Christina W. Schnohr

The Health Behaviour in School-aged Children (HBSC) study: methodological developments and current tensions

Objectives:To describe the methodological development of the HBSC survey since its inception and explore methodological tensions that need to be addressed in the ongoing work on this and other large-scale cross-national surveys.Methods:Using archival data and conversations with members of the network, we collaboratively analysed our joint understandings of the survey’s methodology.Results:We identified four tensions that are likely to be present in upcoming survey cycles: (1) maintaining quality standards against a background of rapid growth, (2) continuous improvement with limited financial resources, (3) accommodating analysis of trends with the need to improve and adapt questionnaire content, and (4) meeting the differing requirements of scientific and policy audiences.Conclusions: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.

Does educational level influence the effects of smoking, alcohol, physical activity, and obesity on mortality? A prospective population study.

Objectives: This study aims at examining whether the relation between established risk factors and mortality differs with socioeconomic status as measured by level of education. Methods: A population-based sample of 14,399 women and 16,236 men aged 20 - 93 years from Copenhagen was stratified into three educational levels measured as basic schooling, and the effect of smoking habits, alcohol consumption, physical activity, and body mass index, respectively, on mortality was assessed. Results: Those with the lowest level of education were most frequently heavy smokers, heavy drinkers, physically inactive, and obese. During a mean follow up of 16 years 10,952 subjects died. Compared with subjects with the lowest educational level, women with the highest educational level had a relative risk of 0.80 (95% CI; 0.70 - 0.91), and men of 0.71 (0.65 - 0.78). Heavy smoking compared with never smoking implied a more than twofold increased risk at all three educational levels among both men and women. The relation between alcohol intake and mortality was J-shaped on all three educational levels. There were decreasing risk functions describing the relations between physical activity and mortality on all three strata. Further, subjects who were either very lean or obese had increased risks of death compared with those of normal weight at all educational levels in both genders. Conclusions: The difference in distribution of the main known risk factors may be part of the explanation for the differences in mortality risk. However, these risk factors seem to influence mortality equally at different educational levels. Therefore, social inequalities in mortality do not seem to be explained only by differences in effect of lifestyle risk factors, but are also related to the social rank or unexamined factors within.

Measuring mental health and well-being of school-children in 15 European countries using the KIDSCREEN-10 index

Objectives:To test the psychometric properties and measurement results of the KIDSCREEN-10 Mental Health Index in school children from 15 European countries.Methods:Within the cross-sectional Health Behaviour in School-aged Children 2005/2006 Survey, 78,000 pupils aged 11, 13, 15 answered the KIDSCREEN and additional measures. Cronbach’s alpha, Rasch partial credit model itemfit and ANOVAs were conducted.Results:Cronbach’s alpha was 0.81, Rasch infit mean square residuals were 0.7–1.3. Mean scores varied 0.8 standard deviation across countries. Older pupils (effect size [ES] = 0.6), girls (ES = 0.2), pupils with low socio-economic status (ES = 0.5) or frequent health complaints (r = 0.5) reported decreased mental health.Conclusions:The KIDSCREEN-10 displayed good psychometric properties. Measured differences between countries, age, gender, SES, and health complaints comply with theoretical considerations.

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

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.

Bullying among Greenlandic schoolchildren: Development since 1994 and relations to health and health behaviour

Objectives. The objective was to examine the development in the prevalence of bullying behaviours among Greenlandic schoolchildren and the association with health outcome and health behaviour. Study design. The study was based on three school surveys among Greenlandic schoolchildren contributing to the Health Behaviour in School-aged Children (HBSC) survey, a WHO collaborative study. The surveys were carried out in Greenland in 1994, 1998 and 2002, with respective participations of 1322, 1648 and 891 pupils of 11, 13 and 15 years of age. Methods. The trends in bullying behaviours from 1994 to 2002 was analysed by means of descriptive statistics. The strengths of associations in the patterning of the bullying behaviours in their relation to health indicators (physical symptoms, psychological well-being and smoking and alcohol use) were analysed by means of logistic regression. Results. There has been an increase in the occurrence of bullying among Greenlandic schoolchildren since 1994, and significant changes have occurred in the different types of bullying behaviours. Consistent patterns were observed between types of bullying behaviours, and health behaviour, since pupils engaged in bullying were more likely to be smokers and to have been drunk several times. Strong associations were observed between disliking school and being engaged in bullying, whether this was as a victim, a bully, or both. There was no clear patterning of associations when it came to health indicators, except for significantly higher odds of stomach ache for the bullies, and sleeping difficulties and low self-rated health for pupils both being bullied and bullying others. Conclusions. Being engaged in bullying is widespread among Greenlandic schoolchildren and is found to be associated with disliking school and detrimental health behaviours. (Int J Circumpolar Health 2006; 65(4): 305–312).

Absolute and relative family affluence and psychosomatic symptoms in adolescents

Previous research on the links between income inequality and health and socioeconomic differences in health suggests that relative differences in affluence impact health and well-being more than absolute affluence. This study explored whether self-reported psychosomatic symptoms in adolescents relate more closely to relative affluence (i.e., relative deprivation or rank affluence within regions or schools) than to absolute affluence. Data on family material assets and psychosomatic symptoms were collected from 48,523 adolescents in eight countries (Austria, Belgium, Canada, Norway, Scotland, Poland, Turkey, and Ukraine) as part of the 2009/10 Health Behaviour in School-aged Children study. Multilevel regression analyses of the data showed that relative deprivation (Yitzhaki Index, calculated in regions and in schools) and rank affluence (in regions) (1) related more closely to symptoms than absolute affluence, and (2) related to symptoms after differences in absolute affluence were held constant. However, differences in family material assets, whether they are measured in absolute or relative terms, account for a significant variation in adolescent psychosomatic symptoms. Conceptual and empirical issues relating to the use of material affluence indices to estimate socioeconomic position are discussed.

Psychometric Validation of the Revised Family Affluence Scale: a Latent Variable Approach

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 scale correlated with parental reported income groups in six out of eight countries. Findings support a revision to six items in the family affluence scale.

The Role of Individual- and Macro-Level Social Determinants on Young Adolescents’ Psychosomatic Complaints:

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 country-level 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 school-related 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.

Changes since 1980 in body mass index and the prevalence of overweight among inschooling children in Nuuk, Greenland

Abstract Objective. The aim of the study was to examine the trends which have occurred during the past generation in body mass index (BMI) and in the prevalence of overweight and obesity among children in public schools in Nuuk, Greenland. Study design. The study is a retrospective cohort study of BMI among inschooling children (age 6 or 7 years old). A database was created on the basis of files from school-nurses containing information on height and weight among children having attended school in Nuuk since 1970. The database contained 10,121 measurements in total, whereas 2,801 were on inschooling children. Measurements from these children form the basis of this study. Mean and quartiles of BMI among the inschooling children in 5-year intervals were used to determine the development in BMI since 1980. On the basis of international cut-points (1) for use among children and adolescents, the proportion of overweight and obese children and the trends since 1980 were determined. Results. The mean BMI has risen by a total of a bit more than 6% since 1980, corresponding to a rise of 1.2–3.8% for every 5-year period. Increases are also observed when assessing the proportion of overweight and obese, which were 6.6% and 0.9%, respectively, among the inschooling children during the period 1980-1984. These proportions increased to 16.5% and 5.2%, respectively, in 2000-2004. Conclusion. This study has provided evidence that during the past two decades, children in Nuuk have undergone a development towards a higher prevalence of overweight and obesity. (Int J Circumpolar Health 2005; 64(2):157–162)

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.