Association of bedtime and sleep duration with attention problems in children aged 6-7 years: A large-scale cross-sectional study in Shenzhen, China

AIM: This study aimed to examine the independent and interactive associations of bedtime and nighttime sleep duration with attention problems in a large sample of Chinese children. METHODS: This cross-sectional study used data from the 2021 Longhua Cohort Study of Children (LCCS) in Shenzhen, China, including 16,437 children. Bedtime and nighttime sleep duration were parent-reported. Attention problems were assessed using the SNAP-26 inattention subscale, classified into four severity categories. Ordinal logistic regression was used to examine associations, adjusting for sociodemographic factors. Interaction between bedtime and sleep duration was tested. RESULTS: In mutually adjusted models, later bedtime was significantly associated with increased odds of attention problems in a dose-response manner. Compared with bedtime before 9:00 p.m., the AORs were 2.00 (95% CI: 1.43-2.79) for 9:00-10:00 p.m., 3.41 (95% CI: 2.42-4.80) for 10:00-11:00 p.m., and 8.12 (95% CI: 5.32-12.39) for after 11:00 p.m. Each 1-h increase in sleep duration was associated with 14% lower odds of attention problems (AOR = 0.86, 95% CI: 0.80-0.93), after adjusting for bedtime. In sensitivity analysis, children sleeping <9 h had significantly higher odds of attention problems compared with those sleeping ≥10 h (AOR = 1.47, 95% CI: 1.22-1.77). No significant interactions were found between bedtime and sleep duration (p > 0.05). CONCLUSIONS: Both late bedtime and short sleep duration were independently associated with attention problems in Chinese children. Early bedtimes and adequate sleep duration may be associated with fewer attention problems.