Background Mental wellbeing is an important focus in surveys among adolescents. Several relevant instruments are available. In the Nordic part of the Health Behaviour in School-aged Children (HBSC) study 2022, four different scales for the measurement of wellbeing, were employed: Cantril’s Ladder, the WHO-5 Wellbeing Index, the seven-item Short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS), and the HBSC Health Complaints Scale. This study aims to examine statistically to what extent these scales overlap or measure distinctly different aspects of mental wellbeing. Methods Data stem from the Nordic part of the HBSC 2022 study (n = 28 189). In all statistical analyses, data are weighted to ensure equal representation of genders, age groups (ages 11, 13, and 15 years), and countries (Denmark, Finland, Iceland, Norway, Sweden). Adjustments were made for cluster effects (school classes). The statistical analyses included factor analysis, general linear modeling, variants of latent variable analysis, and structural equation modeling including bifactor modeling. Results Exploratory factor analysis produced three factors corresponding well to the three multi-item instruments, with the single item Cantril’s ladder loading on the factor defined by the WHO-5 Wellbeing Index. Confirmatory factor analysis produced good fit for a model with one factor consisting of the three positively worded scales and a separate factor for health complaints, but with a high negative correlation between the two factors. Analyses of each of the four scales against gender, age, and 16 other covariates, showed strikingly similar patterns of associations. In an analysis based on a hierarchical model, adjustments for the general mental wellbeing (second-order) factor reduced associations between the first-order factors (one for each scale) and covariates substantially. Latent variable and bifactor modeling confirmed that most of the covariance among all items from all scales combined was captured by one general dimension. Information curve analysis showed that for all scales, the most reliable scores were obtained for participants with below average latent scores. Conclusion The study indicates that the four scales essentially reflect one underlying dimension. In studies such as HBSC, efforts should be made to use instruments that cover distinctly different aspects of mental health and wellbeing.

Loneliness in adolescence is a serious threat to quality of life. The purpose of this study was to examine the association between loneliness and ease of communication with parents and friends, and whether the association was different for boys and girls. The study used data from the Danish arm of the international Health Behaviour in School-aged Children (HBSC). The surveys in 2010, 2014 and 2018 included nationally representative samples of students in the age groups, 11-, 13- and 15-year-olds (n = 10,425). Loneliness was measured by one item and ease of communication with parents and friends by the HBSC Ease of Communication Measure. Multilevel multivariate logistic regression was applied to study the associations between ease of communication and loneliness. Stratified analysis and interaction analysis tested the modifying effect of sex on the associations. The prevalence of loneliness wa 4.3

1) to study time trends in the prevalence of recurrent dizziness among adolescents in Denmark 1991–2022, and 2) to examine how dizziness was associated with sociodemographic factors, mental health related factors, health status, and health behaviours in 2022. The study focused on recurrent dizziness, i.e. episodes of dizziness several times a week during the last six months. Data stem from the Danish arm of the international Health Behaviour in School-aged Children (HBSC) study which included 11-, 13- and 15-year-olds from random samples of schools in nine comparable surveys from 1991 to 2022, n = 40,102. We applied multivariate logistic regression analyses in the 2022 dataset (n = 5,737) to examine how dizziness was associated with other factors. In 2022, the prevalence of recurrent dizziness was 14.3

Objectives To examine trends in socioeconomic inequality in adolescent health over three decades, across fifteen health indicators: overweight, underweight, headache, stomachache, backpain, emotional symptoms, difficulties falling asleep, loneliness, low life satisfaction, low self-rated heath, smoking, drunkenness, physical inactivity, low vegetable intake, and inadequate toothbrushing.Methods The Health Behaviour in School-aged Children (HBSC) study in Denmark included nine identical surveys of 11-15-year-olds from 1991 to 2022, n = 35,423. For each health indicator, we measured absolute and relative socioeconomic inequality by prevalence differences and odds ratios between low and high socioeconomic groups.Results There was socioeconomic inequality in thirteen health indicators, e.g., the OR (95% CI) for overweight in low vs. high socioeconomic groups was 2.22 (1.95-2.49). This social inequality persisted across health indicators throughout the study period with two deviations: Underweight was not associated with socioeconomic background and drunkenness was persistently most prevalent in higher socioeconomic groups.Conclusion The political efforts to reduce socioeconomic inequality in health seems to have failed. It is important to improve monitoring of adolescent health and implement improved policies to tackle socioeconomic inequality in adolescent health.

Aims: The aim was to examine how loneliness was associated with bullying victimization at school and online. Methods: We used data from the Danish arm of the international Health Behavior in School-aged Children (HBSC) study from 2022. The study population was a nationally representative sample of 11–15-year-olds who completed the internationally standardized HBSC questionnaire at school, n = 5382. Multilevel logistic regression was applied to study the associations between bullying victimization and loneliness. Results: The prevalence of reporting loneliness often or very often was 9.0%; 6.3% of the sample experienced habitual bullying victimization at school, and 4.8% incurred cyberbullying. There was a strong and graded association between loneliness and bullying victimization at school and cyberbullying. The associations were significant for boys and girls, and the association between exposure to bullying at school and loneliness was steeper for boys than girls. The gradients were steeper for physical bullying than for cyberbullying. Students exposed to habitual bullying in both contexts had an adjusted OR (95% CI) of 11.21 (6.99–17.98) for loneliness. Conclusion: Exposure to bullying at school and cyberbullying are strongly associated with loneliness. It is important to reduce bullying at school and on the internet and to promote effective interventions to reduce continuing loneliness.

Abstract Background: Loneliness in adolescence is a serious threat to quality of life, and it is important to identify possible predictors. The purpose of this study was to examine the association between loneliness and close relationships with parents and friends in a community sample of adolescents, and whether this association varied by sex, age group, and socioeconomic status. Methods: The study used data from the Danish arm of the international Health Behaviour in School-aged Children (HBSC) study in 2010, 2014 and 2018 that included nationally representative samples of students in the age groups, 11-, 13- and 15-year-olds (n=10,425). Loneliness was measured by one item and close relationships with parents was measured by the HBSC Ease of Communication Measure. Multilevel logistic regression was applied to study the associations between ease of communication and loneliness. Stratified analysis and interaction analysis tested the modifying effect of sex on the associations. Results: A large majority (80.1%) of students had close relationships with both parents and friends, 16.3% had close relationships with only one of these parties, and 3.6% with neither any parent nor any friend. The prevalence of loneliness was 6.0%. There was a strong and graded association between loneliness and lack of close relationships. The odds ratios for loneliness were around 8.0 in the groups with the weakest relationships. Stratified analysis showed that girls were more vulnerable to lack of close relationships. Conclusion: The remarkably strong association between lack of close relationships and loneliness – especially for girls – calls for further studies that explore which aspects of loneliness and which aspects of social relationships drive this association. From an intervention point of view, the study suggests that interventions to fight loneliness should include efforts to strengthen social relations among peers at school.

This study investigated profiles of perceived social support and their associations with mental health indicators for male and female adolescents. The sample was a nationally representative group of Danish adolescents age 13–16 years (Male N = 1114; Female N = 1065). Latent profile analysis was used to identify profiles of perceived social support from different sources (classmate, teacher, family, friend). Three distinct profiles of perceived social support were identified for both genders: ‘High’ support from all sources (54.4% of males; 55.5% of females), ‘Moderate’ support from all sources (31.6% of males; 28.8% of females) and ‘Low friend’ support with moderate support from other sources (13.9% of males; 15.7% of females). The ‘high’ perceived support profile was associated with optimal mental health; the ‘moderate’ perceived support profile was associated with lower wellbeing and more frequent emotional symptoms; and the ‘low friend’ perceived support profile was associated with the lowest levels of wellbeing and, specifically for females, higher frequency of emotional symptoms. Results highlight typical profiles of perceived social support among adolescents, and demonstrate nuanced associations between perceived social support and mental health indicators, with notable gender differences.

Many young adolescents experiment with substance use which can have substantial health implications later in life. This study examined trends in substance use among Danish adolescents from 2002 to 2018, including exclusive and dual current use of alcohol and cigarettes. Data on 13- and 15-year-olds (N = 15,295) from five comparable cross-sectional Health Behavior in School-aged Children (HBSC) surveys were used. Cochran-Armitage test for trend assessed the development in substance use patterns over time. Overall, a decreasing trend in current use of alcohol and cigarettes was found among Danish adolescents during the 16-year study period: from 71.7% in 2002 to 51.6% in 2018. In 2018, most adolescents (41.8%) currently used alcohol exclusively, 8.6% had a dual current use of cigarettes and alcohol, and 1.3% smoked cigarettes exclusively. Trends in alcohol use differed according to age groups, while no gender-specific trends in substance use were found. Findings suggest that a significant prevention potential in adolescent substance use remains, and future initiatives may focus on dual use of substances as well as tailored efforts to specific subgroups in high risk of using substances.

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.

BACKGROUNDUnderweight among adolescents is an important clinical and public health issue. It is associated with adverse health outcomes throughout the life-span and may reflect food poverty, unhealthy eating habits, or some underlying health conditions.OBJECTIVETo study prevalence and trends in underweight among adolescents 1998-2018, to examine social inequality in underweight, and whether social inequality changed over time.METHODSData were derived from 6 cross-sectional school surveys from The Health Behaviour in School-aged Children study in Denmark. The study included 11-, 13-, and 15-year-old schoolchildren in random samples of schools in 1998, 2002, 2006, 2010, 2014, and 2018 (n = 22,177). Underweight was determined by body mass index-for-age thinness grade 2-3 (the Cole and Lobstein method). Socioeconomic status was determined using occupational social class (the Danish OSC Measurement).RESULTSThe overall prevalence of underweight was 3.1% among boys and 5.3% among girls (P < 0.0001) and decreased by age (P < 0.0001) among both boys and girls. The prevalence of underweight was almost stable from 1998 to 2018. There was no observed absolute or relative social inequality in the prevalence of underweight among boys or girls.CONCLUSIONThe prevalence of underweight in 11- to 15-year-olds was significantly higher among girls than boys. The prevalence remained stable from 1998 to 2018. There was no significant association between SES and prevalence of underweight. It is important to elucidate the underlying causes of underweight such as malnutrition, eating disorders, eating problems, loss of appetite, chronic diseases, insufficient knowledge of nutrients effects on bodily functions, and persistent pain.

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.

Chronic backpain among adolescents is important because the prevalence is high, above 10%, and more than 10% of all adolescents experience impacts on important day-to-day activities. Chronic backpain tracks into adulthood and is associated with several health problems. The objective was to study trends in the prevalence of chronic backpain among adolescents 1991–2018, to examine the association with socioeconomic status (SES), and whether this association changed over time. The study used data from eight comparable cross-sectional school surveys of nationally representative samples of 11–15-year-olds in 1991, 1994, 1998, 2002, 2006, 2010, 2014, and 2018, which constitute the Danish arm of the international Health Behaviour in School-aged Children (HBSC) study. The participation rate was 74.6% of the eligible study population, n = 29,952. Chronic backpain was defined as self-reported backpain daily or several days a week during the last 6 months. The prevalence of chronic backpain was 11.1%, significantly increasing from 8.9% in 1991 to 11.7% in 2018. The OR for chronic backpain was 1.20 (95% CI: 1.10–1.31) in middle, and 1.56 (95% CI: 1.41–1.73) in low compared to high SES. Sensitivity analyses with two other cut-points for backpain frequency showed similar associations. Conclusion: Chronic backpain is common among adolescents and the prevalence increased from 1991 to 2018. The prevalence was highest in lower SES families. We recommend increased efforts to prevent chronic backpain.

Chronic backpain among adolescents is important because the prevalence and the burden of disability is high. Chronic backpain tracks into adulthood and is associated with several health problems. The objective was to study trends in the prevalence of chronic backpain among adolescents 1991-2018, to examine the association with socioeconomic status (SES) and whether this association changed over time. The study used data from eight comparable cross-sectional school-surveys of nationally representative samples of 11-15-year-olds in 1991, 1994, 1998, 2002, 2006, 2010, 2014 and 2018, the Danish arm of the international Health Behaviour in School-aged Children (HBSC) study. The participation rate was 88.0%, n=29,952. Chronic backpain was defined as self-reported backpain daily or several days a week during the last six months. The prevalence of chronic backpain was 11.1%, significantly increasing from 8.9% in 1991 to 11.7% in 2018. The OR for chronic backpain was 1.20 (1.10-1.31) in middle and 1.56 (1.41-1.73) in low compared to high OSC. Sensitivity analyses with two other cut-points for backpain frequency showed similar associations. Conclusion: Chronic backpain is common among adolescents and the prevalence increased from 1991 to 2918. The prevalence was highest in lower SES families. We recommend increased efforts to prevent chronic backpain.

At present there are different positions regarding trends in adolescent mental health. Can we trust trend data on the mental health among adolescents in the Nordic countries? Some question the trustworthiness of adolescent self-reports, which describe ordinary daily hassles as health complaints, which cannot be interpreted as signs of mental disorders. In addition, today there is a more open climate for talking about mental issues, which can lead to an overestimation of the prevalence of mental disorders. Statistics on mental health services statistics report increased psychopharmaceutic prescriptions as well as consumption of professional care. Such data argues for increased governmental investment in adolescent mental health services. Is this pattern due to increased availability of mental health services and/or increased prevalence of mental health problems in the adolescent population? A concern is that data availability influences policymaking and allocation of resources. If there is an emphasis on self-reported data from adolescents that may an increased risk of medicalization of young people's dealing with their daily lives. If on the other hand the reported problems among young people is disregarded, this would be against the UN Child Convention. The survey data has important qualities especially if the data is analysed and reported properly. The validation of survey measure has been done both regarding psychometric quality and content validity. Advanced analysis of the data can draw a more nuanced picture. Moreover, some screening instruments have been developed as a first step towards making diagnosis. Instead the HBSC surveys ask boys and girls about their health and well-being, social environment and health behaviours. HBSC uses findings at national and international levels to gain new insights into young people's health and wellbeing, understand the social determinants of health, and inform policy and practice to improve young people's lives.

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. 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). 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. There was a persistent absolute and relative social inequality in overweight and obesity 1998–2018 among Danish adolescents.

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.

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Sammanfattning:Forskning om utvecklingen av ungdomars psykiska hälsa är utmanande. Begreppets mångsidighet gör vetenskapsteoretiska och metodologiska reflektioner nödvändiga. Data ska samlas in som kan ge möjlighet att följa utvecklingen över tid, vilket kräver goda mätinstrument, god infrastruktur för datainsamling och kompetens att mäta och analysera. Det är en paradox att den självrapporterade psykiska hälsan försämras särskilt hos tonårsflickor i ett land som välfärdslandet Sverige. En översikt ges av tidigare forskning kring trender i ungdomars psykiska hälsa inom ramen studien Skolbarns hälsovanor. Ytterligare multidisciplinär forskning med olika komplementande ansatser behövs för att bättre fylla kunskapsluckorna. AbstractResearch on the development of adolescent mental health is challenging. The complexity of the phenomenon makes scientific and methodological reflections necessary. Data must be collected enhancing analysis of the developments over time, which requires good measuring instruments, infrastructure for data collection and competence in analysing and reporting.It is a paradox that the self-reported mental health deteriorates, especially among teenage girls in the Swedish welfare state. Previous research on trends in young people's mental health in the Health Behaviour in School-aged Children study is reviewed. Further multidisciplinary research with different complementary approaches is needed to better fill the knowledge gaps. Key words: Psykisk hälsa, enkätundersökning, mätmetodik, tidserier, tonåringar

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.

The aim is to discuss methodological challenges for research on adolescent positive mental health. A first consideration is which questions should the measurement instrument answer. In the clinical context it should have the properties of giving enough information for making a diagnosis of high quality. In the public health context, its objective may be to give information that enables the researcher to describe trends at the population level and provide guidance on areas of intervention. The HBSC study is monitoring the health and health behaviour of school-aged children in a public health context. It is a population survey, defined by the form of data collection and the method of analysis. The data is collected by questionnaire from a representative sample of school-aged children. It tries to answer descriptive questions (What, who, when?), but also tries to explore causal associations (Why?), given the limitations of the cross-sectional design. Surveys have advantages: Good for gathering descriptive data; Can cover a wide range of topics. Are relatively inexpensive to use; Can include large number of respondents; and Can be analysed using a variety of existing software. Among the disadvantages can be mentioned: Self-report may lead to biased reporting; Data may provide a general picture but lack depth; Difficult to obtain adequate information on context; and Differences in understanding: it is difficult to formulate questions in such a way that it will mean exactly same thing to each respondent. The choice of measurement tools or indicators involves both theoretical and practical issues. Multidisciplinary research teams may include different theoretical traditions, which is an asset but also make it necessary to be explicit regarding overall aims of the study. Most often the theoretical issues focus one of three topics: the value of the types of data; the relative scientific rigor of the data; or basic, underlying philosophies of evaluation.