Digital Device Use, Sleep Quality, and Well-Being Among Chinese Engineering Undergraduates

This study aimed to examine associations among total daily digital device use, sleep quality, and well-being in Chinese engineering undergraduates. It also sought to assess a contemporaneous indirect statistical association through sleep quality and to distinguish between-person differences from within-person deviations.

Two survey waves conducted in June 2024 and December 2024 to January 2025 yielded 887 observations from 598 students, including 289 who participated at both waves. Students reported device-use duration, sleep quality, sleep duration, and well-being. Population-averaged generalized estimating equations, planned use-group contrasts, cluster-bootstrap path analysis, and Mundlak-type within-between decomposition adjusted for sociodemographic and academic covariates and survey wave.

Reported device use of 6 h/day or more was associated with lower well-being (b=-0.192, 95% CI -0.322 to -0.062) and poorer sleep quality (b=0.127, 95% CI 0.019 to 0.236). Compared with 3 to <6 h/day, ≥6 h/day was associated with poorer outcomes, whereas differences for <3 h/day were not statistically significant. Sleep quality formed a small negative indirect statistical association between high use and well-being (ab=-0.045, bootstrap 95% CI -0.091 to -0.003). Significant associations were concentrated between persons; within-person deviations were not consistently associated with concurrent changes in sleep or well-being.

The between-person findings suggest that high total device use may be a preliminary marker of students who also report poorer sleep and well-being. The ≥6-h/day category is not a validated threshold, and the findings do not show that reducing an individual student's use would improve these outcomes. Student support should consider digital-use patterns alongside sleep difficulties rather than impose uniform time limits.