Predicting longitudinal changes in patterns of tobacco and nicotine product use among adolescents: A Latent Transition Analysis based on the X:IT study.

INTRODUCTION: Understanding factors influencing the transition from non-use to tobacco and nicotine product initiation among adolescents is crucial for designing and implementing effective preventive strategies. This study explores transition patterns among 13-15-year-old adolescents in lower secondary school, focusing on the transition from non-use to tobacco and nicotine product initiation and the influence of individual, social, risk behavioral, and mental health factors on this transition. METHODS: Based on data from a Danish smoking prevention trial between 2017 and 2019, this study employed questionnaire surveys at three time points: baseline (start of seventh grade, n = 1,990, response rate = 86.3%), eight-month follow-up (end of seventh grade, n = 1,666, response rate = 74,8%), and 20-month follow-up (end of eighth grade, n = 1,149, response rate = 70,6%). Tobacco and nicotine use indicators included current and lifetime use of cigarettes and lifetime use of e-cigarettes, smokeless tobacco, and hookah. A latent transition analysis was applied to identify longitudinal transition patterns across waves and to explore predictors of these patterns. RESULTS: Three user classes emerged across all waves: none-use, lifetime e-cigarette and cigarette use, and poly-tobacco use. While the most prevalent class was the non-user class (71%-86%), the proportion of the lifetime e-cigarette and cigarette class increased over time (from 12% to 17%). Similarly, the poly-tobacco user class increased from 2% to 12%. The probability of transitioning from non-use to lifetime e-cigarette and cigarette use increased from 0.5% at baseline to 12% by the second follow-up, while the probability of transitioning from lifetime e-cigarette and cigarette use remained stable over time (12%-15%). Across all waves, elevated risk behavior predicted this transition. For instance, binge-drinking (OR = 3.76, 95% CI: 1.51-9.34), susceptibility to smoking (OR = 7.63, 95% CI: 3.68-16.83), and truancy (OR = 7.00, 95% CI: 1.98-24.59) influenced the transition from non-use at baseline to lifetime e-cigarette and cigarette use at first follow-up. Additionally, boys, adolescents with low socioeconomic status, low life satisfaction, and those with smoking friends or parents were more likely to transition from non-use to lifetime e-cigarette and cigarette use. CONCLUSION: This study demonstrates that sociodemographic, social risk, behavioral, and mental health factors impact the transition from non-use to lifetime e-cigarette and cigarette use. The findings provide valuable insights for developing targeted preventive strategies focusing on these influencing factors.

Factors sustaining legitimacy of smoking in Vocational Education and Training (VET) schools: a qualitative needs assessment.

BACKGROUND: Most adult smokers started smoking in their teenage years, which increases the risk of nicotine dependence. In Denmark, there is a high prevalence of youth smoking among students in Vocational Education and Training (VET). However, reducing and preventing smoking in this group is a major challenge. This article presents a needs assessment aimed to explore factors sustaining legitimacy of smoking in VET schools and consider the measures needed to prepare VET schools' implementation of smoking reduction and prevention interventions. METHODS: Participant observations were conducted in four VET classes representing three VET schools in Denmark with a duration of four days each. Individual, semi-structured interviews were conducted with teachers, managers, and a student advisor, as well as four focus groups with a total of 20 students. Interviews were audio-taped, transcribed, and the data material was analyzed following Malterud's systematic text condensation. FINDINGS: Factors that helped sustain legitimacy of smoking in VET schools included a positive and normalized attitude towards smoking at home and among friends, an understanding of smoking as an integral and expected practice in VET professions and schools, a perceived reliance on smoking as an icebreaker in new social relations and as a pedagogical tool, and smoking as a habit and a means to deal with boredom and stress relief. CONCLUSIONS: The factors sustaining legitimacy of smoking in VET schools are reciprocal and call for smoking reduction and prevention intervention efforts which consider and address social influence, habitual behavior, and psychological needs, as well as changes at the policy level.

Price elasticity of demand for cigarettes among youths in high-income countries: a systematic review.

Aims: Smoking in youth remains a major public health issue. As increasing tobacco prices is considered one of the most effective prevention strategies, examining youth's responsiveness to price changes on cigarettes will provide crucial knowledge. This study aims systematically to review research examining the price elasticity of demand for cigarettes among youths (<30 years of age) in high-income countries. Methods: Searches were conducted in three databases (Web of Science, Pubmed and Scopus). Inclusion criteria were publications within the past 10 years (2011-2021) written in English and with a population of youths below 30 years of age, concerning price elasticity of demand for cigarettes and from high-income countries. Searches were screened by two independent reviewers and the quality of studies was assessed using a quality assessment tool. Results: Four outcomes related to price elasticity of demand for cigarettes were examined in six studies included in this review; that is, cigarette initiation, consumption, prevalence and cessation. Overall, findings indicate that increasing tobacco prices affect youth tobacco use. The effect was associated with gender and age; young women were more price sensitive concerning smoking initiation, whereas young men were more price sensitive concerning cigarette prevalence and consumption. Moreover, younger age was associated with higher price elasticity. Conclusions: Estimates for price elasticity varied across the included studies. This may be caused by differences in data sources, collection methods used and country of origin. Most included studies were of older date. Therefore, to make reliable predictions of the expected effects of increased tobacco prices, further examinations of up-to-date and locally embedded measures are required.

Evaluating the Effects of Denmark's New Tobacco Control Act on Young People's Use of Nicotine Products: A Study Protocol of the §SMOKE Study.

(1) Background: In December 2020, a broad majority of political parties in Denmark agreed on a new tobacco control act. In addition, price increases on tobacco in 2020 and 2022 became part of the Danish Finance Act. This study protocol describes the study "§SMOKE-A Study of Tobacco, Behavior, and Regulations" designed to monitor and evaluate the implementation and effect of the new strengthened tobacco control acts. The overall aim is to monitor tobacco use among young people before, during, and after implementation of the new tobacco control legislation, including an increased price on tobacco, a ban on point-of-sale tobacco displays, and plain packaging. Subgoals are to monitor overall use of nicotine products, attitudes, and norms. (2) Methods: This study is designed as a five-year impact evaluation with repeated cross-sectional survey data collections. The baseline survey was conducted before implementing an increased price on tobacco, the first step in the new legislation, initiated 1 April 2020. Study participants (n = 37,500) were a random sample of individuals living in Denmark aged 15 to 29 years. (3) Conclusions: This study examines the impact of the new strengthened tobacco control legislation in Denmark from 2020 to 2025. The findings of this study are relevant to other countries facing implementation of similar measures to explore intended and unintended consequences of the legislation and help to identify how the legislation could be further improved.

Exploring factors associated with smokeless tobacco use among young people: A systematic scoping review.

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Use of Tobacco and Nicotine Products among Young People in Denmark-Status in Single and Dual Use.

Lots of new tobacco or nicotine products are being launched, e.g., e-cigarettes and smokeless tobacco, which appeal especially to the youngest part of the population. For example, the use of smokeless tobacco among Danish youth rose from approx. 2% in 2010 to 9% in 2020. Hence, there is an urgent need to follow and intervene against youth tobacco or nicotine product use. This study explored the current use of cigarettes, e-cigarettes, heated tobacco, and smokeless tobacco among Danish 15- to 29-year-olds. Further, we examined the concurrent use of two products or more. We used a nationwide survey conducted among 15- to 29-year-olds in February and March 2020. Overall, approx. 35,700 individuals received the questionnaire of which 35.5% responded (n = 13,315). One out of five (20.1%) smoked cigarettes, half of them daily, the other half occasionally. About one in twenty (3.9%) used e-cigarettes (daily or occasionally), and more than one in three (31.6%) had tried e-cigarettes. The use of heated tobacco among Danish youth is still relatively limited (0.3%). In comparison, about 9% used smokeless tobacco (daily or occasionally). Overall, 27.0% stated that they use at least one type of tobacco or nicotine product, while 5.6% used more than one product. Monitoring tobacco-related behavior in youth provides extremely important information for, e.g., policymakers and health professionals.

Socioeconomic Differences in Cigarette Smoking and Alternative Tobacco Product Use Among Adolescents in a School-Based Smoking Preventive Intervention: Findings From the Second Year of the X:IT II Study.

Background: Health interventions may differently impact adolescents from diverse backgrounds. This study examined whether a smoking preventive intervention was equally effective in preventing cigarette smoking and use of alternative tobacco products (ATPs, i.e., snus, e-cigarettes, and waterpipe) among students from different socioeconomic backgrounds, i.e., occupational social classes (OSC). Methods: Data was from the school-based intervention X:IT II targeting 13- to 15-year-olds Danes. The intervention focused on three main components: smoke-free school time, smoke-free curriculum, and parental involvement. In total, 46 schools were included at baseline (N = 2,307, response rate = 86.3%). Using a difference-in-differences approach, changes in current smoking and ever use of ATPs were estimated among students in high versus low OSC at second follow-up. Analyses were based on available cases (N = 826) and multiple imputations of missing data at the second follow-up (N = 1,965). Results: At baseline (age 13), 1.0% of students from high OSC and 4.8% from low OSC currently smoked cigarettes, while this was the case among 24.5 and 25.6%, respectively, at the second follow-up (age 15). Estimates indicated that social inequalities in current smoking diminished over time (p < 0.001). Regarding ATPs, 10.0% of high OSC students and 13.9% of low OSC students had ever used ATPs at baseline, while at second follow-up, 46.8 and 60.8%, respectively, had ever used ATPs. Estimates indicated that social inequalities in ever use of ATPs widened over time (p < 0.001). Conclusions: The X:IT II intervention seemed to diminish socioeconomic disparities in smoking over the study period. Meanwhile, social inequalities in ever use of ATPs increased. Therefore, besides focusing on narrowing the social disparities in cigarette smoking, future efforts may, to a larger extent, focus on adolescents' use of ATPs.

Assessing Differences in the Implementation of Smoke-Free Contracts-A Cross-Sectional Analysis from the School Randomized Controlled Trial X:IT.

OBJECTIVE: The X:IT study is a school-based smoking preventive intervention that has previously been evaluated in a large randomized controlled trial (RCT) with good effects. However, the actual effect for participating students depends on the individual implementation. The aim of this study was to examine the implementation of smoke-free contract, which is one of the three main intervention components. Specifically, we examined whether it was implemented equally across family occupational social class (OSC), separately for boys and girls, the joint effect of OSC and gender, and the participants' own reasons for not signing a contract. RESULTS: Overall, the smoke-free contract was well implemented; 81.8% of pupils (total N = 2.015) signed a contract (girls 85.1, boys 78.6%). We found a social gradient among girls; more than 90% were in OSC group I vs. 75% in group VI. Among boys, however, we found no difference across OSC. Boys in all the OSC groups had about half the odds (i.e., medium OSC boys: OR = 0.48 (95% CI: 0.32-0.72) of having a smoke-free contract compared to girls from a high OSC. CONCLUSION: future interventions should include initiatives to involve families from all OSC groups and allow for different preferences among boys and girls.

Gender and socioeconomic disparities in reasons for not smoking cigarettes among Danish adolescents.

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.

Places to Smoke: Exploring Smoking-Related Practices among Danish Adolescents.

Several established school smoking prevention initiatives involve restrictions on places to smoke. The focus on tobacco control in schools is due to the risk of smoking initiation during adolescence and the perception of this life stage as a period of time when health behavior is established. Hence, this period of time is considered to be ideal for health-promoting initiatives. This paper is part of an ethnographic study on adolescents' perceptions of tobacco use. Focus groups and field observations were used to explore adolescents' smoking-related practices related to smoking bans at schools. The findings show that smoking, as a place-based practice, is influenced by locally embedded rules and carries social implications resulting in a distinction between smokers and non-smokers. The distinction between smokers and non-smokers contributes to the retention of a stereotypical view of smokers and, moreover, stigmatizes smokers. According to this, restrictions on places to smoke within the school should be considered carefully in order to avoid stigma or ethical issues.

School Coordinators' Perceptions of Organizational Readiness Is Associated with Implementation Fidelity in a Smoking Prevention Program: Findings from the X:IT II Study.

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.

Who are the young users of tobacco products? Prevalence and characteristics of Danish adolescents who have either smoked cigarettes, used alternative tobacco products, or used both.

Aims: We examined characteristics (smoking in social relations, binge drinking, and well-being measures) of Danish 13-year-olds in relation to their tobacco use patterns. Ever use of cigarettes exclusively, ever use of alternative tobacco products (ATPs; e-cigarettes, snus, or waterpipe) exclusively, and use of both cigarettes and ATPs were studied. Methods: We used self-reported data from students at 46 Danish schools in 2017 comprising 2,307 students (response rate = 86%). Multi-level logistic regression analyses were used to examine the associations between student characteristics and the odds for having ever used any tobacco products, smoked cigarettes exclusively, used ATPs exclusively, or used both cigarettes and ATPs compared with never use of any tobacco products. Unadjusted estimates and estimates adjusted for gender were reported. Results: A significant minority of youth (13.2%) had used one or more tobacco products. Of these, 2.0% had exclusively smoked cigarettes, 7.2% had exclusively used ATPs, and 4.0% had used both. Findings showed that all included characteristics (families' and friends' smoking, binge drinking, and well-being characteristics) were associated with using any tobacco product; however, students with friends who smoked, had been binge drinking, and had low well-being at home had notably higher odds for having both smoked cigarettes and used ATPs compared to the other tobacco use patterns. Conclusion: ATPs were popular among Danish adolescents compared with conventional cigarettes. Thus, prevention efforts among adolescents should not merely focus on the health risks of conventional cigarette smoking but also on ATPs. Students with diverse tobacco use patterns were similar on various characteristics. However, findings indicate that adolescents who had used both conventional cigarettes and ATPs constitute a more risk-averse group in special need of prevention efforts. Gender did not markedly influence the results. These findings may help future strategies aiming at the youngest adolescents at risk of using tobacco products.

Estimating future smoking in Danish youth - effects of three prevention strategies.

Aims: Preventing smoking and aiding cessation among youth and young adults carries the possibility of reducing future smoking prevalence significantly. This paper estimates the impact on future smoking prevalence of 25 year olds by increasing tobacco prices, securing indoor smoke-free homes and implementing school-based multi-tiered interventions. Methods: Utilizing a multi-state Markov model, a status quo projection of the smoking prevalence from years 2017 to 2030 were compared with projections of the smoking prevalence in 2030 considering the impact of the three prevention strategies. Results: In a status quo projection, 27.0% of Danish 25-year-old females are expected to be smokers in 2030, while 13.2% would be smokers in 2030 were all three prevention strategies in effect from 2019. By itself, increasing tobacco prices by 50% reduced the prevalence of smokers among 25-year-old females to 14.8% in 2030, a relative reduction of 47.5%. For 25-year-old males in 2030 the reductions were similar, with a prevalence of 16.6% when all three prevention strategies were in effect, a relative reduction of 51.5%. Conclusions: Implementing increasing tobacco prices, indoor smoke-free homes and school-based multi-tiered interventions in Denmark is likely to significantly decrease youth smoking prevalence in the future. However, these three strategies will not produce a smoke-free generation without other initiatives.

Trends in socioeconomic differences in daily smoking among 15-year-old Danes 1991-2014.

Aim: To examine trends in socioeconomic differences in daily smoking among 15-year-old Danes between 1991-2014, using occupational social class as indicator of socioeconomic status. Methods: The study included 15-year-olds participating in seven Danish Health Behaviour in School-aged Children studies between 1991-2014, n = 8,641. The analyses focused on absolute socioeconomic differences (prevalence difference between low and high occupational social class) and relative socioeconomic differences communicated by odds ratio for daily smoking. Results: The prevalence of daily smoking declined from 18.6% in 1991 to 4.5% in 2014. Across all surveys, the prevalence was 8.9% in high, 12.8% in middle and 16.5% in low occupational social classes (p < 0.0001). The absolute socioeconomic differences increased from 1991 to 2006 and declined thereafter. Across all survey years, the odds ratio (95% confidence interval) for daily smoking was 1.40 (1.19-1.65) in middle and 1.90 (1.56-2.32) in low versus high occupational social classes. The statistical interaction between occupational social class and survey year was significant (p = 0.0404), suggesting increasing relative socioeconomic differences from 1991 to 2014. Conclusions: There was a substantial decline in daily smoking among 15-year-olds between 1991-2014 in all occupational social class groups. The prevalence of daily smoking was highest in the low occupational social class during the entire period. The absolute socioeconomic differences in daily smoking increased between 1991-2006 and declined thereafter. The relative socioeconomic differences increased over 1991-2014. Studies of change in socioeconomic differences over time should address both absolute and relative socioeconomic differences as they may result in different conclusions and because important improvement in prevalence patterns may be disguised by exclusive focus on changes in relative socioeconomic differences.

Study protocol of the X:IT II - a school-based smoking preventive intervention.

BACKGROUND: The X:IT intervention, conducted in 2010 to 2013, showed overall smoking preventive effect. However, parts of the intervention appeared less appealing to children from families with lower socioeconomic backgrounds. Therefore, the intervention components were modified and an evaluation of the amended intervention X:IT II is needed to show the effect of this revised intervention and whether children from different social backgrounds benefits equally from the current intervention. METHODS: Main intervention components are smoke free schools, a curricular component, and parental involvement (smoke free agreements and talks about tobacco). Components have been revised from the first version; 1) previously, schools should be smoke free on the school ground and were encouraged to hide smoking so that it wasn't visible to pupils from the school ground. Now they are encouraged to tighten the rules so that no pupils or teachers smoke during the school day, no matter where they are; 2) the specifically developed educational material (Up in Smoke) has been revised so that all materials are online and all texts has a ARI; 3) the parental involvement is now targeted multiple groups of parents, e.g. parents that are smokers, and parents of children that smoke. Language used is simpler and the website for parents presents very specific examples. X:IT is implemented in 46 Danish public schools from fall 2017 until summer 2020. Data is collected through electronic questionnaires to students and coordinators four times (fall 2017, spring/summer 2018, 2019 and 2020). Further, qualitative interviews and observations are conducted. DISCUSSION: Prevalence of smoking among Danish adolescents is high compared to other Nordic countries and there is social inequality in smoking, leaving individuals from the lowest social backgrounds at higher risk. Although there has been an overall decline in smoking among Danish adolescents over the last decades, a recent levelling of this development indicates an urgent need for smoking prevention in Denmark. The X:IT intervention has the potential to prevent uptake of smoking among adolescents. However, there is a particular need for evaluating the effectiveness of the revised X:IT intervention, X:IT II, with focus on the effect across socioeconomic groups of adolescents. TRIAL REGISTRATION: Current Controlled Trials ISRCTN31292019 , date of registration 24/10/2017. Retrospectively registered.

Implementation fidelity and adolescent smoking: The X:IT study-A school randomized smoking prevention trial.

BACKGROUND: Assessing the actual implementation of multi-component interventions can provide important knowledge for future interventions. Intervention components may be implemented differently, knowledge about this can provide an understanding of which components are essential and therefore must be included. The aim of this study was to examine the implementation of one, two, or all three main intervention components at the individual level and to assess the association to current smoking among 13 year-olds in the X:IT study. METHODS: Data stems from a cluster-randomized controlled trial in 94 Danish elementary schools (51 intervention; 43 control schools). Implementation was measured by aspects of adherence, dose, quality of delivery, and participant responsiveness based on questionnaire data from 4161 pupils at baseline (mean-age: 12.5 years) and 3764 pupils at first follow-up eight months later. Coordinator responses from 49 intervention schools were also included. Associations between individual level implementation of the three main components and pupil smoking were examined through a 3-level logistic regression model. RESULTS: Although implementation fidelity for the three main intervention components was good, only one third (38.8%) of pupils in intervention schools were exposed to full implementation of the intervention. Among these pupils odds ratio for smoking was 0.25 (95% CI: 0.15 - 0.42). CONCLUSIONS: School-based programs can be very effective if carefully implemented. Future school-based smoking preventive initiatives should include multiple components, and seek to enhance implementation quality of all components.

Importance of implementation level when evaluating the effect of the Hi Five Intervention on infectious illness and illness-related absenteeism.

BACKGROUND: There is limited research on the importance of implementation when evaluating the effect of hand hygiene interventions in school settings in developed countries. The aim of this study was to examine the association between an implementation index and the effect of the intervention. The Hi Five Intervention was evaluated in a 3-armed cluster randomized controlled trial involving 43 randomly selected Danish schools. METHODS: Analyses investigating the association between implementation of the Hi Five Intervention and infectious illness days, infectious illness episodes, illness-related absenteeism, and hand hygiene were carried out in a multilevel model (school, class, and child). RESULTS: The level of implementation was associated with hand hygiene and potentially associated with number of infectious illness days and infectious illness episodes among children. This association was not found for illness-related absenteeism. CONCLUSIONS: Classes that succeeded in achieving a high level of implementation of the Hi Five Intervention had a lower number of infectious illness days and infectious illness episodes, suggesting that the Hi Five Intervention, if implemented adequately, may be relevant as a tool to decrease infectious illness in a Danish school setting.

High impact of implementation on school-based smoking prevention: the X:IT study-a cluster-randomized smoking prevention trial.

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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. TRIAL REGISTRATION: Current Controlled Trials ISRCTN77415416.

Trends in Social Inequality in Tooth Brushing among Adolescents: 1991-2014.

This study examines whether social inequality in tooth brushing frequency among adolescents changed from 1991 to 2014. The data material was seven comparable cross-sectional studies of nationally representative samples of 11- to 15-year-olds in Denmark with data about frequency of tooth brushing and occupation of parents. The total number of participants was 31,464, of whom 21.7% brushed their teeth less than the recommended 2 times a day. The absolute social inequality measured as prevalence difference between low and high social class increased from 7.7% in 1991 to 14.6% in 2014. The relative social inequality assessed by odds ratios for infrequent tooth brushing also increased from 1991 to 2014.

Effects of the X:IT smoking intervention: a school-based cluster randomized trial.

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.