Health and quality of life of patients with haemophilia: A national study of 124 Danish men.

PURPOSE: In the past decades, haemophilia treatment has greatly improved the health of persons with haemophilia (PWH). This study compares PWH to the general population on social conditions and health. METHODS: In December 2021, all Danes with moderate or severe haemophilia A or B, or von Willebrands disease type 3 were invited to participate in an online self-report survey concerning sociodemographic factors, self-rated health, teeth status, chronic health conditions, symptoms and loneliness. This study compares responses from the 124 adult male PWH with responses from a male general population sample (N = 4849). Analyses used logistic regression, controlling for age and highest completed education. RESULTS: Fewer PWH were in the oldest age group (65-84 years). Controlling for age, no significant differences were found regarding cohabitation status or education. Fewer PWH were employed (OR = .48, [.33-.71])-particularly in the 45-64 age group. PWH were less likely to report good health (OR = .49, [.31-.77]). The odds of joint disease was much higher (OR = 13.00, [8.37-20.28]). Also, hypertension (OR = 2.25, [1.13-5.65]) and previous stroke (OR = 2.51, [1.44-3.50]) were more frequent. PWH were more likely to report pain in the arms/hands/legs/hips (OR = 2.94, [1.92-4.52]), but less likely to report pain in the head/neck/shoulder (OR = .66, [.45-.96]). CONCLUSION: The disease burden of haemophilia has improved so PWH resembles the general population in areas such as marriage and education. However, even for young PWH, the disease still imposes a significant burden from hemophilia arthropathy and pain in extremities and joints. Middle-aged PWH also have poorer levels of employment than same-aged peers.

Measurement of hearing impairment among Greenlandic school-children: association between self-reported data and clinical examinations.

BACKGROUND: Multiple ear infections is causing hearing impairment among children all over the world and the health and social consequences track into early adolescence and later in life, if not treated. The monitoring of prevalence in a population is important to assess the need for interventions in a population. METHODS: One hundred eighty  five children from 5 to 10th grade from Sisimiut town and the nearby settlements participated in a clinical examination to have ear-examination and pure tone audiometry. Participants filled out a questionnaire at home with their parents before the clinical examination, and hearing impairment was collected as individual self-reports and as audiometric measurements. RESULTS: A total of 185 children between 9 and 15 years of age (median: 11 years, IQR: 10-13) were included, 60% (n = 111) were girls. 247 (70%) of the 355 available otoscopies were clinically assessed as normal. Cohen's Kappa coefficient was 0.31. Eighteen children (10%) were found to have hearing impairment. None of the children had hearing aids. Test performance for self-reports were that sensitivity was 56% and specificity was 87%. The predictive value of a positive test was 31%, and the predictive value of a negative test was 95%. 32 children (17%) reported hearing impairment to the extent that they were not able to keep up in school, of which half reported that it had lasted for more than one year. 7 of the 32 children reporting hearing impairment (22%) reported that the extent of their hearing impairment was affecting their classroom experience so they were not able to follow. CONCLUSION: Self-reported and clinically screening for hearing impairment are two different concepts. Even though the two concepts are statistically correlated, the correlation coefficients are low. The test performance indicated that self-reported data might be measuring hearing as an experience in a social environment and not directly comparable to pure tone audiometry which examines hearing in controlled testing conditions. Since both measure hearing impairment, they supplement each other in research on impaired hearing, and the choice of measure should relate to the purpose and method of the investigation.

Cyberbullying and traditional bullying among Nordic adolescents and their impact on life satisfaction.

Aims: The aim of this study was to investigate the prevalence of cybervictimization in the six Nordic countries and to assess its overlap with traditional bullying. A further aim was to examine potential associations between life satisfaction, on the one hand, and traditional bullying and cyberbullying on the other. Methods: Analyses were based on data from the 2013/2014 Health Behaviour in School-aged Children study. It included 32,210 boys and girls, aged 11, 13, and 15, living in the six Nordic countries. Results: The prevalence of cyberbullying by both pictures and by messages was around 2% in all the Nordic countries except Greenland. There it was considerably higher. The prevalence of being bullied in a traditional manner varied widely by country. For boys, this type of bullying was most frequent in the youngest age group and then decreased steadily in the older age groups. Girls were on average more likely to be cyberbullied. Cyberbullying was more common among 13- and 15-year-olds than 11-year-olds. Higher family affluence was unrelated to the risk of cyberbullying. However, it was related to traditional bullying and combined forms of bullying. Compared with intact families, cybervictimization was commoner among single-parent families and stepfamilies. Adjusting for age, gender, family affluence, and family structure, those subjected to cyberbullying had lower life satisfaction than those who were not bullied. Conclusions: We found relatively little overlap between cyberbullying and traditional bullying, indicating that the two may be separate phenomena stemming from different mechanisms, at least in the Nordic context.

"Development in well-being and social function among Danish hemophilia patients with HIV: a three-wave panel study spanning 24 years".

BACKGROUND: Between 1975 and 1985 a total of 91 Danish patients with moderate and severe hemophilia (PWH) was infected with HIV constituting a major scandal in the Danish health care system. This study describes the burden of HIV infection among Danish PWH by evaluating changes from 1988 to 2012 in well-being, social function, experiencing stigma and openness about disease among Danish HIV+ PWH. METHODS: Three anonymous surveys were conducted in 1988, 2001 and 2012 targeting all Danish patients with moderate to severe hemophilia. Survey responses were received from 53, 21 and 18 HIV+ PWH respectively. A matched comparison sample of HIV- PWH was identified for each survey-year, using propensity score matching. Differences for each survey-year and trends over time were analyzed using ordinal logistic regression. RESULTS: In 1988, HIV+ PWH had more psychosomatic symptoms than HIV- PWH, but in 2001 life satisfaction was higher among HIV+ PWH than among HIV- PWH. Tests of differences in trend over time showed larger improvements in life satisfaction among HIV+ PWH than HIV- PWH, while HIV- PWH showed an increase in educational level compared to HIV+ PWH. Analysis restricted to HIV+ PWH showed an increase in perceived stigmatization. CONCLUSIONS: Differences between Danish HIV+ and HIV- PWH regarding well-being and psychosomatic symptoms seem to have evened out between 1988 and 2012. However, results suggest that HIV+ PWH still experience stigmatization and lower levels of education.

Joint Mobility and Physical Function of Danish Hemophilia Patients: A Three-Wave Panel Study Spanning 24 Years.

BACKGROUND: The positive effects of factor treatment of hemophilia are well established, but the long-term outcomes are not well documented. This panel study evaluated changes in bleeding frequency, joint mobility, physical function, and symptoms in Danish patients with moderate to severe hemophilia A or B over 24 years. METHODS: Three anonymous surveys were conducted in 1988, 2001, and 2012 targeting Danish patients with moderate to severe hemophilia, and the study participants, respectively, were 128, 156, and 164 male patients with hemophilia (PWH). The number of bleeding episodes, the use of factor concentrate, comorbidities, joint mobility, physical function, and symptoms were evaluated by means of self-reporting. Trends over time were analyzed using ordinal and multinomial logistic-regression models controlling for age group. RESULTS: The proportion of PWH in the oldest age group (55-88 years) increased from 4% in 1988 to 18% in 2012. In 1988, a high risk of bleeding episodes was primarily found in the age group of 16-34 years. In 2012, a high risk was primarily found in the age group of 35-54 years. Joint mobility and physical function increased significantly from 1988 to 2012 but showed a noticeable decrement in the older age groups, even in 2012. Pain in the extremities, anxiety, and depression decreased significantly, but back pain increased. No significant changes were found for 7 other symptoms. CONCLUSIONS: Significant improvements in joint mobility and physical function have occurred over the last 24 years, but PWH > 35 years still experience a decline in these areas with age. This decline underscores the importance of life-long treatment and continuous rehabilitation of PWH.

Social inequalities in self-rated health: A comparative cross-national study among 32,560 Nordic adolescents.

AIMS: We aimed to estimate the magnitude of socioeconomic inequality in self-rated health among Nordic adolescents (aged 11, 13 and 15 years) using the Family Affluence Scale (a composite measure of material assets) and perceived family wealth as indicators of socioeconomic status. METHODS: Data were collected from the Health Behaviour in School-aged Children (HBSC) survey in 2013-2014. A sample of 32,560 adolescents from Denmark, Norway, Finland, Iceland, Greenland and Sweden was included in the study. Age-adjusted regression analyses were used to estimate associations between fair or poor self-rated health and the ridit scores for family affluence and perceived wealth. RESULTS: The pooled relative index of inequality of 2.10 indicates that the risk of fair or poor health was about twice as high for young people with the lowest family affluence relative to those with the highest family affluence. The relative index of inequality for observed family affluence was highest in Denmark and lowest in Norway. For perceived family wealth, the pooled relative index of inequality of 3.99 indicates that the risk of fair or poor health was about four times as high for young people with the lowest perceived family wealth relative to those with the highest perceived family wealth. The relative index of inequality for perceived family wealth was highest in Iceland and lowest in Greenland. CONCLUSIONS: Social inequality in self-rated health among adolescents was found to be robust across subjective and objective indicators of family affluence in the Nordic welfare states.

Risk factors for not completing health interventions and the potential impact on health inequalities between educational groups - a mixed method study from Denmark.

BACKGROUND: Individual-based interventions aim to improve patient self-management of chronic disease and to improve lifestyle among people at high risk, to reduce the prevalence of diseases contributing to health inequality. The present study investigates risk factors for uncompleted health interventions, via a combination of quantitative and qualitative methods. METHODS: From a health centre in Copenhagen, questionnaire data on educational level, gender, age, and cohabitation status from 104 participants in health interventions were used to examine risks for dropout. Qualitative telephone interviews further investigated risk factors among 17 participants who were registered as uncompleted. RESULTS: Our findings show that there is a significantly higher prevalence of uncompleted courses among participants below age 60 (OR 3.38, 95 % CI 1.08; 10.55) and an insignificantly higher prevalence among people with low education (OR 1.82, 95 % CI 0.66; 5.03). Qualitative elaboration of these findings points to low self-control in jobs and a higher degree of comorbidity and treatment of diseases among the lower educated as determinants for not completing, but not lower motivation or less positive attitude toward the intervention itself. CONCLUSIONS: This study indicates a social difference in dropout, and if dropout is to be prevented, there is a need to acknowledge factors such as organization of the intervention, lack of job flexibility, and comorbidity. If these factors are not addressed, people with low socioeconomic status will most likely have reduced opportunities for making healthy choices, in this case, completing the intervention, and this may increase health inequality.

Semantics bias in cross-national comparative analyses: is it good or bad to have "fair" health?

The Health Behavior in School-aged Children is a cross-national study collecting data on social and health indicators on adolescents in 43 countries. The study provides comparable data on health behaviors and health outcomes through the use of a common protocol, which have been a back bone of the study sine its initiation in 1983. Recent years, researchers within the study have noticed a questionable comparability on the widely used item on self-rated health. One of the four response categories to the item "Would you say your health is….?" showed particular variation, as the response category "Fair" varied from 20 % in Latvia and Moldova to 3-4 % in Bulgaria and Macedonia. A qualitative mini-survey of the back-translations showed that the response category "Fair" had a negative slant in 25 countries, a positive slant in 10 countries and was considered neutral in 9 countries. This finding indicates that there are what may be called semantic issues affecting comparability in international studies, since the same original word (in an English original) is interpreted differently across countries and cultures. The paper test and discuss a few possible explanations to this, however, only leaving to future studies to hold a cautious approach to international comparisons if working with the self-rated health item with four response categories.

Trend analyses in the health behaviour in school-aged children study: methodological considerations and recommendations.

BACKGROUND: This article presents the scope and development of the Health Behaviour in School-aged Children (HBSC) study, reviews trend papers published on international HBSC data up to 2012 and discusses the efforts made to produce reliable trend analyses. METHODS: The major goal of this article is to present the statistical procedures and analytical strategies for upholding high data quality, as well as reflections from the authors of this article on how to produce reliable trends based on an international study of the magnitude of the HBSC study. HBSC is an international cross-sectional study collecting data from adolescents aged 11-15 years, on a broad variety of health determinants and health behaviours. RESULTS: A number of methodological challenges have stemmed from the growth of the HBSC-study, in particular given that the study has a focus on monitoring trends. Some of those challenges are considered. When analysing trends, researchers must be able to assess whether a change in prevalence is an expression of an actual change in the observed outcome, whether it is a result of methodological artefacts, or whether it is due to changes in the conceptualization of the outcome by the respondents. CONCLUSION: The article present recommendations to take a number of the considerations into account. The considerations imply methodological challenges, which are core issues in undertaking trend analyses.

Equating the HBSC Family Affluence Scale across survey years: a method to account for item parameter drift using the Rasch model.

PURPOSE: To investigate the measurement invariance (MI) of the Family Affluence Scale (FAS) measured in the Health Behavior in School-aged Children (HBSC) survey, and to describe a method for equating the scale when MI is violated across survey years. METHODS: This study used a sample of 14,076 Norwegian and 17,365 Scottish adolescents from the 2002, 2006 and 2010 HBSC surveys to investigate the MI of the FAS across survey years. Violations of MI in the form of differential item functioning (DIF) due to item parameter drift (IPD) were modeled within the Rasch framework to ensure that the FAS scores from different survey years remain comparable. RESULTS: The results indicate that the FAS is upwardly biased due to IPD in the computer item across survey years in the Norwegian and Scottish samples. Ignoring IPD across survey years resulted in the conclusion that family affluence is increasing quite consistently in Norway and Scotland. However, the results show that a large part of the increase in the FAS scores can be attributed to bias in the FAS because of IPD across time. The increase in the FAS was more modest in Scotland and slightly negative in Norway once the DIF in the computer item was accounted for in this study. CONCLUSIONS: When the comparison of family affluence is necessary over different HBSC survey years or when the longitudinal implications of family affluence are of interest, it is necessary to account for IPD in interpretation of changes in family affluence across time.

Probably the most active population in the world: accelerometer measurements of 72 school-children in Greenland.

Physical activity is the most important lifestyle factor to contribute to a healthy early life. International recommendations are that children should be vigorously physically active for at least 1 h per day, and in Greenland, authorities have claimed a goal of being the world's most active population. Since 1994, the Health Behaviour in School-aged Children (HBSC) has measured physical activity among school-children in Greenland by questionnaire data, but the measurement properties of self-reported data in comparison to more objectively measured accelerometer data are unknown. The present paper describes the first study using clinical measures of physical activity among Greenlandic youth. Seventy-two school-children (56% girls) with a mean age of 12 years (range 25%; 75% was 11.5; 12.25) wore accelerometers for seven consecutive days, and data produced significant and informative findings for both practice and future research. Fifty-two per cent of the school-children met the international recommendations of being physically active >1 h per day, when measured by accelerometers, but self-reported data reported a prevalence of 10% meeting the recommendations. A majority of this sample of Greenlandic school-children lives up to international recommendations, which indicates that the goal of being the world's most active population is within reach.

Neurosyphilis among people with and without HIV infection: A Danish nationwide prospective, population-based cohort study 2015-2021.

BACKGROUND: Comparative data on clinical presentation, laboratory characteristics, treatment, and outcome of neurosyphilis (NS) in people living with HIV (PLWH) and NS patients without HIV are scarce. METHODS: Nationwide, population-based, prospective cohort study on all adults with NS diagnosed between 2015 and 2021 at departments of infectious diseases in Denmark. RESULTS: We identified 108 patients with NS, which equals a yearly incidence of 0.3/100,000 adults. The median age was 49 years, 85 (79%) were male, 43 (40%) were men having sex with men and 20 (22%) were PLWH. Ninety-five (88%) had early NS, 37 (34%) had ocular or ocular and otogenic NS, and 27 (25%) had symptomatic meningitis. Most common symptoms were visual disturbance (44%), skin rash (40%), fatigue (26%) and chancre (17%). Median CSF leukocyte count was 27 × 106 cells/L. PLWH less often had neurological deficits (p = 0.02). Unfavorable outcome was observed in 23 (21%) at discharge of whom 0 were PLWH (p = 0.01). Among the 88 NS patients without HIV a CSF leukocyte count of ≥ 30 × 106 cells/L was associated with unfavorable outcome (OR = 3.3 (95% confidence interval: 1.1-10.4)). CONCLUSIONS: PLWH with NS have better outcomes than NS patients without HIV infection.

The association between high recreational physical activity and physical activity as a part of daily living in adolescents and availability of local indoor sports facilities and sports clubs.

AIM: The aim of this study was to examine how vigorous physical activity (recreational physical activity) (VPA) and moderate to vigorous physical activity as a part of daily life (MVPA) is associated with structural characteristics (availability of sports facilities and sports clubs with child members) in Greenlandic adolescents. MATERIAL AND METHODS: Data from the 2006 Health Behaviour in School-aged Children survey including 2,430 children aged 11-17 years was used. Logistic regression models were developed with dichotomous measures on VPA and MVPA as outcomes, number of indoor sports facilities and of sports clubs with child members as independent variables, and adjusted for age, gender, family affluence (FAS), and type of habitation (capital, town or village). RESULTS: High VPA increased with access to indoor facilities, while high MVPA was less likely (odds ratio (OR) 0.54 (0.42-0.70)) if indoor sports facilities were present, both unadjusted and adjusted. Access to a local sports club increased OR for high VPA both unadjusted and adjusted to about 2.3 for five or more clubs, while access to sports clubs was not associated with unadjusted MVPA, negatively associated if adjusted for age, gender and FAS but positively associated if also adjusted for indoor sports facilities. CONCLUSIONS: Access to indoor sports facilities itself had a positive association with high VPA, but was persistently negatively associated with high MVPA. Presence of sports clubs with child members was positively associated with high VPA while the association with high MVPA was more complex. The findings have implications for public health planning.

Lower thriving among females with hearing impairment than males - a cross-sectional study of 185 primary and secondary students in Greenland.

The prevalence of ear infections and hearing i mpairment among Greenlandic children is amajor public health problem, and studies investigating the association between hearing impairment and thriving among Greenlandic children are scarce. The aim of this study was to examine the association between hearing impairment and thriving in asample of school-children in Sisimiut, Greenland. This cross-sectional study included children from 5th to 10th grade from two schools in Sisimiut and two schools located in nearby settlements. Participants filled out aquestionnaire and underwent ear examination and audiometry. Binary logistic regression examined the associations of hearing impairment and thriving variables defined as self-rated health, headache and school satisfaction. 179 children participated from schools in Sisimiut, and 6 children were from schools in settlements. The prevalence of hearing impairment was 10% among school-children in Sisimiut. There was atendency among girls with hearing impairment to have higher odds ratios for low self-rated health, often headache and low school-satisfaction. This study indicates that girls with hearing impairment are more susceptible to low thriving compared to girls with normal hearing. Interventions targeting the thriving of hearing impairment among children in Greenland should take gender differences into account.

Examination of hearing loss among school-aged children in Greenland.

BACKGROUND: The highest prevalence of chronic suppurative otitis media is seen among children in Greenland. The purpose of this study was to investigate the prevalence of hearing loss among school children in Sisimiut, the second-largest city in Greenland. MATERIAL AND METHOD: All 423 children from 5th to 10th grade from the two schools in Sisimiut and the nearby settlements were invited to participate. Participants filled out a questionnaire at home with their parents before ear-examination and audiometry. Risk factors for hearing loss and otitis media (OM) related otoscopy findings were analyzed by binomial logistic regression. RESULTS: A total of 185 children between 9 and 15 years of age (median: 11 years, IQR: 10-13) were included; 60% (n = 111) were girls. Fifty-four children (29%) were found to have hearing impairment using a PTA of 15 dB for either low or high frequencies or both as threshold. When using 25 dB as threshold, the number of children with hearing impairment was 18 (10%). None of the children had hearing aids. Of 355 otoscopies available for evaluation, the majority were normal (n = 249, 70.1%). Perforation of the tympanic membrane was found in six ears (1.7%), of which all were unilateral. Other sequelae related to OM (i.e., circular atrophy and myringosclerosis) were found in 37 ears (10.4%). Children with OM-related otoscopy findings had significantly lower hearing tresholds compared to children without. CONCLUSION: A high prevalence of untreated hearing loss was found among examined school children in Sisimiut. Children with otoscopy findings indicating prior OM had significantly lower hearing tresholds compared to children without.

Greenlandic schoolchildren's compliance with national dietary guidelines.

OBJECTIVE: The aim of the present study was to examine to what extent children and adolescents in Greenland comply with the national dietary guidelines, and to analyse the influence of habitation and family affluence on the compliance with dietary guidelines. DESIGN: Data were from the Health Behaviour in School-aged Children (HBSC) survey in Greenland. The 2006 survey included 2462 students aged 11 to 17 years. RESULTS: The proportion of students complying with the national dietary guidelines varied from 14 % to 87 % depending on the food item. Sweets and soft drinks had the lowest compliance. The oldest children had the following characteristics compared with the younger children: fewer ate traditional Greenlandic foods, fewer ate fruit, fewer ate breakfast daily on school days and more drank soft drinks frequently. More boys than girls ate traditional Greenlandic foods often, while more girls ate vegetables daily. The least favourable eating habits in general were found among children from low affluent families and children in villages. CONCLUSIONS: Many Greenlandic schoolchildren did not comply with the national dietary guidelines. Despite a higher intake of traditional foods as a whole, children in villages and less affluent children were less likely to comply with guidelines. A strong relationship between diet, family affluence and availability was found. The study findings indicate that factors such as availability, cost and seasonal variation are important to the intake of both imported and traditional Greenlandic foods. The findings should be taken into consideration when promoting the national guidelines.

Screen-based activities and physical complaints among adolescents from the Nordic countries.

BACKGROUND: A positive association between time spent on sedentary screen-based activities and physical complaints has been reported, but the cumulative association between different types of screen-based activities and physical complaints has not been examined thoroughly. METHODS: The cross-sectional association between screen-based activity and physical complaints (backache and headache) among students was examined in a sample of 31022 adolescents from Denmark, Sweden, Norway, Finland, Iceland and Greenland, as part of the Health behaviour in school-aged children 2005/06 (HBSC) study. Daily hours spent on screen-based activities and levels of physical complaints were assessed using self-reports. RESULTS: Logistic regression analysis indicated that computer use, computer gaming and TV viewing contributed uniquely to prediction of weekly backache and headache. The magnitude of associations was consistent across types of screen based activities, and across gender. CONCLUSION: The observed associations indicate that time spent on screen-based activity is a contributing factor to physical complaints among young people, and that effects accumulate across different types of screen-based activities.

The effect of structural and functional social relations on smoking among adolescents - data from HBSC Greenland 2018.

The prevalence of adolescent smoking in Greenland is relatively high and remains an important topic to study. The present study reports the prevalence of smoking among Greenlandic adolescents in 2018 and the association between smoking and social relations. The study was based on HBSC Greenland 2018, using a theoretical framework proposed by Due and colleagues, which divides social relations into structural and functional relations. The study showed a statistically significant gender difference in smoking, as 11.4% of the girls reported to smoke compared to 7.9% of the boys. The smoking prevalence increased significantly with age, and differences were also found for a place of residence, as the smoking prevalence was higher in towns and settlements compared to Nuuk. The adolescent smoking prevalence was higher when living in a home with one adult or in a foster family, school home or orphanage, versus living in home with at least two adults. No significant associations were found between adolescent smoking and functional relations. The results are beneficial to consider when applying new interventions to prevent adolescent smoking initiation in Greenland.

How Are Adolescents Sleeping? Adolescent Sleep Patterns and Sociodemographic Differences in 24 European and North American Countries.

PURPOSE: Insufficient and poor sleep patterns are common among adolescents worldwide. Up to now, the evidence on adolescent sleep has been mostly informed by country-specific studies that used different measures and age groups, making direct comparisons difficult. Cross-national data on adolescent sleep that could inform nations and international discussions are lacking. We examined the sleep patterns of adolescents across 24 countries and by gender, age, and affluence groups. METHODS: We obtained sleep data on 165,793 adolescents (mean age 13.5 years; 50.5% girls) in 24 European and North American countries from the recent cross-sectional Health Behaviour in School-aged Children surveys (2013-2014 and 2017-2018). For each country, we calculated the age-standardized mean in sleep duration, timing, and consistency and the proportions meeting sleep recommendations on school and nonschool days from self-reported bedtimes and wake times. We conducted stratified analyses by gender, age, and family affluence group. RESULTS: Adolescent sleep patterns varied cross-nationally. The average sleep duration ranged between 7:47 and 9:07 hours on school days and between 9:31 and 10:22 hours on nonschool days, and the proportion of adolescents meeting sleep recommendations ranged between 32% and 86% on school days and between 79% and 92% on nonschool days. Sleep patterns by gender and affluence groups were largely similar, but older adolescents slept less and went to bed later on school days than younger adolescents in all countries. CONCLUSIONS: The sleep patterns of adolescents vary across countries and sociodemographic groups. Insufficient sleep on school days is common in many countries. Public health and policy efforts to promote healthy adolescent sleep are encouraged.

School-related mediators in social inequalities in smoking: a comparative cross-sectional study of 20,399 adolescents.

BACKGROUND: The aim of this study was to examine the associations between social inequalities and daily smoking among 13 and 15 year olds, and to determine the role of students' academic achievement and school satisfaction in these associations. METHODS: HBSC is an international study including adolescents from 32 countries in Europe, Israel, and North America. The present study was based on information from 20,399 adolescents from Denmark, Sweden, Norway, Finland and the United Kingdom. Data were analysed by regression models. RESULTS: The initial analyses showed significant inequality in daily smoking in all countries except for Sweden. When adjusted for the mediating role of academic achievement, estimates were attenuated, but remained significant in three countries. CONCLUSION: The study found social inequality in daily smoking in Denmark, Sweden, Norway, Finland and United Kingdom, as well as inequalities in students' academic achievement and school satisfaction. The analyses also showed that above average academic achievement was associated with lower OR of smoking. Teachers and politicians may find this information useful, and allocate resources to give higher priority to a supportive environment in schools especially for children and adolescents in lower social groups. Subsequently this prioritisation might contribute to reducing smoking in this group.