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.

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 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 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.

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.

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.

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.

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.

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.

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.

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.

Short report: persistent social inequality in poor self-rated health among adolescents in Denmark 1991-2014.

The aim was to examine trends in social inequality in poor self-rated health (SRH) among adolescents in Denmark 1991-2014. The analysis included 18 996 11-15-year-old school children from the cross-sectional Health Behaviour in School-aged Children studies in 1991, 2002, 2006, 2010 and 2014. Across the five surveys, the prevalence of poor SRH was 14.2%, remaining almost unchanged from 1991 to 2014. The proportion with poor SRH was 12.2% in high, 14.3% in middle and 17.6% in low occupational social class. This social inequality in poor SRH was persistent during the entire study period, both in terms of absolute and relative social inequality.

Parental involvement and association with adolescents' fruit and vegetable intake at follow-up: Process evaluation results from the multi-component school-based Boost intervention.

BACKGROUND: Based on the assumption of parental influence on adolescent behavior, multicomponent school-based dietary interventions often include a parental component. The effect of this intervention component is seldom reported and the evidence is inconsistent. We conducted a systematic process evaluation of the parental component and examined whether the leveal of parental involvement in a large multi-component intervention: the Boost study was associated with adolescents' fruit and vegetable (FV) intake at follow-up. METHODS: The Boost study was targeting FV intake among 1,175 Danish 7th graders (≈13- year-olds) in the school year 2010/11. The study included a school component: free FV in class and curricular activities; a local community component: fact sheets for sports- and youth clubs; and a parental component: presentation of Boost at a parent-school meeting, 6 newsletters to parents, 3 guided student-parent curricular activities, and a student-parent Boost event. STUDY POPULATION: Students whose parent replied to the follow-up survey (n = 347). DATA: Questionnaire data from students, parents and teachers at 20 intervention schools. Process evaluation measures: dose delivered, dose received, appreciation and level of parental involvement. Parental involvement was trichotomized into: low/no (0-2 points), medium (3 points) and high (4-6 points). The association between level of parental involvement and self-reported FV intake (24-h recall), was analyzed using multilevel regression analyses. RESULTS: The Boost study was presented at a parent-school meeting at all intervention schools. The dose delivered was low to moderate for the three other parental elements. Most parents appreciated the intervention and talked with their child about Boost (83.5 %). High, medium and low parental involvement was found among 30.5 %, 29.6 % and 39.4 % of the students respectively. Parental involvement was highest among women. More men agreed that the parental newsletters provided new information. Students with a medium and high level of parental involvement ate 47.5 and 95.2 g more FV per day compared to students with low level/no parental involvement (p = 0.02). CONCLUSIONS: Students with a high level of parental involvement ate significantly more FV at follow-up compared to students with a low level/no parental involvement. Parental involvement in interventions may improve adolescents' FV intake if challenges of implementation can be overcome. TRIAL REGISTRATION: ISRCTN11666034 . Registered 06/01/2012. Retrospectively registered.

Socioeconomic differences in emotional symptoms among adolescents in the Nordic countries: recommendations on how to present inequality.

AIMS: This comparative study examines absolute and relative socioeconomic differences in emotional symptoms among adolescents using standardised data from five Nordic countries and gives recommendations on how to present socioeconomic inequality. METHODS: The Health Behaviour in School-aged Children (HBSC) international cross-sectional study from 2005/2006 provided data on 29,642 11-15-year-old adolescents from nationally random samples in Denmark, Finland, Iceland, Norway and Sweden. The outcome was daily emotional symptoms. Family Affluence Scale (FAS) was used as indicator of socioeconomic position. We applied four summary measures of inequality: Prevalence Difference, Odds Ratio, Slope Index of Inequality and Relative Index of Inequality, and presented the socioeconomic inequality by a graphical illustration of the prevalence of emotional symptoms, the size of the FAS groups and the summary indices of inequality in each country. RESULTS: The prevalence of emotional symptoms ranged from 8.1% in Denmark to 13.2% in Iceland. There were large country variations in the size of the low FAS-group ranging from 2% in Iceland to 12% in Finland. The largest absolute and relative socioeconomic inequalities were found in Iceland and the smallest in Finland for girls and in Denmark for boys. CONCLUSIONS: Emotional symptoms were more common among nordic adolescents from low affluence families this association appeared in the study of both absolute and relative inequality. A comprehensive presentation of socioeconomic inequality should include the prevalence of the health outcome, the size of the socioeconomic groups, and the regression line representing the summary indices of inequality.

The Hi Five study: design of a school-based randomized trial to reduce infections and improve hygiene and well-being among 6-15 year olds in Denmark.

BACKGROUND: Infectious illnesses such as influenza and diarrhea are leading causes of absenteeism among Danish school children. Interventions in school settings addressing hand hygiene have shown to reduce the number of infectious illnesses. However, most of these studies include small populations and almost none of them are conducted as randomized controlled trials. The overall aim of the Hi Five study was to develop, implement and evaluate a multi-component school-based intervention to improve hand hygiene and well-being and to reduce the prevalence of infections among school children in intervention schools by 20% compared to control schools. This paper describes the development and the evaluation design of Hi Five. METHODS/DESIGN: The Hi Five study was designed as a tree-armed cluster-randomized controlled trial. A national random sample of schools (n = 44) was randomized to one of two intervention groups (n = 29) or to a control group with no intervention (n = 15). A total of 8,438 six to fifteen-year-old school children were enrolled in the study. The Hi Five intervention consisted of three components: 1) a curriculum component 2) mandatory daily hand washing before lunch 3) extra cleaning of school toilets during the school day. Baseline data was collected from December 2011 to April 2012. The intervention period was August 2012 to June 2013. The follow-up data was collected from December 2012 to April 2013. DISCUSSION: The Hi Five study fills a gap in international research. This large randomized multi-component school-based hand hygiene intervention is the first to include education on healthy and appropriate toilet behavior as part of the curriculum. No previous studies have involved supplementary cleaning at the school toilets as an intervention component. The study will have the added value of providing new knowledge about usability of short message service (SMS, text message) for collecting data on infectious illness and absenteeism in large study populations. TRIAL REGISTRATION: Current Controlled Trials ISRCTN19287682 , 21 December 2012.

Implementation of strategies to increase adolescents' access to fruit and vegetables at school: process evaluation findings from the Boost study.

BACKGROUND: Access to fruit and vegetables (FV) is associated with adolescents' FV consumption. However, little is known about implementation of strategies to increase access to FV at schools. We examined the implementation of two environmental components designed to increase access to FV at Danish schools. METHODS: We used data from 20 intervention schools involved in the school-based multicomponent Boost trial targeting 13-year-olds' FV consumption. The environmental components at school included daily provision of free FV and promotion of a pleasant eating environment. Questionnaire data was collected by the end of the nine-month intervention period among 1,121 pupils (95%), from all school principals (n = 20) and half way through the intervention period and by the end of the intervention among 114 teachers (44%). The implementation of the components was examined descriptively using the following process evaluation measures; fidelity, dose delivered, dose received and reach. Schools with stable high implementation levels over time were characterised by context, intervention appreciation and implementation of other components. RESULTS: For all process evaluation measures, the level of implementation varied by schools, classes and over time. Dose received: 45% of pupils (school range: 13-72%, class range: 7-77%) ate the provided FV daily; 68% of pupils (school range: 40-93%, class range: 24-100%) reported that time was allocated to eating FV in class. Reach: The intake of FV provided did not differ by SEP nor gender, but more girls and low SEP pupils enjoyed eating FV together. Dose delivered: The proportion of teachers offering FV at a daily basis decreased over time, while the proportion of teachers cutting up FV increased over time. Schools in which high proportions of teachers offered FV daily throughout the intervention period were characterized by being: small; having a low proportion of low SEP pupils; having a school food policy; high teacher- and pupil intervention appreciation; having fewer teachers who cut up FV; and having high implementation of educational components. CONCLUSIONS: The appliance of different approaches and levels of analyses to describe data provided comprehension and knowledge of the implementation process. This knowledge is crucial for the interpretation of intervention effect. TRIAL REGISTRATION: Current Controlled Trials ISRCTN11666034.

The role of curriculum dose for the promotion of fruit and vegetable intake among adolescents: results from the Boost intervention.

BACKGROUND: Multi-component interventions combining educational and environmental strategies have proved effective in increasing children and adolescents' fruit and vegetable intake. However such interventions are complex and difficult to implement and several studies report poor implementation. There is a need for knowledge on the role of dose for behaviour change and for assessment of intervention dose to avoid conclusions that intervention components which are not implemented are ineffective. This study aimed to examine 1) the association between dose of a class curriculum and adolescents' fruit and vegetable intake in a school-based multi-component intervention, 2) if gender and socioeconomic position modify this association. METHODS: We carried out secondary analysis of data from intervention schools in the cluster-randomized Boost study targeting 13-year-olds' fruit and vegetable intake. Teacher- and student data on curriculum dose delivered and received were aggregated to the school-level and class-level (only possible for student data). We analysed the association between curriculum dose and students' (n 995) self-reported fruit and vegetable intake (24-h recall questionnaire) after finalization of the intervention using multi-level analyses. Potential moderation was examined by analyses stratified by gender and socioeconomic position. RESULTS: Average dose received at class-level was significantly associated with students' fruit and vegetable intake (10 g (CI: 0.06, 20.33) per curricular activity received). In stratified analyses the association remained significant among boys only (14 g (CI: 2.84, 26.76) per curricular activity received). The average dose delivered and received at the school-level was not significantly associated with students' intake. CONCLUSIONS: We found a dose-response relationship between number of curricular activities received and adolescents' fruit and vegetable intake. The results indicate that curriculum dose received only mattered for promotion of fruit and vegetable intake among boys. Future studies should explore this gender difference in larger samples to guide the planning of school-based curricular interventions with regards to the optimal number of curricular activities required to promote behavioural change in subgroups with low fruit and vegetable intake at baseline. TRIAL REGISTRATION: Current Controlled Trials ISRCTN11666034.

Emotional symptoms among adolescents: epidemiological analysis of individual-, classroom- and school-level factors.

BACKGROUND: Large proportions of schoolchildren suffer from emotional symptoms and there are large variations across schools. It is unknown to what degree this variation is due to composition of schoolchildren in each school or to contextual factors. Objectives are to identify factors at individual, classroom and school levels associated with emotional symptoms. METHOD: Data stem from the Danish contribution to the international Health Behaviour in School-aged Children study 2010 including 4922 schoolchildren aged 11-15-years from a random sample of schools and including data from school leaders. Emotional symptoms are defined as daily presence of at least one of four symptoms: feeling low, irritable or bad tempered, nervous and having difficulties falling asleep. Multilevel multivariable logistic regression analyses are applied to identify and quantify factors at individual, classroom and school level. RESULTS: Schoolchildren from low (odds ratio (OR) 1.70, 95% CI: 1.33-2.17) and medium (OR 1.50, 95% CI: 1.22-1.85) occupational social class (OSC), girls (OR 1.32, 95% CI: 1.13-1.56) and schoolchildren exposed to bullying (OR 3.82, 95% CI: 2.71-5.40), had increased odds for emotional symptoms. A negative classroom climate was associated with emotional symptoms (OR 1.29, 95% CI: 0.99-1.69) and so was being part of classrooms with a high prevalence of bullying (OR 1.28, 95% CI: 1.0-1.60). CONCLUSION: Female sex, low OSC, single parent family, exposure to bullying and a high prevalence of bullying within a class are all associated with emotional symptoms. Most variation across schools is explained by individual-level factors but psychosocial aspects of the classroom environment also play a role.

Trends in overweight prevalence among 11-, 13- and 15-year-olds in 25 countries in Europe, Canada and USA from 2002 to 2010.

BACKGROUND: The purpose of this study was to assess recent changes in the prevalence of overweight (including obesity) among 11-, 13- and 15-year-olds in 33 countries from 2002 to 2010. METHODS: Data from 25 countries from three consecutive survey cycles (2002, 2006 and 2010) that had at least 80% response rate for self-reported height, weight and age were analysed using logistic regression analysis. RESULTS: Overweight prevalence increased among boys in 13 countries and among girls in 12 countries; in 10 countries, predominantly in Eastern Europe, an increase was observed for both boys and girls. Stabilization in overweight rates was noted in the remaining countries; none of the countries exhibited a decrease over the 8-year period examined. In the majority of countries (20/25) there were no age differences in trends in overweight prevalence. CONCLUSION: In over half of the countries examined overweight prevalence did not change during 2002-2010. However, increasing overweight prevalence was noted in many Eastern European countries over this time period. Overweight prevalence remained high in several countries in Europe and North America. These patterns call for continued research in youth overweight and highlight the need to understand cross-national differences by examining macro-level indicators. Such research should feed into developing sound translations and practices to prevent and reduce overweight in youth.

Implementing a free school-based fruit and vegetable programme: barriers and facilitators experienced by pupils, teachers and produce suppliers in the Boost study.

BACKGROUND: Multi-component interventions which combine educational and environmental strategies appear to be most effective in increasing fruit and vegetable (FV) intake in adolescents. However, multi-component interventions are complex to implement and often poorly implemented. Identification of barriers and facilitators for implementation is warranted to improve future interventions.This study aimed to explore implementation of two intervention components which addressed availability and accessibility of FV in the multi-component, school-based Boost study which targeted FV intake among Danish 13-year-olds and to identify barriers and facilitators for implementation among pupils, teachers and FV suppliers. METHODS: We conducted focus group interviews with 111 13-year-olds and 13 teachers, completed class observations at six schools, and conducted telephone interviews with all involved FV suppliers. Interviews were transcribed, coded and analysed using qualitative analytical procedures. RESULTS: FV suppliers affected the implementation of the FV programme at schools and thereby pupils' intake through their timing of delivery and through the quality, quantity and variety of the delivered FV. Teachers influenced the accessibility and appearance of FV by deciding if and when the pupils could eat FV and whether FV were cut up. Different aspects of time acted as barriers for teachers' implementation of the FV programme: time spent on having a FV break during lessons, time needed to prepare FV and time spent on pupils' misbehaviour and not being able to handle getting FV. Teacher timing of cutting up and serving FV could turn into a barrier for pupils FV intake due to enzymatic browning. The appearance of FV was important for pupils' intake, especially for girls. FV that did not appeal to the pupils e.g. had turned brown after being cut up were thrown around as a part of a game by the pupils, especially boys. Girls appreciated the social dimension of eating FV together to a larger extent than boys. CONCLUSIONS: Limited time and pupils' misbehaviour were barriers for teachers' implementation. Establishing FV delivery to schools as a new routine challenged FV suppliers' implementation. Food aesthetics were important for most pupils' FV intake while the social dimension of eating FV together seemed more important to girls than boys. TRIAL REGISTRATION: Current Controlled Trials ISRCTN11666034.