Later school start time may produce benefits but more evidence is needed

Many studies have been conducted to examine the impact for pupils of later school start times, some of which can be found in previous issues of Best Evidence in Brief. This Campbell systematic review summarises the findings from 17 studies to examine the evidence on the impact of later school start times on pupils’ mental health and academic performance.

The studies included in the review were randomised controlled trials, controlled before-and-after studies and interrupted time series studies with data for pupils aged 13 to 19 and that compared different school start times. The studies reported on 11 interventions in six countries, with a total of almost 300,000 pupils.

The main results of the review suggest that later school starts may be associated with positive academic benefits and psychosocial outcomes. Later school start times also appear to be associated with an increase in the amount of sleep children get. Effect sizes ranged from +0.38 to +2.39, equivalent to an extra 30 minutes to 2 hours of sleep each night. However, the researchers point out that, overall, the quality of the body of evidence is very low, and so the effects of later school start times cannot be determined with any confidence.

Source: Later school start times for supporting the education, health, and well-being of high school students: a systematic review (December 2017), A Campbell Systematic Review 2017:15

Later starts for teenagers could improve achievement and safety

In 2014, The American Academy of Pediatrics (AAP) recommended that secondary schools start no earlier than 8.30am to accommodate teenagers’ changing biological sleep cycles, which dictate later sleeping and waking times. The AAP cited studies finding that teenagers who don’t get enough sleep demonstrate poor academic performance and a higher risk of road accidents. Furthermore, getting the nine hours of sleep recommended for teenagers becomes a challenge in adolescence when sleep cycles make it difficult for them to fall asleep before 11pm.

A group of sleep researchers from Harvard University, Oxford University, and the University of Nevada recently made their own recommendations that school start times for teenagers should synchronise with their biology, ideally calling for classes to start at 10am for 16-year-olds and 11am for 18-year-olds. They stated that a 7am wake time for teenagers is equivalent to a 4.30am wake time for a teacher in their 50s. The authors explained that the biological changes requiring teenagers to both sleep and wake later coupled with the early start times of most schools in the US leads to 2-3 hours of sleep loss every day. This amount of sleep deprivation hinders memory, metabolism, and psychological health.

The authors describe several studies of later start times, which consistently show health and academic benefits for pupils. They urge policy makers to consider that later start times are less expensive to implement than most other interventions to improve teenage health and academic achievement.

Source: Synchronizing Education to Adolescent Biology: ‘Let Teens Sleep, Start School Later’ (2015), Learning, Media and Technology, 40(2).

Do early school start times lead to poor performance at primary age?

A study of 718 elementary schools in Kentucky examined associations between school start times and performance and revealed that – at least for children from better-off families – earlier start times in elementary school were associated with poorer school performance.

The research started out with two main hypotheses: that early start times would be associated with underperformance; and children from poorer backgrounds would show the greatest disadvantage.

Key findings included:

  • Earlier start times were associated with poorer test scores, lower school rank, and more absences from school.
  • Schools with fewer children who qualify for subsidised meals showed a significant relationship between early start times and poor performance.
  • Later start times were associated with more children held back to repeat a school year (the authors think theirs is the first study to look at this issue and suggest caution over this finding).

Much of the previous research on school start times and learning considers the effect on older children. The authors reported that the current study offers some of the first evidence that early school start times may influence learning in elementary school.

The authors were surprised that their analysis revealed that later start times did not seem to benefit poorer children and suggested that “the delay in start times may not be sufficient to overcome the numerous other obstacles that children in poverty face, including obstacles to obtaining adequate sleep.”

The study controlled for variables such as teacher-student ratio, student ethnicity, and location.

Source: Earlier school start times as a risk factor for poor school performance: An examination of public elementary schools in the commonwealth of Kentucky (2015), Journal of Educational Psychology