Adolescents who do not get enough sleep are more likely to be overweight (1); not
engage in daily physical activity (2); suffer from depressive symptoms (2); engage
in unhealthy risk behaviors such as drinking, smoking tobacco, and using illicit drugs
(2); and perform poorly in school (3). However, insufficient sleep is common among
high school students, with less than one third of U.S. high school students sleeping
at least 8 hours on school nights (4). In a policy statement published in 2014, the
American Academy of Pediatrics (AAP) urged middle and high schools to modify start
times as a means to enable students to get adequate sleep and improve their health,
safety, academic performance, and quality of life (5). AAP recommended that “middle
and high schools should aim for a starting time of no earlier than 8:30 a.m.” (5).
To assess state-specific distributions of public middle and high school start times
and establish a pre-recommendation baseline, CDC and the U.S. Department of Education
analyzed data from the 2011–12 Schools and Staffing Survey (SASS). Among an estimated
39,700 public middle, high, and combined schools* in the United States, the average
start time was 8:03 a.m. Overall, only 17.7% of these public schools started school
at 8:30 a.m. or later. The percentage of schools with 8:30 a.m. or later start times
varied greatly by state, ranging from 0% in Hawaii, Mississippi, and Wyoming to more
than three quarters of schools in Alaska (76.8%) and North Dakota (78.5%). A school
system start time policy of 8:30 a.m. or later provides teenage students the opportunity
to achieve the 8.5–9.5 hours of sleep recommended by AAP (5) and the 8–10 hours recommended
by the National Sleep Foundation (6).
Every few years, the U.S. Department of Education conducts SASS, which provides data
on the condition of elementary and secondary education in the United States. SASS
consists of several questionnaires, including those tailored to schools, teachers,
principals, school districts, and library media centers. SASS is a mail-based survey,
with telephone and field follow-up, and uses a stratified probability sample design.†
For the 2011–12 school year, the sample included about 10,250 traditional public schools
and 750 public charter schools, with a unit response rate for public schools of 72.5%.
As part of the school questionnaire in the 2011–12 school year, respondents were asked,
“At what time do most of the students in this school begin the school day?” Because
AAP recommends school start times of 8:30 a.m. or later for both middle schools and
high schools, the analyses in this report include public middle schools, high schools,
and schools with combined grades. Average start time (with standard error) and percentage
distribution of start times were calculated by school level and state. Results are
weighted to reflect the complex sample design and to account for nonresponse and other
adjustments.
Among an estimated 39,700 U.S. public middle, high, and combined schools (with an
estimated total enrollment of 26.3 million students), the average start time was 8:03
a.m. Forty-two states reported that 75%–100% of their public schools had early start
times (before 8:30 a.m.) (Figure). Overall, only 17.7% of public schools (with an
estimated total enrollment of 4.2 million students), started school at 8:30 a.m. or
later (Table). The proportion was lowest for high schools (14.4%) and highest for
combined schools (23.4%). The percentage of schools that started at 8:30 a.m. or later
varied greatly by state, ranging from 0% in Hawaii, Mississippi, and Wyoming to 76.8%
in Alaska and 78.5% in North Dakota. North Dakota and Alaska also reported the latest
average school start times (8:31 a.m. and 8:33 a.m., respectively), whereas Louisiana
reported the earliest average school start time (7:40 a.m.) and the largest percentage
of schools starting before 7:30 a.m. (29.9%).
Discussion
Obtaining adequate sleep is important for achieving optimal health. Among adolescents,
insufficient sleep has been associated with adverse risk behaviors (2), poor health
outcomes (1), and poor academic performance (3). In view of these negative outcomes,
the high prevalence of insufficient sleep among high school students is of substantial
public health concern. Healthy People 2020 includes a sleep objective for adolescents:
to “increase the proportion of students in grades 9 through 12 who get sufficient
sleep (defined as 8 or more hours of sleep on an average school night).Ӥ However,
the proportion of students who get enough sleep has remained approximately 31% since
2007 (4), the first year that the national Youth Risk Behavior Survey included a question
about sleep, meaning that more than two thirds of high school students do not get
enough sleep. Multiple contributors to insufficient sleep in this population might
exist. In puberty, biological rhythms commonly shift so that adolescents become sleepy
later at night and need to sleep later in the morning (7). These biological changes
are often combined with poor sleep hygiene (including irregular bedtimes and the presence
of televisions, computers, or mobile phones in the bedroom) (8). During the school
week, the chief determinant of wake times is school start time (9). The combination
of delayed bedtimes and early school start times results in inadequate sleep for a
large portion of the adolescent population.
Citing evidence of the benefits of delayed school start times for adolescents, AAP
released a policy statement in 2014 that encouraged middle and high schools to modify
start times to enable students to get sufficient sleep and subsequently improve their
health, safety, academic performance, and quality of life (5). AAP recommended that
schools start at 8:30 a.m. or later (5), but this was the case in only one in six
U.S. public middle and high schools, with substantial variation by state. Because
school start times are determined at the district or even individual school level,
local stakeholders have the most influence on whether start times change in their
communities.
Groups seeking to delay school start times in their district often face resistance.
Common barriers to delaying school start times include concerns about increased transportation
costs because of changes in bus schedules; potential for traffic congestion for students
and faculty; difficulty in scheduling after-school activities, especially athletic
programs; and lack of education in some communities about the importance of sleep
and school start times.¶ Advocates for delayed start times might benefit from 1) becoming
familiar with research about the negative impact of insufficient sleep and early start
times on adolescents’ health, well-being, and academic performance; 2) identification
of persons who might be impacted by the decision to delay start times, including parties
involved in transportation and school athletic programs, as well as students, teachers,
and school staff; and 3) preparing responses to common arguments against delaying
start times. Many school systems have successfully overcome barriers to delay start
times.**
Among the possible public health interventions for increasing sufficient sleep among
adolescents, delaying school start times has the potential for the greatest population
impact by changing the environmental context for students in entire school districts.
However, a late school start time does not preclude the need for other interventions
that have the potential to improve the sleep of adolescents. Health care providers
who treat adolescents, both in and outside of school settings, should educate patients
and parents about the importance of adequate sleep, as well as factors that contribute
to insufficient sleep among adolescents. Parents can help their children practice
good sleep hygiene (i.e., habits that help promote good sleep). A regular bedtime
and rise time, including on weekends, is recommended for everyone, whether they are
children, adolescents, or adults.†† In addition, adolescents with parent-set bedtimes
usually get more sleep than those whose parents do not set bedtimes (8). Adolescents
who are exposed to more light (such as room lighting or from electronics) in the evenings
are less likely to get enough sleep (8). Technology use (e.g., computers, video gaming,
or mobile phones) might also contribute to late bedtimes (8) and parents might consider
implementing a “media curfew” or removing these technologies from the bedroom. Finally,
parents might benefit themselves and their children by setting a good example. Adolescent
sleep habits tend to reflect their parents’ sleep habits (10).
Summary
What is already known on this topic?
The American Academy of Pediatrics (AAP) has urged middle and high schools to modify
school start times to enable adolescent students to get sufficient sleep and improve
their health, safety, academic performance, and quality of life. AAP recommends that
schools aim to start no earlier than 8:30 a.m.
What is added by this report?
During the 2011–12 school year, before publication of the new AAP recommendations,
only 17.7% of public middle and high schools in the United States started school at
8:30 a.m. or later. The percentage varied greatly by state, ranging from 0% in Hawaii,
Mississippi, and Wyoming to more than three quarters of schools in Alaska (76.8%)
and North Dakota (78.5%).
What are the implications for public health practice?
School start time policies are established at the district and individual school levels.
Educating parents and school system decision-makers about the impact of sleep deprivation
on adolescent health and academic performance might lead to adoption of later start
times.