Patterns of screen use and their association with sleep among medical students: a cross-sectional study

Background: Screen use and reduced sleep have become an integral part of medical education and daily life, raising concerns regarding the potential impact on health. This study investigated screen time patterns, sleep characteristics, and their associations among medical students. Aim: To assess daily screen time, nocturnal and daytime sleep patterns, and perceived adverse effects of screen use among Bulgarian and foreign medical students, and to investigate the associations between screen time and certain sleep characteristics. Methods: A cross-sectional questionnaire-based study was conducted among 1,063 medical students. Data on daily screen time, purpose of screen use, perceived adverse effects, nocturnal sleep duration, bedtime, daytime sleep, and lifestyle characteristics were collected. Group comparisons were performed according to student status (Bulgarian vs. foreign) and sex, and correlation analyses were used to assess associations between screen time and sleep-related parameters. Entertainment (78.3%) and studying/scientific activities (72.5%) were the most common purposes of screen use. Mean nocturnal sleep duration was 6.68 ± 1.18 h; 42.0% of students slept < 7 h/night, while 40.8% reported a usual bedtime after midnight. Overall, 55.3% reported daytime sleep, of whom 61.9% had naps lasting >30 min. Greater screen time was consistently, but weakly associated with later bedtime, whereas its association with nocturnal sleep duration was weak and limited to selected subgroups. Screen time also had a weak positive association with daytime sleep duration. Conclusions: Prolonged screen exposure and suboptimal sleep patterns are common among medical students. Greater screen time appears to be more strongly associated with delayed sleep timing than reduced sleep duration. Promoting healthier screen use habits and sleep hygiene are necessary.