Chronic backpain among adolescents in Denmark: trends 1991-2018 and association with socioeconomic status.

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. What is Known: • Chronic backpain among adolescents is common, has a high burden of disability, is associated with several health problems, and tracks into adulthood. What is New: • The prevalence of chronic backpain among adolescents in Denmark increased from 8.9% in 1991 to 11.7% in 2018. • The prevalence was highest among adolescents from lower SES families.

Underweight among adolescents in Denmark: prevalence, trends (1998-2018), and association of underweight with socioeconomic status.

BACKGROUND: Underweight 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. OBJECTIVE: To study prevalence and trends in underweight among adolescents 1998-2018, to examine social inequality in underweight, and whether social inequality changed over time. METHODS: Data 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). RESULTS: The 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. CONCLUSION: The 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.

Underweight among adolescents is an important clinical and public health issue as it may reflect food poverty, unhealthy eating habits, or some underlying health problem. The aim was to study prevalence and trends in underweight among adolescents 1998­2018 and to examine social inequality in underweight. We used data from 6 cross-sectional school surveys from Denmark. Across all surveys, the number of participants was 22,177 11-, 13-, and 15-year-old students. The prevalence of thinness grades 2 and 3 were taken as indicators of underweight and were 3.1% among boys and 5.3% among girls. This prevalence was almost stable from 1998 to 2018. Contrary to overweight, which is usually more prevalent in lower socioeconomic groups, underweight was not associated with socioeconomic status. There were 2 exceptions: the prevalence of underweight among girls was highest in those from high socioeconomic groups in1998, while the prevalence among boys was highest in those from low socioeconomic groups in 2018. Underweight conditions in adolescents need careful medical examinations to elucidate the underlying causes of underweight, for example, malnutrition, eating disorders, eating problems, loss of appetite, voluntary uptake of fad diets, chronic disease, insufficient knowledge of nutrients that impact their bodily functions, mental health problems, and persistent pain.

Difficulties falling asleep among adolescents: Social inequality and time trends 1991-2018.

Sleep problems in adolescence are increasingly common, and associated with adverse health and psychological outcomes. Adolescents' sleep problems may be related to the family's socioeconomic status, but studies are few and no study has examined whether social inequality in sleep problems changes as sleep problems become increasingly common. This study examined trends in difficulties falling asleep among adolescents in Denmark, whether this sleep problem was associated with socioeconomic status, and whether this association changed from 1991 to 2018. The study applied data from eight comparable surveys among 11-15 year olds in Denmark 1991-2018, the Danish arm of the international Health Behaviour in School-aged Children study, N = 30,002. The prevalence of daily difficulties falling asleep increased from 7.0% to 13.4% in 1991-2018 with higher frequencies among girls and younger adolescents. The odds ratio (95% confidence interval) for daily difficulties was 1.14 (1.05-1.24) in middle and 1.52 (1.37-1.69) in low compared with high socioeconomic status. The absolute social inequality in difficulties falling asleep was persistent in 1991-2018 whereas the relative social inequality may have decreased. The increasing prevalence and the social inequality in difficulties falling asleep among adolescents is a serious public health concern that calls for more attention and efforts.

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.

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.

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.

Breakfast frequency among adolescents: associations with measures of family functioning.

OBJECTIVE: To investigate (i) associations between adolescents' frequency of breakfast and family functioning (close relations to parents, quality of family communication and family support) and (ii) if any observed associations between breakfast frequency and family functioning vary by sociodemographic factors. DESIGN: School-based cross-sectional study. Students completed a web-based questionnaire. Associations were estimated by multilevel multivariate logistic regression. SETTING: Danish arm of the Health Behaviour in School-aged Children study, 2014. SUBJECTS: Adolescents aged 13 and 15 years (n 3054) from a random sample of forty-one schools. RESULTS: Nearly one-quarter of the adolescents had low breakfast frequency. Low breakfast frequency was associated with low family functioning measured by three dimensions. The OR (95 % CI) of low breakfast frequency was 1·81 (1·40, 2·33) for adolescents who reported no close relations to parents, 2·28 (1·61, 3·22) for adolescents who reported low level of quality of family communication and 2·09 (1·39, 3·15) for adolescents who reported low level of family support. Joint effect analyses suggested that the odds of low breakfast frequency among adolescents with low family functioning compared with high family functioning were highest among adolescents being girls, immigrants and living in other than a traditional family structure. CONCLUSIONS: Low breakfast frequency was associated with low family functioning measured by close relations to parents, quality of family communication and family support. Further, analyses suggested that the associations were more pronounced among girls, immigrants and adolescents from other family structure than traditional. The study highlights the importance of the family setting in promoting regular breakfast frequency among adolescents.

Loneliness and Ethnic Composition of the School Class: A Nationally Random Sample of Adolescents.

Loneliness is a public health concern that increases the risk for several health, behavioral and academic problems among adolescents. Some studies have suggested that adolescents with an ethnic minority background have a higher risk for loneliness than adolescents from the majority population. The increasing numbers of migrant youth around the world mean growing numbers of heterogeneous school environments in many countries. Even though adolescents spend a substantial amount of time at school, there is currently very little non-U.S. research that has examined the importance of the ethnic composition of school classes for loneliness in adolescence. The present research aimed to address this gap by exploring the association between loneliness and three dimensions of the ethnic composition in the school class: (1) membership of ethnic majority in the school class, (2) the size of own ethnic group in the school class, and (3) the ethnic diversity of the school class. We used data from the Danish 2014 Health Behaviour in School-aged Children survey: a nationally representative sample of 4383 (51.2 % girls) 11-15-year-olds. Multilevel logistic regression analyses revealed that adolescents who did not belong to the ethnic majority in the school class had increased odds for loneliness compared to adolescents that belonged to the ethnic majority. Furthermore, having more same-ethnic classmates lowered the odds for loneliness. We did not find any statistically significant association between the ethnic diversity of the school classes and loneliness. The study adds novel and important findings to how ethnicity in a school class context, as opposed to ethnicity per se, influences adolescents' loneliness.

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.

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.

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

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

Bullying at School, Cyberbullying, and Loneliness: National Representative Study of Adolescents in Denmark.

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.

Validity of self-reported height and weight among adolescents: the importance of reporting capability.

BACKGROUND: This study proposes a new approach for investigating bias in self-reported data on height and weight among adolescents by studying the relevance of participants' self-reported response capability. The objectives were 1) to estimate the prevalence of students with high and low self-reported response capability for weight and height in a self-administrated questionnaire survey among 11-15 year old Danish adolescents, 2) to estimate the proportion of missing values on self-reported height and weight in relation to capability for reporting height and weight, and 3) to investigate the extent to which adolescents' response capability is of importance for the accuracy and precision of self-reported height and weight. Also, the study investigated the impact of students' response capability on estimating prevalence rates of overweight. METHODS: Data was collected by a school-based cross-sectional questionnaire survey among students aged 11-15 years in 13 schools in Aarhus, Denmark, response rate =89%, n = 2100. Response capability was based on students' reports of perceived ability to report weight/height and weighing/height measuring history. Direct measures of height and weight were collected by school health nurses. RESULTS: One third of the students had low response capability for weight and height, respectively, and every second student had low response capability for BMI. The proportion of missing values on self-reported weight and height was significantly higher among students who were not weighed and height measured recently and among students who reported low recall ability. Among both boys and girls the precision of self-reported height and weight tended to be lower than among students with low response capability. Low response capability was related to BMI (z-score) and overweight prevalence among girls. These findings were due to a larger systematic underestimation of weight among girls who were not weighed recently (-1.02 kg, p < 0.0001) and among girls with low recall ability for weight (-0.99 kg, p = 0.0024). CONCLUSION: This study indicates that response capability may be relevant for the accuracy of girls' self-reported measurements of weight and height. Consequently, by integrating items on response capability in survey instruments, participants with low capability can be identified. Similar analyses based on other and less selected populations are recommended.

Do eating behaviors in the general population account for country variance in glycemic control among adolescents with diabetes: the Hvidoere Study Group and the Health Behaviour in School-Aged Children study.

BACKGROUND: The Hvidoere Study Group (HSG) has demonstrated major differences in glycemic control between pediatric diabetes centers which remain largely unexplained. This study investigates whether these differences are partly attributable to healthy eating norms in the background population. METHODS: The study involved adolescents from 18 countries from (i) the Health Behaviour in School-Aged Children study (HBSC) and (ii) the HSG. There were 94 387 participants from representative HBSC samples of 11-, 13- and 15-yr-olds and 1483 11- to 15-yr-old adolescents with diabetes from the HSG. The frequency of intake of fruit, vegetables, sweets, sugary soft drinks, and daily breakfast was compared between the two groups. The glycemic control of the adolescents in the HSG cohort was determined by measuring glycated hemoglobin (HbA1c). RESULTS: Across countries in the HSBC survey, there was substantial variation in prevalence of healthy eating behavior and even greater variation between adolescents from the HSG centers. In all countries more adolescents with diabetes reported healthy eating behavior compared to national norms. In individuals healthy eating behavior had a significant effect on the individual level HbA1c. There was no significant correlation between the frequencies of these healthy eating behaviors at (i) the national level and (ii) diabetes center level and the center mean HbA1c. CONCLUSIONS: Although individual healthy eating behavior is associated with better glycemic control at the individual level, such eating behavior does not explain the center differences in HbA1c. Similarly, the reported healthy eating norm of the background populations does not explain the variation in glycemic control among centers.

Postthrombotic syndrome and quality of life in patients with iliofemoral venous thrombosis treated with catheter-directed thrombolysis.

BACKGROUND: Postthrombotic syndrome (PTS) is a common complication after iliofemoral venous thrombosis, often resulting in poor quality of life (QOL) among the affected patients. This study assessed development of PTS and its effect on QOL among patients treated for iliofemoral venous thrombosis by catheter-directed thrombolysis. METHODS: Patients admitted with an iliofemoral venous thrombosis and treated with catheter-directed thrombolysis at Gentofte University Hospital from 1999 to 2008 were invited to participate. Duplex ultrasound imaging was used to assess venous patency and valve function. Each patient completed the generic Short-Form 36-item (SF-36) health survey assessment, producing physical component (PCS) and mental component summary (MCS) scores, and the disease-specific Venous Insufficiency Epidemiological and Economic Study (VEINES)-Quality of Life (QOL)/Symptoms (Sym), questionnaires to assess QOL. PTS was assessed using the Villalta scale. RESULTS: The study included 109 patients. Median follow-up was 71 months. PTS developed in 18 patients (16.5%) and of those, initial thrombolysis was successful in 13. Patients with PTS had significantly worse mean ± standard deviation scores than patients without PTS on VEINES-QOL (34.2 ± 9.6 vs 53.1 ± 6.6; P < .0001), VEINES-Sym (34.0 ± 8.8 vs 53.2 ± 6.6; P < .0001), SF-36 MCS (44.2 ± 15.5 vs 52.3 ± 11.0; P = .005), and SF-36 PCS (42.3 ± 9.1 vs 53.5 ± 7.8; P < .0001) subscales. Patients with reflux or chronic occlusions, or both, had significantly lower mean ± SD scores than patients with patent veins without reflux on VEINES-QOL (43.5 ± 14.3 vs 51.0 ± 8.8; P = .044) and SF-36 PCS (47.2 ± 10.9 vs 52.4 ± 8.5; P = .049) scales. CONCLUSION: PTS was associated with worse QOL, although only a few patients developed PTS after catheter-directed thrombolysis of iliofemoral venous thrombosis. Patients with patent veins and sufficient valves have higher QOL scores than patients with reflux and occluded veins.

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

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

Recurrent abdominal pain among adolescents: trends and social inequality 1991-2018.

OBJECTIVES: The association between socioeconomic status and recurrent abdominal pain (RAP) among adolescents is an understudied issue. No study has examined whether such an association changes over time. The aim was to examine trends in RAP among adolescents in Denmark from 1991 to 2018, to examine whether there was social inequality in RAP and whether this inequality varied over time. METHODS: The study used data from the Danish part of the international Health Behaviour in School-aged Children (HBSC) study of nationally representative samples of 11-, 13- and 15-year-olds. This study pooled data from eight comparable surveys from 1991 to 2018, overall participation rate 88.0%, n=30,048. The definition of RAP was self-reported stomach-ache daily or several days per week during the past six months. We reported absolute inequality as prevalence difference in RAP between low and high socioeconomic status and relative inequality as odds ratio for RAP by socioeconomic status. RESULTS: In the entire study population, 5.6% reported RAP, 3.1% among boys and 7.8% among girls. There was a significant increase in RAP from 1991 to 2018 among boys and girls, test for trend, p<0.0001. The prevalence of RAP was significantly higher in low than high socioeconomic status, OR=1.63 (95% CI: 1.42-1.87). The absolute social inequality in RAP fluctuated with no consistent increasing or decreasing pattern. CONCLUSIONS: The prevalence of RAP increased from 1991 to 2018. The prevalence was significantly higher among girls than among boys, and significantly higher in low socioeconomic status families. Professionals should be aware of RAP as common and potentially serious health problems among children and adolescents. In addition to clinical examination it is important to focus on improving the child's quality of life, reduce parents' and children's concerns about the seriousness of the condition, and consider supplements to medicine use.

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.

Socioeconomic inequality in exposure to bullying during adolescence: a comparative, cross-sectional, multilevel study in 35 countries.

OBJECTIVES: We examined the socioeconomic distribution of adolescent exposure to bullying internationally and documented the contribution of the macroeconomic environment. METHODS: We used an international survey of 162,305 students aged 11, 13, and 15 years from nationally representative samples of 5998 schools in 35 countries in Europe and North America for the 2001-2002 school year. The survey used standardized measures of exposure to bullying and socioeconomic affluence. RESULTS: Adolescents from families of low affluence reported higher prevalence of being victims of bullying (odds ratio [OR] = 1.13; 95% confidence interval [CI] = 1.10, 1.16). International differences in prevalence of exposure to bullying were not associated with the economic level of the country (as measured by gross national income) or the school, but wide disparities in affluence at a school and large economic inequality (as measured by the Gini coefficient) at the national level were associated with an increased prevalence of exposure to bullying. CONCLUSIONS: There is socioeconomic inequality in exposure to bullying among adolescents, leaving children of greater socioeconomic disadvantage at higher risk of victimization. Adolescents who attend schools and live in countries where socioeconomic differences are larger are at higher risk of being bullied.

Does school environment affect 11-year-olds' fruit and vegetable intake in Denmark?

It is often found that adolescents eat too little fruit and vegetables. We examined the importance of school for 11-year-olds' daily intake measured by food frequency- and 24-h recall questionnaires in Danish data from the European 2003 Pro Children Survey. Multilevel logistic regression analyses included matched student-parent-school questionnaire data (N=1410) from a random sample of 59 schools and were conducted for fruit and vegetables separately: 1) without explanatory variables, to decompose the between-school and within-school variance; 2) with individual level covariates (socioeconomic position, parental intake, etc.) to examine if the between-school variance was attributable to different student compositions of schools; and 3) with individual- and school-level covariates (school availability of fruit/vegetables and unhealthy food) to examine the effect of context. Additional analyses stratified by gender and home availability of fruit/vegetables examined if school food availability influenced subgroups differently. Between-school variations were quantified by intra class correlations and median odds ratios. We found that 40% of the students ate > or = 200 g fruit/day and 25% ate > or = 130 g vegetables/day. Most of the total variance in students' intake occurred at the individual level (93-98%). There were larger between-school variations in vegetable intake than in fruit intake. Fruit and vegetable consumption clustered within schools to a larger degree for boys than girls. The between-school variance did not differ by home availability. Boys and students from high availability homes consumed more fruit and/or vegetables if enrolled in schools with access to fruit/vegetables and unhealthy food or contrarily with no food available versus schools with only fruit/vegetables available. The small school-level effects on 11-year-olds' fruit and vegetable intake imply that family level interventions may be more important and that the success of school interventions will rely on the degree of parental involvement.