Associations between excessive screen time and school and out-of-school injuries among adolescents: A population-based study

Most adolescents spend excessive screen time (with television viewing, computer/console gaming, discussion forums/chatting online, internet surfing, doing homework, and electronic mails) which may impact the occur-ring of various types of school and out-of-school injuries. We assessed their associations and potential con-founding factors among 1559 middle-school students from north-eastern France (mean age=13.5 +/- 1.3). Participants completed a questionnaire including socioeconomic features, daily screen time for various screen-based activities (coded 1=<2, 2 = 2-4, 3=>= 5 h; daily-total-screen time level (TDST) was defined as their sum, categorized into <7/7-11/>= 12), various injury types during the school-year, behavior and health diffi-culties (BHDs; alcohol/tobacco/cannabis/other illicit drugs use, suffered physical/verbal violence, sexual abuse, poor family-peer support, sleep difficulty, depressive symptoms, suicide attempt, and time at onset). Most sub-jects had TDST >= 7 (82.3 %). There were dose-effect associations of TDST with school-physical/sports training, school-free-time, out-of-school-sports, and single/repeated injuries (sex-age-adjusted odds ratio reaching 4.45). BHDs explained up to 39 % of these associations. The frequency of subjects without various BHDs decreased with age since age 10 more quickly among the participants with both TDST >= 7 and injury than among the others. Our findings may inform health care providers, parents, schools, and public policy that reducing elevated screen time is efficient to prevent injuries and BHDs among adolescents.