EnCLASS survey

The National Adolescent Health and Substance Use Survey in Middle and High Schools (ENCLASS) is a national, biennial online survey. It is a statistical survey based on a random sample.


The National adolescent health and substance use survey in middle and high schools (EnCLASS)  is a biennial online survey conducted in schools throughout France (including the French overseas territories). It is the result of a collaboration between the research teams behind the international Health Behaviour in School-aged Children (HBSC) survey and the European School Survey Project on Alcohol and other Drugs (ESPAD).


The ENCLASS survey is the result of a merger, carried out for the first time in 2018, of two international surveys carries out in schools.

Since 1994, France has been participating in Health Behaviour in School-aged Children (HBSC) survey under the aegis of the World Health Organisation). Every 4 years, in a growing number of countries in Europe and North America (48 in 2018), pupils ages 11, 13, and 15 are questioned anonymously and confidentially in class about their health, their health behaviours, and their experiences at school.

Since 1999, France has also been taking part in the European School Survey Project on Alcohol and other Drugs (ESPAD) survey . The survey takes place in schools every 4 years at the same time in around forty countries, using a common protocol.


The survey is carried out by the ENCLASS association, with the support of the OFDT, Santé publique France (the National Public Health Agency), INSERM units U1018 and U1027 (the National Institute for Health and Medical Research), the EHESP (École des hautes études en santé publique, the School of Public Health), and the DEPP (Direction de l’évaluation, de la prospective et de la performance, the Performance and Prospective Studies Department of the Ministry of National Education).

The Ministry of National Education, via the National Directorate on School Teaching (DGESCO), and the Ministry of Agriculture, via the General Directorate for Education and Research (DGER), are actively involved in the ENCLASS system, in particular by providing access to the schools that will be conducting the survey in the selected classes.


The aim of the survey is to understand how 11-18-year-olds perceive their health experiences in the broadest sense: to identify the determinants of their health; to highlight trends; to make comparisons with similar surveys at national or international level; to study the main health behaviours, including at-risk behaviour such as the use of psychoactive substances (tobacco, alcohol, cannabis, etc.); and finally to facilitate the implementation of health promotion initiatives that are directly in line with epidemiological findings. As well as providing a ‘snapshot’ of the overall state of perceived health and the experiences and risk behaviours of French schoolchildren, and enabling international comparisons to be made, these studies make it possible to carry out understanding adolescent behaviour, identifying the mechanisms and determinants involved, providing the data needed to monitor prevention policies aimed at this population, and, ultimately, improving their health.

The survey guarantees to represent middle schools on a national and regional level.


Using the DEPP databases, several hundred middle schools and high schools are selected at random throughout France, as well as around fifty primary schools to survey CM2 classes (5th graders). In each school, two classes are drawn at random to take part in the survey. The data is collected on a computer during a dedicated lesson. Pupils in the classes concerned receive a temporary individual code enabling them to connect to the online questionnaire in a unique and anonymous way.

The first edition of the survey took place in 2018 and the second wave of EnCLASS was conducted in spring 2022. A limited version of ENCLASS was also carried out during the winter of 2021 among 3e (9th grade) pupils.

EnCLASS 2022 has been recognised as being of general interest and of statistical quality by the French National Council for Statistical Information (CNIL).