Digital Device Use before Bedtime and Sleep Quality among Secondary School Adolescents in Baghdad: A Cross-Sectional Study

Adolescent sleep health has declined alongside the spread of digital devices, yet local data from Iraq remain scarce. This study aimed to estimate the prevalence of poor sleep quality among secondary school students in Baghdad and to examine its association with digital device use, sleep habits and socio-demographic characteristics. A cross-sectional analytical study was conducted from January to April 2024 in the Al-Karkh Al-Oula educational directorate, Baghdad. Using multi-stage random sampling across seven school sectors, 400 students aged 15–17 years were enrolled from public and private schools. Data were collected with a self-administered bilingual questionnaire that included the Pittsburgh Sleep Quality Index (PSQI), and a global score above 5 defined poor sleep quality. Chi-square tests and binary logistic regression were used for analysis. The sample comprised 188 males (47.0%) and 212 females (53.0%), with a mean age of 16.0 ± 0.81 years. Overall, 244 students (61.0%) had poor sleep quality, and only 23.0% slept the recommended seven hours or more per night. Poor sleep was more common among females than males (71.7% vs. 49.0%; p < 0.001) and among students living in crowded homes (69.8% vs. 35.3%; p < 0.001). Daily device use of two hours or more was the strongest independent predictor of poor sleep quality (OR = 2.97; 95% CI: 2.07–4.27), followed by bedtime at or after 10 pm (OR = 2.25), sleep-onset latency longer than 30 minutes (OR = 2.03), device shutdown at or after 10 pm (OR = 1.62), hypnotic medication use (OR = 1.57) and morning dissatisfaction (OR = 1.41). Poor sleep quality affects about six in ten secondary school adolescents in Baghdad and is linked mainly to long evening screen use, late bedtimes and crowded homes. School-based sleep-hygiene education, family counselling and attention to housing conditions are recommended.