Smartphone Usage and Sleep Quality in Korean Middle School Students During the COVID-19 Pandemic.

OBJECTIVE: This study evaluated the quality of sleep and smartphone addiction in Korean adolescents during the coronavirus disease 19 pandemic and analyzed their effects on perceived quality of life. METHODS: An online survey system provided by the Gwangmyeong City Health Center located in Gyeonggi-do, Korea, was completed by 1,678 local middle school students from April 1 to June 30, 2021. We measured quality of life using the KIDSCREEN-27 health-related quality of life questionnaire, quality of sleep using the Korean version of the Pittsburgh Sleep Quality Index, and smartphone addiction using the Smartphone Addiction Self-Diagnosis Scale. Bed times, wake times, and total sleep hours were also recorded. RESULTS: Sleep quality and quantity were directly associated with smartphone addiction. The results indicated that lower quality of life was associated with lower sleep quality, delayed onset of sleep, shorter total sleep time, and higher smartphone addiction. Female students reported lower quality of life, lower sleep quality, delayed sleep phases, shorter total sleep hours, and higher smartphone addiction scores than did male students. CONCLUSION: Our results suggest that adolescents' quality of life is threatened by poor sleep, which in turn could be due to unhealthy smartphone usage. Girls were more heavily affected by this trend than were boys. Preparations to intervene for further mental health issues that might follow are necessary.