smartphone usage status, sleep pattern, health-related quality of life, and physical activity among adolescents from before to during the covid-19 confinement: a cross-sectional study

background: finding behavioral changes in youth during the covid-19 pandemic may provide a better image of the negative impact of quarantine on their mental and physical health. the purpose of the present research was to examine the smartphone usage status, sleep pattern, health-related quality of life, and physical activity among adolescents from before to during the covid-19 confinement. methods: the present study used a descriptive-comparative design. the participants were 384 male and female students aged 16 to 18 years (mean age of 16.84±1.06 years) in grades 11 and 12 from the high-schools of golestan province, iran, in 2020. screen time, sleep pattern, health-related quality of life, and physical activity were measured using standard questionnaires. paired-sample t test was employed to compare the means of the constructs of the study from “before” to “during” the covid-19 pandemic. independent t test was used to measure gender differences. results: results shed light on the increments in smartphone use and decrements in sleep quality, health-related quality of life, and physical activity among adolescents from “before” to “during” the covid-19 pandemic (all p 0.001). girls had significantly higher use of smartphones in both “before” (p=0.003) and “during” (p 0.001) the pandemic compared with boys. however, no other gender differences were found among male and female adolescents (all p 0.05). conclusion: the findings of this study revealed the effects of policies related to covid-19 pandemic on health-related behaviors among adolescents and emphasized the importance of adopting appropriate coping strategies to promote healthy lifestyle during confinement.