Preventing Stress among High School Students in Denmark through the Multicomponent Healthy High School Intervention-The Effectiveness at First Follow-Up.

Stress is a widespread phenomenon and young people especially are experiencing high levels of stress. School-related factors are the most frequently self-reported stressors among adolescents, but few interventions have targeted the school environment. This study evaluated the effectiveness of the Healthy High School (HHS) intervention on stress at a 9-month follow-up. The study included 5201 first-year high school students (~16 years) in Denmark. Participating schools were randomized into the HHS intervention (N = 15) or control group (N = 15). Baseline measurements were conducted in August 2016 and the follow-up was conducted in May 2017. The intervention was designed to promote well-being (primary outcome) by focusing on physical activity, meals, sleep, sense of security, and stress (secondary outcomes). The intervention comprised: structural initiatives at the school level; a teaching material; peer-led innovation workshops; and a smartphone app. The 10-item Perceived Stress Scale was used to measure stress. Intervention effects on perceived stress were estimated using an intention-to-treat approach with multiple imputations of missing data and multilevel general linear regression modelling. A total of 4577 students answered the baseline questionnaire. No statistically significant difference was found in stress between students at intervention and control schools at the follow-up (mean score: 16.7 versus 16.7, adjusted b = 0.42, 95% CI: -0.16;1.00). The HHS Study is one of the first large randomized controlled trials targeting school environmental stressors. Potential implementation failures and the failures of the program theory are discussed.

Parental Illness and Life Satisfaction among Young People: A Cross-Sectional Study of the Importance of School Factors.

BACKGROUND: The aim of this study was to examine the relationship between parental illness and life satisfaction among Danish adolescents and the potential modifying effect of positive school experiences. Moreover, we describe the use of student counsellor services among adolescents with and without ill parents. METHODS: Data included 9565 adolescents primarily aged 13-19 years, who participated in the cross-sectional Well-being Despite Study. Multilevel logistic regression models including joint effect analyses were performed. RESULTS: Parental illness was strongly associated with life satisfaction. Negative school experiences were more frequent among adolescents with ill parents and strongly associated with low life satisfaction for all students. However, joint effect analyses did not show effect modification by school-related variables. The odds ratio of having talked to a student counsellor was highest for adolescents with multiple ill parents, compared to no ill parents. CONCLUSIONS: Parental illness is a strong predictor of low life satisfaction among adolescents; the impact depends on number of ill parents, whether parental illness is physical or mental, and their level of impairment. Positive school experiences were less frequent in adolescents of ill parents and did not counteract the effect of parental illness on life satisfaction.

From questionnaire to practical application: A quality of life profile for populations with diverse disabilities.

AIMS: Existing quality of life questionnaires are either disease specific or generic in their assessment of themes which are perceived important to the quality of life in populations with disabilities. To be able to improve quality of life in a population with diverse disabilities there was a need for a cross-disability instrument. The Electronic Quality of Life (EQOL)-questionnaire was developed to meet this need. It is crucial that such an instrument is validated, easy to use, and interpret by, for example, clinicians and policy planners. This study aims to test the content validity of the EQOL questionnaire and to construct a user-friendly, cross-disability quality of life profile. METHODS: To further test the content validity of the EQOL-questionnaire, we conducted field test analyses on 318 individuals (aged 16-64) with self-reported disabilities. Comments on the questionnaire were scrutinised and sorted. A profile with six domains of quality of life was developed. Model fit was evaluated by confirmatory factor analysis and content validity was evaluated based on distributions. RESULTS: The EQOL-questionnaire was found to have an acceptable content validity and respondents from the field test found that it features important themes of quality of life. The confirmatory factor analysis estimated a satisfying model fit by the root-mean-squared error of approximation (0.06), whereas the comparative fit index and goodness of fit index indicated poorer model fit. Graphical charts, with colour categories for user-friendly interpretation, were constructed. CONCLUSION: By identifying themes reported as problematic, the EQOL-profile can be used to inform and target interventions aiming to improve quality of life in populations with diverse disabilities.

Study Protocol for Evaluation of an Extended Maintenance Intervention on Life Satisfaction and BMI Among 7-14-Year-Old Children Following a Stay at a Residential Health Camp in Denmark.

Background: It is challenging to maintain effects of public health interventions. For residential health camps benefits often disappear as the child returns home. Furthermore, long-term effects are often not measured or reported. This paper presents the study protocol for an evaluation of an extended maintenance intervention offered to children who have completed a 10-week residential health camp at one of the five Danish Christmas Seal Houses (DCSH). The target group of DSCH is 7-14-year-olds with social, mental, and/or overweight issues and the overall aim of the camp is to increase life satisfaction and a healthy lifestyle. The primary aim of this study is to assess the effectiveness of the maintenance intervention on children's life satisfaction (primary outcome) and BMI Z-score (secondary outcome) 1 year after health camp. Methods: The extended maintenance intervention is developed by DCSH and delivered to each child and family individually by an intervention coordinator to help children maintain positive benefits of the health camp on life satisfaction and health behaviors after returning to their homes. Intervention activities target the child and the family. The effect will be tested in a quasi-experimental design: The intervention is offered to half of the children at one of the five DSCH (intervention group, N~144) while the other half and the children at the other four DSCH receive a standard maintenance intervention (control group, N~894). Children will complete questionnaires on life satisfaction measured by an adapted version of the Cantril ladder and height and weight prior to health camp, at the end of health camp, 3 months and 1 year after the end of health camp. To enable per protocol analysis and nuanced interpretation of effect estimates, we will monitor the implementation of the intervention by a process evaluation study among children, parents, and follow up coordinators using qualitative and quantitative methods. Discussion: We present a systematic approach to evaluating practice-based interventions in a research design. The study will provide new knowledge on the effectiveness of individualized maintenance interventions on long-term effects on life satisfaction and weight loss among children. Trial registration: Prospectively registered at Current Controlled Trials ISRCTN 13011465 https://www.isrctn.com/ISRCTN13011465.

What characterizes schools and students participating in health promoting school-based intervention studies? Findings from the healthy high school study.

The Healthy High School (HHS) intervention was developed to promote well-being among first-year high school students (~16 years of age) in Denmark by targeting stress, physical activity, meal habits, sleep, and sense of community. Thirty-one schools were randomly allocated to intervention (16 schools) or control (15 schools) groups in a cluster-randomized controlled trial. The purpose of this short communication was to compare characteristics of students and schools between 1) schools accepting to participate in the HHS study and non-participating schools using national survey data and 2) intervention and control schools using HHS baseline data. We included cross-sectional data from the Danish National Youth Study 2014 on 119 schools and 22,935 first-year students to characterize participating schools and students. At baseline (August 2016), students (n = 4577; 88.0%) and principals (n = 29; 96.7%) completed online questionnaires. Compared to non-participating schools, fewer HHS schools perceived their school as being popular and offered weekly sport activities outside school hours. More HHS schools had teachers engaged in health promotion activities and focused on stress prevention. The characteristics of HHS students did not differ markedly from non-participating high school students. There were no socio-demographic, outcome or contextual differences between the study arms. To ensure successful recruitment of schools it is important that the intervention meets the need of the schools and that the advantages of participation are explicit. This underlines the need for a thorough needs assessment prior to intervention development, co-creation of intervention activities with school staff, and a well-planned recruitment strategy.

Why Do Some Adolescents Manage Despite Parental Illness? Identifying Promotive Factors.

PURPOSE: This study aimed to examine the association between social support, leisure time, school experience, and well-being among adolescents with an ill parent. Moreover, we explored the cumulative effect of promotive factors in relation to well-being. METHODS: The population included a subsample of 676 students reporting serious or chronic parental illness, selected from a nationwide Danish survey, the Well-being Despite Study. Well-being was measured by the five-item World Health Organization Well-Being Index. Social support included support from parents, siblings, and friends. A positive school experience encompassed trust in teachers, classroom community, and overall judgment of the school. Leisure time included frequency of activities and having enough time for friends and oneself. We performed multilevel logistic regression analyses using SAS 9.4. RESULTS: Social support, a positive school experience, and leisure time were positively associated with well-being. For instance, for boys and girls who felt they had enough time to themselves, the odds ratio of moderate to high well-being was 3.7 (95% confidence interval [CI]: 1.8-7.7) and 2.9 (95% CI: 1.9-4.3) respectively, compared with boys and girls who did not. Cumulative analyses showed increasing odds of moderate to high well-being with increasing number of promotive factors, the odds ratio being 39.7 (CI 95%: 11.6-136.2) among adolescents with 10 promotive factors compared with adolescents with 0-5 promotive factors. CONCLUSIONS: Social support, a positive school experience, and satisfying leisure time may be important promotive factors, and the results point toward a more ecological approach to improve well-being among adolescents with ill parents.

Socio-economic differences in smoking among adolescents in a school-based smoking intervention: The X:IT II study.

Aims: Socio-economic inequalities in health behaviour may be influenced by health interventions. We examined whether the X:IT II intervention, aiming at preventing smoking in adolescence, was equally effective among students from different occupational social classes (OSC). Methods: We used data from the multi-component school-based smoking preventive intervention X:IT II, targeting 13- to 15-year-olds in Denmark. The intervention was tested in 46 schools with 2307 eligible students at baseline (response rate=86.6%) and had three main intervention components: smoke-free school time, smoke-free curriculum and parental involvement. We used a difference-in-difference design and estimated the change in current smoking after the first year of implementation in high versus low OSC. Analyses were based on available cases (N=1190) and imputation of missing data at follow-up (N=1967). Results: We found that 1% of the students from high OSC and 4.9% from low OSC were smokers at baseline (imputed data), and 8.2% of the students from high OSC and 12.2% from low OSC were smokers at follow-up. Difference-in-difference estimates were close to zero, indicating no differential trajectory. Conclusions: As intended, the X:IT II intervention, designed to apply equally to students from all socio-economic groups, did not seem to create different trajectories in current smoking among adolescents in high and low socio-economic groups. To diminish social inequality in health, future studies should carefully consider the ability to affect all socio-economic groups equally, or even to appeal mainly to participants from lower socio-economic groups, as they are often the ones most in need of intervention.

Trends in social inequality in overweight and obesity among adolescents in Denmark 1998-2018.

OBJECTIVES: The aim was to analyze trends in overweight and obesity in relation to socioeconomic position among Danish adolescents in the 20-year period 1998-2018. METHODS: The study used data on self-reported height and weight and parents' occupational social class (OSC) from 11-, 13- and 15-year-old schoolchildren in 1998, 2002, 2006, 2010, 2014 and 2018, n = 22,177. The analyses included absolute social inequality in overweight/obesity (prevalence difference between low and high OSC) and relative social inequality (OR for overweight/obesity). RESULTS: In the total sample, the prevalence of overweight and obesity was 9.7% and 1.4%, respectively, with significantly higher prevalence in low than high OSC. There were significantly increasing trends in both overweight and obesity 1998-2018 in low OSC and no significant increase in high OSC. The OR for overweight was 1.59 (1.42-1.74) in middle and 2.16 (1.89-2.46) in low OSC, OR for obesity 1.74 (1.29-2.34) in middle and 2.97 (2.15-4.11) in low OSC. Associations were not modified by survey year. CONCLUSIONS: There was a persistent absolute and relative social inequality in overweight and obesity 1998-2018 among Danish adolescents.

Intake of sugar sweetened soft drinks among adolescents: Trends and social inequality in Denmark 2002-2018.

BACKGROUND: Intake of sugar sweetened soft drinks (SSSD) has decreased among adolescents, but trends in social inequality in SSSD intake are unknown. AIM: Examine trends in social inequality in SSSD intake among adolescents in Denmark during 2002-2018. METHODS: Five Health Behaviour in School-aged Children surveys with data on SSSD intake and parents' occupational social class (OSC) from nationally representative samples of 11, 13 and 15 year olds, n =20,112. RESULTS: The overall prevalence of daily SSSD intake decreased from 10.1% in 2002 to 6.4% in 2018. The prevalence decreased in both high OSC (from 8% to 5%) and middle OSC (from 10% to 6%) but remained around 12% in low OSC. The odds ratio (OR) estimates of low compared with high OSC increased over the years around an overall OR of 2.01 (1.74-2.34). CONCLUSIONS: Danish adolescents' SSSD intake decreased during 2002-2018 and was higher the lower the parents' OSC. Thus, social inequality increased during 2002-2018.

Study protocol of the Healthy High School study: a school-based intervention to improve well-being among high school students in Denmark.

BACKGROUND: The prevalence of low well-being, perceived stress and unhealthy behaviours is high among high school students, but few interventions have addressed these problems. The aim of this paper is to present a study protocol of a cluster randomised controlled trial evaluating the Healthy High School (HHS) intervention programme. The intervention programme is designed to improve well-being (primary outcome) by preventing 1) stress and promoting 2) sleep, 3) sense of community, 4) physical activity (PA) and 5) regular and healthy meals among high school students in Denmark. METHODS: The development of the HHS study was guided by the Intervention Mapping protocol. The intervention comprises four components: 1) a teaching material, 2) a smartphone app, 3) a catalogue focusing on environmental changes, and 4) a peer-led innovation workshop aiming at inspiring students to initiate and participate in various movement activities. The HHS study employs a cluster-randomised controlled trial design. Thirty-one high schools across Denmark were randomly allocated to intervention (16 schools) or control (15 schools) groups. The study included all first-year students (~ 16 years of age) (n = 5976 students). Timeline: Intervention: August 2016 - June 2017. Collection of questionnaire data: Baseline (August 2016), 1st follow-up (May 2017) and 2nd follow-up (April 2018). All students were invited to participate in a monthly sub-study about perceived stress using text messages for data collection (September 2016 - June 2017). PA was objectively assessed among a sub-sample of students using accelerometers (Axivity, AX3) in August 2016 and May 2017. PRIMARY OUTCOME MEASURES: Student well-being measured by the Cantril Ladder and the five item World Health Organisation Well-being Index (individual level outcomes). SECONDARY OUTCOME MEASURES: Stress (10-item Perceived Stress Scale), sleep (quantity and quality), PA (hours of moderate-to-vigorous PA per week, hours of daily sedentary time and average daily PA), meal habits (daily intake of breakfast, lunch, snacks and water), and strong sense of community in class and at school, respectively (individual level outcomes). The study encompasses process and effect evaluation as well as health economic analyses. TRIAL REGISTRATION: ISRCTN ISRCTN43284296, 28 April 2017, retrospectively registered.

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.

Self-efficacy and social competence reduce socioeconomic inequality in emotional symptoms among schoolchildren.

BACKGROUND: Many adolescents experience mental health problems which may have serious consequences for short- and long-term health and wellbeing. This study investigates socioeconomic inequality in emotional symptoms, self-efficacy and social competence. Further, whether self-efficacy and social competence reduce socioeconomic inequalities in emotional symptoms. METHODS: Data stem from the cross-sectional Danish Health Behaviour in School-aged Children Methodology Development Survey 2012. Data were collected among all schoolchildren in grades 5-9 (11-15-year-olds) in 23 public schools in two municipalities. Participation rate was 76.8% (n = 3969). Analyses of the associations between daily emotional symptoms, occupational social class, self-efficacy and social competence were performed through logistic regression analyses using SAS version 9.3. Multilevel logistic regression analyses were used to study effect modification. RESULTS: Schoolchildren from lower socioeconomic positions have higher odds for daily emotional symptoms and lower levels of high self-efficacy and high social competence compared to schoolchildren from higher socioeconomic positions. High self-efficacy and high social competence buffer the association between socioeconomic position and emotional symptoms, i.e. they seem to protect children and adolescents from lower socioeconomic strata against the higher risk of daily emotional symptoms. CONCLUSIONS: High self-efficacy and high social competence buffer the negative effects of low socioeconomic status on emotional symptoms among schoolchildren. Self-efficacy and social competence can be promoted e.g. through school-based initiatives and may be an effective way to improve mental health and reduce socioeconomic inequality in emotional symptoms among children and adolescents.

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.

Cross-country comparisons of trends in adolescent psychosomatic symptoms - a Rasch analysis of HBSC data from four Nordic countries.

BACKGROUND: To analyse the psychometric properties of the HBSC Symptom Checklist (HBSC-SCL) on psychosomatic symptoms with a focus on the operating characteristics of the items, and on the impacts of measurement distortions on the comparisons of person measures across time and between countries. METHODS: Data were collected in 1993/94, 1997/98, 2001/02, 2005/06, 2008/09, 2013/14 in Denmark, Finland, Norway and Sweden as part of the Health Behaviour in School-aged Children (HBSC) study. Data comprised 116,531 students 11, 13 and 15 years old. Rasch analysis was conducted of the HBSC-SCL consisting of eight items with a focus on Differential Item Functioning (DIF) and item threshold ordering. The impacts of DIF and threshold disordering on trend analyses were analysed in a subsample consisting of 15 years old students. RESULTS: One item shows evidence of severe DIF and the categorisation of some items does not seem to work as intended. Analyses of changes based on proportions of psychosomatic symptoms show that bad item functioning affects some comparisons between countries across time: A four percentage point difference between 15 years old girls in Finland and Sweden concerning the rate of increase of psychosomatic symptoms from 1994 to 2014 disappears when the problems with DIF and disordered item thresholds are taken into account. Although the proportions of students with psychosomatic symptoms are clearly higher 2014 than 1994 in all four countries the shape of most trends is nonlinear. CONCLUSIONS: Some of the cross-country comparisons were distorted because of DIF and problems related to disordering of the item thresholds. The comparisons among girls between Finland and Sweden were affected by the problems pertaining to the original measure of psychosomatic symptoms, while the trend patterns among boys were not much affected. In addition to confirming increasing rates of adolescent mental health problems in the Nordic countries, the substantive analyses in the current study show that Finland is joining Sweden in having the sharpest increase among older adolescents, in particular among girls. To improve the functioning of the scale the DIF item could be removed or replaced and response categories collapsed in post hoc analyses.

Living with a disability: a qualitative study of associations between social relations, social participation and quality of life.

PURPOSE: We explored which shared aspects of social relations were considered important to the quality of life of persons between the ages of 10 and 40 years living with a disability. We examined how social relations were experienced as affecting quality of life and social participation. MATERIALS AND METHODS: Fifteen focus groups involving 48 persons with disabilities were conducted using photo elicitation, preference ranking and props. Focus group interviews were supplemented with seven individual interviews with individuals unable to participate in focus groups. All focus group interviews and individual interviews were audiotaped, transcribed, and thematic data analysis was conducted. RESULTS: We identified caregiving, dependency, and understanding as essential for quality of life. Acceptance from society, discrimination and prejudice, and the ability to participate in society were also highlighted as affecting quality of life. The use of social tactics to avoid confrontation with certain aspects of their disability was common among participants. CONCLUSIONS: Across disabilities, caregiving, dependency, understanding and acceptance, and discrimination and prejudice were all important aspects for the quality of life of the individuals. Social relations were closely related to social participation, and the latter affected the quality of life of the participants. Social tactics were used to navigate social relations. Implications for rehabilitation We suggest to formalize the concept of social tactics and use it in patient education to enhance quality of life in individuals living with disabilities. People may accept and learn to cope with the impact of their disability, but how they maintain their social participation and social relations also impact on their quality of life. In their assessment, professionals working with individuals with disabilities should, therefore, give more priority to analyze the impact of social relations. When intervening, an effort to establish and maintain social relations should be considered along with psychological help, allocation of aids and economical support aiming to enhance quality of life and social participation among individuals with disabilities. When evaluating efforts to improve quality of life, it is important to investigate whether the intervention has improved the social relations.

Increasing prevalence of emotional symptoms in higher socioeconomic strata: Trend study among Danish schoolchildren 1991-2014.

Aims: The aims of this study were: (a) to examine trends in daily emotional symptoms among 11- to 15-year-olds from 1991 to 2014 in Denmark, and (b) to examine trends in social inequality in daily emotional symptoms, that is, whether the differences in prevalence between adolescents with parents of varying occupational social class changed over time. Methods: We combined seven comparable cross-sectional Health Behaviour in School-aged Children surveys (N=31,169). Daily emotional symptoms were measured by the HBSC Symptom Check List and occupational social class (OSC) by students' reports about parents' occupation. We calculated absolute (per cent) differences in emotional symptoms between high and low OSC and relative differences by odds ratio for emotional symptoms by parents' OSC. Results: Eight per cent reported at least one daily emotional symptoms, with an increasing trend from 1991 to 2014 (p<0.001). The prevalence in high, middle and low OSC was 6.2%, 7.4% and 10.6% (p<0.0001). From 1991 to 2014, there was an increase in the prevalence of daily emotional symptoms in high (p<0.0001) and middle (p<0.0001) but not low OSC (p=0.4404). This resulted in a diminishing absolute social inequality in emotional symptoms. The statistical interaction between OSC and survey year was significant (p=0.0023) and suggests a diminishing relative social inequality in emotional symptoms from 1991 to 2014. Conclusions: There was an increasing prevalence of daily emotional symptoms from 1991 to 2014 and a diminishing social inequality in prevalence of daily emotional symptoms in terms of both absolute and relative social inequality.

Evaluation of the smoking intervention X:IT after the second year: A randomized controlled trial.

Aims:Review studies on the long-term effects of school-based smoking interventions show mixed results. X:IT was a three-year cluster randomized controlled trial to prevent uptake of smoking among Danish students from age 13 years until age 15 years which previously proved effective in preventing smoking after the first year of intervention. The aim of this paper was to conduct the pre-planned analyses of the effects of the X:IT intervention on smoking after the second year. Methods: We used self-reported questionnaire data from students at baseline, first, second, and third follow-up (n at second follow-up=3269, response rate=79.4%). Data from third follow-up were not suitable for analysis. Outcome measure: 'current smoking', dichotomised into smoke daily, weekly, monthly or more seldom versus do not smoke. We performed multilevel, logistic regression analyses of available cases and intention-to-treat (ITT) analyses, replacing missing outcome values by multiple imputation. Results: The prevalence of smoking increased from 5.8% at baseline to 17.0% at second follow-up among students at intervention schools, and from 7.6% to 18.7% among students at control schools. Analyses of available cases and ITT analyses did not support X:IT being effective in preventing smoking after the second year of intervention. Conclusions: Although X:IT was effective after the first year of intervention, we were not able to demonstrate any effects after the second year. Implementation of the intervention was lower in the second year compared to the first year which indicates that the missing effect of the intervention at second follow-up is due to lack of implementation.

Persistent social inequality in medicine use for headache among adolescents in Denmark 1991-2014.

BACKGROUND: Socioeconomic variation in adolescents' medicine use behaviour is an understudied issue. OBJECTIVES: To examine the association between socioeconomic background and medicine use for headache among adolescents, and how this association changes over time. METHODS: Data stem from the Danish part of the international Health Behaviour in School-aged Children (HBSC) study 1991-2014 with data about parents' occupational social class (OSC) and self-reported medicine use for headache, n = 26,685. This study examined absolute social inequality (percent difference between high and low OSC) and relative social inequality (odds ratio for medicine use by OSC). RESULTS: In total, 40.5% used medicine for headache in the past month. There was a significant increase from 32.3% in 1991 to 42.8% in 2002 (test for trend, p < 0.0001) and very little change 2002-2014. This pattern was similar in high, middle and low OSC. The prevalence of medicine use for headache in high, middle and low OSC was 36.2%, 41.5% and 44.8% (p < 0.0001). The OR (95% CI) for medicine use was 1.25 (1.18-1.324) in middle and 1.43 (1.33-1.54) in low OSC. CONCLUSIONS: Medicine use for headache increased 1991-2002 and remained stable 2002-2014. There was increasing medicine use for headache with decreasing OSC; this social inequality was persistent 1991-2014.

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.

Conceptualization, operationalization, and content validity of the EQOL-questionnaire measuring quality of life and participation for persons with disabilities.

BACKGROUND: Measurement of quality of life demands thoroughly developed and validated instruments. The development steps from theory to concepts and from empirical data to items are sparsely described in the literature of questionnaire development. Furthermore, there seems to be a need for an instrument measuring quality of life and participation in a population with diverse disabilities. The aim of this paper was to present and discuss the initial steps in the development of the Electronic Quality of Life questionnaire (EQOL). METHODS: The development of EQOL included six steps: 1) Establishing conceptual understanding; 2) Development of interview guides which build on the conceptual understanding; 3) Qualitative interviews of 55 participants (10-40 years old) with different types and severities of disabilities; 4) Conceptualization of domains identified in the qualitative data through thematic analysis; 5) Operationalization of the identified domains into items and; 6) Evaluation of content validity of the first version of the EQOL-measure. Content validity was examined by cognitive interviews with participants in the target group as well as by continuous feedback from an advisory board. RESULTS: We identified six domains (function and health, environment (physical and social), social network, wellbeing, occupation, and managing strategies) based on themes derived from the qualitative interviews and on conceptual discussions within the author group. These domains were incorporated in a conceptual model and items were generated to measure the content of each domain. Participants expressed satisfaction with EQOL but most participants felt that there were too many items. CONCLUSIONS: In total, 191 items were included in the questionnaire. Participants felt that the EQOL-questionnaire was relevant to their quality of life and participation. We have shown that it is possible to include quality of life and participation for people with various disabilities in one instrument. Although capturing less detail than a condition specific instrument, EQOL includes aspects perceived important for people with disabilities who are not included in general surveys. This is relevant when for example evaluating environmental adaptations and when comparing populations with various disabilities.