Target Population

The target population of the ESPAD project is students that turn 16 years old during the calendar year of the data collection. Students who are unable to understand or for other reasons cannot answer the questionnaire without assistance - e.g. retarded, mentally disturbed or severely handicapped - are not included in the target population. If a country wants to add an additional age group it is recommended to choose 18 year olds. During the data collection of spring 2007 students born in 1991 were the (primary) target population. If students of the target population are split in two or more grades this should be taken into consideration by sampling classes from all relevant grades.

The goal of the sampling process is to obtain a national and gender wise representative data set and it is up to each national ESPAD researcher to find the optimal method of sampling. The number of participating students is however suggested not to be below 2.400, which allows breakdowns by sex and another variable. If a national complementary goal of a country's participation in the ESPAD project is to compare subgroups, for example regions, the number of course needs to be larger.

Data collection instrument and field procedure

The questionnaire contains core as well as optional questions. All countries should employ the core questions. They include some background variables, alcohol, tobacco and drug related questions as well as some questions for methodological purposes. There are also optional modules on "Integration", "Mainstream", "Psycho-social measures", "Cannabis" and "Deviance". Countries are welcome to include one or two modules in the questionnaire as well as a small number of country specific questions of special interest. Field-testing the questionnaire is highly recommended for countries joining the ESPAD project. A translation-back translation process is also highly recommended.

March/April is the recommended period of data collection. It is of great importance to use a survey leader trusted by the students. Consequently, it is up to each ESPAD researcher to decide whether teachers or research assistants should be carrying out the survey. Survey leaders receive written instructions describing how to perform the survey and how to fill out the standardised classroom report. The questionnaires are answered anonymously and to make sure the students do feel that their integrity is safe it is highly recommended to offer individual envelopes for the students to seal the completed forms within. To avoid discussions of the survey among the students it is preferable that the data collection is done at the same time in case several classes are sampled from the same school.

Data processing and international reports

Each country is free to write their own national report(s). An obligation however is to submit a standardised report on the methodological aspects of the survey process to the coordinators. Another obligation is to deliver the national datasets, to be merged into a common ESPAD database. Cleaning and merging of the national datasets as well as the database maintanance is carried out by the Database manager located at the University of Akureyri, Iceland. The methodology reports and the database are used by the coordinators in the process of writing the international ESPAD report.

The objective of the international reports is mainly descriptive, i.e. to compare students' alcohol and drug use in participating countries and to study changes. The descriptive report is by no means supposed to be the only international report. On the contrary, the available data will be sufficient for many studies, including analysis of the various modules. Different thematic groups within the ESPAD-project work with different module questions while individual ESPAD researchers also are able to apply for copies of the database in order to analyse specific questions of their interest.

More information is available in the document ESPAD Project History.