Lack of sleep poses many risks to our health and well-being. Over time, it may increase the risk of chronic health problems and early death, and in the shorter term, not getting enough sleep affects our thinking and memory. So it’s not surprising that many studies indicate that when children sleep more, performance in school, attendance, and other health outcomes improve. Much of this research shows that delaying study start times is an effective way to achieve these results (Centers for Disease Control and Prevention epidemiologists [CDC] A review of this data was published in school health magazine in April 2016).
Based on a large body of research, both American Academy of Pediatrics The AAP and the CDC have called for a delay in starting school for teens.
Now, a new study that prospectively looked at the effect of delayed school start times on a number of performance and health outcomes in Seattle public schools adds more evidence that the change is smart.
The A study published on December 12, 2018 in the journal science progressAnd the I found that delaying the start of high school by about an hour increased the amount of sleep students got each day by more than half an hour. The study also showed that starting the school day later was associated with improved academic performance and reduced sleepiness in children.
The results were very expressive, says one of the study authors, Horacio de la Iglesia, Ph.D., professor of biology at the University of Washington in Seattle. “A single action like delaying the start time by about an hour had a huge impact.”
When schools start later, grades, attendance and sleep improve
In Seattle, most middle schools and all high schools have changed the start of the school day from 7:50 a.m. to 8:45 a.m. starting in 2016.
To analyze the effect of this change on sleep and performance, researchers from the University of Washington and the Salk Institute for Biological Studies had 92 second-year students at two high schools in Seattle wearing non-stop wrist activity monitors for two weeks in the spring of 2016, when the school start was 7:50 a.m. Another group of 88 sophomores (also from the same two schools) wore the same type of activity tracker for two weeks in 2017, about seven months after changing school start times to 8:45 a.m.
Activity monitors data collected about light and movement every 15 minutes. Students were asked to press a sign on the clock each time they fell asleep and when they woke up. The researchers also asked the students to complete a daily diary (recording things like when they went to sleep, if they took a nap, when they woke up) and to fill out a one-time questionnaire designed to measure factors such as how sleepy they feel during the day and mood.
The data showed that students slept more on school nights after switching to later start times than students did when school started early. In 2017, sophomores slept an average of 34 minutes more each night than the group of sophomores who tracked their sleep in 2016.
In addition to more sleep, the study found that later wake times were associated with 4.5% higher scores. “This was a massive increase,” says Dr. de la Iglesia.
It should also be noted that one school in which students who wore activity tracking devices had more students who were economically disadvantaged than other schools.
Both tardiness and absences decreased in the first period at that school, so levels matched that of the other, more affluent high school in the study, explains lead author, Gideon Dunster, a doctoral candidate in the Department of Biology at the University of Washington. .
That school, which had students from richer backgrounds, experienced no difference in tardiness or absence in the first period after changing school start time – a finding that Dunster theorizes might have to do with the fact that these students were less likely to have to rely on the means Public transportation and most likely a parent has driven it to school.
Study is one of the first students to follow up with students prospectively after school start times are late
While this data is not the first to suggest that delaying school start times for adolescents has benefits, it is one of the first experiments designed to investigate this question in a prospective manner, comparing students’ behavior and sleep times before and after the change.
Cora Collette Bryuner, MD, MPHA member of the Department of Adolescent Medicine and the Department of Orthopedics and Sports Medicine at Seattle Children’s Hospital and professor of pediatrics at the University of Washington School of Medicine, says the study design and findings are noteworthy.
Dr. Breuner, who was not involved in the research and serves as chair of the Adolescence Committee of the American Academy of Pediatrics, compares what we know about delayed school start times to a connecting dot puzzle. “We’re starting to get the picture,” she says.
She also notes that the study shows that delaying the start of school did not cause children to stay up late and not get enough sleep. “There is a misconception that children will stay late,” she says.
Dunster says the limitations of the research include the fact that the researchers weren’t able to follow every student.
Also, the data all come from students in Seattle. “How do we know if we’ll see the same effect in Florida?” Notes de la Iglesia.
The study cannot show causation, says Dunster, which means that it is impossible to tell based on the study design whether school start times were responsible for students sleeping more (and other findings) in 2017, or other factors that did.
De la Iglesia notes that lack of sleep has well-established negative effects, she says, “So far, no one has shown the opposite—that children deteriorate worse with delayed school start and increased sleep.”
Currently, teens across the United States start school early and tend to not sleep enough
What the data shows is that across the United States, high schools and middle schools start early. according to CDC Report 2015up to 93 percent of high schools and 83 percent of middle schools in the United States start their day before 8:30 a.m.
If the new results hold true for other schools across the country, it means that many students could do better in school, sleep more, and potentially have better attendance, if school start times were later.
The consequences of not getting enough rest are numerous and severe for adolescents. Children who do not get enough sleep are at risk of developing obesity; depression; unhealthy behaviors such as drinking, smoking, and drug use; more prone to mood, behavior and attention problems; And poor performance in school, according to Center for Disease Control.
An important point to remember is that preteens and teens’ biological clocks are naturally geared toward falling asleep later in the evening and waking up later in the morning. Teens and teens need more sleep each day than adults.
Due to teens’ busy schedules, their natural body clocks geared toward later bedtimes, and their use of light-emitting devices such as smartphones and computers that can interfere with circadian rhythms, teens are more likely to get less sleep than go to bed Early if their days start early.
The American Academy of Sleep Medicine (AASM) recommends that children between the ages of 13 and 18 regularly sleep 8 to 10 hours per night for optimal health; but according to Center for Disease Control73% of high school students don’t get enough sleep on school nights.
Changing school start times requires addressing many logistical challenges
Is this evidence enough to urge schools across the country to postpone their start times? It won’t be easy, Breuner says.
There is a logistics need to know. Communities that rely on school buses will need to coordinate bus schedule switches. Sports practices and competitions will be affected. And if teens’ school schedules are late, they may not be finished in time to care for younger siblings right after those students finish school, for example.
But Breuner says the benefits are likely worth exploring those logistics. The finding that tardiness and absences are lower in lower-income communities with later school start points to a potential way to reduce the learning gap that currently exists among students from different socioeconomic backgrounds.
“If kids are late, they may not go to school at all,” Bryuner says. A late start to the day may help these children get to school on time, encourage them to attend, and give them more comfort.
“I think you’ll see massive changes in mood, better self-esteem, less anxiety, and less depression,” says Bryuner. “You may also see an improvement in teachers’ job satisfaction as they experience children who are more alert, alert, ready to learn — and who themselves get more sleep.”