Association of bedtime and sleep duration with attention problems in children aged 6-7 years: A large-scale cross-sectional study in Shenzhen, China.
Both late bedtime and short sleep duration were independently associated with attention problems in Chinese children, with later bedtimes showing a dose-response relationship and each 1-hour increase in sleep duration associated with 14% lower odds of attention problems.
Key Findings
Results
Later bedtime was significantly associated with increased odds of attention problems in a dose-response manner among children aged 6-7 years.
Compared with bedtime before 9:00 p.m., the AOR was 2.00 (95% CI: 1.43-2.79) for bedtime 9:00-10:00 p.m.
AOR was 3.41 (95% CI: 2.42-4.80) for bedtime 10:00-11:00 p.m.
AOR was 8.12 (95% CI: 5.32-12.39) for bedtime after 11:00 p.m.
Associations were found in mutually adjusted models that controlled for sociodemographic factors and sleep duration simultaneously.
Ordinal logistic regression was used with attention problems classified into four severity categories assessed via the SNAP-26 inattention subscale.
Results
Each 1-hour increase in nighttime sleep duration was associated with 14% lower odds of attention problems after adjusting for bedtime.
AOR = 0.86 (95% CI: 0.80-0.93) per 1-hour increase in sleep duration.
This association was independent of bedtime in mutually adjusted models.
Sleep duration was parent-reported.
Results
Children sleeping fewer than 9 hours had significantly higher odds of attention problems compared with those sleeping 10 or more hours.
AOR = 1.47 (95% CI: 1.22-1.77) for children sleeping less than 9 hours versus those sleeping 10 or more hours.
This finding came from a sensitivity analysis using categorical sleep duration groupings.
The reference group was children sleeping ≥10 hours.
Results
No significant interaction was found between bedtime and sleep duration in their association with attention problems.
Interaction p-value was greater than 0.05.
This indicates that the effects of bedtime and sleep duration on attention problems were independent and did not modify each other.
Both variables were tested simultaneously in mutually adjusted models.
Methods
The study used a large cross-sectional sample of 16,437 children aged 6-7 years from the 2021 Longhua Cohort Study of Children (LCCS) in Shenzhen, China.
Data were drawn from the 2021 Longhua Cohort Study of Children (LCCS) in Shenzhen, China.
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, adjusting for sociodemographic factors.
What This Means
This research suggests that both going to bed late and not getting enough sleep are independently linked to attention problems in young children. The study examined over 16,000 children aged 6-7 years in Shenzhen, China, and found that the later a child went to bed, the more likely they were to have attention difficulties — with children going to bed after 11:00 p.m. being about eight times more likely to have attention problems compared to those in bed before 9:00 p.m. Each additional hour of sleep was also associated with fewer attention problems, and children getting less than 9 hours of sleep were about 47% more likely to have attention problems than those getting 10 or more hours.
Importantly, bedtime and sleep duration each had their own separate effect on attention — they did not interact with or cancel out each other. This means that even if a child sleeps the same number of hours, going to bed later was still associated with more attention problems, and vice versa. The effects of timing and duration of sleep appear to operate through different pathways.
This research suggests that ensuring children have early, consistent bedtimes and sufficient total sleep may be important for their attention and cognitive functioning. Because this was a cross-sectional study (a snapshot in time), it cannot prove that late bedtimes or short sleep directly cause attention problems, but the strong dose-response pattern for bedtime timing strengthens the case for a meaningful relationship. These findings may have practical relevance for families and public health recommendations around children's sleep habits.
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Wu J, Zheng L, Cheng Z, Liao T, Zhang J, Lei H, et al.. (2026). Association of bedtime and sleep duration with attention problems in children aged 6-7 years: A large-scale cross-sectional study in Shenzhen, China.. Sleep medicine. https://doi.org/10.1016/j.sleep.2026.109045