Impact of sleep difficulty on single and repeated injuries in adolescents

Injuries are frequent and may be caused by sleep difficulty in youth. This study assessed the impact of sleep difficulty on single and repeated school and out-of-school injuries and the confounding role of socioeconomic factors and school, behaviour and health-related difficulties among adolescents. The study population included 1559 middle-school adolescents from north-eastern France (mean age 13.5, SD 1.3) who completed at the end of school year a self-administered questionnaire to gather school and out-of-school injuries during the school year, and to assess sleep difficulty and previous injury risk factors which were socioeconomic factors (family structure, parents' education, father's occupation, and family income), school performance, obesity, alcohol/tobacco/cannabis/hard drugs use, health status, psychological health, and involvement-in-violence. For sleep difficulty and behaviour and health-related difficulties their first occurring over adolescent's life course was gathered. Multinomial logistic regression models were used retaining only sleep difficulty and other risk factors which had started before the school year (thus before the injuries studied). School and out-of-school injuries and sleep difficulty were frequent. The adolescents with sleep difficulty without medical treatment had a higher risk of single school and out-of-school injuries (gender-age-adjusted odds ratio gaOR 1.86 and 1.76, respectively) and a much higher risk of repeated school and out-of-school injuries (≥2 injuries; gaOR 2.43 and 3.73, respectively). The adolescents with persistent sleep difficulty despite a medical treatment also had a higher risk of single school and out-of-school injury (gaOR 2.31 and 1.78, respectively), and a much higher risk of repeated school and out-of-school injuries (gaOR 4.92 and 4.36, respectively). Socioeconomic factors had a moderate contribution (<27%) while school, behaviour and health-related difficulties had a high contribution (reaching 71%) to the association between sleep difficulty and single/repeated injuries. The role of these factors differed between single/repeated school/out-of-school injuries. Injury prevention should focus on screening and monitoring sleep difficulty and previous difficulties, especially among adolescents with socioeconomic difficulties, via physician-parent-school-adolescent collaborations.