[Profile of first year secondary school children involved in the anti-smoking prevention trial "PEPITES"].

Background: Many programs which aim to reduce tobacco consumption in young people are carried out in the school environment, addressing a "captive audience" and monitoring the actions over a period of several years. The approaches identified as promising involve putting in place a tobacco prevention program throughout the entire school years incorporated in the school program. Several studies showed that early initiation to psychoactive substances is a strong predictor of addiction. Considering the above points, an intervention trial on tobacco prevention covering the four years of secondary school (±11-15 years old) was implemented in the Essonne area, in France.

Method: This study was based on a cluster randomized trial comparing three groups: two intervention groups and a control group. The present paper describes the school children (1st year in six secondary schools) included in the trial. It studies the national representativity of this population, the comparability between the control and intervention groups and the items link to tobacco initiation.

Results: When considering tobacco behavior in 2014, the included population was representative of the school children in 1st year of secondary school in France with 11.5% of tobacco initiation and 2.5% of regular smokers. The groups were comparable except for four items (family and friends smoking, only child, sensitive urban areas). With this knowledge on factors linked to smoking behaviors this population can be included in the trial analysis.

Conclusion: The study of the included population will help to perform the trial analysis and authorize the transferability of the trial results if positive.