Background Sleep plays an important role in mental health and wellbeing, and sleep habits (bedtime, waketime and duration) are associated with emotional and behavioural issues in children. Weekday-to-weekend sleep variability is associated with behaviour problems in children and with mental health difficulties in adolescence, but fewer studies have looked at the link to emotional difficulties in younger children. This study uses data from surveys of children/parents at primary schools in Bradford to 1) describe the sleep patterns of children and 2) examine associations between sleep patterns and behavioural and emotional difficulties. We utilise data from the prospective multi-ethnic pregnancy and birth cohort study, Born in Bradford (BiB).

Methods The BiB Growing-up study followed-up over 5000 children and their families from the BiB birth cohort, between 2017 and 2021, when the children were aged 7–11 years. Parents were asked questions about their child’s sleep habits (bedtime, wake time, and sleep duration). An additional measure of weekday-to weekend sleep variability was calculated. In preliminary analysis we used quantile regression to estimate the median and interquartile range for bedtimes stratified by ethnicity and socioeconomic status, standardised to the mean age of the sample (9 years and 8 months). Further planned analyses will examine associations between sleep habit variables (bedtime timing, sleep duration, weekday-weekend sleep variability) and Strengths and Difficulties Questionnaire (SDQ) scores (indicative of behavioural and emotional difficulties), controlling for demographics such as age, sex, deprivation, ethnicity, number in household.

Results Bedtime was strongly associated with ethnicity, for weekdays and weekends (e.g. median weekday bedtime of 8.25pm for White British children compared to 8.55pm for Asian and Pakistani children). Bedtime, particularly at the weekend, was also strongly associated with deprivation level (e.g. median weekend bedtime in least deprived groups was 9.05pm compared to 10.00pm in the most deprived group). Conversely, sleep duration was not associated with ethnicity or deprivation, with a median sleep duration of 10 hours across all groups. Additional findings about the cross-sectional associations between sleep habit variables and behavioural and emotional difficulties will be reported.

Conclusion Sleep and bedtimes habits are a modifiable lifestyle factor that could potentially improve child wellbeing. The BiB Growing up data will allow us to describe and understand the sleep patterns of children in Bradford and to test associations with concurrent behavioural and emotional difficulties. Implications, including the possible value of sleep advice to parents, will be considered.