoping review. The studies were primarily undertaken in the US and the Scandinavian countries, and the majority explored smokeless tobacco use without distinguishing between the specific types. Smokeless tobacco users were more likely to be male, non-Hispanic white, engaging in physical activity, and using other substances, including cigarettes and alcohol. The role of friends and family were identified as critical factors that were related to the use of smokeless tobacco. This scoping review suggests that preventative measures against smokeless tobacco use should focus on peer and family members' roles and that these measures may benefit from targeting males. Additional research, including systematic reviews on this area to validate the identified associated factors, would improve the understanding of smokeless tobacco use.

Background: Uptake of smoking in adolescence is still of major public health concern. Evaluations of school-based programmes for smoking prevention show mixed results. The aim of this study was to examine the effect of X:IT, a multi-component school-based programme to prevent adolescent smoking. Methods: Data from a Danish cluster randomized trial included 4041 year-7 students (mean age: 12.5) from 51 intervention and 43 control schools. Outcome measure ‘current smoking’ was dichotomized into smoking daily, weekly, monthly or more seldom vs do not smoke. Analyses were adjusted for baseline covariates: sex, family socioeconomic position (SEP), best friend’s smoking and parental smoking. We performed multilevel, logistic regression analyses of available cases and intention-to-treat (ITT) analyses, replacing missing outcome values by multiple imputation. Results: At baseline, 4.7% and 6.8% of the students at the intervention and the control schools smoked, respectively. After 1 year of the intervention, the prevalence was 7.9% and 10.7%, respectively. At follow-up, 553 students (13.7%) did not answer the question on smoking. Available case analyses: crude odds ratios (OR) for smoking at intervention schools compared with control schools: 0.65 (0.48-0.88) and adjusted: 0.70 (0.47-1.04). ITT analyses: crude OR for smoking at intervention schools compared with control schools: 0.67 (0.50-0.89) and adjusted: 0.61 (0.45-0.82). Conclusions: Students at intervention schools had a lower risk of smoking after a year of intervention in year 7. This multi-component intervention involving educational, parental and context-related intervention components seems to be efficient in lowering or postponing smoking uptake in Danish adolescents.

Adolescent smoking is still highly prevalent in Denmark. One in four 13-year olds indicates that they have tried to smoke, and one in four 15-year olds answer that they smoke regularly. Smoking is more prevalent in socioeconomically disadvantaged populations in Denmark as well as in most Western countries. Previous school-based programs to prevent smoking have shown contrasting results internationally. In Denmark, previous programs have shown limited or no effect. This indicates a need for developing a well-designed, comprehensive, and multi-component intervention aimed at Danish schools with careful implementation and thorough evaluation.

Objective: To examine gender and socioeconomic differences in adolescents’ reasons for not smoking cigarettes using self-reported data from Danish 14-year-olds (N = 1,559) collected in 2018. χ²-tests were used to assess whether the proportion of students who rated 12 statements as important reasons for not smoking cigarettes differed according to gender and family occupational social class (OSC). Results: More girls than boys stated that thinking the taste of cigarettes is disgusting, not being allowed to smoke by parents, knowing smoking is dangerous, not being allowed to smoke before the age of 18, not wanting to be addicted to smoking, and that smoking makes you smell bad were important reasons for choosing not to smoke cigarettes. More boys than girls reported exercising a lot and having a partner that does not smoke as important reasons for not smoking cigarettes. More students with a high OSC compared with a low OSC stated exercising a lot and that smoking makes you smell bad were important reasons. In conclusion, reasons for not smoking cigarettes differed substantially across gender and less according to socioeconomic position.

School organizational readiness to implement interventions may play an important role for the actual obtained implementation level, and knowledge about organizational readiness prior to intervention start can help pinpoint how to optimize support to the schools. In this study, we applied a novel heuristic, R = MC² to assess school organizational readiness prior to implementation of a multicomponent smoking prevention program. Furthermore, we examined the association to actual implementation after the first year of study. We used questionnaire data from school coordinators at 40 schools in Denmark who had accepted to implement the multi-component smoking prevention intervention—X:IT II—in the school year 2017–2018 including three main components: (1) Rules on smoke-free school time, (2) A smoke-free curriculum, and (3) Parental involvement. On behalf of the school, a school coordinator answered a baseline questionnaire about the organizational readiness and a follow-up questionnaire about implementation of the three components after first year of study. Readiness was measured by summing aspects of motivation (relative advantage, compatibility, complexity, and priority), general capacity (culture, climate, and staff capacity), and innovation-specific capacity (knowledge, skills, and abilities). Based on school coordinators’ perceptions, almost all schools had good general capacity while the other two areas of readiness varied across schools; overall, 56.8% of schools (N = 25) had good motivation for implementing the X:IT II intervention and 61.3% (N = 27) had high innovation-specific capacity. Half of the schools had high overall readiness defined as high motivation and high innovation-specific capacity. Schools with high overall readiness implemented the rules on smoke-free school time, smoke-free curriculum, and parental involvement to a higher degree than schools with low overall readiness. All participating schools possessed sufficient levels of general capacity, e.g., a well-functioning organizational culture and sufficient staff capacity. High levels of motivation and innovation-specific capacity were positively associated with the schools’ actual implementation of the main intervention components. This way of conceptualizing and measuring organizational readiness may be useful in future studies, i.e., in studies where enhancing readiness is a main objective.