While these challenges are not trivial, the structure of the HBSC network and its long-term experience in working through such challenges renders it likely that HBSC can provide a model of other similar studies facing these tensions.

The aim was to develop and test a brief revised version of the family affluence scale. A total of 7120 students from Denmark, Greenland, Italy, Norway, Poland, Romania, Scotland and Slovakia reported on a list of 16 potential indicators of affluence. Responses were subject to item screening and test of dimensionality. Bifactor analysis revealed a strong general factor of affluence in all countries, but with additional specific factors in all countries. The specific factors mainly reflected overlapping item content. Item screening was conducted to eliminate items with low discrimination and local dependence, reducing the number of items from sixteen to six: Number of computers, number of cars, own bedroom, holidays abroad, dishwasher, and bathroom. The six-item version was estimated with Samejima's graded response model, and tested for differential item functioning by country. Three of the six items were invariant across countries, thus anchoring the scale to a common metric across countries. The six-item Child Ind Res (2016) 9:771-784

The KIDSCREEN-10 displayed good psychometric properties. Measured differences between countries, age, gender, SES, and health complaints comply with theoretical considerations.

BackgroundA 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.MethodsThe 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.ResultsLogistic 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.ConclusionThe 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.

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 (2013e2014 and 2017e2018). For each country, we calculated the age-standardized mean in sleep duration, timing, and consistency and the proportions meeting IMPLICATIONS AND CONTRIBUTION Conflicts of interest: The authors have no conflicts of interest to disclose. Disclosure: This supplement was supported by the World Health Organization European Office and the University of Glasgow. The articles have been peerreviewed and edited by the editorial staff of the Journal of Adolescent Health. The opinions or views expressed in this supplement are those of the authors and do not necessarily represent the official position of the funder.

Family affluence scale, Differential item functioning, Health Behaviour in School-aged Children (HBSC), Comparability, Validity,

This study examines the social determinants of psychosomatic complaints in young adolescents. Using data from the Health Behaviour in School-aged Children (HBSC) study, psychosomatic complaints are studied in 98,773 adolescents (11-and 13-year-olds; 48% 11-year-olds, 52% 13-year-olds; 52% females, 48% males) from 34 European countries. Individual-level determinants, including family-, peer-and school-related factors as well as countrylevel determinants (Human Development Index [HDI]) are considered. In line with existing evidence, results revealed more psychosomatic complaints in young adolescents experiencing stress inducing familial-, peer-and schoolrelated factors. Negative effects of poor friendships, negative class climate, school pressure, and high media use were more pronounced for girls. After controlling for these factors, a higher HDI was related to a lower risk for psychosomatic complaints. Gender-specific intervention programs should aim at improving the quality of relationships, especially among peers, to prevent psychosomatic complaints among young adolescents.

Adolescence is a critical period where many patterns of health and health behaviour are formed. The objective of this study was to investigate cross-national variation in the relationship between family affluence and adolescent life satisfaction, and the impact of national income and income inequality on this relationship. Data from the 2006 Health Behaviour in School-aged Children: WHO collaborative Study (N = 58,352 across 35 countries) were analysed using multilevel linear and logistic regression analyses for outcome measures life satisfaction score and binary high/low life satisfaction. National income and income inequality were associated with aggregated life satisfaction score and prevalence of high life satisfaction. Within-country socioeconomic inequalities in life satisfaction existed even after adjustment for family structure. This relationship was curvilinear and varied cross-nationally. Socioeconomic inequalities were greatest in poor countries and in countries with unequal income distribution. GDP (PPP US$) and Gini did not explain between country variance in socioeconomic inequalities in life satisfaction. The existence of, and variation in, within-country socioeconomic inequalities in adolescent life satisfaction highlights the importance of identifying and addressing mediating factors during this life stage.