Efficacy of an instant messaging-based life-skills training program to prevent behavioral risk factors among adolescents in Europe: study protocol of a cluster-randomized controlled trial

Background: One of the most significant risk factors for cancer and several other adverse health outcomes is nicotine and tobacco use. Life-skills training programs conducted within the school curriculum are effective in preventing substance use, including nicotine and tobacco use, however, large-scale implementation is hindered by time, organizational and financial constraints. Providing life-skills training programs via smartphones may be a more economical and scalable approach. SUNRISE SmartCoach is the first life skills training program to use instant messaging and storytelling to present life-skills training in an emotional and engaging way. This study protocol outlines a cluster-randomized controlled trial testing the efficacy of SUNRISE SmartCoach among adolescents in eight European countries. Methods: A two-arm, parallel-group, cluster-randomized, controlled trial will be conducted to test the efficacy of SUNRISE SmartCoach in comparison to an assessment only control group. The study participants will be assessed at baseline and at follow-ups after 6 and 18 months. The fully automated program is based on social cognitive theory and aims to improve self-management skills, social skills, and resistance to addictive behavior. Participants in the intervention group will receive online feedback on their life skills via Smartphone, as well as individually tailored coaching dialogues via WhatsApp or Viber over four months, to improve life skills. Active program engagement will be stimulated by interactive features such as quiz questions, message- and picture-contests, and integration of a friendly competition in which program users collect credits with each interaction. Study participants will be 3,500 secondary and upper secondary school students between the ages of 14 and 17 years from eight European countries: Switzerland, Greece, Slovenia, Spain, Cyprus, Italy, Belgium, and Romania. The primary outcome criterion will be nicotine or tobacco use within 30 days preceding the follow-up assessment at month 18. Secondary outcomes include the use of other substances, such as alcohol and cannabis, social skills, perceived stress, healthy eating habits, and quality of life. Discussion: This is the first randomized controlled study testing the efficacy of an instant messenger- and storytelling-based life-skills training program to prevent nicotine and tobacco use as well as other behavioral risk factors among adolescents. If this intervention approach proves to be effective, it could be easily implemented in various settings and could reach large numbers of young people in a cost-effective way. Trial registration: NCT06922201 (registration date: 2025-04-09).