Sleep in New Zealand children aged 7–9: associations with ethnicity, socioeconomic status, and achievement in reading and mathematics

Abstract

The aims were (1) to investigate differences by ethnicity and socioeconomic status (SES) in objective measures of sleep in children aged 7-9 years and (2) determine whether measures of sleep predict child achievement in reading or mathematics after controlling for ethnicity and SES. Methods: Four groups of parent-child dyads were recruited: M aori, low-SES schools (n = 18); M aori, high-SES schools (n = 17); New Zealand European, low-SES schools (n = 18); New Zealand European, high-SES schools (n = 17). Child sleep was measured by actigraphy. Parents and teachers reported child daytime sleepiness and behavior, and children completed a self-report of anxiety symptoms. Teachers also reported on child achievement in reading and mathematics. Results: Children from low-SES schools went to bed later on school nights (F[1,68] = 12.150, P =.001) and woke later (F[1,68] = 15.978, P <.001) than children from high-SES schools but had similar sleep duration. There were no differences related to ethnicity. Children from low-SES schools were almost 3 times more likely to be below national standards for mathematics. Children not meeting academic standards in mathematics had a later sleep start time, lower sleep period efficiency, and a decreased total sleep time. However, when SES and sleep period efficiency were modeled together neither were found to significantly influence achievement in mathematics. Conclusions: In this study, SES influenced sleep timing but not the quality and quantity of sleep in 7-to 9-year-old children, and a significant independent effect of sleep efficiency on learning could not be demonstrated.

Socioeconomic factors, sleep timing and duration, and amygdala resting-state functional connectivity in children

“…Lower family income-to-needs ratio and parental education were associated with later weekday and weekend sleep midpoints in children. These findings are consistent with those of previous studies linking socioeconomic disadvantage with later bedtimes in children ( 4 , 22 – 26 ). Later sleep midpoint may suggest that sleep timing is misaligned with optimal functioning of the circadian system ( 28 ).…”

“…Later sleep timing has been related to delayed circadian functioning and sleep problems (21). Socioeconomic disadvantage has been frequently associated with later bedtimes in children (4,(22)(23)(24)(25)(26). Fewer studies have focused on sleep midpoint, which captures variability in both bedtime and wake-up time.…”

“…On weekends, children who go to bed later may be able to sleep in later, and in this way, get enough sleep; yet, their sleep timing is still later. While some previous studies have distinguished between weekday and weekend sleep timing ( 4 , 22 , 28 ), others have not ( 27 , 29 ). Overall, few studies have considered sleep duration and timing simultaneously while distinguishing between weekdays and weekends.…”