Data collection and the survey instrument
HBSC is a school-based survey with data collected through self-completion questionnaires administered in the classroom. Fieldwork for each cross-national survey is carried out over a period of around seven to eight months, from October to May of the following year. This reflects the sampling strategy used in each country in order to achieve the mean ages of 11.5, 13.5 and 15.5.

The HBSC survey instrument is a standard questionnaire developed by the international research network and used by all participating countries.

Each survey questionnaire contains a core set of questions looking at the following:

• Background factors: demographics and maturation, social background (family structure, socio-economic status)
  
  
• Individual and social resources: body image, family support, peers, school environment
  
  
• Health behaviours: physical activity, eating and dieting, smoking, alcohol use, cannabis use, sexual behaviour, violence and bullying, injuries
  
  
• Health outcomes: symptoms, life satisfaction, self-reported health, Body Mass Index

Many countries also include additional items in their national questionnaire that are of particular interest on a national level.

International data
The data collected in each country is sent to the HBSC Data Bank at the University of Bergen, Norway. It is then cleaned and compiled into an international data file by the Norwegian Social Science Data Services (NSD) under the guidance of the study's Data Bank Manager.

When all national data has been received and accepted according to the Protocol, the files are merged and the combined data file is made available to the Principal Investigators of each participating country.

The production of the final international data file is usually 4-5 months after the deadline for submission of national data sets.

The international data file is restricted for the use of member country teams for a period of three years, after which time the data is available for external use by agreement with the International Coordinator and the Principal Investigators.

Data Analysis:

The international standard questionnaire enables the collection of common data across all participating countries and thus enables the quantification of patterns of key health behaviours, health indicators and contextual variables. These data allow cross-national comparisons to be made and, with successive surveys, trend data is gathered and may be examined at both the national and cross-national level.

Data analysis is carried out by members of the research network working individually and in topic focus groups.

The study encompasses school systems, embraces many cultures and languages (within and between countries). Every effort is made to standardise the methods employed across countries in order to achieve the best possible comparable data that a cross-national survey will allow.

More detailed information on methodological aspects of the data analysis can be found in the International Reports from each survey.
more information on data access procedures…